ignore .swiftpm/ folder (#324)

fixes floatingPanel(_ vc: FloatingPanelController, contentOffsetForPinning) name

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,40 @@
+> Please fill out this template appropriately when filing a bug report.
+>
+> Please remove this line and everything above it before submitting.
+
+### Description
+
+### Expected behavior
+
+### Actual behavior
+
+### Steps to reproduce
+
+**Code example that reproduces the issue**
+
+
+**How do you display panel(s)?**
+
+* Add as child view controllers
+* Present modally
+
+**How many panels do you displays?**
+
+* 1 
+* 2+
+
+### Environment
+
+**Library version**
+
+**Installation method**
+
+* CocoaPods
+* Carthage
+* Swift Package Manager
+ 
+**iOS version(s)**
+
+
+**Xcode version**
+

.gitignore

@@ -22,6 +22,7 @@ xcuserdata/
 *.moved-aside
 *.xccheckout
 *.xcscmblueprint
+*.xcsettings
 
 ## Obj-C/Swift specific
 *.hmap
@@ -29,6 +30,9 @@ xcuserdata/
 *.dSYM.zip
 *.dSYM
 
+## Swift Package Manager Specific
+.swiftpm/
+
 ## Playgrounds
 timeline.xctimeline
 playground.xcworkspace

.travis.yml

@@ -1,44 +1,71 @@
-language: swift
+language: objective-c
 branches:
   only:
     - master
 cache:
   directories:
-  - build
-  - vendor
   - /usr/local/Homebrew
   - $HOME/Library/Caches/Homebrew
+before_cache:
+  - brew cleanup
 env:
   global:
   - LANG=en_US.UTF-8
   - LC_ALL=en_US.UTF-8
-skip_cleanup: true
 jobs:
   include:
-  - stage: carthage
+  - stage: "Builds"
+    osx_image: xcode9.4
+    script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.1 clean build
+    name: "Swift 4.1"
+  - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.2 clean build
     osx_image: xcode10
+    name: "Swift 4.2"
+  - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.0 clean build
+    osx_image: xcode10.3
+    name: "Swift 5.0"
+  - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.1 SUPPORTS_MACCATALYST=NO clean build
+    # SUPPORTS_MACCATALYST=NO because Xcode 11 runs on macOS 10.14 in Travis CI
+    osx_image: xcode11
+    name: "Swift 5.1"
+
+  - stage: "Tests"
+    osx_image: xcode10.3
+    script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=10.3.1,name=iPhone SE'
+    name: "iPhone SE (iOS 10.3)"
+  - script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=11.4,name=iPhone 7'
+    osx_image: xcode10.3
+    name: "iPhone 7 (iOS 11.4)"
+  - script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=12.2,name=iPhone X'
+    osx_image: xcode10.3
+    name: "iPhone X (iOS 12.2)"
+  - script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=13.0,name=iPhone 11'
+    osx_image: xcode11
+    name: "iPhone X (iOS 13.0)"
+
+  - stage: Build examples
+    osx_image: xcode11
+    script: xcodebuild -scheme Maps -sdk iphonesimulator clean build
+    name: "Maps"
+  - script: xcodebuild -scheme Stocks -sdk iphonesimulator clean build
+    osx_image: xcode11
+    name: "Stocks"
+  - script: xcodebuild -scheme Samples -sdk iphonesimulator clean build
+    osx_image: xcode11
+    name: "Samples"
+
+  - stage: Carthage
+    osx_image: xcode11
     before_install:
     - brew update
     - brew outdated carthage || brew upgrade carthage
     script:
     - carthage build --no-skip-current
 
-  - stage: podspec
-    osx_image: xcode10
+  - stage: CocoaPods
+    osx_image: xcode11
+    before_install: 
+    - gem install cocoapods
     script:
-    - pod spec lint
-
-  - stage: check Maps example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Maps -sdk iphonesimulator clean build
-
-  - stage: check Stocks example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Stocks -sdk iphonesimulator clean build
-
-  - stage: check Samples example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Samples -sdk iphonesimulator clean build
+    - pod spec lint --allow-warnings
+    - pod lib lint --allow-warnings

Examples/Maps/Maps.xcodeproj/project.pbxproj

@@ -7,13 +7,14 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		543844BD23D2BE2000D5EDE4 /* MapKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 543844BC23D2BE2000D5EDE4 /* MapKit.framework */; };
+		549D23D2233C77D5008EF4D7 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23D1233C77D5008EF4D7 /* FloatingPanel.framework */; };
+		549D23D3233C77D5008EF4D7 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23D1233C77D5008EF4D7 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		54B5112A216C3D840033A6F3 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54B51129216C3D840033A6F3 /* AppDelegate.swift */; };
 		54B5112C216C3D840033A6F3 /* ViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54B5112B216C3D840033A6F3 /* ViewController.swift */; };
 		54B5112F216C3D840033A6F3 /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 54B5112D216C3D840033A6F3 /* Main.storyboard */; };
 		54B51131216C3D860033A6F3 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 54B51130216C3D860033A6F3 /* Assets.xcassets */; };
 		54B51134216C3D860033A6F3 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 54B51132216C3D860033A6F3 /* LaunchScreen.storyboard */; };
-		54B5113F216C407F0033A6F3 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 54B5113E216C407F0033A6F3 /* FloatingPanel.framework */; };
-		54B51140216C407F0033A6F3 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 54B5113E216C407F0033A6F3 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -23,7 +24,7 @@
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
-				54B51140216C407F0033A6F3 /* FloatingPanel.framework in Embed Frameworks */,
+				549D23D3233C77D5008EF4D7 /* FloatingPanel.framework in Embed Frameworks */,
 			);
 			name = "Embed Frameworks";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -31,6 +32,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		543844BC23D2BE2000D5EDE4 /* MapKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = MapKit.framework; path = System/Library/Frameworks/MapKit.framework; sourceTree = SDKROOT; };
+		549D23D1233C77D5008EF4D7 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		54B51126216C3D840033A6F3 /* Maps.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Maps.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		54B51129216C3D840033A6F3 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		54B5112B216C3D840033A6F3 /* ViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ViewController.swift; sourceTree = "<group>"; };
@@ -38,7 +41,6 @@
 		54B51130216C3D860033A6F3 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		54B51133216C3D860033A6F3 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		54B51135216C3D860033A6F3 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
-		54B5113E216C407F0033A6F3 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -46,19 +48,29 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				54B5113F216C407F0033A6F3 /* FloatingPanel.framework in Frameworks */,
+				543844BD23D2BE2000D5EDE4 /* MapKit.framework in Frameworks */,
+				549D23D2233C77D5008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		543844BB23D2BE1F00D5EDE4 /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				543844BC23D2BE2000D5EDE4 /* MapKit.framework */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 		54B5111D216C3D840033A6F3 = {
 			isa = PBXGroup;
 			children = (
-				54B5113E216C407F0033A6F3 /* FloatingPanel.framework */,
+				549D23D1233C77D5008EF4D7 /* FloatingPanel.framework */,
 				54B51128216C3D840033A6F3 /* Maps */,
 				54B51127216C3D840033A6F3 /* Products */,
+				543844BB23D2BE1F00D5EDE4 /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -312,7 +324,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -331,7 +343,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Examples/Maps/Maps/ViewController.swift

@@ -21,7 +21,11 @@ class ViewController: UIViewController, MKMapViewDelegate, UISearchBarDelegate,
 
         // Initialize FloatingPanelController and add the view
         fpc.surfaceView.backgroundColor = .clear
-        fpc.surfaceView.cornerRadius = 9.0
+        if #available(iOS 11, *) {
+            fpc.surfaceView.cornerRadius = 9.0
+        } else {
+            fpc.surfaceView.cornerRadius = 0.0
+        }
         fpc.surfaceView.shadowHidden = false
 
         searchVC = storyboard?.instantiateViewController(withIdentifier: "SearchPanel") as? SearchPanelViewController
@@ -103,6 +107,7 @@ class ViewController: UIViewController, MKMapViewDelegate, UISearchBarDelegate,
             let progress = max(0.0, min((tipY  - y) / 44.0, 1.0))
             self.searchVC.tableView.alpha = progress
         }
+        debugPrint("NearbyPosition : ",vc.nearbyPosition)
     }
 
     func floatingPanelWillBeginDragging(_ vc: FloatingPanelController) {
@@ -135,29 +140,45 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl
     @IBOutlet weak var tableView: UITableView!
     @IBOutlet weak var searchBar: UISearchBar!
     @IBOutlet weak var visualEffectView: UIVisualEffectView!
-    
+
+    // For iOS 10 only
+    private lazy var shadowLayer: CAShapeLayer = CAShapeLayer()
+
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.dataSource = self
         tableView.delegate = self
         searchBar.placeholder = "Search for a place or address"
-        let textField = searchBar.value(forKey: "_searchField") as! UITextField
-        textField.font = UIFont(name: textField.font!.fontName, size: 15.0)
+        searchBar.setSearchText(fontSize: 15.0)
 
         hideHeader()
-
     }
 
     override func viewDidLayoutSubviews() {
         super.viewDidLayoutSubviews()
-        if #available(iOS 10, *) {
+        if #available(iOS 11, *) {
+        } else {
+            // Exmaple: Add rounding corners on iOS 10
             visualEffectView.layer.cornerRadius = 9.0
             visualEffectView.clipsToBounds = true
+
+            // Exmaple: Add shadow manually on iOS 10
+            view.layer.insertSublayer(shadowLayer, at: 0)
+            let rect = visualEffectView.frame
+            let path = UIBezierPath(roundedRect: rect,
+                                    byRoundingCorners: [.topLeft, .topRight],
+                                    cornerRadii: CGSize(width: 9.0, height: 9.0))
+            shadowLayer.frame = visualEffectView.frame
+            shadowLayer.shadowPath = path.cgPath
+            shadowLayer.shadowColor = UIColor.black.cgColor
+            shadowLayer.shadowOffset = CGSize(width: 0.0, height: 1.0)
+            shadowLayer.shadowOpacity = 0.2
+            shadowLayer.shadowRadius = 3.0
         }
     }
 
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return 2
+        return 100
     }
 
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
@@ -168,12 +189,10 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl
                 cell.iconImageView.image = UIImage(named: "mark")
                 cell.titleLabel.text = "Marked Location"
                 cell.subTitleLabel.text = "Golden Gate Bridge, San Francisco"
-            case 1:
+            default:
                 cell.iconImageView.image = UIImage(named: "like")
                 cell.titleLabel.text = "Favorites"
                 cell.subTitleLabel.text = "0 Places"
-            default:
-                break
             }
         }
         return cell
@@ -252,3 +271,15 @@ class SearchHeaderView: UIView {
         self.clipsToBounds = true
     }
 }
+
+extension UISearchBar {
+    func setSearchText(fontSize: CGFloat) {
+        #if swift(>=5.1) // Xcode 11 or later
+            let font = searchTextField.font
+            searchTextField.font = font?.withSize(fontSize)
+        #else
+            let textField = value(forKey: "_searchField") as! UITextField
+            textField.font = textField.font?.withSize(fontSize)
+        #endif
+    }
+}

Examples/Samples/Samples.xcodeproj/project.pbxproj

@@ -14,9 +14,9 @@
 		545DB9F821511E6400CA77B8 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 545DB9F621511E6400CA77B8 /* LaunchScreen.storyboard */; };
 		545DBA0321511E6400CA77B8 /* SampleTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DBA0221511E6400CA77B8 /* SampleTests.swift */; };
 		545DBA0E21511E6400CA77B8 /* SampleUITests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DBA0D21511E6400CA77B8 /* SampleUITests.swift */; };
+		549D23CB233C7779008EF4D7 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CA233C7779008EF4D7 /* FloatingPanel.framework */; };
+		549D23CC233C7779008EF4D7 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CA233C7779008EF4D7 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		54B51116216AFE5F0033A6F3 /* UIExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54B51115216AFE5F0033A6F3 /* UIExtensions.swift */; };
-		54B5113C216C40670033A6F3 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 54B5113B216C40670033A6F3 /* FloatingPanel.framework */; };
-		54B5113D216C40670033A6F3 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 54B5113B216C40670033A6F3 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		54CDC5D8215BBE23007D205C /* UIComponents.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CDC5D7215BBE23007D205C /* UIComponents.swift */; };
 /* End PBXBuildFile section */
 
@@ -38,13 +38,13 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXCopyFilesBuildPhase section */
-		54B5111C216C3B300033A6F3 /* Embed Frameworks */ = {
+		549D23CD233C7779008EF4D7 /* Embed Frameworks */ = {
 			isa = PBXCopyFilesBuildPhase;
 			buildActionMask = 2147483647;
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
-				54B5113D216C40670033A6F3 /* FloatingPanel.framework in Embed Frameworks */,
+				549D23CC233C7779008EF4D7 /* FloatingPanel.framework in Embed Frameworks */,
 			);
 			name = "Embed Frameworks";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -65,8 +65,8 @@
 		545DBA0921511E6400CA77B8 /* SamplesUITests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = SamplesUITests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		545DBA0D21511E6400CA77B8 /* SampleUITests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SampleUITests.swift; sourceTree = "<group>"; };
 		545DBA0F21511E6400CA77B8 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		549D23CA233C7779008EF4D7 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		54B51115216AFE5F0033A6F3 /* UIExtensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIExtensions.swift; sourceTree = "<group>"; };
-		54B5113B216C40670033A6F3 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		54CDC5D7215BBE23007D205C /* UIComponents.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIComponents.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -75,7 +75,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				54B5113C216C40670033A6F3 /* FloatingPanel.framework in Frameworks */,
+				549D23CB233C7779008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -99,12 +99,11 @@
 		545DB9E121511E6300CA77B8 = {
 			isa = PBXGroup;
 			children = (
-				54B5113B216C40670033A6F3 /* FloatingPanel.framework */,
+				549D23CA233C7779008EF4D7 /* FloatingPanel.framework */,
 				545DB9EC21511E6300CA77B8 /* Sources */,
 				545DBA0121511E6400CA77B8 /* Tests */,
 				545DBA0C21511E6400CA77B8 /* UITests */,
 				545DB9EB21511E6300CA77B8 /* Products */,
-				545DBA1B2151CC1000CA77B8 /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -151,13 +150,6 @@
 			path = UITests;
 			sourceTree = "<group>";
 		};
-		545DBA1B2151CC1000CA77B8 /* Frameworks */ = {
-			isa = PBXGroup;
-			children = (
-			);
-			name = Frameworks;
-			sourceTree = "<group>";
-		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -165,10 +157,11 @@
 			isa = PBXNativeTarget;
 			buildConfigurationList = 545DBA1221511E6400CA77B8 /* Build configuration list for PBXNativeTarget "Samples" */;
 			buildPhases = (
+				54D7209621D4DB970054A255 /* ShellScript */,
 				545DB9E621511E6300CA77B8 /* Sources */,
 				545DB9E721511E6300CA77B8 /* Frameworks */,
 				545DB9E821511E6300CA77B8 /* Resources */,
-				54B5111C216C3B300033A6F3 /* Embed Frameworks */,
+				549D23CD233C7779008EF4D7 /* Embed Frameworks */,
 			);
 			buildRules = (
 			);
@@ -285,6 +278,26 @@
 		};
 /* End PBXResourcesBuildPhase section */
 
+/* Begin PBXShellScriptBuildPhase section */
+		54D7209621D4DB970054A255 /* ShellScript */ = {
+			isa = PBXShellScriptBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputFileListPaths = (
+			);
+			inputPaths = (
+			);
+			outputFileListPaths = (
+			);
+			outputPaths = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "/usr/libexec/PlistBuddy -c \"Set :CFBundleVersion $(git rev-parse --abbrev-ref HEAD)($(git rev-parse --short HEAD))\" \"$SRCROOT/$INFOPLIST_FILE\"\n";
+		};
+/* End PBXShellScriptBuildPhase section */
+
 /* Begin PBXSourcesBuildPhase section */
 		545DB9E621511E6300CA77B8 /* Sources */ = {
 			isa = PBXSourcesBuildPhase;
@@ -478,7 +491,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelSample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -497,7 +510,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelSample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Examples/Samples/Sources/Base.lproj/Main.storyboard

@@ -1,11 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="14460.31" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="RoN-h0-uBD">
-    <device id="retina4_7" orientation="portrait">
-        <adaptation id="fullscreen"/>
-    </device>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="15705" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="RoN-h0-uBD">
+    <device id="retina5_9" orientation="portrait" appearance="light"/>
     <dependencies>
         <deployment identifier="iOS"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="14460.20"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="15706"/>
         <capability name="Safe area layout guides" minToolsVersion="9.0"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
@@ -13,9 +11,9 @@
         <!--Navigation Controller-->
         <scene sceneID="Cjh-iX-VQw">
             <objects>
-                <navigationController id="RoN-h0-uBD" sceneMemberID="viewController">
-                    <navigationBar key="navigationBar" contentMode="scaleToFill" insetsLayoutMarginsFromSafeArea="NO" id="hNW-5m-Omi">
-                        <rect key="frame" x="0.0" y="20" width="375" height="44"/>
+                <navigationController storyboardIdentifier="RootNavigationController" id="RoN-h0-uBD" sceneMemberID="viewController">
+                    <navigationBar key="navigationBar" contentMode="scaleToFill" insetsLayoutMarginsFromSafeArea="NO" largeTitles="YES" id="hNW-5m-Omi">
+                        <rect key="frame" x="0.0" y="44" width="375" height="96"/>
                         <autoresizingMask key="autoresizingMask"/>
                     </navigationBar>
                     <connections>
@@ -31,22 +29,22 @@
             <objects>
                 <viewController id="jF4-A0-Eq6" customClass="SampleListViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="Smh-Bd-AAc">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="812"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <tableView clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="plain" separatorStyle="default" rowHeight="-1" estimatedRowHeight="-1" sectionHeaderHeight="28" sectionFooterHeight="28" translatesAutoresizingMaskIntoConstraints="NO" id="7IS-PU-x0P">
-                                <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                                <rect key="frame" x="0.0" y="0.0" width="375" height="812"/>
                                 <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                 <prototypes>
                                     <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="default" indentationWidth="10" reuseIdentifier="Cell" textLabel="M0G-C8-hAO" style="IBUITableViewCellStyleDefault" id="ySY-oA-g81">
-                                        <rect key="frame" x="0.0" y="28" width="375" height="44"/>
+                                        <rect key="frame" x="0.0" y="28" width="375" height="43.666667938232422"/>
                                         <autoresizingMask key="autoresizingMask"/>
                                         <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="ySY-oA-g81" id="sXB-nH-2g2">
-                                            <rect key="frame" x="0.0" y="0.0" width="375" height="43.5"/>
+                                            <rect key="frame" x="0.0" y="0.0" width="375" height="43.666667938232422"/>
                                             <autoresizingMask key="autoresizingMask"/>
                                             <subviews>
                                                 <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Title" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" id="M0G-C8-hAO">
-                                                    <rect key="frame" x="15" y="0.0" width="345" height="43.5"/>
+                                                    <rect key="frame" x="15" y="0.0" width="345" height="43.666667938232422"/>
                                                     <autoresizingMask key="autoresizingMask"/>
                                                     <fontDescription key="fontDescription" type="system" pointSize="17"/>
                                                     <nil key="textColor"/>
@@ -61,13 +59,19 @@
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
                             <constraint firstItem="7IS-PU-x0P" firstAttribute="top" secondItem="Smh-Bd-AAc" secondAttribute="top" id="6yd-jv-ey3"/>
-                            <constraint firstItem="7IS-PU-x0P" firstAttribute="leading" secondItem="TkN-Oh-wF8" secondAttribute="leading" id="Z6Y-Dc-cei"/>
-                            <constraint firstItem="7IS-PU-x0P" firstAttribute="bottom" secondItem="TkN-Oh-wF8" secondAttribute="bottom" id="fNW-DP-lhV"/>
-                            <constraint firstItem="7IS-PU-x0P" firstAttribute="trailing" secondItem="TkN-Oh-wF8" secondAttribute="trailing" id="vfY-Rc-FOI"/>
+                            <constraint firstItem="7IS-PU-x0P" firstAttribute="leading" secondItem="39L-Nq-qfp" secondAttribute="leading" id="Z6Y-Dc-cei"/>
+                            <constraint firstItem="7IS-PU-x0P" firstAttribute="bottom" secondItem="Smh-Bd-AAc" secondAttribute="bottom" id="fNW-DP-lhV"/>
+                            <constraint firstItem="7IS-PU-x0P" firstAttribute="trailing" secondItem="39L-Nq-qfp" secondAttribute="trailing" id="vfY-Rc-FOI"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="TkN-Oh-wF8"/>
+                        <viewLayoutGuide key="safeArea" id="39L-Nq-qfp"/>
                     </view>
-                    <navigationItem key="navigationItem" title="Samples" id="wCF-su-7up"/>
+                    <navigationItem key="navigationItem" title="Samples" id="wCF-su-7up">
+                        <barButtonItem key="rightBarButtonItem" title="Settings" id="rbH-U3-XyA">
+                            <connections>
+                                <action selector="showDebugMenu:" destination="jF4-A0-Eq6" id="j02-db-ZM5"/>
+                            </connections>
+                        </barButtonItem>
+                    </navigationItem>
                     <connections>
                         <outlet property="tableView" destination="7IS-PU-x0P" id="YFM-9W-eP4"/>
                     </connections>
@@ -76,22 +80,96 @@
             </objects>
             <point key="canvasLocation" x="57" y="27"/>
         </scene>
-        <!--Item 2-->
+        <!--Settings View Controller-->
+        <scene sceneID="Bd0-D2-agO">
+            <objects>
+                <viewController storyboardIdentifier="SettingsViewController" id="C1X-9Z-TyQ" customClass="SettingsViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" insetsLayoutMarginsFromSafeArea="NO" id="af9-Zr-Ppc">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="197.33333333333334"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" distribution="fillProportionally" alignment="center" spacing="16" translatesAutoresizingMaskIntoConstraints="NO" id="n93-ZL-fmC">
+                                <rect key="frame" x="32" y="16" width="311" height="181.33333333333334"/>
+                                <subviews>
+                                    <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Version: 1.0" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="WmC-Tq-NDN">
+                                        <rect key="frame" x="118.33333333333334" y="0.0" width="74.333333333333343" height="21"/>
+                                        <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                                        <nil key="textColor"/>
+                                        <nil key="highlightedColor"/>
+                                    </label>
+                                    <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="UINavigationBar" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Ulg-gS-ah0">
+                                        <rect key="frame" x="90.666666666666686" y="37" width="130" height="25"/>
+                                        <fontDescription key="fontDescription" style="UICTFontTextStyleHeadline"/>
+                                        <nil key="textColor"/>
+                                        <nil key="highlightedColor"/>
+                                    </label>
+                                    <stackView opaque="NO" contentMode="scaleToFill" alignment="center" spacing="126" translatesAutoresizingMaskIntoConstraints="NO" id="uEf-g4-CeU">
+                                        <rect key="frame" x="23.333333333333343" y="78" width="264.66666666666663" height="38"/>
+                                        <subviews>
+                                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Large Titles" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="ogl-S5-4tJ">
+                                                <rect key="frame" x="0.0" y="8.9999999999999982" width="89.666666666666671" height="20.333333333333329"/>
+                                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                                <nil key="textColor"/>
+                                                <nil key="highlightedColor"/>
+                                            </label>
+                                            <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" translatesAutoresizingMaskIntoConstraints="NO" id="js8-Qv-lUC">
+                                                <rect key="frame" x="215.66666666666666" y="3.6666666666666714" width="50.999999999999972" height="31"/>
+                                                <connections>
+                                                    <action selector="toggleLargeTitle:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="FJS-Ty-mCY"/>
+                                                </connections>
+                                            </switch>
+                                        </subviews>
+                                    </stackView>
+                                    <stackView opaque="NO" contentMode="scaleToFill" spacing="126" translatesAutoresizingMaskIntoConstraints="NO" id="ZtZ-Dz-4cC">
+                                        <rect key="frame" x="23.333333333333343" y="132" width="264.66666666666663" height="49.333333333333343"/>
+                                        <subviews>
+                                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Translucent" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Z5i-rm-QgL">
+                                                <rect key="frame" x="0.0" y="0.0" width="89.666666666666671" height="49.333333333333336"/>
+                                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                                <nil key="textColor"/>
+                                                <nil key="highlightedColor"/>
+                                            </label>
+                                            <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" translatesAutoresizingMaskIntoConstraints="NO" id="s6b-j9-8Kw">
+                                                <rect key="frame" x="215.66666666666666" y="0.0" width="50.999999999999972" height="49.333333333333336"/>
+                                                <connections>
+                                                    <action selector="toggleTranslucent:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="nL4-3L-9hh"/>
+                                                </connections>
+                                            </switch>
+                                        </subviews>
+                                    </stackView>
+                                </subviews>
+                            </stackView>
+                        </subviews>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <constraints>
+                            <constraint firstItem="0hr-ty-yWm" firstAttribute="bottom" secondItem="n93-ZL-fmC" secondAttribute="bottom" id="2Ey-ou-E1M"/>
+                            <constraint firstAttribute="trailing" secondItem="n93-ZL-fmC" secondAttribute="trailing" constant="32" id="DdZ-eB-F5s"/>
+                            <constraint firstItem="n93-ZL-fmC" firstAttribute="leading" secondItem="af9-Zr-Ppc" secondAttribute="leading" constant="32" id="TyK-GP-Ari"/>
+                            <constraint firstItem="n93-ZL-fmC" firstAttribute="top" secondItem="af9-Zr-Ppc" secondAttribute="topMargin" constant="16" id="mbC-6H-z9M"/>
+                        </constraints>
+                        <viewLayoutGuide key="safeArea" id="0hr-ty-yWm"/>
+                    </view>
+                    <size key="freeformSize" width="375" height="197.33000000000001"/>
+                    <connections>
+                        <outlet property="largeTitlesSwicth" destination="js8-Qv-lUC" id="FOm-6k-ffi"/>
+                        <outlet property="translucentSwicth" destination="s6b-j9-8Kw" id="jmf-WH-bzZ"/>
+                        <outlet property="versionLabel" destination="WmC-Tq-NDN" id="Woh-kK-U0m"/>
+                    </connections>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="M9h-4V-3M0" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="708" y="-200"/>
+        </scene>
+        <!--Layout 2-->
         <scene sceneID="lRc-OZ-sL4">
             <objects>
                 <viewController id="RpE-lI-27a" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="JER-jz-KSq">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="812"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Item 2" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="AiP-dx-mFn">
-                                <rect key="frame" x="163.5" y="323" width="48" height="21"/>
-                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
-                                <nil key="textColor"/>
-                                <nil key="highlightedColor"/>
-                            </label>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="IvG-yp-yzI">
-                                <rect key="frame" x="20" y="20" width="39" height="30"/>
+                                <rect key="frame" x="20" y="44" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="RpE-lI-27a" eventType="touchUpInside" id="hj3-Xv-6Gq"/>
@@ -101,35 +179,59 @@
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
-                            <constraint firstItem="IvG-yp-yzI" firstAttribute="top" secondItem="2Cd-km-qEk" secondAttribute="top" id="18k-sV-PgT"/>
-                            <constraint firstItem="AiP-dx-mFn" firstAttribute="centerY" secondItem="JER-jz-KSq" secondAttribute="centerY" id="NUc-tM-0dN"/>
-                            <constraint firstItem="AiP-dx-mFn" firstAttribute="centerX" secondItem="JER-jz-KSq" secondAttribute="centerX" id="hwP-mu-Vmz"/>
-                            <constraint firstItem="IvG-yp-yzI" firstAttribute="leading" secondItem="2Cd-km-qEk" secondAttribute="leading" constant="20" id="pYt-jE-CTF"/>
+                            <constraint firstItem="IvG-yp-yzI" firstAttribute="top" secondItem="954-Dk-zvc" secondAttribute="top" id="18k-sV-PgT"/>
+                            <constraint firstItem="954-Dk-zvc" firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="IvG-yp-yzI" secondAttribute="trailing" id="mpr-u5-MZu"/>
+                            <constraint firstItem="IvG-yp-yzI" firstAttribute="leading" secondItem="954-Dk-zvc" secondAttribute="leading" constant="20" id="pYt-jE-CTF"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="2Cd-km-qEk"/>
+                        <viewLayoutGuide key="safeArea" id="954-Dk-zvc"/>
                     </view>
-                    <tabBarItem key="tabBarItem" tag="1" title="Item 2" id="qb3-RB-B28"/>
+                    <tabBarItem key="tabBarItem" tag="1" title="Layout 2" id="qb3-RB-B28"/>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="NhZ-u5-Beh" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="326" y="1575"/>
+            <point key="canvasLocation" x="-308" y="1546"/>
         </scene>
-        <!--Item 1-->
+        <!--Layout 3-->
+        <scene sceneID="r9h-Ql-gIv">
+            <objects>
+                <viewController id="pOk-Zm-vD9" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="85d-ub-G8k">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="812"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NbG-e8-HdI">
+                                <rect key="frame" x="20" y="44" width="39" height="30"/>
+                                <state key="normal" title="Close"/>
+                                <connections>
+                                    <action selector="closeWithSender:" destination="pOk-Zm-vD9" eventType="touchUpInside" id="111-PD-Pop"/>
+                                    <action selector="closeWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="1Rg-YG-TtU"/>
+                                </connections>
+                            </button>
+                        </subviews>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <constraints>
+                            <constraint firstItem="0ao-SI-QZW" firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="NbG-e8-HdI" secondAttribute="trailing" id="K9F-6x-KWn"/>
+                            <constraint firstItem="NbG-e8-HdI" firstAttribute="top" secondItem="0ao-SI-QZW" secondAttribute="top" id="nsE-so-rTl"/>
+                            <constraint firstItem="NbG-e8-HdI" firstAttribute="leading" secondItem="0ao-SI-QZW" secondAttribute="leading" constant="20" id="sF4-Dm-aoY"/>
+                        </constraints>
+                        <viewLayoutGuide key="safeArea" id="0ao-SI-QZW"/>
+                    </view>
+                    <tabBarItem key="tabBarItem" tag="2" title="Layout 3" id="RJD-TF-Sdh"/>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="Oe3-FT-q1C" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="332" y="1546"/>
+        </scene>
+        <!--Layout 1-->
         <scene sceneID="m6X-j6-yBM">
             <objects>
                 <viewController id="lto-Zc-Vtp" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="ji9-Ez-N7i">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="812"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Item 1" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="uoW-c8-9wx">
-                                <rect key="frame" x="164.5" y="323" width="46" height="21"/>
-                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
-                                <nil key="textColor"/>
-                                <nil key="highlightedColor"/>
-                            </label>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="eFN-tN-4Ct">
-                                <rect key="frame" x="20" y="20" width="39" height="30"/>
+                                <rect key="frame" x="20" y="44" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="YL4-GP-ZEZ"/>
@@ -139,18 +241,47 @@
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
-                            <constraint firstItem="eFN-tN-4Ct" firstAttribute="leading" secondItem="f88-U8-Vja" secondAttribute="leading" constant="20" id="5BT-yZ-EKe"/>
-                            <constraint firstItem="uoW-c8-9wx" firstAttribute="centerY" secondItem="ji9-Ez-N7i" secondAttribute="centerY" id="Nyw-Wt-78z"/>
-                            <constraint firstItem="eFN-tN-4Ct" firstAttribute="top" secondItem="f88-U8-Vja" secondAttribute="top" id="hUV-3a-XkY"/>
-                            <constraint firstItem="uoW-c8-9wx" firstAttribute="centerX" secondItem="ji9-Ez-N7i" secondAttribute="centerX" id="wDv-OH-7PX"/>
+                            <constraint firstItem="eFN-tN-4Ct" firstAttribute="leading" secondItem="5Ns-4l-Ufg" secondAttribute="leading" constant="20" id="5BT-yZ-EKe"/>
+                            <constraint firstItem="5Ns-4l-Ufg" firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="eFN-tN-4Ct" secondAttribute="trailing" id="OzZ-Dz-RNF"/>
+                            <constraint firstItem="eFN-tN-4Ct" firstAttribute="top" secondItem="5Ns-4l-Ufg" secondAttribute="top" id="hUV-3a-XkY"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="f88-U8-Vja"/>
+                        <viewLayoutGuide key="safeArea" id="5Ns-4l-Ufg"/>
                     </view>
-                    <tabBarItem key="tabBarItem" title="Item 1" id="HEV-kf-jxH"/>
+                    <tabBarItem key="tabBarItem" title="Layout 1" id="HEV-kf-jxH"/>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="bkL-bc-hZC" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="-380" y="1576"/>
+            <point key="canvasLocation" x="-962" y="1546"/>
+        </scene>
+        <!--Intrinsic View Controller-->
+        <scene sceneID="wtJ-qZ-aCl">
+            <objects>
+                <viewController storyboardIdentifier="IntrinsicViewController" title="Intrinsic View Controller" id="aK0-kv-mTu" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="eLM-xc-d9e">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="1000" verticalHuggingPriority="1000" horizontalCompressionResistancePriority="1000" verticalCompressionResistancePriority="1000" text="Change this text" textAlignment="center" lineBreakMode="tailTruncation" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="ge4-RW-Gmz">
+                                <rect key="frame" x="24" y="24" width="327" height="20.333333333333329"/>
+                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                <nil key="textColor"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                        </subviews>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <constraints>
+                            <constraint firstAttribute="trailing" secondItem="ge4-RW-Gmz" secondAttribute="trailing" constant="24" id="V59-MD-Lcg"/>
+                            <constraint firstItem="ge4-RW-Gmz" firstAttribute="leading" secondItem="eLM-xc-d9e" secondAttribute="leading" constant="24" id="hAO-P0-7Kw"/>
+                            <constraint firstItem="ge4-RW-Gmz" firstAttribute="top" secondItem="eLM-xc-d9e" secondAttribute="top" constant="24" id="j0s-fd-MYj"/>
+                            <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="ge4-RW-Gmz" secondAttribute="bottom" constant="24" id="tEn-PO-nVD"/>
+                        </constraints>
+                        <viewLayoutGuide key="safeArea" id="ouu-g9-OiX"/>
+                    </view>
+                    <size key="freeformSize" width="375" height="778"/>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="DfE-fL-zy5" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="2753" y="734"/>
         </scene>
         <!--Tab Bar View Controller-->
         <scene sceneID="nQ5-PV-qFw">
@@ -164,33 +295,34 @@
                     <connections>
                         <segue destination="lto-Zc-Vtp" kind="relationship" relationship="viewControllers" id="6hP-AH-YiH"/>
                         <segue destination="RpE-lI-27a" kind="relationship" relationship="viewControllers" id="g6X-Sq-uSW"/>
+                        <segue destination="pOk-Zm-vD9" kind="relationship" relationship="viewControllers" id="OPp-iO-iDK"/>
                     </connections>
                 </tabBarController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="Z9x-EI-p2b" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="-183" y="806"/>
+            <point key="canvasLocation" x="-706" y="749"/>
         </scene>
         <!--Modal View Controller-->
         <scene sceneID="C9P-Ns-Qrq">
             <objects>
                 <viewController storyboardIdentifier="ModalViewController" id="bYI-y3-Rzb" customClass="ModalViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="qwo-GK-p1U">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="724"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="vut-mK-Y4t" customClass="SafeAreaView" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="0.0" y="667" width="375" height="0.0"/>
+                                <rect key="frame" x="0.0" y="724" width="375" height="0.0"/>
                                 <color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                             </view>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="sbF-Az-7sy">
-                                <rect key="frame" x="20" y="20" width="39" height="30"/>
+                                <rect key="frame" x="20" y="0.0" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="MSC-ch-YJK"/>
                                 </connections>
                             </button>
                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" alignment="top" spacing="44" translatesAutoresizingMaskIntoConstraints="NO" id="9p4-06-y2T">
-                                <rect key="frame" x="139.5" y="108" width="96" height="252"/>
+                                <rect key="frame" x="134.66666666666666" y="88" width="106" height="326"/>
                                 <subviews>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="i9x-x5-n1q">
                                         <rect key="frame" x="0.0" y="0.0" width="80" height="30"/>
@@ -213,8 +345,15 @@
                                             <action selector="moveToTipWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="BmL-91-9ai"/>
                                         </connections>
                                     </button>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="swr-XM-GzZ">
+                                        <rect key="frame" x="0.0" y="222" width="106" height="30"/>
+                                        <state key="normal" title="Move to hidden"/>
+                                        <connections>
+                                            <action selector="moveToHiddenWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="jfJ-0f-fdk"/>
+                                        </connections>
+                                    </button>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="szf-HE-QTk">
-                                        <rect key="frame" x="0.0" y="222" width="96" height="30"/>
+                                        <rect key="frame" x="0.0" y="296" width="96" height="30"/>
                                         <state key="normal" title="Update layout"/>
                                         <connections>
                                             <action selector="updateLayout:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="Woz-a7-YMJ"/>
@@ -225,35 +364,36 @@
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
-                            <constraint firstItem="sbF-Az-7sy" firstAttribute="top" secondItem="GBa-yx-8to" secondAttribute="top" id="3VR-hj-zeQ"/>
-                            <constraint firstItem="9p4-06-y2T" firstAttribute="top" secondItem="GBa-yx-8to" secondAttribute="top" constant="88" id="41n-Fn-hi3"/>
+                            <constraint firstItem="sbF-Az-7sy" firstAttribute="top" secondItem="kjr-TP-fcM" secondAttribute="top" id="3VR-hj-zeQ"/>
+                            <constraint firstItem="9p4-06-y2T" firstAttribute="top" secondItem="kjr-TP-fcM" secondAttribute="top" constant="88" id="41n-Fn-hi3"/>
                             <constraint firstAttribute="bottom" secondItem="vut-mK-Y4t" secondAttribute="bottom" id="6eq-Kt-heZ"/>
-                            <constraint firstItem="sbF-Az-7sy" firstAttribute="leading" secondItem="GBa-yx-8to" secondAttribute="leading" constant="20" id="T2G-1L-PRs"/>
-                            <constraint firstItem="vut-mK-Y4t" firstAttribute="leading" secondItem="qwo-GK-p1U" secondAttribute="leading" id="gVC-jv-VJX"/>
-                            <constraint firstItem="vut-mK-Y4t" firstAttribute="trailing" secondItem="GBa-yx-8to" secondAttribute="trailing" id="jkq-p2-lUm"/>
-                            <constraint firstItem="9p4-06-y2T" firstAttribute="centerX" secondItem="qwo-GK-p1U" secondAttribute="centerX" id="l8t-p3-ETf"/>
-                            <constraint firstItem="vut-mK-Y4t" firstAttribute="top" secondItem="GBa-yx-8to" secondAttribute="bottom" id="rMy-JT-t4B"/>
+                            <constraint firstItem="sbF-Az-7sy" firstAttribute="leading" secondItem="kjr-TP-fcM" secondAttribute="leading" constant="20" id="T2G-1L-PRs"/>
+                            <constraint firstItem="vut-mK-Y4t" firstAttribute="leading" secondItem="kjr-TP-fcM" secondAttribute="leading" id="gVC-jv-VJX"/>
+                            <constraint firstItem="vut-mK-Y4t" firstAttribute="trailing" secondItem="kjr-TP-fcM" secondAttribute="trailing" id="jkq-p2-lUm"/>
+                            <constraint firstItem="9p4-06-y2T" firstAttribute="centerX" secondItem="kjr-TP-fcM" secondAttribute="centerX" id="l8t-p3-ETf"/>
+                            <constraint firstItem="vut-mK-Y4t" firstAttribute="top" secondItem="kjr-TP-fcM" secondAttribute="bottom" id="rMy-JT-t4B"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="GBa-yx-8to"/>
+                        <viewLayoutGuide key="safeArea" id="kjr-TP-fcM"/>
                     </view>
+                    <size key="freeformSize" width="375" height="778"/>
                     <connections>
                         <outlet property="safeAreaView" destination="vut-mK-Y4t" id="r9P-XF-wLd"/>
                     </connections>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="fbi-LZ-M4Y" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="561" y="806"/>
+            <point key="canvasLocation" x="1375" y="734"/>
         </scene>
         <!--Nested Scroll View Controller-->
         <scene sceneID="TfC-A3-4R0">
             <objects>
                 <viewController storyboardIdentifier="NestedScrollViewController" id="LAe-jm-k6f" customClass="NestedScrollViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="414-Wy-0t1">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <scrollView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="sBe-tN-uMi">
-                                <rect key="frame" x="0.0" y="32" width="375" height="635"/>
+                                <rect key="frame" x="0.0" y="32" width="375" height="746"/>
                                 <subviews>
                                     <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" translatesAutoresizingMaskIntoConstraints="NO" id="lFR-Sp-Sj1">
                                         <rect key="frame" x="0.0" y="0.0" width="375" height="968"/>
@@ -329,20 +469,21 @@
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <gestureRecognizers/>
                         <constraints>
-                            <constraint firstItem="sBe-tN-uMi" firstAttribute="leading" secondItem="414-Wy-0t1" secondAttribute="leading" id="8Qd-my-knA"/>
+                            <constraint firstItem="sBe-tN-uMi" firstAttribute="leading" secondItem="ufS-Rf-F2F" secondAttribute="leading" id="8Qd-my-knA"/>
                             <constraint firstItem="sBe-tN-uMi" firstAttribute="top" secondItem="414-Wy-0t1" secondAttribute="top" constant="32" id="9Js-LU-lNr"/>
                             <constraint firstAttribute="bottom" secondItem="sBe-tN-uMi" secondAttribute="bottom" id="jzB-47-P7e"/>
-                            <constraint firstAttribute="trailing" secondItem="sBe-tN-uMi" secondAttribute="trailing" id="nHG-wg-pLP"/>
+                            <constraint firstItem="ufS-Rf-F2F" firstAttribute="trailing" secondItem="sBe-tN-uMi" secondAttribute="trailing" id="nHG-wg-pLP"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="sL5-d5-za2"/>
+                        <viewLayoutGuide key="safeArea" id="ufS-Rf-F2F"/>
                         <connections>
                             <outletCollection property="gestureRecognizers" destination="tOa-bf-zGz" appends="YES" id="zle-Sz-M3U"/>
                             <outletCollection property="gestureRecognizers" destination="SCk-hG-weZ" appends="YES" id="OcK-FK-Lac"/>
                             <outletCollection property="gestureRecognizers" destination="Fvp-Z6-eVc" appends="YES" id="Fds-J5-YCg"/>
                         </connections>
                     </view>
-                    <size key="freeformSize" width="375" height="667"/>
+                    <size key="freeformSize" width="375" height="778"/>
                     <connections>
+                        <outlet property="nestedScrollView" destination="xba-kG-VQ2" id="ddV-kf-37A"/>
                         <outlet property="scrollView" destination="sBe-tN-uMi" id="h4S-Zl-cLO"/>
                     </connections>
                 </viewController>
@@ -363,7 +504,7 @@
                     </connections>
                 </swipeGestureRecognizer>
             </objects>
-            <point key="canvasLocation" x="1311" y="806"/>
+            <point key="canvasLocation" x="2097" y="734"/>
         </scene>
         <!--Detail View Controller-->
         <scene sceneID="b6k-zi-3wn">
@@ -373,8 +514,19 @@
                         <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
+                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="8yw-OC-Ubk">
+                                <rect key="frame" x="0.0" y="690" width="375" height="88"/>
+                                <color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                <constraints>
+                                    <constraint firstAttribute="height" constant="88" id="jwV-YU-tXG"/>
+                                </constraints>
+                            </view>
+                            <view alpha="0.5" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Kva-Z7-0qY" customClass="OnSafeAreaView" customModule="Samples" customModuleProvider="target">
+                                <rect key="frame" x="0.0" y="44" width="375" height="734"/>
+                                <color key="backgroundColor" red="0.0078431372550000003" green="0.72156862749999995" blue="0.45882352939999999" alpha="1" colorSpace="calibratedRGB"/>
+                            </view>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="noi-1a-5bZ" customClass="CloseButton" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="319" y="12" width="44" height="44"/>
+                                <rect key="frame" x="319" y="44" width="44" height="44"/>
                                 <constraints>
                                     <constraint firstAttribute="height" constant="44" id="0jg-5D-A1F"/>
                                     <constraint firstAttribute="width" constant="44" id="1Cq-PA-wgW"/>
@@ -383,22 +535,25 @@
                                     <action selector="closeWithSender:" destination="YC8-ae-15L" eventType="touchUpInside" id="Z2v-19-S5k"/>
                                 </connections>
                             </button>
-                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="8yw-OC-Ubk">
-                                <rect key="frame" x="0.0" y="690" width="375" height="88"/>
-                                <color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
-                                <constraints>
-                                    <constraint firstAttribute="height" constant="88" id="jwV-YU-tXG"/>
-                                </constraints>
-                            </view>
-                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Kva-Z7-0qY" customClass="OnSafeAreaView" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="0.0" y="734" width="375" height="44"/>
-                                <color key="backgroundColor" red="0.0078431372550000003" green="0.72156862749999995" blue="0.45882352939999999" alpha="1" colorSpace="calibratedRGB"/>
-                                <constraints>
-                                    <constraint firstAttribute="height" constant="44" id="DQJ-cY-cKx"/>
-                                </constraints>
-                            </view>
+                            <stackView opaque="NO" contentMode="scaleToFill" distribution="fillProportionally" alignment="center" spacing="8" translatesAutoresizingMaskIntoConstraints="NO" id="qux-uG-4o2">
+                                <rect key="frame" x="8" y="52" width="148.33333333333334" height="31"/>
+                                <subviews>
+                                    <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="fitToBounds" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="7lq-d3-PKi">
+                                        <rect key="frame" x="0.0" y="5.3333333333333357" width="91.333333333333329" height="20.333333333333332"/>
+                                        <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                        <nil key="textColor"/>
+                                        <nil key="highlightedColor"/>
+                                    </label>
+                                    <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" on="YES" translatesAutoresizingMaskIntoConstraints="NO" id="0MA-lV-KjS">
+                                        <rect key="frame" x="99.333333333333329" y="0.0" width="50.999999999999986" height="31"/>
+                                        <connections>
+                                            <action selector="modeChanged:" destination="YC8-ae-15L" eventType="valueChanged" id="IQ8-u2-Rib"/>
+                                        </connections>
+                                    </switch>
+                                </subviews>
+                            </stackView>
                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" spacing="22" translatesAutoresizingMaskIntoConstraints="NO" id="tP3-oJ-4EB">
-                                <rect key="frame" x="130.5" y="108" width="114" height="82"/>
+                                <rect key="frame" x="130.66666666666666" y="132" width="114" height="134"/>
                                 <subviews>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="c5r-jU-haj">
                                         <rect key="frame" x="0.0" y="0.0" width="114" height="30"/>
@@ -415,24 +570,35 @@
                                             <segue destination="bYI-y3-Rzb" kind="presentation" identifier="PresentModallySegue" id="3yq-HE-Tgn"/>
                                         </connections>
                                     </button>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="01L-lp-oy6">
+                                        <rect key="frame" x="0.0" y="104" width="114" height="30"/>
+                                        <state key="normal" title="Update Layout"/>
+                                        <connections>
+                                            <action selector="buttonPressed:" destination="YC8-ae-15L" eventType="touchUpInside" id="zTb-sq-B6f"/>
+                                        </connections>
+                                    </button>
                                 </subviews>
                             </stackView>
                         </subviews>
-                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <color key="backgroundColor" red="1" green="0.83234566450000003" blue="0.47320586440000001" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                         <gestureRecognizers/>
                         <constraints>
-                            <constraint firstItem="noi-1a-5bZ" firstAttribute="top" secondItem="g7l-kO-y7q" secondAttribute="top" constant="12" id="EQy-cr-F2Y"/>
-                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="centerX" secondItem="g7l-kO-y7q" secondAttribute="centerX" id="EsD-Vf-dNZ"/>
+                            <constraint firstItem="noi-1a-5bZ" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" id="EQy-cr-F2Y"/>
+                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="centerX" secondItem="aOK-7l-cA6" secondAttribute="centerX" id="EsD-Vf-dNZ"/>
+                            <constraint firstItem="Kva-Z7-0qY" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" id="Fff-HL-4mo"/>
                             <constraint firstItem="8yw-OC-Ubk" firstAttribute="bottom" secondItem="g7l-kO-y7q" secondAttribute="bottom" id="JOL-wC-w74"/>
-                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="leading" secondItem="tAi-nk-rDB" secondAttribute="leading" id="RiJ-Hb-OOZ"/>
-                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="trailing" secondItem="tAi-nk-rDB" secondAttribute="trailing" id="Sof-yL-mwK"/>
-                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="top" secondItem="tAi-nk-rDB" secondAttribute="top" constant="88" id="Zhb-Ss-epe"/>
-                            <constraint firstItem="Kva-Z7-0qY" firstAttribute="trailing" secondItem="tAi-nk-rDB" secondAttribute="trailing" id="kkp-Yo-FQW"/>
-                            <constraint firstItem="tAi-nk-rDB" firstAttribute="trailing" secondItem="noi-1a-5bZ" secondAttribute="trailing" constant="12" id="lv9-Nf-HNB"/>
-                            <constraint firstItem="Kva-Z7-0qY" firstAttribute="leading" secondItem="tAi-nk-rDB" secondAttribute="leading" id="oVC-i1-TwS"/>
-                            <constraint firstItem="tAi-nk-rDB" firstAttribute="bottom" secondItem="Kva-Z7-0qY" secondAttribute="bottom" id="rW2-mF-5DR"/>
+                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="leading" secondItem="aOK-7l-cA6" secondAttribute="leading" id="RiJ-Hb-OOZ"/>
+                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="trailing" secondItem="aOK-7l-cA6" secondAttribute="trailing" id="Sof-yL-mwK"/>
+                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" constant="88" id="Zhb-Ss-epe"/>
+                            <constraint firstItem="Kva-Z7-0qY" firstAttribute="trailing" secondItem="aOK-7l-cA6" secondAttribute="trailing" id="kkp-Yo-FQW"/>
+                            <constraint firstItem="aOK-7l-cA6" firstAttribute="trailing" secondItem="noi-1a-5bZ" secondAttribute="trailing" constant="12" id="lv9-Nf-HNB"/>
+                            <constraint firstItem="qux-uG-4o2" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" constant="8" id="naa-cf-ZIc"/>
+                            <constraint firstItem="Kva-Z7-0qY" firstAttribute="leading" secondItem="aOK-7l-cA6" secondAttribute="leading" id="oVC-i1-TwS"/>
+                            <constraint firstItem="aOK-7l-cA6" firstAttribute="bottom" secondItem="Kva-Z7-0qY" secondAttribute="bottom" id="rW2-mF-5DR"/>
+                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="top" relation="greaterThanOrEqual" secondItem="tP3-oJ-4EB" secondAttribute="bottom" constant="88" id="vKQ-h9-uKt"/>
+                            <constraint firstItem="qux-uG-4o2" firstAttribute="leading" secondItem="g7l-kO-y7q" secondAttribute="leading" constant="8" id="zXb-R9-bMO"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="tAi-nk-rDB"/>
+                        <viewLayoutGuide key="safeArea" id="aOK-7l-cA6"/>
                         <connections>
                             <outletCollection property="gestureRecognizers" destination="6Ca-p8-7uF" appends="YES" id="xOy-f1-NZE"/>
                             <outletCollection property="gestureRecognizers" destination="SPY-Vr-XDT" appends="YES" id="vgS-Am-jhQ"/>
@@ -442,6 +608,8 @@
                     <size key="freeformSize" width="375" height="778"/>
                     <connections>
                         <outlet property="closeButton" destination="noi-1a-5bZ" id="eWQ-ha-8y7"/>
+                        <outlet property="intrinsicHeightConstraint" destination="vKQ-h9-uKt" id="QpA-WD-b17"/>
+                        <outlet property="modeChangeView" destination="qux-uG-4o2" id="1Nq-fE-dXw"/>
                         <segue destination="bYI-y3-Rzb" kind="show" identifier="ShowSegue" id="r1P-2i-NDe"/>
                     </connections>
                 </viewController>
@@ -462,7 +630,7 @@
                     </connections>
                 </pongPressGestureRecognizer>
             </objects>
-            <point key="canvasLocation" x="1440.8" y="-23.388305847076463"/>
+            <point key="canvasLocation" x="653.60000000000002" y="733.74384236453204"/>
         </scene>
         <!--Debug Text View Controller-->
         <scene sceneID="Bkq-O7-q4A">
@@ -520,24 +688,26 @@ Section 1.10.33 of "de Finibus Bonorum et Malorum", written by Cicero in 45 BC
                         </subviews>
                         <color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
-                            <constraint firstItem="rN1-HL-YHv" firstAttribute="leading" secondItem="ix0-2W-gQN" secondAttribute="leading" id="7V3-KL-vXd"/>
+                            <constraint firstItem="rN1-HL-YHv" firstAttribute="leading" secondItem="5ET-zC-lCb" secondAttribute="leading" id="7V3-KL-vXd"/>
                             <constraint firstAttribute="bottom" secondItem="rN1-HL-YHv" secondAttribute="bottom" id="efD-U5-Tet"/>
                             <constraint firstItem="rN1-HL-YHv" firstAttribute="top" secondItem="9YG-0j-Zzg" secondAttribute="top" constant="17" id="fiO-LL-nSC"/>
-                            <constraint firstItem="rN1-HL-YHv" firstAttribute="trailing" secondItem="ix0-2W-gQN" secondAttribute="trailing" id="lfg-EE-euw"/>
+                            <constraint firstItem="rN1-HL-YHv" firstAttribute="trailing" secondItem="5ET-zC-lCb" secondAttribute="trailing" id="lfg-EE-euw"/>
                         </constraints>
-                        <viewLayoutGuide key="safeArea" id="ix0-2W-gQN"/>
+                        <viewLayoutGuide key="safeArea" id="5ET-zC-lCb"/>
                     </view>
                     <size key="freeformSize" width="375" height="778"/>
                     <connections>
                         <outlet property="textView" destination="rN1-HL-YHv" id="gmr-Uf-jd8"/>
+                        <outlet property="textViewTopConstraint" destination="fiO-LL-nSC" id="Rum-TN-c2e"/>
+                        <outlet property="view" destination="9YG-0j-Zzg" id="jhb-eT-nEn"/>
                     </connections>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="x1h-y1-h8q" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="729" y="-23"/>
+            <point key="canvasLocation" x="-1" y="734"/>
         </scene>
     </scenes>
     <inferredMetricsTieBreakers>
-        <segue reference="3yq-HE-Tgn"/>
+        <segue reference="r1P-2i-NDe"/>
     </inferredMetricsTieBreakers>
 </document>

Examples/Samples/Sources/UIExtensions.swift

@@ -5,21 +5,39 @@
 
 import UIKit
 
-extension UIView {
-    var layoutInsets: UIEdgeInsets {
-        if #available(iOS 11.0, *) {
-            return safeAreaInsets
-        } else {
-            return layoutMargins
-        }
-    }
+protocol LayoutGuideProvider {
+    var topAnchor: NSLayoutYAxisAnchor { get }
+    var bottomAnchor: NSLayoutYAxisAnchor { get }
+}
+extension UILayoutGuide: LayoutGuideProvider {}
 
-    var layoutGuide: UILayoutGuide {
-        if #available(iOS 11.0, *) {
-            return safeAreaLayoutGuide
-        } else {
-            return layoutMarginsGuide
-        }
+class CustomLayoutGuide: LayoutGuideProvider {
+    let topAnchor: NSLayoutYAxisAnchor
+    let bottomAnchor: NSLayoutYAxisAnchor
+    init(topAnchor: NSLayoutYAxisAnchor, bottomAnchor: NSLayoutYAxisAnchor) {
+        self.topAnchor = topAnchor
+        self.bottomAnchor = bottomAnchor
     }
 }
 
+extension UIViewController {
+    var layoutInsets: UIEdgeInsets {
+        if #available(iOS 11.0, *) {
+            return view.safeAreaInsets
+        } else {
+            return UIEdgeInsets(top: topLayoutGuide.length,
+                                left: 0.0,
+                                bottom: bottomLayoutGuide.length,
+                                right: 0.0)
+        }
+    }
+
+    var layoutGuide: LayoutGuideProvider {
+        if #available(iOS 11.0, *) {
+            return view!.safeAreaLayoutGuide
+        } else {
+            return CustomLayoutGuide(topAnchor: topLayoutGuide.bottomAnchor,
+                                     bottomAnchor: bottomLayoutGuide.topAnchor)
+        }
+    }
+}

Examples/Stocks/Stocks.xcodeproj/project.pbxproj

@@ -7,13 +7,13 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
-		5433F24B21717EA300BDAA5D /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 5433F24A21717EA300BDAA5D /* FloatingPanel.framework */; };
-		5433F24C21717EA300BDAA5D /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 5433F24A21717EA300BDAA5D /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		548DF95421705BE00041922A /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 548DF95321705BE00041922A /* AppDelegate.swift */; };
 		548DF95621705BE00041922A /* ViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 548DF95521705BE00041922A /* ViewController.swift */; };
 		548DF95921705BE00041922A /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 548DF95721705BE00041922A /* Main.storyboard */; };
 		548DF95B21705BE10041922A /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 548DF95A21705BE10041922A /* Assets.xcassets */; };
 		548DF95E21705BE10041922A /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 548DF95C21705BE10041922A /* LaunchScreen.storyboard */; };
+		549D23CF233C77CF008EF4D7 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */; };
+		549D23D0233C77CF008EF4D7 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -23,7 +23,7 @@
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
-				5433F24C21717EA300BDAA5D /* FloatingPanel.framework in Embed Frameworks */,
+				549D23D0233C77CF008EF4D7 /* FloatingPanel.framework in Embed Frameworks */,
 			);
 			name = "Embed Frameworks";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -31,7 +31,6 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
-		5433F24A21717EA300BDAA5D /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		548DF95021705BE00041922A /* Stocks.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Stocks.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		548DF95321705BE00041922A /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		548DF95521705BE00041922A /* ViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ViewController.swift; sourceTree = "<group>"; };
@@ -39,6 +38,7 @@
 		548DF95A21705BE10041922A /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		548DF95D21705BE10041922A /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		548DF95F21705BE10041922A /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -46,7 +46,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				5433F24B21717EA300BDAA5D /* FloatingPanel.framework in Frameworks */,
+				549D23CF233C77CF008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -56,7 +56,7 @@
 		548DF94721705BE00041922A = {
 			isa = PBXGroup;
 			children = (
-				5433F24A21717EA300BDAA5D /* FloatingPanel.framework */,
+				549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */,
 				548DF95221705BE00041922A /* Stocks */,
 				548DF95121705BE00041922A /* Products */,
 			);
@@ -312,7 +312,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -331,7 +331,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Examples/Stocks/Stocks/ViewController.swift

@@ -114,6 +114,7 @@ class FloatingPanelStocksLayout: FloatingPanelLayout {
         case .full: return 56.0
         case .half: return 262.0
         case .tip: return 85.0 + 44.0 // Visible + ToolView
+        default: return nil
         }
     }
 

FloatingPanel.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name                = "FloatingPanel"
-  s.version             = "1.2.3"
+  s.version             = "1.7.3"
   s.summary             = "FloatingPanel is a clean and easy-to-use UI component of a floating panel interface."
   s.description         = <<-DESC
 FloatingPanel is a clean and easy-to-use UI component for a new interface introduced in Apple Maps, Shortcuts and Stocks app.
@@ -13,8 +13,7 @@ The new interface displays the related contents and utilities in parallel as a u
   s.platform            = :ios, "10.0"
   s.source              = { :git => "https://github.com/SCENEE/FloatingPanel.git", :tag => "v#{s.version}" }
   s.source_files        = "Framework/Sources/*.swift"
-  s.swift_version       = "4.2"
-  s.pod_target_xcconfig = { 'SWIFT_WHOLE_MODULE_OPTIMIZATION' => 'YES', 'APPLICATION_EXTENSION_API_ONLY' => 'YES' }
+  s.swift_versions      = ["4.0", "4.2", "5.0"]
 
   s.framework           = "UIKit"
 

Framework/FloatingPanel.xcodeproj/project.pbxproj

@@ -7,18 +7,27 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		542753C622C49A6E00D17955 /* FloatingPanelLayoutTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */; };
+		54352E9621A51A2500CBCA08 /* FloatingPanelTransitioning.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */; };
+		54352E9821A521CA00CBCA08 /* FloatingPanelView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54352E9721A521CA00CBCA08 /* FloatingPanelView.swift */; };
 		5450EEE421646DF500135936 /* FloatingPanelBehavior.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5450EEE321646DF500135936 /* FloatingPanelBehavior.swift */; };
 		545DB9CB2151169500CA77B8 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 545DB9C12151169500CA77B8 /* FloatingPanel.framework */; };
-		545DB9D02151169500CA77B8 /* ViewTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9CF2151169500CA77B8 /* ViewTests.swift */; };
-		545DB9D22151169500CA77B8 /* FloatingPanelController.h in Headers */ = {isa = PBXBuildFile; fileRef = 545DB9C42151169500CA77B8 /* FloatingPanelController.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		545DB9D02151169500CA77B8 /* FloatingPanelControllerTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */; };
+		545DB9D22151169500CA77B8 /* FloatingPanel.h in Headers */ = {isa = PBXBuildFile; fileRef = 545DB9C42151169500CA77B8 /* FloatingPanel.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		545DB9DE215118C800CA77B8 /* UIExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9DD215118C800CA77B8 /* UIExtensions.swift */; };
 		545DB9E021511AC100CA77B8 /* FloatingPanelController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9DF21511AC100CA77B8 /* FloatingPanelController.swift */; };
 		545DBA2B2152383100CA77B8 /* GrabberHandleView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DBA2A2152383100CA77B8 /* GrabberHandleView.swift */; };
+		546055BF2333C4740069F400 /* Utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C722C49A8F00D17955 /* Utils.swift */; };
+		549E944522CF295D0050AECF /* FloatingPanelPositionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 549E944422CF295D0050AECF /* FloatingPanelPositionTests.swift */; };
+		54A6B6B122968B530077F348 /* FloatingPanelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54A6B6B022968B530077F348 /* FloatingPanelTests.swift */; };
+		54A6B6B622968F710077F348 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 54A6B6B522968F710077F348 /* LaunchScreen.storyboard */; };
+		54A6B6B82296A8520077F348 /* FloatingPanelSurfaceViewTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54A6B6B72296A8520077F348 /* FloatingPanelSurfaceViewTests.swift */; };
 		54ABD7AF216CCFF7002E6C13 /* Logger.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54ABD7AE216CCFF7002E6C13 /* Logger.swift */; };
 		54CDC5D3215B6D5A007D205C /* FloatingPanelSurfaceView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CDC5D2215B6D5A007D205C /* FloatingPanelSurfaceView.swift */; };
 		54CDC5D5215B6D8D007D205C /* FloatingPanelBackdropView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CDC5D4215B6D8D007D205C /* FloatingPanelBackdropView.swift */; };
 		54CFBFC3215CD045006B5735 /* FloatingPanelLayout.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CFBFC2215CD045006B5735 /* FloatingPanelLayout.swift */; };
-		54CFBFC5215CD09C006B5735 /* FloatingPanel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CFBFC4215CD09C006B5735 /* FloatingPanel.swift */; };
+		54CFBFC5215CD09C006B5735 /* FloatingPanelCore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CFBFC4215CD09C006B5735 /* FloatingPanelCore.swift */; };
+		54E740CD218AFD67005C1A34 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54E740CC218AFD67005C1A34 /* AppDelegate.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -29,24 +38,42 @@
 			remoteGlobalIDString = 545DB9C02151169500CA77B8;
 			remoteInfo = FloatingModalController;
 		};
+		54E740DC218AFE9F005C1A34 /* PBXContainerItemProxy */ = {
+			isa = PBXContainerItemProxy;
+			containerPortal = 545DB9B82151169500CA77B8 /* Project object */;
+			proxyType = 1;
+			remoteGlobalIDString = 54E740C9218AFD67005C1A34;
+			remoteInfo = TestingHost;
+		};
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelLayoutTests.swift; sourceTree = "<group>"; };
+		542753C722C49A8F00D17955 /* Utils.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Utils.swift; sourceTree = "<group>"; };
+		54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelTransitioning.swift; sourceTree = "<group>"; };
+		54352E9721A521CA00CBCA08 /* FloatingPanelView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelView.swift; sourceTree = "<group>"; };
 		5450EEE321646DF500135936 /* FloatingPanelBehavior.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelBehavior.swift; sourceTree = "<group>"; };
 		545DB9C12151169500CA77B8 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
-		545DB9C42151169500CA77B8 /* FloatingPanelController.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FloatingPanelController.h; sourceTree = "<group>"; };
+		545DB9C42151169500CA77B8 /* FloatingPanel.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FloatingPanel.h; sourceTree = "<group>"; };
 		545DB9C52151169500CA77B8 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		545DB9CA2151169500CA77B8 /* FloatingPanelTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = FloatingPanelTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
-		545DB9CF2151169500CA77B8 /* ViewTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ViewTests.swift; sourceTree = "<group>"; };
+		545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelControllerTests.swift; sourceTree = "<group>"; };
 		545DB9D12151169500CA77B8 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		545DB9DD215118C800CA77B8 /* UIExtensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIExtensions.swift; sourceTree = "<group>"; };
 		545DB9DF21511AC100CA77B8 /* FloatingPanelController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelController.swift; sourceTree = "<group>"; };
 		545DBA2A2152383100CA77B8 /* GrabberHandleView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GrabberHandleView.swift; sourceTree = "<group>"; };
+		549E944422CF295D0050AECF /* FloatingPanelPositionTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelPositionTests.swift; sourceTree = "<group>"; };
+		54A6B6B022968B530077F348 /* FloatingPanelTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelTests.swift; sourceTree = "<group>"; };
+		54A6B6B522968F710077F348 /* LaunchScreen.storyboard */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; path = LaunchScreen.storyboard; sourceTree = "<group>"; };
+		54A6B6B72296A8520077F348 /* FloatingPanelSurfaceViewTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelSurfaceViewTests.swift; sourceTree = "<group>"; };
 		54ABD7AE216CCFF7002E6C13 /* Logger.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Logger.swift; sourceTree = "<group>"; };
 		54CDC5D2215B6D5A007D205C /* FloatingPanelSurfaceView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelSurfaceView.swift; sourceTree = "<group>"; };
 		54CDC5D4215B6D8D007D205C /* FloatingPanelBackdropView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelBackdropView.swift; sourceTree = "<group>"; };
 		54CFBFC2215CD045006B5735 /* FloatingPanelLayout.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelLayout.swift; sourceTree = "<group>"; };
-		54CFBFC4215CD09C006B5735 /* FloatingPanel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanel.swift; sourceTree = "<group>"; };
+		54CFBFC4215CD09C006B5735 /* FloatingPanelCore.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanelCore.swift; sourceTree = "<group>"; };
+		54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = FloatingPanelTesting.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		54E740CC218AFD67005C1A34 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
+		54E740D8218AFD6A005C1A34 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -65,6 +92,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		54E740C7218AFD67005C1A34 /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
@@ -73,6 +107,7 @@
 			children = (
 				545DB9C32151169500CA77B8 /* Sources */,
 				545DB9CE2151169500CA77B8 /* Tests */,
+				54E740CB218AFD67005C1A34 /* TestingApp */,
 				545DB9C22151169500CA77B8 /* Products */,
 			);
 			sourceTree = "<group>";
@@ -82,6 +117,7 @@
 			children = (
 				545DB9C12151169500CA77B8 /* FloatingPanel.framework */,
 				545DB9CA2151169500CA77B8 /* FloatingPanelTests.xctest */,
+				54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -90,11 +126,13 @@
 			isa = PBXGroup;
 			children = (
 				545DB9C52151169500CA77B8 /* Info.plist */,
-				545DB9C42151169500CA77B8 /* FloatingPanelController.h */,
+				545DB9C42151169500CA77B8 /* FloatingPanel.h */,
 				545DB9DF21511AC100CA77B8 /* FloatingPanelController.swift */,
-				54CFBFC4215CD09C006B5735 /* FloatingPanel.swift */,
+				54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */,
+				54CFBFC4215CD09C006B5735 /* FloatingPanelCore.swift */,
 				54CFBFC2215CD045006B5735 /* FloatingPanelLayout.swift */,
 				5450EEE321646DF500135936 /* FloatingPanelBehavior.swift */,
+				54352E9721A521CA00CBCA08 /* FloatingPanelView.swift */,
 				54CDC5D2215B6D5A007D205C /* FloatingPanelSurfaceView.swift */,
 				54CDC5D4215B6D8D007D205C /* FloatingPanelBackdropView.swift */,
 				545DBA2A2152383100CA77B8 /* GrabberHandleView.swift */,
@@ -107,12 +145,27 @@
 		545DB9CE2151169500CA77B8 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
-				545DB9CF2151169500CA77B8 /* ViewTests.swift */,
+				54A6B6B022968B530077F348 /* FloatingPanelTests.swift */,
+				545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */,
+				542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */,
+				54A6B6B72296A8520077F348 /* FloatingPanelSurfaceViewTests.swift */,
+				549E944422CF295D0050AECF /* FloatingPanelPositionTests.swift */,
+				542753C722C49A8F00D17955 /* Utils.swift */,
 				545DB9D12151169500CA77B8 /* Info.plist */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
 		};
+		54E740CB218AFD67005C1A34 /* TestingApp */ = {
+			isa = PBXGroup;
+			children = (
+				54E740CC218AFD67005C1A34 /* AppDelegate.swift */,
+				54E740D8218AFD6A005C1A34 /* Info.plist */,
+				54A6B6B522968F710077F348 /* LaunchScreen.storyboard */,
+			);
+			path = TestingApp;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXHeadersBuildPhase section */
@@ -120,7 +173,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				545DB9D22151169500CA77B8 /* FloatingPanelController.h in Headers */,
+				545DB9D22151169500CA77B8 /* FloatingPanel.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -157,19 +210,37 @@
 			);
 			dependencies = (
 				545DB9CD2151169500CA77B8 /* PBXTargetDependency */,
+				54E740DD218AFE9F005C1A34 /* PBXTargetDependency */,
 			);
 			name = FloatingPanelTests;
 			productName = FloatingModalControllerTests;
 			productReference = 545DB9CA2151169500CA77B8 /* FloatingPanelTests.xctest */;
 			productType = "com.apple.product-type.bundle.unit-test";
 		};
+		54E740C9218AFD67005C1A34 /* TestingApp */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 54E740D9218AFD6A005C1A34 /* Build configuration list for PBXNativeTarget "TestingApp" */;
+			buildPhases = (
+				54E740C6218AFD67005C1A34 /* Sources */,
+				54E740C7218AFD67005C1A34 /* Frameworks */,
+				54E740C8218AFD67005C1A34 /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = TestingApp;
+			productName = TestingHost;
+			productReference = 54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */;
+			productType = "com.apple.product-type.application";
+		};
 /* End PBXNativeTarget section */
 
 /* Begin PBXProject section */
 		545DB9B82151169500CA77B8 /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastSwiftUpdateCheck = 1000;
+				LastSwiftUpdateCheck = 1010;
 				LastUpgradeCheck = 1000;
 				ORGANIZATIONNAME = scenee;
 				TargetAttributes = {
@@ -179,6 +250,10 @@
 					};
 					545DB9C92151169500CA77B8 = {
 						CreatedOnToolsVersion = 10.0;
+						TestTargetID = 54E740C9218AFD67005C1A34;
+					};
+					54E740C9218AFD67005C1A34 = {
+						CreatedOnToolsVersion = 10.1;
 					};
 				};
 			};
@@ -188,6 +263,7 @@
 			hasScannedForEncodings = 0;
 			knownRegions = (
 				en,
+				Base,
 			);
 			mainGroup = 545DB9B72151169500CA77B8;
 			productRefGroup = 545DB9C22151169500CA77B8 /* Products */;
@@ -196,6 +272,7 @@
 			targets = (
 				545DB9C02151169500CA77B8 /* FloatingPanel */,
 				545DB9C92151169500CA77B8 /* FloatingPanelTests */,
+				54E740C9218AFD67005C1A34 /* TestingApp */,
 			);
 		};
 /* End PBXProject section */
@@ -215,6 +292,14 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		54E740C8218AFD67005C1A34 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				54A6B6B622968F710077F348 /* LaunchScreen.storyboard in Resources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */
@@ -225,11 +310,13 @@
 				54CDC5D3215B6D5A007D205C /* FloatingPanelSurfaceView.swift in Sources */,
 				54CFBFC3215CD045006B5735 /* FloatingPanelLayout.swift in Sources */,
 				54CDC5D5215B6D8D007D205C /* FloatingPanelBackdropView.swift in Sources */,
-				54CFBFC5215CD09C006B5735 /* FloatingPanel.swift in Sources */,
+				54352E9821A521CA00CBCA08 /* FloatingPanelView.swift in Sources */,
+				54CFBFC5215CD09C006B5735 /* FloatingPanelCore.swift in Sources */,
 				54ABD7AF216CCFF7002E6C13 /* Logger.swift in Sources */,
 				545DB9E021511AC100CA77B8 /* FloatingPanelController.swift in Sources */,
 				5450EEE421646DF500135936 /* FloatingPanelBehavior.swift in Sources */,
 				545DBA2B2152383100CA77B8 /* GrabberHandleView.swift in Sources */,
+				54352E9621A51A2500CBCA08 /* FloatingPanelTransitioning.swift in Sources */,
 				545DB9DE215118C800CA77B8 /* UIExtensions.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -238,7 +325,20 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				545DB9D02151169500CA77B8 /* ViewTests.swift in Sources */,
+				54A6B6B122968B530077F348 /* FloatingPanelTests.swift in Sources */,
+				545DB9D02151169500CA77B8 /* FloatingPanelControllerTests.swift in Sources */,
+				549E944522CF295D0050AECF /* FloatingPanelPositionTests.swift in Sources */,
+				542753C622C49A6E00D17955 /* FloatingPanelLayoutTests.swift in Sources */,
+				54A6B6B82296A8520077F348 /* FloatingPanelSurfaceViewTests.swift in Sources */,
+				546055BF2333C4740069F400 /* Utils.swift in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+		54E740C6218AFD67005C1A34 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				54E740CD218AFD67005C1A34 /* AppDelegate.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -250,6 +350,11 @@
 			target = 545DB9C02151169500CA77B8 /* FloatingPanel */;
 			targetProxy = 545DB9CC2151169500CA77B8 /* PBXContainerItemProxy */;
 		};
+		54E740DD218AFE9F005C1A34 /* PBXTargetDependency */ = {
+			isa = PBXTargetDependency;
+			target = 54E740C9218AFD67005C1A34 /* TestingApp */;
+			targetProxy = 54E740DC218AFE9F005C1A34 /* PBXContainerItemProxy */;
+		};
 /* End PBXTargetDependency section */
 
 /* Begin XCBuildConfiguration section */
@@ -378,6 +483,8 @@
 		545DB9D62151169500CA77B8 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
+				BUILD_LIBRARY_FOR_DISTRIBUTION = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -397,8 +504,9 @@
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
+				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -406,6 +514,8 @@
 		545DB9D72151169500CA77B8 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
+				BUILD_LIBRARY_FOR_DISTRIBUTION = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -424,7 +534,8 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanel;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 4.2;
+				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
@@ -434,7 +545,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -442,8 +555,9 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
 			};
 			name = Debug;
 		};
@@ -452,7 +566,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -460,11 +576,177 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
+			};
+			name = Release;
+		};
+		54E740DA218AFD6A005C1A34 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Debug;
+		};
+		54E740DB218AFD6A005C1A34 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
 		};
+		54E79ADF224F6C9800717BC6 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
+				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_MODULES = YES;
+				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_ENABLE_OBJC_WEAK = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
+				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
+				CLANG_WARN_UNREACHABLE_CODE = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				CODE_SIGN_IDENTITY = "iPhone Developer";
+				COPY_PHASE_STRIP = NO;
+				CURRENT_PROJECT_VERSION = 1;
+				DEBUG_INFORMATION_FORMAT = dwarf;
+				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_TESTABILITY = YES;
+				GCC_C_LANGUAGE_STANDARD = gnu11;
+				GCC_DYNAMIC_NO_PIC = NO;
+				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_OPTIMIZATION_LEVEL = 0;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"DEBUG=1",
+					"$(inherited)",
+				);
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
+				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_VARIABLE = YES;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
+				MTL_FAST_MATH = YES;
+				ONLY_ACTIVE_ARCH = YES;
+				SDKROOT = iphoneos;
+				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				VERSIONING_SYSTEM = "apple-generic";
+				VERSION_INFO_PREFIX = "";
+			};
+			name = Test;
+		};
+		54E79AE0224F6C9800717BC6 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_IDENTITY = "";
+				CODE_SIGN_STYLE = Automatic;
+				DEFINES_MODULE = YES;
+				DYLIB_COMPATIBILITY_VERSION = 1;
+				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
+				INFOPLIST_FILE = Sources/Info.plist;
+				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanel;
+				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
+				SKIP_INSTALL = YES;
+				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "TEST DEBUG __FP_LOG";
+				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 4.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Test;
+		};
+		54E79AE1224F6C9800717BC6 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
+			};
+			name = Test;
+		};
+		54E8AC6A2286CFB6000C5A12 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = "@executable_path/Frameworks";
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Test;
+		};
 /* End XCBuildConfiguration section */
 
 /* Begin XCConfigurationList section */
@@ -472,6 +754,7 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D32151169500CA77B8 /* Debug */,
+				54E79ADF224F6C9800717BC6 /* Test */,
 				545DB9D42151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
@@ -481,6 +764,7 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D62151169500CA77B8 /* Debug */,
+				54E79AE0224F6C9800717BC6 /* Test */,
 				545DB9D72151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
@@ -490,11 +774,22 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D92151169500CA77B8 /* Debug */,
+				54E79AE1224F6C9800717BC6 /* Test */,
 				545DB9DA2151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		54E740D9218AFD6A005C1A34 /* Build configuration list for PBXNativeTarget "TestingApp" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				54E740DA218AFD6A005C1A34 /* Debug */,
+				54E740DB218AFD6A005C1A34 /* Release */,
+				54E8AC6A2286CFB6000C5A12 /* Test */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 /* End XCConfigurationList section */
 	};
 	rootObject = 545DB9B82151169500CA77B8 /* Project object */;

Framework/FloatingPanel.xcodeproj/xcshareddata/xcschemes/FloatingPanel.xcscheme

@@ -23,12 +23,33 @@
       </BuildActionEntries>
    </BuildAction>
    <TestAction
-      buildConfiguration = "Debug"
+      buildConfiguration = "Test"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
+         <TestableReference
+            skipped = "NO"
+            parallelizable = "YES"
+            testExecutionOrdering = "random">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "545DB9C92151169500CA77B8"
+               BuildableName = "FloatingPanelTests.xctest"
+               BlueprintName = "FloatingPanelTests"
+               ReferencedContainer = "container:FloatingPanel.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
       </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "545DB9C02151169500CA77B8"
+            BuildableName = "FloatingPanel.framework"
+            BlueprintName = "FloatingPanel"
+            ReferencedContainer = "container:FloatingPanel.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <AdditionalOptions>
       </AdditionalOptions>
    </TestAction>

Framework/Sources/FloatingPanel.swift

@@ -1,795 +0,0 @@
-//
-//  Copyright © 2018 Shin Yamamoto. All rights reserved.
-//
-
-import UIKit
-
-///
-/// FloatingPanel presentation model
-///
-class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate {
-    /* Cause 'terminating with uncaught exception of type NSException' error on Swift Playground
-     unowned let view: UIView
-     */
-    let surfaceView: FloatingPanelSurfaceView
-    let backdropView: FloatingPanelBackdropView
-    var layoutAdapter: FloatingPanelLayoutAdapter
-    var behavior: FloatingPanelBehavior
-
-    weak var scrollView: UIScrollView? {
-        didSet {
-            guard let scrollView = scrollView else { return }
-            scrollView.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
-            scrollBouncable = scrollView.bounces
-            scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
-        }
-    }
-    weak var userScrollViewDelegate: UIScrollViewDelegate?
-
-    var safeAreaInsets: UIEdgeInsets! {
-        get { return layoutAdapter.safeAreaInsets }
-        set { layoutAdapter.safeAreaInsets = newValue }
-    }
-
-    unowned let viewcontroller: FloatingPanelController
-
-    private(set) var state: FloatingPanelPosition = .tip {
-        didSet { viewcontroller.delegate?.floatingPanelDidChangePosition(viewcontroller) }
-    }
-
-    private var isBottomState: Bool {
-        let remains = layoutAdapter.layout.supportedPositions.filter { $0.rawValue > state.rawValue }
-        return remains.count == 0
-    }
-
-    let panGesture: FloatingPanelPanGestureRecognizer
-    var isRemovalInteractionEnabled: Bool = false
-
-    private var animator: UIViewPropertyAnimator?
-    private var initialFrame: CGRect = .zero
-    private var initialScrollOffset: CGPoint = .zero
-    private var transOffsetY: CGFloat = 0
-    private var interactionInProgress: Bool = false
-
-    // Scroll handling
-    private var stopScrollDeceleration: Bool = false
-    private var scrollBouncable = false
-    private var scrollIndictorVisible = false
-
-    // MARK: - Interface
-
-    init(_ vc: FloatingPanelController, layout: FloatingPanelLayout, behavior: FloatingPanelBehavior) {
-        viewcontroller = vc
-        surfaceView = vc.view as! FloatingPanelSurfaceView
-        backdropView = FloatingPanelBackdropView()
-        backdropView.backgroundColor = .black
-        backdropView.alpha = 0.0
-
-        self.layoutAdapter = FloatingPanelLayoutAdapter(surfaceView: surfaceView,
-                                                        backdropView: backdropView,
-                                                        layout: layout)
-        self.behavior = behavior
-
-        state = layoutAdapter.layout.initialPosition
-
-        panGesture = FloatingPanelPanGestureRecognizer()
-
-        if #available(iOS 11.0, *) {
-            panGesture.name = "FloatingPanelSurface"
-        }
-
-        super.init()
-
-        surfaceView.addGestureRecognizer(panGesture)
-        panGesture.addTarget(self, action: #selector(handle(panGesture:)))
-        panGesture.delegate = self
-    }
-
-    func setUpViews(in vc: UIViewController) {
-        unowned let view = vc.view!
-
-        view.insertSubview(backdropView, belowSubview: surfaceView)
-        backdropView.frame = view.bounds
-
-        layoutAdapter.prepareLayout(toParent: vc)
-    }
-
-    func move(to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil) {
-        move(from: state, to: to, animated: animated, completion: completion)
-    }
-
-    func present(animated: Bool, completion: (() -> Void)? = nil) {
-        self.layoutAdapter.activateLayout(of: nil)
-        move(from: nil, to: layoutAdapter.layout.initialPosition, animated: animated, completion: completion)
-    }
-
-    func dismiss(animated: Bool, completion: (() -> Void)? = nil) {
-        move(from: state, to: nil, animated: animated, completion: completion)
-    }
-
-    private func move(from: FloatingPanelPosition?, to: FloatingPanelPosition?, animated: Bool, completion: (() -> Void)? = nil) {
-        if to != .full {
-            lockScrollView()
-        }
-
-        if animated {
-            let animator: UIViewPropertyAnimator
-            switch (from, to) {
-            case (nil, let to?):
-                animator = behavior.addAnimator(self.viewcontroller, to: to)
-            case (let from?, let to?):
-                animator = behavior.moveAnimator(self.viewcontroller, from: from, to: to)
-            case (let from?, nil):
-                animator = behavior.removeAnimator(self.viewcontroller, from: from)
-            case (nil, nil):
-                fatalError()
-            }
-
-            animator.addAnimations { [weak self] in
-                guard let self = self else { return }
-
-                self.updateLayout(to: to)
-                if let to = to {
-                    self.state = to
-                }
-            }
-            animator.addCompletion { _ in
-                completion?()
-            }
-            animator.startAnimation()
-        } else {
-            self.updateLayout(to: to)
-            if let to = to {
-                self.state = to
-            }
-            completion?()
-        }
-    }
-
-    // MARK: - Layout update
-
-    private func updateLayout(to target: FloatingPanelPosition?) {
-        self.layoutAdapter.activateLayout(of: target)
-    }
-
-    private func getBackdropAlpha(with translation: CGPoint) -> CGFloat {
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-
-        let next = directionalPosition(with: translation)
-        let pre = redirectionalPosition(with: translation)
-        let nextY = layoutAdapter.positionY(for: next)
-        let preY = layoutAdapter.positionY(for: pre)
-
-        let nextAlpha = layoutAdapter.layout.backdropAlphaFor(position: next)
-        let preAlpha = layoutAdapter.layout.backdropAlphaFor(position: pre)
-
-        if preY == nextY {
-            return preAlpha
-        } else {
-            return preAlpha + max(min(1.0, 1.0 - (nextY - currentY) / (nextY - preY) ), 0.0) * (nextAlpha - preAlpha)
-        }
-    }
-
-    // MARK: - UIGestureRecognizerDelegate
-
-    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
-                                  shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
-        guard gestureRecognizer == panGesture else { return false }
-
-        /* log.debug("shouldRecognizeSimultaneouslyWith", otherGestureRecognizer) */
-
-        // all gestures of the tracking scroll view should be recognized in parallel
-        // and handle them in self.handle(panGesture:)
-        return scrollView?.gestureRecognizers?.contains(otherGestureRecognizer) ?? false
-    }
-
-    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
-        guard gestureRecognizer == panGesture else { return false }
-
-        /* log.debug("shouldBeRequiredToFailBy", otherGestureRecognizer) */
-
-        // The tracking scroll view's gestures should begin without waiting for the pan gesture failure.
-        // `scrollView.gestureRecognizers` can contains the following gestures
-        // * UIScrollViewDelayedTouchesBeganGestureRecognizer
-        // * UIScrollViewPanGestureRecognizer (scrollView.panGestureRecognizer)
-        // * _UIDragAutoScrollGestureRecognizer
-        // * _UISwipeActionPanGestureRecognizer
-        // * UISwipeDismissalGestureRecognizer
-        if let scrollView = scrollView,
-            let scrollGestureRecognizers = scrollView.gestureRecognizers,
-            scrollGestureRecognizers.contains(otherGestureRecognizer) {
-            return false
-        }
-
-        // Long press gesture should begin without waiting for the pan gesture failure.
-        if otherGestureRecognizer is UILongPressGestureRecognizer {
-            return false
-        }
-
-        // Do not begin any other gestures until the pan gesture fails.
-        return true
-    }
-
-    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
-        guard gestureRecognizer == panGesture else { return false }
-
-        log.debug("shouldRequireFailureOf", otherGestureRecognizer)
-
-        // Should begin the pan gesture without waiting for the tracking scroll view's gestures.
-        // `scrollView.gestureRecognizers` can contains the following gestures
-        // * UIScrollViewDelayedTouchesBeganGestureRecognizer
-        // * UIScrollViewPanGestureRecognizer (scrollView.panGestureRecognizer)
-        // * _UIDragAutoScrollGestureRecognizer
-        // * _UISwipeActionPanGestureRecognizer
-        // * UISwipeDismissalGestureRecognizer
-        if let scrollView = scrollView {
-            // On short contents scroll, `_UISwipeActionPanGestureRecognizer` blocks
-            // the panel's pan gesture if not returns false
-            if let scrollGestureRecognizers = scrollView.gestureRecognizers,
-                scrollGestureRecognizers.contains(otherGestureRecognizer) {
-                return false
-            }
-        }
-
-        switch otherGestureRecognizer {
-        case is UIPanGestureRecognizer,
-             is UISwipeGestureRecognizer,
-             is UIRotationGestureRecognizer,
-             is UIScreenEdgePanGestureRecognizer,
-             is UIPinchGestureRecognizer:
-            // Do not begin the pan gesture until these gestures fail
-            return true
-        default:
-            // Should begin the pan gesture witout waiting tap/long press gestures fail
-            return false
-        }
-    }
-
-    var grabberAreaFrame: CGRect {
-        let grabberAreaFrame = CGRect(x: surfaceView.bounds.origin.x,
-                                     y: surfaceView.bounds.origin.y,
-                                     width: surfaceView.bounds.width,
-                                     height: FloatingPanelSurfaceView.topGrabberBarHeight * 2)
-        return grabberAreaFrame
-    }
-
-    // MARK: - Gesture handling
-    private let offsetThreshold: CGFloat = 5.0 // Optimal value from testing
-    @objc func handle(panGesture: UIPanGestureRecognizer) {
-        log.debug("Gesture >>>>", panGesture)
-        let velocity = panGesture.velocity(in: panGesture.view)
-
-        switch panGesture {
-        case scrollView?.panGestureRecognizer:
-            guard let scrollView = scrollView else { return }
-
-            log.debug("SrollPanGesture ScrollView.contentOffset >>>", scrollView.contentOffset.y, scrollView.contentSize, scrollView.bounds.size)
-
-            // Prevent scoll slip by the top bounce when the scroll view's height is
-            // less than the content's height
-            if scrollView.isDecelerating == false, scrollView.contentSize.height > scrollView.bounds.height {
-                scrollView.bounces = (scrollView.contentOffset.y > offsetThreshold)
-            }
-
-            if surfaceView.frame.minY > layoutAdapter.topY {
-                switch state {
-                case .full:
-                    let point = panGesture.location(in: surfaceView)
-                    if grabberAreaFrame.contains(point) {
-                        // Preserve the current content offset in moving from full.
-                        scrollView.contentOffset.y = initialScrollOffset.y
-                    } else {
-                        // Prevent over scrolling in moving from full.
-                        scrollView.contentOffset.y = scrollView.contentOffsetZero.y
-                    }
-                case .half, .tip:
-                    guard scrollView.isDecelerating == false else {
-                        // Don't fix the scroll offset in animating the panel to half and tip.
-                        // It causes a buggy scrolling deceleration because `state` becomes
-                        // a target position in animating the panel on the interaction from full.
-                        return
-                    }
-                    // Fix the scroll offset in moving the panel from half and tip.
-                    scrollView.contentOffset.y = initialScrollOffset.y
-                }
-
-                // Always hide a scroll indicator at the non-top.
-                if interactionInProgress {
-                    lockScrollView()
-                }
-            } else {
-                // Always show a scroll indicator at the top.
-                if interactionInProgress {
-                    unlockScrollView()
-                }
-            }
-        case panGesture:
-            let translation = panGesture.translation(in: panGesture.view!.superview)
-            let location = panGesture.location(in: panGesture.view)
-
-            log.debug(panGesture.state, ">>>", "translation: \(translation.y), velocity: \(velocity.y)")
-
-            if shouldScrollViewHandleTouch(scrollView, point: location, velocity: velocity) {
-                return
-            }
-
-            if let animator = self.animator, animator.isInterruptible {
-                animator.stopAnimation(true)
-                self.animator = nil
-            }
-
-            switch panGesture.state {
-            case .began:
-                panningBegan()
-            case .changed:
-                if interactionInProgress == false {
-                    startInteraction(with: translation)
-                }
-                panningChange(with: translation)
-            case .ended, .cancelled, .failed:
-                panningEnd(with: translation, velocity: velocity)
-            case .possible:
-                break
-            }
-        default:
-            return
-        }
-    }
-
-    private func shouldScrollViewHandleTouch(_ scrollView: UIScrollView?, point: CGPoint, velocity: CGPoint) -> Bool {
-        // When no scrollView, nothing to handle.
-        guard let scrollView = scrollView else { return false }
-
-        // For _UISwipeActionPanGestureRecognizer
-        if let scrollGestureRecognizers = scrollView.gestureRecognizers {
-            for gesture in scrollGestureRecognizers {
-                guard gesture.state == .began || gesture.state == .changed
-                else { continue }
-
-                if gesture !=  scrollView.panGestureRecognizer {
-                    return true
-                }
-            }
-        }
-
-        guard
-            state == .full,                   // When not .full, don't scroll.
-            interactionInProgress == false,   // When interaction already in progress, don't scroll.
-            scrollView.frame.contains(point), // When point not in scrollView, don't scroll.
-            !grabberAreaFrame.contains(point) // When point within grabber area, don't scroll.
-        else {
-            return false
-        }
-
-        log.debug("ScrollView.contentOffset >>>", scrollView.contentOffset.y)
-
-        let offset = scrollView.contentOffset.y - scrollView.contentOffsetZero.y
-        if  abs(offset) > offsetThreshold {
-            return true
-        }
-        if scrollView.isDecelerating {
-            return true
-        }
-        if velocity.y < 0 {
-            return true
-        }
-
-        return false
-    }
-
-    private func panningBegan() {
-        // A user interaction does not always start from Began state of the pan gesture
-        // because it can be recognized in scrolling a content in a content view controller.
-        // So do nothing here.
-        log.debug("panningBegan")
-    }
-
-    private func panningChange(with translation: CGPoint) {
-        log.debug("panningChange")
-
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-
-        var frame = initialFrame
-        frame.origin.y = currentY
-        surfaceView.frame = frame
-        backdropView.alpha = getBackdropAlpha(with: translation)
-
-        viewcontroller.delegate?.floatingPanelDidMove(viewcontroller)
-    }
-
-    private func panningEnd(with translation: CGPoint, velocity: CGPoint) {
-        log.debug("panningEnd")
-        if interactionInProgress == false {
-            initialFrame = surfaceView.frame
-        }
-
-        stopScrollDeceleration = (surfaceView.frame.minY > layoutAdapter.topY) // Projecting the dragging to the scroll dragging or not
-
-        let targetPosition = self.targetPosition(with: translation, velocity: velocity)
-        let distance = self.distance(to: targetPosition, with: translation)
-
-        endInteraction(for: targetPosition)
-
-        if isRemovalInteractionEnabled, isBottomState {
-            if startRemovalAnimation(with: translation, velocity: velocity, distance: distance) {
-                return
-            }
-        }
-
-        viewcontroller.delegate?.floatingPanelDidEndDragging(viewcontroller, withVelocity: velocity, targetPosition: targetPosition)
-        viewcontroller.delegate?.floatingPanelWillBeginDecelerating(viewcontroller)
-
-        startAnimation(to: targetPosition, at: distance, with: velocity)
-    }
-
-    private func startRemovalAnimation(with translation: CGPoint, velocity: CGPoint, distance: CGFloat) -> Bool {
-        let posY = layoutAdapter.positionY(for: state)
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-        let safeAreaBottomY = layoutAdapter.safeAreaBottomY
-        let vth = behavior.removalVelocity
-        let pth = max(min(behavior.removalProgress, 1.0), 0.0)
-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: max(min(velocity.y/distance, vth), 0.0)) : .zero
-
-        guard (safeAreaBottomY - posY) != 0 else { return false }
-        guard (currentY - posY) / (safeAreaBottomY - posY) >= pth || velocityVector.dy == vth else { return false }
-
-        viewcontroller.delegate?.floatingPanelDidEndDraggingToRemove(viewcontroller, withVelocity: velocity)
-        let animator = self.behavior.removalInteractionAnimator(self.viewcontroller, with: velocityVector)
-        animator.addAnimations { [weak self] in
-            guard let self = self else { return }
-            self.updateLayout(to: nil)
-        }
-        animator.addCompletion({ [weak self] (_) in
-            guard let self = self else { return }
-            self.viewcontroller.removePanelFromParent(animated: false)
-            self.viewcontroller.delegate?.floatingPanelDidEndRemove(self.viewcontroller)
-        })
-        animator.startAnimation()
-        return true
-    }
-
-    private func startInteraction(with translation: CGPoint) {
-        /* Don't lock a scroll view to show a scroll indicator after hitting the top */
-        log.debug("startInteraction")
-        initialFrame = surfaceView.frame
-        if let scrollView = scrollView {
-            initialScrollOffset = scrollView.contentOffset
-        }
-        transOffsetY = translation.y
-
-        viewcontroller.delegate?.floatingPanelWillBeginDragging(viewcontroller)
-
-        interactionInProgress = true
-    }
-
-    private func endInteraction(for targetPosition: FloatingPanelPosition) {
-        log.debug("endInteraction for \(targetPosition)")
-        interactionInProgress = false
-
-        // Prevent to keep a scoll view indicator visible at the half/tip position
-        if targetPosition != .full {
-            lockScrollView()
-        }
-    }
-
-    private func getCurrentY(from rect: CGRect, with translation: CGPoint) -> CGFloat {
-        let dy = translation.y - transOffsetY
-        let y = rect.offsetBy(dx: 0.0, dy: dy).origin.y
-
-        let topY = layoutAdapter.topY
-        let topBuffer = layoutAdapter.layout.topInteractionBuffer
-        let bottomY = layoutAdapter.bottomY
-        let bottomBuffer = layoutAdapter.layout.bottomInteractionBuffer
-
-        if let scrollView = scrollView, scrollView.panGestureRecognizer.state == .changed {
-            let preY = surfaceView.frame.origin.y
-            if preY > 0 && preY > y {
-                return max(topY, min(bottomY, y))
-            }
-        }
-        return max(topY - topBuffer, min(bottomY + bottomBuffer, y))
-    }
-
-    private func startAnimation(to targetPosition: FloatingPanelPosition, at distance: CGFloat, with velocity: CGPoint) {
-        log.debug("startAnimation", targetPosition, distance, velocity)
-        let targetY = layoutAdapter.positionY(for: targetPosition)
-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: max(min(velocity.y/distance, 30.0), -30.0)) : .zero
-        let animator = behavior.interactionAnimator(self.viewcontroller, to: targetPosition, with: velocityVector)
-        animator.addAnimations { [weak self] in
-            guard let self = self else { return }
-            if self.state == targetPosition {
-                self.surfaceView.frame.origin.y = targetY
-                self.layoutAdapter.setBackdropAlpha(of: targetPosition)
-            } else {
-                self.updateLayout(to: targetPosition)
-            }
-            self.state = targetPosition
-        }
-        animator.addCompletion { [weak self] pos in
-            guard let self = self else { return }
-            guard
-                self.interactionInProgress == false,
-                animator == self.animator,
-                pos == .end
-                else { return }
-            self.finishAnimation(at: targetPosition)
-        }
-        animator.startAnimation()
-        self.animator = animator
-    }
-
-    private func finishAnimation(at targetPosition: FloatingPanelPosition) {
-        log.debug("finishAnimation \(targetPosition)")
-        self.animator = nil
-        self.viewcontroller.delegate?.floatingPanelDidEndDecelerating(self.viewcontroller)
-
-        stopScrollDeceleration = false
-        // Don't unlock scroll view in animating view when presentation layer != model layer
-        if targetPosition == .full {
-            unlockScrollView()
-        }
-    }
-
-    private func distance(to targetPosition: FloatingPanelPosition, with translation: CGPoint) -> CGFloat {
-        let topY = layoutAdapter.topY
-        let middleY = layoutAdapter.middleY
-        let bottomY = layoutAdapter.bottomY
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-        switch targetPosition {
-        case .full:
-            return CGFloat(fabs(Double(currentY - topY)))
-        case .half:
-            return CGFloat(fabs(Double(currentY - middleY)))
-        case .tip:
-            return CGFloat(fabs(Double(currentY - bottomY)))
-        }
-    }
-
-    private func directionalPosition(with translation: CGPoint) -> FloatingPanelPosition {
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-
-        let supportedPositions: Set = layoutAdapter.layout.supportedPositions
-
-        if supportedPositions.count == 1 {
-            return state
-        }
-
-        switch supportedPositions {
-        case [.full, .half]: return translation.y >= 0 ? .half : .full
-        case [.half, .tip]: return translation.y >= 0 ? .tip : .half
-        case [.full, .tip]: return translation.y >= 0 ? .tip : .full
-        default:
-            let middleY = layoutAdapter.middleY
-
-            switch state {
-            case .full:
-                if translation.y <= 0 {
-                    return .full
-                }
-                return currentY > middleY ? .tip : .half
-            case .half:
-                return currentY > middleY ? .tip : .full
-            case .tip:
-                if translation.y >= 0 {
-                    return .tip
-                }
-                return currentY > middleY ? .half : .full
-            }
-        }
-    }
-
-    private func redirectionalPosition(with translation: CGPoint) -> FloatingPanelPosition {
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-
-        let supportedPositions: Set = layoutAdapter.layout.supportedPositions
-
-        if supportedPositions.count == 1 {
-            return state
-        }
-
-        switch supportedPositions {
-        case [.full, .half]: return translation.y >= 0 ? .full : .half
-        case [.half, .tip]: return translation.y >= 0 ? .half : .tip
-        case [.full, .tip]: return translation.y >= 0 ? .full : .tip
-        default:
-            let middleY = layoutAdapter.middleY
-
-            switch state {
-            case .full:
-                return currentY > middleY ? .half : .full
-            case .half:
-                return .half
-            case .tip:
-                return currentY > middleY ? .tip : .half
-            }
-        }
-    }
-
-    // Distance travelled after decelerating to zero velocity at a constant rate.
-    // Refer to the slides p176 of [Designing Fluid Interfaces](https://developer.apple.com/videos/play/wwdc2018/803/)
-    private func project(initialVelocity: CGFloat) -> CGFloat {
-        let decelerationRate = UIScrollView.DecelerationRate.normal.rawValue
-        return (initialVelocity / 1000.0) * decelerationRate / (1.0 - decelerationRate)
-    }
-
-    private func targetPosition(with translation: CGPoint, velocity: CGPoint) -> (FloatingPanelPosition) {
-        let currentY = getCurrentY(from: initialFrame, with: translation)
-        let supportedPositions: Set = layoutAdapter.layout.supportedPositions
-
-        if supportedPositions.count == 1 {
-            return state
-        }
-
-        switch supportedPositions {
-        case [.full, .half]:
-            return targetPosition(from: [.full, .half], at: currentY, velocity: velocity)
-        case [.half, .tip]:
-            return targetPosition(from: [.half, .tip], at: currentY, velocity: velocity)
-        case [.full, .tip]:
-            return targetPosition(from: [.full, .tip], at: currentY, velocity: velocity)
-        default:
-            /*
-             [topY|full]---[th1]---[middleY|half]---[th2]---[bottomY|tip]
-             */
-            let topY = layoutAdapter.topY
-            let middleY = layoutAdapter.middleY
-            let bottomY = layoutAdapter.bottomY
-
-            let target: FloatingPanelPosition
-            let forwardYDirection: Bool
-
-            switch state {
-            case .full:
-                target = .half
-                forwardYDirection = true
-            case .half:
-                if (currentY < middleY) {
-                    target = .full
-                    forwardYDirection = false
-                } else {
-                    target = .tip
-                    forwardYDirection = true
-                }
-            case .tip:
-                target = .half
-                forwardYDirection = false
-            }
-
-            let redirectionalProgress = max(min(behavior.redirectionalProgress(viewcontroller, from: state, to: target), 1.0), 0.0)
-
-            let th1: CGFloat
-            let th2: CGFloat
-
-            if forwardYDirection {
-                th1 = topY + (middleY - topY) * redirectionalProgress
-                th2 = middleY + (bottomY - middleY) * redirectionalProgress
-            } else {
-                th1 = middleY - (middleY - topY) * redirectionalProgress
-                th2 = bottomY - (bottomY - middleY) * redirectionalProgress
-            }
-
-            switch currentY {
-            case ..<th1:
-                if project(initialVelocity: velocity.y) >= (middleY - currentY) {
-                    return .half
-                } else {
-                    return .full
-                }
-            case ...middleY:
-                if project(initialVelocity: velocity.y) <= (topY - currentY) {
-                    return .full
-                } else {
-                    return .half
-                }
-            case ..<th2:
-                if project(initialVelocity: velocity.y) >= (bottomY - currentY) {
-                    return .tip
-                } else {
-                    return .half
-                }
-            default:
-                if project(initialVelocity: velocity.y) <= (middleY - currentY) {
-                    return .half
-                } else {
-                    return .tip
-                }
-            }
-        }
-    }
-
-    private func targetPosition(from positions: [FloatingPanelPosition], at currentY: CGFloat, velocity: CGPoint) -> FloatingPanelPosition {
-        assert(positions.count == 2)
-
-        let top = positions[0]
-        let bottom = positions[1]
-
-        let topY = layoutAdapter.positionY(for: top)
-        let bottomY = layoutAdapter.positionY(for: bottom)
-
-        let target = top == state ? bottom : top
-        let redirectionalProgress = max(min(behavior.redirectionalProgress(viewcontroller, from: state, to: target), 1.0), 0.0)
-
-        let th = topY + (bottomY - topY) * redirectionalProgress
-
-        switch currentY {
-        case ..<th:
-            if project(initialVelocity: velocity.y) >= (bottomY - currentY) {
-                return bottom
-            } else {
-                return top
-            }
-        default:
-            if project(initialVelocity: velocity.y) <= (topY - currentY) {
-                return top
-            } else {
-                return bottom
-            }
-        }
-    }
-
-    // MARK: - ScrollView handling
-
-    private func lockScrollView() {
-        guard let scrollView = scrollView else { return }
-
-        scrollView.isDirectionalLockEnabled = true
-        scrollView.bounces = false
-        scrollView.showsVerticalScrollIndicator = false
-    }
-
-    private func unlockScrollView() {
-        guard let scrollView = scrollView else { return }
-
-        scrollView.isDirectionalLockEnabled = false
-        scrollView.bounces = scrollBouncable
-        scrollView.showsVerticalScrollIndicator = scrollIndictorVisible
-    }
-
-
-    // MARK: - UIScrollViewDelegate Intermediation
-    override func responds(to aSelector: Selector!) -> Bool {
-        return super.responds(to: aSelector) || userScrollViewDelegate?.responds(to: aSelector) == true
-    }
-
-    override func forwardingTarget(for aSelector: Selector!) -> Any? {
-        if userScrollViewDelegate?.responds(to: aSelector) == true {
-            return userScrollViewDelegate
-        } else {
-            return super.forwardingTarget(for: aSelector)
-        }
-    }
-
-    func scrollViewDidEndScrollingAnimation(_ scrollView: UIScrollView) {
-        if state != .full {
-            initialScrollOffset = scrollView.contentOffset
-        }
-        userScrollViewDelegate?.scrollViewDidEndScrollingAnimation?(scrollView)
-    }
-
-    func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
-        if stopScrollDeceleration {
-            targetContentOffset.pointee = scrollView.contentOffset
-            stopScrollDeceleration = false
-        } else {
-            userScrollViewDelegate?.scrollViewWillEndDragging?(scrollView, withVelocity: velocity, targetContentOffset: targetContentOffset)
-        }
-    }
-}
-
-class FloatingPanelPanGestureRecognizer: UIPanGestureRecognizer {
-    override weak var delegate: UIGestureRecognizerDelegate? {
-        get {
-            return super.delegate
-        }
-        set {
-            guard newValue is FloatingPanel else {
-                let exception = NSException(name: .invalidArgumentException,
-                                            reason: "FloatingPanelController's built-in pan gesture recognizer must have its controller as its delegate.",
-                                            userInfo: nil)
-                exception.raise()
-                return
-            }
-            super.delegate = newValue
-        }
-    }
-}

Framework/Sources/FloatingPanelBackdropView.swift

@@ -6,4 +6,6 @@
 import UIKit
 
 /// A view that presents a backdrop interface behind a floating panel.
-public class FloatingPanelBackdropView: UIView { }
+public class FloatingPanelBackdropView: UIView {
+    public var dismissalTapGestureRecognizer: UITapGestureRecognizer!
+}

Framework/Sources/FloatingPanelBehavior.swift

@@ -6,12 +6,28 @@
 import UIKit
 
 public protocol FloatingPanelBehavior {
-    /// Returns the progress to redirect to the previous position
+    /// Asks the behavior if the floating panel should project a momentum of a user interaction to move the proposed position.
     ///
-    /// The progress is represented by a floating-point value between 0.0 and 1.0, inclusive, where 1.0 indicates the floating panel is impossible to move to the next posiiton. The default value is 0.5. Values less than 0.0 and greater than 1.0 are pinned to those limits.
+    /// The default implementation of this method returns true. This method is called for a layout to support all positions(tip, half and full).
+    /// Therefore, `proposedTargetPosition` can only be `FloatingPanelPosition.tip` or `FloatingPanelPosition.full`.
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool
+
+    /// Returns a deceleration rate to calculate a target position projected a dragging momentum.
+    ///
+    /// The default implementation of this method returns the normal deceleration rate of UIScrollView.
+    func momentumProjectionRate(_ fpc: FloatingPanelController) -> CGFloat
+
+    /// Returns the progress to redirect to the previous position.
+    ///
+    /// The progress is represented by a floating-point value between 0.0 and 1.0, inclusive, where 1.0 indicates the floating panel is impossible to move to the next position. The default value is 0.5. Values less than 0.0 and greater than 1.0 are pinned to those limits.
     func redirectionalProgress(_ fpc: FloatingPanelController, from: FloatingPanelPosition, to: FloatingPanelPosition) -> CGFloat
 
     /// Returns a UIViewPropertyAnimator object to project a floating panel to a position on finger up if the user dragged.
+    ///
+    /// - Attention:
+    /// By default, it returns a non-interruptible animator to prevent a propagation of the animation to a content view.
+    /// However returning an interruptible animator is working well depending on a content view and it can be better
+    /// than using a non-interruptible one.
     func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator
 
     /// Returns a UIViewPropertyAnimator object to add a floating panel to a position.
@@ -46,13 +62,35 @@ public protocol FloatingPanelBehavior {
     ///
     /// Default is a spring animator with 1.0 damping ratio. This method is called when FloatingPanelController.isRemovalInteractionEnabled is true.
     func removalInteractionAnimator(_ fpc: FloatingPanelController, with velocity: CGVector) -> UIViewPropertyAnimator
+
+
+    /// Asks the behavior whether the rubber band effect is enabled in moving over a given edge of the surface view.
+    ///
+    /// This method allows the behavior to activate the rubber band effect to a given edge of the surface view. By default, the effect is disabled.
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool
 }
 
 public extension FloatingPanelBehavior {
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
+        return false
+    }
+
+    func momentumProjectionRate(_ fpc: FloatingPanelController) -> CGFloat {
+        #if swift(>=4.2)
+        return UIScrollView.DecelerationRate.normal.rawValue
+        #else
+        return UIScrollViewDecelerationRateNormal
+        #endif
+    }
+
     func redirectionalProgress(_ fpc: FloatingPanelController, from: FloatingPanelPosition, to: FloatingPanelPosition) -> CGFloat {
         return 0.5
     }
 
+    func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
+        return defaultBehavior.interactionAnimator(fpc, to: targetPosition, with: velocity)
+    }
+
     func addAnimator(_ fpc: FloatingPanelController, to: FloatingPanelPosition) -> UIViewPropertyAnimator {
         return UIViewPropertyAnimator(duration: 0.25, curve: .easeInOut)
     }
@@ -80,13 +118,21 @@ public extension FloatingPanelBehavior {
                                         initialVelocity: velocity)
         return UIViewPropertyAnimator(duration: 0, timingParameters: timing)
     }
+
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
+        return false
+    }
 }
 
-class FloatingPanelDefaultBehavior: FloatingPanelBehavior {
-    func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
+private let defaultBehavior = FloatingPanelDefaultBehavior()
+
+public class FloatingPanelDefaultBehavior: FloatingPanelBehavior {
+    public init() { }
+
+    public func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
         let timing = timeingCurve(with: velocity)
         let animator = UIViewPropertyAnimator(duration: 0, timingParameters: timing)
-        animator.isInterruptible = false
+        animator.isInterruptible = false // Prevent a propagation of the animation(spring etc) to a content view
         return animator
     }
 

Framework/Sources/FloatingPanelController.swift

@@ -12,9 +12,14 @@ public protocol FloatingPanelControllerDelegate: class {
     // if it returns nil, FloatingPanelController uses the default behavior
     func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior?
 
-    func floatingPanelDidChangePosition(_ vc: FloatingPanelController) // changed the settled position in the model layer
+    /// Called when the floating panel has changed to a new position. Can be called inside an animation block, so any
+    /// view properties set inside this function will be automatically animated alongside the panel.
+    func floatingPanelDidChangePosition(_ vc: FloatingPanelController)
 
-    func floatingPanelDidMove(_ vc: FloatingPanelController) // any offset changes
+    /// Asks the delegate if dragging should begin by the pan gesture recognizer.
+    func floatingPanelShouldBeginDragging(_ vc: FloatingPanelController) -> Bool
+
+    func floatingPanelDidMove(_ vc: FloatingPanelController) // any surface frame changes in dragging
 
     // called on start of dragging (may require some time and or distance to move)
     func floatingPanelWillBeginDragging(_ vc: FloatingPanelController)
@@ -27,6 +32,20 @@ public protocol FloatingPanelControllerDelegate: class {
     func floatingPanelDidEndDraggingToRemove(_ vc: FloatingPanelController, withVelocity velocity: CGPoint)
     // called when its views are removed from a parent view controller
     func floatingPanelDidEndRemove(_ vc: FloatingPanelController)
+
+    /// Asks the delegate if the other gesture recognizer should be allowed to recognize the gesture in parallel.
+    ///
+    /// By default, any tap and long gesture recognizers are allowed to recognize gestures simultaneously.
+    func floatingPanel(_ vc: FloatingPanelController, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool
+
+    /// Asks the delegate for a content offset of the tracked scroll view to be pinned when a floating panel moves
+    ///
+    /// If you do not implement this method, the controller uses a value of the content offset plus the content insets
+    /// of the tracked scroll view. Your implementation of this method can return a value for a navigation bar with a large
+    /// title, for example.
+    ///
+    /// This method will not be called if the controller doesn't track any scroll view.
+    func floatingPanel(_ vc: FloatingPanelController, contentOffsetForPinning trackedScrollView: UIScrollView) -> CGPoint
 }
 
 public extension FloatingPanelControllerDelegate {
@@ -37,6 +56,9 @@ public extension FloatingPanelControllerDelegate {
         return nil
     }
     func floatingPanelDidChangePosition(_ vc: FloatingPanelController) {}
+    func floatingPanelShouldBeginDragging(_ vc: FloatingPanelController) -> Bool {
+        return true
+    }
     func floatingPanelDidMove(_ vc: FloatingPanelController) {}
     func floatingPanelWillBeginDragging(_ vc: FloatingPanelController) {}
     func floatingPanelDidEndDragging(_ vc: FloatingPanelController, withVelocity velocity: CGPoint, targetPosition: FloatingPanelPosition) {}
@@ -45,31 +67,85 @@ public extension FloatingPanelControllerDelegate {
 
     func floatingPanelDidEndDraggingToRemove(_ vc: FloatingPanelController, withVelocity velocity: CGPoint) {}
     func floatingPanelDidEndRemove(_ vc: FloatingPanelController) {}
+
+    func floatingPanel(_ vc: FloatingPanelController, shouldRecognizeSimultaneouslyWith gestureRecognizer: UIGestureRecognizer) -> Bool {
+        return false
+    }
+    func floatingPanel(_ vc: FloatingPanelController, contentOffsetForPinning trackedScrollView: UIScrollView) -> CGPoint {
+        return CGPoint(x: 0.0, y: 0.0 - trackedScrollView.contentInset.top)
+    }
 }
 
-public enum FloatingPanelPosition: Int, CaseIterable {
+
+public enum FloatingPanelPosition: Int {
     case full
     case half
     case tip
+    case hidden
+
+    static var allCases: [FloatingPanelPosition] {
+        return [.full, .half, .tip, .hidden]
+    }
+
+    func next(in positions: [FloatingPanelPosition]) -> FloatingPanelPosition {
+        #if swift(>=4.2)
+        guard
+            let index = positions.firstIndex(of: self),
+            positions.indices.contains(index + 1)
+            else { return self }
+        #else
+        guard
+            let index = positions.index(of: self),
+            positions.indices.contains(index + 1)
+            else { return self }
+        #endif
+        return positions[index + 1]
+    }
+
+    func pre(in positions: [FloatingPanelPosition]) -> FloatingPanelPosition {
+        #if swift(>=4.2)
+        guard
+            let index = positions.firstIndex(of: self),
+            positions.indices.contains(index - 1)
+            else { return self }
+        #else
+        guard
+            let index = positions.index(of: self),
+            positions.indices.contains(index - 1)
+            else { return self }
+        #endif
+        return positions[index - 1]
+    }
 }
 
 ///
 /// A container view controller to display a floating panel to present contents in parallel as a user wants.
 ///
-public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGestureRecognizerDelegate {
-
+open class FloatingPanelController: UIViewController {
     /// Constants indicating how safe area insets are added to the adjusted content inset.
     public enum ContentInsetAdjustmentBehavior: Int {
         case always
         case never
     }
 
+    /// A flag used to determine how the controller object lays out the content view when the surface position changes.
+    public enum ContentMode: Int {
+        /// The option to fix the content to keep the height of the top most position.
+        case `static`
+        /// The option to scale the content to fit the bounds of the root view by changing the surface position.
+        case fitToBounds
+    }
+
     /// The delegate of the floating panel controller object.
-    public weak var delegate: FloatingPanelControllerDelegate?
+    public weak var delegate: FloatingPanelControllerDelegate?{
+        didSet{
+            didUpdateDelegate()
+        }
+    }
 
     /// Returns the surface view managed by the controller object. It's the same as `self.view`.
     public var surfaceView: FloatingPanelSurfaceView! {
-        return view as? FloatingPanelSurfaceView
+        return floatingPanel.surfaceView
     }
 
     /// Returns the backdrop view managed by the controller object.
@@ -84,7 +160,7 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
 
     // The underlying gesture recognizer for pan gestures
     public var panGestureRecognizer: UIPanGestureRecognizer {
-        return floatingPanel.panGesture
+        return floatingPanel.panGestureRecognizer
     }
 
     /// The current position of the floating panel controller's contents.
@@ -102,7 +178,7 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
         return floatingPanel.behavior
     }
 
-    /// The content insets of the tracking scroll view derived from the safe area of the parent view
+    /// The content insets of the tracking scroll view derived from this safe area
     public var adjustedContentInsets: UIEdgeInsets {
         return floatingPanel.layoutAdapter.adjustedContentInsets
     }
@@ -123,66 +199,149 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
         set { set(contentViewController: newValue) }
         get { return _contentViewController }
     }
+    
+    /// The NearbyPosition determines that finger's nearby position.
+    public var nearbyPosition: FloatingPanelPosition {
+        let currentY = surfaceView.frame.minY
+        return floatingPanel.targetPosition(from: currentY, with: .zero)
+    }
+    
+    public var contentMode: ContentMode = .static {
+        didSet {
+            guard position != .hidden else { return }
+            activateLayout()
+        }
+    }
+
     private var _contentViewController: UIViewController?
 
-    private var floatingPanel: FloatingPanel!
-    private var layoutInsetsObservations: [NSKeyValueObservation] = []
+    private(set) var floatingPanel: FloatingPanelCore!
+    private var preSafeAreaInsets: UIEdgeInsets = .zero // Capture the latest one
+    private var safeAreaInsetsObservation: NSKeyValueObservation?
+    private let modalTransition = FloatingPanelModalTransition()
 
-    required init?(coder aDecoder: NSCoder) {
+    required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
-
-        floatingPanel = FloatingPanel(self,
-                                      layout: fetchLayout(for: self.traitCollection),
-                                      behavior: fetchBehavior(for: self.traitCollection))
+        setUp()
     }
 
     /// Initialize a newly created floating panel controller.
-    public init() {
+    public init(delegate: FloatingPanelControllerDelegate? = nil) {
         super.init(nibName: nil, bundle: nil)
+        self.delegate = delegate
+        setUp()
+    }
 
-        floatingPanel = FloatingPanel(self,
+    private func setUp() {
+        _ = FloatingPanelController.dismissSwizzling
+
+        modalPresentationStyle = .custom
+        transitioningDelegate = modalTransition
+
+        floatingPanel = FloatingPanelCore(self,
                                       layout: fetchLayout(for: self.traitCollection),
                                       behavior: fetchBehavior(for: self.traitCollection))
     }
 
+    private func didUpdateDelegate(){
+        floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
+        floatingPanel.behavior = fetchBehavior(for: self.traitCollection)
+    }
+
+    // MARK:- Overrides
+
     /// Creates the view that the controller manages.
-    override public func loadView() {
+    open override func loadView() {
         assert(self.storyboard == nil, "Storyboard isn't supported")
 
-        let view = FloatingPanelSurfaceView()
-        view.backgroundColor = .white
+        let view = FloatingPanelPassThroughView()
+        view.backgroundColor = .clear
+
+        backdropView.frame = view.bounds
+        view.addSubview(backdropView)
+
+        surfaceView.frame = view.bounds
+        view.addSubview(surfaceView)
 
         self.view = view as UIView
     }
 
-    public override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
+    open override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        if #available(iOS 11.0, *) {}
+        else {
+            // Because {top,bottom}LayoutGuide is managed as a view
+            if preSafeAreaInsets != layoutInsets,
+                floatingPanel.isDecelerating == false {
+                self.update(safeAreaInsets: layoutInsets)
+            }
+        }
+    }
+
+    open override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
+        super.viewWillTransition(to: size, with: coordinator)
+
+        if view.translatesAutoresizingMaskIntoConstraints {
+            view.frame.size = size
+            view.layoutIfNeeded()
+        }
+    }
+
+    open override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
         super.willTransition(to: newCollection, with: coordinator)
+        self.prepare(for: newCollection)
+    }
 
-        // Change layout for a new trait collection
-        updateLayout(for: newCollection)
+    open override func viewWillDisappear(_ animated: Bool) {
+        super.viewWillDisappear(animated)
+        safeAreaInsetsObservation = nil
+    }
 
+    // MARK:- Child view controller to consult
+    #if swift(>=4.2)
+    open override var childForStatusBarStyle: UIViewController? {
+        return contentViewController
+    }
+
+    open override var childForStatusBarHidden: UIViewController? {
+        return contentViewController
+    }
+
+    open override var childForScreenEdgesDeferringSystemGestures: UIViewController? {
+        return contentViewController
+    }
+
+    open override var childForHomeIndicatorAutoHidden: UIViewController? {
+        return contentViewController
+    }
+    #else
+    open override var childViewControllerForStatusBarStyle: UIViewController? {
+        return contentViewController
+    }
+
+    open override var childViewControllerForStatusBarHidden: UIViewController? {
+        return contentViewController
+    }
+
+    open override func childViewControllerForScreenEdgesDeferringSystemGestures() -> UIViewController? {
+        return contentViewController
+    }
+
+    open override func childViewControllerForHomeIndicatorAutoHidden() -> UIViewController? {
+        return contentViewController
+    }
+    #endif
+
+    // MARK:- Internals
+    func prepare(for newCollection: UITraitCollection) {
+        guard newCollection.shouldUpdateLayout(from: traitCollection) else { return }
+        // Change a layout & behavior for a new trait collection
+        reloadLayout(for: newCollection)
+        activateLayout()
         floatingPanel.behavior = fetchBehavior(for: newCollection)
     }
 
-    public override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
-        super.traitCollectionDidChange(previousTraitCollection)
-        guard previousTraitCollection != traitCollection else { return }
-
-        if let parent = parent {
-            self.update(safeAreaInsets: parent.layoutInsets)
-        }
-    }
-
-    public override func viewDidAppear(_ animated: Bool) {
-        super.viewDidAppear(animated)
-
-        // Need to update safeAreaInsets here to ensure that the `adjustedContentInsets` has a correct value.
-        // Because the parent VC does not call viewSafeAreaInsetsDidChange() expectedly and
-        // `view.safeAreaInsets` has a correct value of the bottom inset here.
-        if let parent = parent {
-            self.update(safeAreaInsets: parent.layoutInsets)
-        }
-    }
+    // MARK:- Privates
 
     private func fetchLayout(for traitCollection: UITraitCollection) -> FloatingPanelLayout {
         switch traitCollection.verticalSizeClass {
@@ -198,12 +357,16 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
     }
 
     private func update(safeAreaInsets: UIEdgeInsets) {
-        // preserve the current content offset
-        let contentOffset = scrollView?.contentOffset
+        guard
+            preSafeAreaInsets != safeAreaInsets
+            else { return }
 
-        floatingPanel.safeAreaInsets = safeAreaInsets
+        log.debug("Update safeAreaInsets", safeAreaInsets)
 
-        scrollView?.contentOffset = contentOffset ?? .zero
+        // Prevent an infinite loop on iOS 10: setUpLayout() -> viewDidLayoutSubviews() -> setUpLayout()
+        preSafeAreaInsets = safeAreaInsets
+
+        activateLayout()
 
         switch contentInsetAdjustmentBehavior {
         case .always:
@@ -214,17 +377,72 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
         }
     }
 
-    private func updateLayout(for traitCollection: UITraitCollection) {
+    private func reloadLayout(for traitCollection: UITraitCollection) {
         floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
 
-        guard let parent = parent else { return }
+        if let parent = self.parent {
+            if let layout = layout as? UIViewController, layout == parent {
+                log.warning("A memory leak will occur by a retain cycle because \(self) owns the parent view controller(\(parent)) as the layout object. Don't let the parent adopt FloatingPanelLayout.")
+            }
+            if let behavior = behavior as? UIViewController, behavior == parent {
+                log.warning("A memory leak will occur by a retain cycle because \(self) owns the parent view controller(\(parent)) as the behavior object. Don't let the parent adopt FloatingPanelBehavior.")
+            }
+        }
+    }
 
-        floatingPanel.layoutAdapter.prepareLayout(toParent: parent)
+    private func activateLayout() {
+        floatingPanel.layoutAdapter.prepareLayout(in: self)
+
+        // preserve the current content offset if contentInsetAdjustmentBehavior is `.always`
+        var contentOffset: CGPoint?
+        if contentInsetAdjustmentBehavior == .always {
+            contentOffset = scrollView?.contentOffset
+        }
+
+        floatingPanel.layoutAdapter.updateHeight()
         floatingPanel.layoutAdapter.activateLayout(of: floatingPanel.state)
+
+        if let contentOffset = contentOffset {
+            scrollView?.contentOffset = contentOffset
+        }
     }
 
     // MARK: - Container view controller interface
 
+    /// Shows the surface view at the initial position defined by the current layout
+    public func show(animated: Bool = false, completion: (() -> Void)? = nil) {
+        // Must apply the current layout here
+        reloadLayout(for: traitCollection)
+        activateLayout()
+
+        if #available(iOS 11.0, *) {
+            // Must track the safeAreaInsets of `self.view` to update the layout.
+            // There are 2 reasons.
+            // 1. This or the parent VC doesn't call viewSafeAreaInsetsDidChange() on the bottom
+            // inset's update expectedly.
+            // 2. The safe area top inset can be variable on the large title navigation bar(iOS11+).
+            // That's why it needs the observation to keep `adjustedContentInsets` correct.
+            safeAreaInsetsObservation = self.observe(\.view.safeAreaInsets, options: [.initial, .new, .old]) { [weak self] (vc, change) in
+                guard change.oldValue != change.newValue else { return }
+                self?.update(safeAreaInsets: vc.layoutInsets)
+            }
+        } else {
+            // KVOs for topLayoutGuide & bottomLayoutGuide are not effective.
+            // Instead, update(safeAreaInsets:) is called at `viewDidLayoutSubviews()`
+        }
+
+        move(to: floatingPanel.layoutAdapter.layout.initialPosition,
+             animated: animated,
+             completion: completion)
+    }
+
+    /// Hides the surface view to the hidden position
+    public func hide(animated: Bool = false, completion: (() -> Void)? = nil) {
+        move(to: .hidden,
+             animated: animated,
+             completion: completion)
+    }
+
     /// Adds the view managed by the controller as a child of the specified view controller.
     /// - Parameters:
     ///     - parent: A parent view controller object that displays FloatingPanelController's view. A container view controller object isn't applicable.
@@ -241,43 +459,34 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
         precondition((parent is UITableViewController) == false, "UITableViewController should not be the parent because the view is a table view so that a floating panel doens't work well")
         precondition((parent is UICollectionViewController) == false, "UICollectionViewController should not be the parent because the view is a collection view so that a floating panel doens't work well")
 
-        view.frame = parent.view.bounds
         if let belowView = belowView {
             parent.view.insertSubview(self.view, belowSubview: belowView)
         } else {
             parent.view.addSubview(self.view)
         }
 
-        layoutInsetsObservations.removeAll()
-
-        // Must track safeAreaInsets/{top,bottom}LayoutGuide of the `parent.view`
-        // to update floatingPanel.safeAreaInsets`. There are 2 reasons.
-        // 1. The parent VC doesn't call viewSafeAreaInsetsDidChange() on the bottom
-        // inset's update expectedly.
-        // 2. The safe area top inset can be variable on the large title navigation bar.
-        // That's why it needs the observation to keep `adjustedContentInsets` correct.
-        if #available(iOS 11.0, *) {
-            let observaion = parent.observe(\.view.safeAreaInsets) { [weak self] (vc, chaneg) in
-                guard let self = self else { return }
-                self.update(safeAreaInsets: vc.layoutInsets)
-            }
-            layoutInsetsObservations.append(observaion)
-        } else {
-            // KVOs for topLayoutGuide & bottomLayoutGuide are not effective.
-            // Instead, safeAreaInsets will be updated in viewDidAppear()
-        }
-
+        #if swift(>=4.2)
         parent.addChild(self)
+        #else
+        parent.addChildViewController(self)
+        #endif
 
-        // Must set a layout again here because `self.traitCollection` is applied correctly once it's added to a parent VC
-        floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
-        floatingPanel.behavior = fetchBehavior(for: traitCollection)
+        view.frame = parent.view.bounds // Needed for a correct safe area configuration
+        view.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            self.view.topAnchor.constraint(equalTo: parent.view.topAnchor, constant: 0.0),
+            self.view.leftAnchor.constraint(equalTo: parent.view.leftAnchor, constant: 0.0),
+            self.view.rightAnchor.constraint(equalTo: parent.view.rightAnchor, constant: 0.0),
+            self.view.bottomAnchor.constraint(equalTo: parent.view.bottomAnchor, constant: 0.0),
+            ])
 
-        floatingPanel.setUpViews(in: parent)
-
-        floatingPanel.present(animated: animated) { [weak self] in
-            guard let self = self else { return }
+        show(animated: animated) { [weak self] in
+            guard let `self` = self else { return }
+            #if swift(>=4.2)
             self.didMove(toParent: parent)
+            #else
+            self.didMove(toParentViewController: parent)
+            #endif
         }
     }
 
@@ -291,15 +500,22 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
             return
         }
 
-        layoutInsetsObservations.removeAll()
-
-        floatingPanel.dismiss(animated: animated) { [weak self] in
-            guard let self = self else { return }
-
+        hide(animated: animated) { [weak self] in
+            guard let `self` = self else { return }
+            #if swift(>=4.2)
             self.willMove(toParent: nil)
+            #else
+            self.willMove(toParentViewController: nil)
+            #endif
+
             self.view.removeFromSuperview()
-	      	self.backdropView.removeFromSuperview()
+
+            #if swift(>=4.2)
             self.removeFromParent()
+            #else
+            self.removeFromParentViewController()
+            #endif
+
             completion?()
         }
     }
@@ -310,36 +526,57 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
     ///     - animated: Pass true to animate the presentation; otherwise, pass false.
     ///     - completion: The block to execute after the view controller has finished moving. This block has no return value and takes no parameters. You may specify nil for this parameter.
     public func move(to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil) {
+        precondition(floatingPanel.layoutAdapter.vc != nil, "Use show(animated:completion)")
         floatingPanel.move(to: to, animated: animated, completion: completion)
     }
 
-    /// Sets the view controller responsible for the content portion of the floating panel..
+    /// Sets the view controller responsible for the content portion of the floating panel.
     public func set(contentViewController: UIViewController?) {
         if let vc = _contentViewController {
+            #if swift(>=4.2)
             vc.willMove(toParent: nil)
+            #else
+            vc.willMove(toParentViewController: nil)
+            #endif
+
             vc.view.removeFromSuperview()
+
+            #if swift(>=4.2)
             vc.removeFromParent()
+            #else
+            vc.removeFromParentViewController()
+            #endif
         }
 
         if let vc = contentViewController {
-            let surfaceView = self.view as! FloatingPanelSurfaceView
-            surfaceView.add(childView: vc.view)
+            #if swift(>=4.2)
             addChild(vc)
+            #else
+            addChildViewController(vc)
+            #endif
+
+            let surfaceView = floatingPanel.surfaceView
+            surfaceView.add(contentView: vc.view)
+
+            #if swift(>=4.2)
             vc.didMove(toParent: self)
+            #else
+            vc.didMove(toParentViewController: self)
+            #endif
         }
 
         _contentViewController = contentViewController
     }
 
     @available(*, unavailable, renamed: "set(contentViewController:)")
-    public override func show(_ vc: UIViewController, sender: Any?) {
+    open  override func show(_ vc: UIViewController, sender: Any?) {
         if let target = self.parent?.targetViewController(forAction: #selector(UIViewController.show(_:sender:)), sender: sender) {
             target.show(vc, sender: sender)
         }
     }
 
     @available(*, unavailable, renamed: "set(contentViewController:)")
-    public override func showDetailViewController(_ vc: UIViewController, sender: Any?) {
+    open  override func showDetailViewController(_ vc: UIViewController, sender: Any?) {
         if let target = self.parent?.targetViewController(forAction: #selector(UIViewController.showDetailViewController(_:sender:)), sender: sender) {
             target.showDetailViewController(vc, sender: sender)
         }
@@ -349,23 +586,30 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
 
     /// Tracks the specified scroll view to correspond with the scroll.
     ///
-    /// - Attention:
-    ///     The specified scroll view must be already assigned to the delegate property because the controller intermediates between the various delegate methods.
-    ///
-    public func track(scrollView: UIScrollView) {
-        floatingPanel.scrollView = scrollView
-        if scrollView.delegate !== floatingPanel {
-            floatingPanel.userScrollViewDelegate = scrollView.delegate
-            scrollView.delegate = floatingPanel
+    /// - Parameters:
+    ///     - scrollView: Specify a scroll view to continuously and seamlessly work in concert with interactions of the surface view or nil to cancel it.
+    public func track(scrollView: UIScrollView?) {
+        guard let scrollView = scrollView else {
+            floatingPanel.scrollView = nil
+            return
         }
+
+        floatingPanel.scrollView = scrollView
+
         switch contentInsetAdjustmentBehavior {
         case .always:
             if #available(iOS 11.0, *) {
                 scrollView.contentInsetAdjustmentBehavior = .never
             } else {
+                #if swift(>=4.2)
                 children.forEach { (vc) in
                     vc.automaticallyAdjustsScrollViewInsets = false
                 }
+                #else
+                childViewControllers.forEach { (vc) in
+                    vc.automaticallyAdjustsScrollViewInsets = false
+                }
+                #endif
             }
         default:
             break
@@ -378,22 +622,62 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
     /// by the controller immediately.
     ///
     /// This method updates the `FloatingPanelLayout` object from the delegate and
-    /// then it calls `layoutIfNeeded()` of the parent's root view to force the view
+    /// then it calls `layoutIfNeeded()` of the root view to force the view
     /// to update the floating panel's layout immediately. It can be called in an
     /// animation block.
     public func updateLayout() {
-        updateLayout(for: view.traitCollection)
+        reloadLayout(for: traitCollection)
+        activateLayout()
     }
 
-    /// Returns the y-coordinate of the point at the origin of the surface view
+    /// Returns the y-coordinate of the point at the origin of the surface view.
     public func originYOfSurface(for pos: FloatingPanelPosition) -> CGFloat {
-        switch pos {
-        case .full:
-            return floatingPanel.layoutAdapter.topY
-        case .half:
-            return floatingPanel.layoutAdapter.middleY
-        case .tip:
-            return floatingPanel.layoutAdapter.bottomY
-        }
+        return floatingPanel.layoutAdapter.positionY(for: pos)
+    }
+}
+
+extension FloatingPanelController {
+    private static let dismissSwizzling: Any? = {
+        let aClass: AnyClass! = UIViewController.self //object_getClass(vc)
+        if let imp = class_getMethodImplementation(aClass, #selector(dismiss(animated:completion:))),
+            let originalAltMethod = class_getInstanceMethod(aClass, #selector(fp_original_dismiss(animated:completion:))) {
+            method_setImplementation(originalAltMethod, imp)
+        }
+        let originalMethod = class_getInstanceMethod(aClass, #selector(dismiss(animated:completion:)))
+        let swizzledMethod = class_getInstanceMethod(aClass, #selector(fp_dismiss(animated:completion:)))
+        if let originalMethod = originalMethod, let swizzledMethod = swizzledMethod {
+            // switch implementation..
+            method_exchangeImplementations(originalMethod, swizzledMethod)
+        }
+        return nil
+    }()
+}
+
+public extension UIViewController {
+    @objc func fp_original_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
+        // Implementation will be replaced by IMP of self.dismiss(animated:completion:)
+    }
+    @objc func fp_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
+        // Call dismiss(animated:completion:) to a content view controller
+        if let fpc = parent as? FloatingPanelController {
+            if fpc.presentingViewController != nil {
+                self.fp_original_dismiss(animated: flag, completion: completion)
+            } else {
+                fpc.removePanelFromParent(animated: flag, completion: completion)
+            }
+            return
+        }
+        // Call dismiss(animated:completion:) to FloatingPanelController directly
+        if let fpc = self as? FloatingPanelController {
+            if fpc.presentingViewController != nil {
+                self.fp_original_dismiss(animated: flag, completion: completion)
+            } else {
+                fpc.removePanelFromParent(animated: flag, completion: completion)
+            }
+            return
+        }
+
+        // For other view controllers
+        self.fp_original_dismiss(animated: flag, completion: completion)
     }
 }

Framework/Sources/FloatingPanelCore.swift

@@ -0,0 +1,946 @@
+//
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import UIKit
+import UIKit.UIGestureRecognizerSubclass // For Xcode 9.4.1
+
+///
+/// FloatingPanel presentation model
+///
+class FloatingPanelCore: NSObject, UIGestureRecognizerDelegate {
+    // MUST be a weak reference to prevent UI freeze on the presentation modally
+    weak var viewcontroller: FloatingPanelController?
+
+    let surfaceView: FloatingPanelSurfaceView
+    let backdropView: FloatingPanelBackdropView
+    var layoutAdapter: FloatingPanelLayoutAdapter
+    var behavior: FloatingPanelBehavior
+
+    weak var scrollView: UIScrollView? {
+        didSet {
+            oldValue?.panGestureRecognizer.removeTarget(self, action: nil)
+            scrollView?.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
+        }
+    }
+
+    private(set) var state: FloatingPanelPosition = .hidden {
+        didSet {
+            if let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidChangePosition(vc)
+            }
+        }
+    }
+
+    private var isBottomState: Bool {
+        let remains = layoutAdapter.supportedPositions.filter { $0.rawValue > state.rawValue }
+        return remains.count == 0
+    }
+
+    let panGestureRecognizer: FloatingPanelPanGestureRecognizer
+    var isRemovalInteractionEnabled: Bool = false
+
+    fileprivate var animator: UIViewPropertyAnimator?
+
+    private var initialFrame: CGRect = .zero
+    private var initialTranslationY: CGFloat = 0
+    private var initialLocation: CGPoint = .nan
+
+    var interactionInProgress: Bool = false
+    var isDecelerating: Bool = false
+
+    // Scroll handling
+    private var initialScrollOffset: CGPoint = .zero
+    private var stopScrollDeceleration: Bool = false
+    private var scrollBouncable = false
+    private var scrollIndictorVisible = false
+
+    // MARK: - Interface
+
+    init(_ vc: FloatingPanelController, layout: FloatingPanelLayout, behavior: FloatingPanelBehavior) {
+        viewcontroller = vc
+
+        surfaceView = FloatingPanelSurfaceView()
+        surfaceView.backgroundColor = .white
+
+        backdropView = FloatingPanelBackdropView()
+        backdropView.backgroundColor = .black
+        backdropView.alpha = 0.0
+
+        self.layoutAdapter = FloatingPanelLayoutAdapter(surfaceView: surfaceView,
+                                                        backdropView: backdropView,
+                                                        layout: layout)
+        self.behavior = behavior
+
+        panGestureRecognizer = FloatingPanelPanGestureRecognizer()
+
+        if #available(iOS 11.0, *) {
+            panGestureRecognizer.name = "FloatingPanelSurface"
+        }
+
+        super.init()
+
+        panGestureRecognizer.floatingPanel = self
+        surfaceView.addGestureRecognizer(panGestureRecognizer)
+        panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
+        panGestureRecognizer.delegate = self
+
+        // Set tap-to-dismiss in the backdrop view
+        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
+        tapGesture.isEnabled = false
+        backdropView.dismissalTapGestureRecognizer = tapGesture
+        backdropView.addGestureRecognizer(tapGesture)
+    }
+
+    func move(to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil) {
+        move(from: state, to: to, animated: animated, completion: completion)
+    }
+
+    private func move(from: FloatingPanelPosition, to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil) {
+        assert(layoutAdapter.isValid(to), "Can't move to '\(to)' position because it's not valid in the layout")
+        guard let vc = viewcontroller else {
+            completion?()
+            return
+        }
+        if state != layoutAdapter.topMostState {
+            lockScrollView()
+        }
+        tearDownActiveInteraction()
+
+        if animated {
+            let animator: UIViewPropertyAnimator
+            switch (from, to) {
+            case (.hidden, let to):
+                animator = behavior.addAnimator(vc, to: to)
+            case (let from, .hidden):
+                animator = behavior.removeAnimator(vc, from: from)
+            case (let from, let to):
+                animator = behavior.moveAnimator(vc, from: from, to: to)
+            }
+
+            animator.addAnimations { [weak self] in
+                guard let `self` = self else { return }
+
+                self.state = to
+                self.updateLayout(to: to)
+            }
+            animator.addCompletion { [weak self] _ in
+                guard let `self` = self else { return }
+                self.animator = nil
+                if self.state == self.layoutAdapter.topMostState {
+                    self.unlockScrollView()
+                } else {
+                    self.lockScrollView()
+                }
+                completion?()
+            }
+            self.animator = animator
+            animator.startAnimation()
+        } else {
+            self.state = to
+            self.updateLayout(to: to)
+            if self.state == self.layoutAdapter.topMostState {
+                self.unlockScrollView()
+            } else {
+                self.lockScrollView()
+            }
+            completion?()
+        }
+    }
+
+    // MARK: - Layout update
+
+    private func updateLayout(to target: FloatingPanelPosition) {
+        self.layoutAdapter.activateFixedLayout()
+        self.layoutAdapter.activateInteractiveLayout(of: target)
+    }
+
+    func getBackdropAlpha(at currentY: CGFloat, with translation: CGPoint) -> CGFloat {
+        let forwardY = (translation.y >= 0)
+        let segment = layoutAdapter.segument(at: currentY, forward: forwardY)
+        let lowerPos = segment.lower ?? layoutAdapter.topMostState
+        let upperPos = segment.upper ?? layoutAdapter.bottomMostState
+
+        let pre = forwardY ? lowerPos : upperPos
+        let next = forwardY ? upperPos : lowerPos
+
+        let nextY = layoutAdapter.positionY(for: next)
+        let preY = layoutAdapter.positionY(for: pre)
+
+        let nextAlpha = layoutAdapter.layout.backdropAlphaFor(position: next)
+        let preAlpha = layoutAdapter.layout.backdropAlphaFor(position: pre)
+
+        if preY == nextY {
+            return preAlpha
+        } else {
+            return preAlpha + max(min(1.0, 1.0 - (nextY - currentY) / (nextY - preY) ), 0.0) * (nextAlpha - preAlpha)
+        }
+    }
+
+    // MARK: - UIGestureRecognizerDelegate
+
+    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
+                                  shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
+        guard gestureRecognizer == panGestureRecognizer else { return false }
+
+        /* log.debug("shouldRecognizeSimultaneouslyWith", otherGestureRecognizer) */
+
+        if let vc = viewcontroller,
+            vc.delegate?.floatingPanel(vc, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
+            return true
+        }
+
+        switch otherGestureRecognizer {
+        case is FloatingPanelPanGestureRecognizer:
+            // All visiable panels' pan gesture should be recognized simultaneously.
+            return true
+        case is UIPanGestureRecognizer,
+             is UISwipeGestureRecognizer,
+             is UIRotationGestureRecognizer,
+             is UIScreenEdgePanGestureRecognizer,
+             is UIPinchGestureRecognizer:
+            // all gestures of the tracking scroll view should be recognized in parallel
+            // and handle them in self.handle(panGesture:)
+            return scrollView?.gestureRecognizers?.contains(otherGestureRecognizer) ?? false
+        default:
+            // Should recognize tap/long press gestures in parallel when the surface view is at an anchor position.
+            let surfaceFrame = surfaceView.layer.presentation()?.frame ?? surfaceView.frame
+            let surfaceY = surfaceFrame.minY
+            let adapterY = layoutAdapter.positionY(for: state)
+
+            return abs(surfaceY - adapterY) < (1.0 / surfaceView.traitCollection.displayScale)
+        }
+    }
+
+    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
+        /* log.debug("shouldBeRequiredToFailBy", otherGestureRecognizer) */
+        if otherGestureRecognizer is FloatingPanelPanGestureRecognizer {
+            // If this panel is the farthest descendant of visiable panels,
+            // its ancestors' pan gesture must wait for its pan gesture to fail
+            if let view = otherGestureRecognizer.view, surfaceView.isDescendant(of: view) {
+                return true
+            }
+        }
+        return false
+    }
+
+    public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
+        guard gestureRecognizer == panGestureRecognizer else { return false }
+
+        /* log.debug("shouldRequireFailureOf", otherGestureRecognizer) */
+
+        // Should begin the pan gesture without waiting for the tracking scroll view's gestures.
+        // `scrollView.gestureRecognizers` can contains the following gestures
+        // * UIScrollViewDelayedTouchesBeganGestureRecognizer
+        // * UIScrollViewPanGestureRecognizer (scrollView.panGestureRecognizer)
+        // * _UIDragAutoScrollGestureRecognizer
+        // * _UISwipeActionPanGestureRecognizer
+        // * UISwipeDismissalGestureRecognizer
+        if let scrollView = scrollView {
+            // On short contents scroll, `_UISwipeActionPanGestureRecognizer` blocks
+            // the panel's pan gesture if not returns false
+            if let scrollGestureRecognizers = scrollView.gestureRecognizers,
+                scrollGestureRecognizers.contains(otherGestureRecognizer) {
+                switch otherGestureRecognizer {
+                case scrollView.panGestureRecognizer:
+                    if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+                        return false
+                    }
+                    return allowScrollPanGesture(for: scrollView)
+                default:
+                    return false
+                }
+            }
+        }
+
+        if let vc = viewcontroller,
+            vc.delegate?.floatingPanel(vc, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
+            return false
+        }
+
+        switch otherGestureRecognizer {
+        case is FloatingPanelPanGestureRecognizer:
+            // If this panel is the farthest descendant of visiable panels,
+            // its pan gesture does not require its ancestors' pan gesture to fail
+            if let view = otherGestureRecognizer.view, surfaceView.isDescendant(of: view) {
+                return false
+            }
+            return true
+        case is UIPanGestureRecognizer,
+             is UISwipeGestureRecognizer,
+             is UIRotationGestureRecognizer,
+             is UIScreenEdgePanGestureRecognizer,
+             is UIPinchGestureRecognizer:
+            // Do not begin the pan gesture until these gestures fail
+            return true
+        default:
+            // Should begin the pan gesture without waiting tap/long press gestures fail
+            return false
+        }
+    }
+
+    var grabberAreaFrame: CGRect {
+        let grabberAreaFrame = CGRect(x: surfaceView.bounds.origin.x,
+                                     y: surfaceView.bounds.origin.y,
+                                     width: surfaceView.bounds.width,
+                                     height: surfaceView.topGrabberBarHeight * 2)
+        return grabberAreaFrame
+    }
+
+    // MARK: - Gesture handling
+
+    @objc func handleBackdrop(tapGesture: UITapGestureRecognizer) {
+        viewcontroller?.dismiss(animated: true) { [weak self] in
+            guard let vc = self?.viewcontroller else { return }
+            vc.delegate?.floatingPanelDidEndRemove(vc)
+        }
+    }
+
+    @objc func handle(panGesture: UIPanGestureRecognizer) {
+        let velocity = panGesture.velocity(in: panGesture.view)
+
+        switch panGesture {
+        case scrollView?.panGestureRecognizer:
+            guard let scrollView = scrollView else { return }
+
+            let location = panGesture.location(in: surfaceView)
+
+            let surfaceMinY = surfaceView.presentationFrame.minY
+            let adapterTopY = layoutAdapter.topY
+            let belowTop = surfaceMinY > (adapterTopY + (1.0 / surfaceView.traitCollection.displayScale))
+            log.debug("scroll gesture(\(state):\(panGesture.state)) --",
+                "belowTop = \(belowTop),",
+                "interactionInProgress = \(interactionInProgress),",
+                "scroll offset = \(scrollView.contentOffset.y),",
+                "location = \(location.y), velocity = \(velocity.y)")
+
+            let offset = scrollView.contentOffset.y - contentOrigin(of: scrollView).y
+
+            if belowTop {
+                // Scroll offset pinning
+                if state == layoutAdapter.topMostState {
+                    if interactionInProgress {
+                        log.debug("settle offset --", initialScrollOffset.y)
+                        scrollView.setContentOffset(initialScrollOffset, animated: false)
+                    } else {
+                        if grabberAreaFrame.contains(location) {
+                            // Preserve the current content offset in moving from full.
+                            scrollView.setContentOffset(initialScrollOffset, animated: false)
+                        }
+                    }
+                } else {
+                    scrollView.setContentOffset(initialScrollOffset, animated: false)
+                }
+
+                // Hide a scroll indicator at the non-top in dragging.
+                if interactionInProgress {
+                    lockScrollView()
+                } else {
+                    if state == layoutAdapter.topMostState, self.animator == nil,
+                        offset > 0, velocity.y < 0 {
+                        unlockScrollView()
+                    }
+                }
+            } else {
+                if interactionInProgress {
+                    // Show a scroll indicator at the top in dragging.
+                    if offset >= 0, velocity.y <= 0 {
+                        unlockScrollView()
+                    } else {
+                        if state == layoutAdapter.topMostState {
+                            // Adjust a small gap of the scroll offset just after swiping down starts in the grabber area.
+                            if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
+                                scrollView.setContentOffset(initialScrollOffset, animated: false)
+                            }
+                        }
+                    }
+                } else {
+                    if state == layoutAdapter.topMostState {
+                        // Hide a scroll indicator just before starting an interaction by swiping a panel down.
+                        if velocity.y > 0, !allowScrollPanGesture(for: scrollView) {
+                            lockScrollView()
+                        }
+                        // Show a scroll indicator when an animation is interrupted at the top and content is scrolled up
+                        if velocity.y < 0, allowScrollPanGesture(for: scrollView) {
+                            unlockScrollView()
+                        }
+
+                        // Adjust a small gap of the scroll offset just before swiping down starts in the grabber area,
+                        if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
+                            scrollView.setContentOffset(initialScrollOffset, animated: false)
+                        }
+                    }
+                }
+            }
+        case panGestureRecognizer:
+            let translation = panGesture.translation(in: panGestureRecognizer.view!.superview)
+            let location = panGesture.location(in: panGesture.view)
+
+            log.debug("panel gesture(\(state):\(panGesture.state)) --",
+                "translation =  \(translation.y), location = \(location.y), velocity = \(velocity.y)")
+
+            if interactionInProgress == false, isDecelerating == false,
+                let vc = viewcontroller, vc.delegate?.floatingPanelShouldBeginDragging(vc) == false {
+                return
+            }
+
+            if let animator = self.animator {
+                guard surfaceView.presentationFrame.minY >= layoutAdapter.topMaxY else { return }
+                log.debug("panel animation(interruptible: \(animator.isInterruptible)) interrupted!!!")
+                if animator.isInterruptible {
+                    animator.stopAnimation(false)
+                    // A user can stop a panel at the nearest Y of a target position so this fine-tunes
+                    // the a small gap between the presentation layer frame and model layer frame
+                    // to unlock scroll view properly at finishAnimation(at:)
+                    if abs(surfaceView.frame.minY - layoutAdapter.topY) <= 1.0 {
+                        surfaceView.frame.origin.y = layoutAdapter.topY
+                    }
+                    animator.finishAnimation(at: .current)
+                } else {
+                    self.endAnimation(false) // Must call it manually
+                }
+            }
+
+            if panGesture.state == .began {
+                panningBegan(at: location)
+                return
+            }
+
+            if shouldScrollViewHandleTouch(scrollView, point: location, velocity: velocity) {
+                return
+            }
+
+            switch panGesture.state {
+            case .changed:
+                if interactionInProgress == false {
+                    startInteraction(with: translation, at: location)
+                }
+                panningChange(with: translation)
+            case .ended, .cancelled, .failed:
+                if interactionInProgress == false {
+                    startInteraction(with: translation, at: location)
+                    // Workaround: Prevent stopping the surface view b/w anchors if the pan gesture
+                    // doesn't pass through .changed state after an interruptible animator is interrupted.
+                    let dy = translation.y - .leastNonzeroMagnitude
+                    layoutAdapter.updateInteractiveTopConstraint(diff: dy,
+                                                                 allowsTopBuffer: true,
+                                                                 with: behavior)
+                }
+                panningEnd(with: translation, velocity: velocity)
+            default:
+                break
+            }
+        default:
+            return
+        }
+    }
+
+    private func shouldScrollViewHandleTouch(_ scrollView: UIScrollView?, point: CGPoint, velocity: CGPoint) -> Bool {
+        // When no scrollView, nothing to handle.
+        guard let scrollView = scrollView else { return false }
+
+        // For _UISwipeActionPanGestureRecognizer
+        if let scrollGestureRecognizers = scrollView.gestureRecognizers {
+            for gesture in scrollGestureRecognizers {
+                guard gesture.state == .began || gesture.state == .changed
+                else { continue }
+
+                if gesture !=  scrollView.panGestureRecognizer {
+                    return true
+                }
+            }
+        }
+
+        guard
+            state == layoutAdapter.topMostState,   // When not top most(i.e. .full), don't scroll.
+            interactionInProgress == false,        // When interaction already in progress, don't scroll.
+            surfaceView.frame.minY == layoutAdapter.topY
+        else {
+            return false
+        }
+
+        // When the current and initial point within grabber area, do scroll.
+        if grabberAreaFrame.contains(point), !grabberAreaFrame.contains(initialLocation) {
+            return true
+        }
+
+        let scrollViewFrame = scrollView.convert(scrollView.bounds, to: surfaceView)
+        guard
+            scrollViewFrame.contains(initialLocation), // When initialLocation not in scrollView, don't scroll.
+            !grabberAreaFrame.contains(point)           // When point within grabber area, don't scroll.
+        else {
+            return false
+        }
+
+        let offset = scrollView.contentOffset.y - contentOrigin(of: scrollView).y
+        // The zero offset must be excluded because the offset is usually zero
+        // after a panel moves from half/tip to full.
+        if  offset > 0.0 {
+            return true
+        }
+        if scrollView.isDecelerating {
+            return true
+        }
+        if velocity.y <= 0 {
+            return true
+        }
+
+        return false
+    }
+
+    private func panningBegan(at location: CGPoint) {
+        // A user interaction does not always start from Began state of the pan gesture
+        // because it can be recognized in scrolling a content in a content view controller.
+        // So here just preserve the current state if needed.
+        log.debug("panningBegan -- location = \(location.y)")
+        initialLocation = location
+
+        guard let scrollView = scrollView else { return }
+        if state == layoutAdapter.topMostState {
+            if grabberAreaFrame.contains(location) {
+                initialScrollOffset = scrollView.contentOffset
+            }
+        } else {
+            initialScrollOffset = scrollView.contentOffset
+        }
+    }
+
+    private func panningChange(with translation: CGPoint) {
+        log.debug("panningChange -- translation = \(translation.y)")
+        let preY = surfaceView.frame.minY
+        let dy = translation.y - initialTranslationY
+
+        layoutAdapter.updateInteractiveTopConstraint(diff: dy,
+                                                     allowsTopBuffer: allowsTopBuffer(for: dy),
+                                                     with: behavior)
+
+        let currentY = surfaceView.frame.minY
+        backdropView.alpha = getBackdropAlpha(at: currentY, with: translation)
+        preserveContentVCLayoutIfNeeded()
+
+        let didMove = (preY != currentY)
+        guard didMove else { return }
+
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidMove(vc)
+        }
+    }
+
+    private func allowsTopBuffer(for translationY: CGFloat) -> Bool {
+        let preY = surfaceView.frame.minY
+        let nextY = initialFrame.offsetBy(dx: 0.0, dy: translationY).minY
+        if let scrollView = scrollView, scrollView.panGestureRecognizer.state == .changed,
+            preY > 0 && preY > nextY {
+            return false
+        } else {
+            return true
+        }
+    }
+
+    private var disabledBottomAutoLayout = false
+    private var disabledAutoLayoutItems: Set<NSLayoutConstraint> = []
+    // Prevent stretching a view having a constraint to SafeArea.bottom in an overflow
+    // from the full position because SafeArea is global in a screen.
+    private func preserveContentVCLayoutIfNeeded() {
+        guard let vc = viewcontroller else { return }
+        guard vc.contentMode != .fitToBounds else { return }
+
+        // Must include topY
+        if (surfaceView.frame.minY <= layoutAdapter.topY) {
+            if !disabledBottomAutoLayout {
+                disabledAutoLayoutItems.removeAll()
+                vc.contentViewController?.view?.constraints.forEach({ (const) in
+                    switch vc.contentViewController?.layoutGuide.bottomAnchor {
+                    case const.firstAnchor:
+                        (const.secondItem as? UIView)?.disableAutoLayout()
+                        const.isActive = false
+                        disabledAutoLayoutItems.insert(const)
+                    case const.secondAnchor:
+                        (const.firstItem as? UIView)?.disableAutoLayout()
+                        const.isActive = false
+                        disabledAutoLayoutItems.insert(const)
+                    default:
+                        break
+                    }
+                })
+            }
+            disabledBottomAutoLayout = true
+        } else {
+            if disabledBottomAutoLayout {
+                disabledAutoLayoutItems.forEach({ (const) in
+                    switch vc.contentViewController?.layoutGuide.bottomAnchor {
+                    case const.firstAnchor:
+                        (const.secondItem as? UIView)?.enableAutoLayout()
+                        const.isActive = true
+                    case const.secondAnchor:
+                        (const.firstItem as? UIView)?.enableAutoLayout()
+                        const.isActive = true
+                    default:
+                        break
+                    }
+                })
+                disabledAutoLayoutItems.removeAll()
+            }
+            disabledBottomAutoLayout = false
+        }
+    }
+
+    private func panningEnd(with translation: CGPoint, velocity: CGPoint) {
+        log.debug("panningEnd -- translation = \(translation.y), velocity = \(velocity.y)")
+
+        if state == .hidden {
+            log.debug("Already hidden")
+            return
+        }
+
+        stopScrollDeceleration = surfaceView.frame.minY > (layoutAdapter.topY + (1.0 / surfaceView.traitCollection.displayScale)) // Projecting the dragging to the scroll dragging or not
+        if stopScrollDeceleration {
+            DispatchQueue.main.async { [weak self] in
+                guard let `self` = self else { return }
+                self.stopScrollingWithDeceleration(at: self.initialScrollOffset)
+            }
+        }
+
+        let currentY = surfaceView.frame.minY
+        let targetPosition = self.targetPosition(from: currentY, with: velocity)
+        let distance = self.distance(to: targetPosition)
+
+        endInteraction(for: targetPosition)
+
+        if isRemovalInteractionEnabled, isBottomState {
+            let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(velocity.y/distance, behavior.removalVelocity)) : .zero
+            // `velocityVector` will be replaced by just a velocity(not vector) when FloatingPanelRemovalInteraction will be added.
+            if shouldStartRemovalAnimation(with: velocityVector), let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidEndDraggingToRemove(vc, withVelocity: velocity)
+                let animationVector = CGVector(dx: abs(velocityVector.dx), dy: abs(velocityVector.dy))
+                startRemovalAnimation(vc, with: animationVector) { [weak self] in
+                    self?.finishRemovalAnimation()
+                }
+                return
+            }
+        }
+
+        if scrollView != nil, !stopScrollDeceleration,
+            surfaceView.frame.minY == layoutAdapter.topY,
+            targetPosition == layoutAdapter.topMostState {
+            self.state = targetPosition
+            self.updateLayout(to: targetPosition)
+            self.unlockScrollView()
+            if let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: .zero, targetPosition: targetPosition)
+            }
+            return
+        }
+
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: velocity, targetPosition: targetPosition)
+        }
+
+        // Workaround: Disable a tracking scroll to prevent bouncing a scroll content in a panel animating
+        let isScrollEnabled = scrollView?.isScrollEnabled
+        if let scrollView = scrollView, targetPosition != .full {
+            scrollView.isScrollEnabled = false
+        }
+
+        startAnimation(to: targetPosition, at: distance, with: velocity)
+
+        // Workaround: Reset `self.scrollView.isScrollEnabled`
+        if let scrollView = scrollView, targetPosition != .full,
+            let isScrollEnabled = isScrollEnabled {
+            scrollView.isScrollEnabled = isScrollEnabled
+        }
+    }
+
+    private func shouldStartRemovalAnimation(with velocityVector: CGVector) -> Bool {
+        let posY = layoutAdapter.positionY(for: state)
+        let currentY = surfaceView.frame.minY
+        let hiddenY = layoutAdapter.positionY(for: .hidden)
+        let vth = behavior.removalVelocity
+        let pth = max(min(behavior.removalProgress, 1.0), 0.0)
+
+        let num = (currentY - posY)
+        let den = (hiddenY - posY)
+
+        guard num >= 0, den != 0, (num / den >= pth || velocityVector.dy == vth)
+        else { return false }
+
+        return true
+    }
+
+    private func startRemovalAnimation(_ vc: FloatingPanelController, with velocityVector: CGVector, completion: (() -> Void)?) {
+        let animator = behavior.removalInteractionAnimator(vc, with: velocityVector)
+
+        animator.addAnimations { [weak self] in
+            self?.state = .hidden
+            self?.updateLayout(to: .hidden)
+        }
+        animator.addCompletion({ _ in
+            self.animator = nil
+            completion?()
+        })
+        self.animator = animator
+        animator.startAnimation()
+    }
+
+    private func finishRemovalAnimation() {
+        viewcontroller?.dismiss(animated: false) { [weak self] in
+            guard let vc = self?.viewcontroller else { return }
+            vc.delegate?.floatingPanelDidEndRemove(vc)
+        }
+    }
+
+    private func startInteraction(with translation: CGPoint, at location: CGPoint) {
+        /* Don't lock a scroll view to show a scroll indicator after hitting the top */
+        log.debug("startInteraction  -- translation = \(translation.y), location = \(location.y)")
+        guard interactionInProgress == false else { return }
+
+        var offset: CGPoint = .zero
+
+        initialFrame = surfaceView.frame
+        if state == layoutAdapter.topMostState, let scrollView = scrollView {
+            if grabberAreaFrame.contains(location) {
+                initialScrollOffset = scrollView.contentOffset
+            } else {
+                initialScrollOffset = contentOrigin(of: scrollView)
+                // Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
+                let scrollOffsetY = (scrollView.contentOffset.y - contentOrigin(of: scrollView).y)
+                if scrollOffsetY < 0 {
+                    offset = CGPoint(x: -scrollView.contentOffset.x, y: -scrollOffsetY)
+                }
+            }
+            log.debug("initial scroll offset --", initialScrollOffset)
+        }
+
+        initialTranslationY = translation.y
+
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelWillBeginDragging(vc)
+        }
+
+        layoutAdapter.startInteraction(at: state, offset: offset)
+
+        interactionInProgress = true
+
+        lockScrollView()
+    }
+
+    private func endInteraction(for targetPosition: FloatingPanelPosition) {
+        log.debug("endInteraction to \(targetPosition)")
+
+        if let scrollView = scrollView {
+            log.debug("endInteraction -- scroll offset = \(scrollView.contentOffset)")
+        }
+
+        interactionInProgress = false
+
+        // Prevent to keep a scroll view indicator visible at the half/tip position
+        if targetPosition != layoutAdapter.topMostState {
+            lockScrollView()
+        }
+
+        layoutAdapter.endInteraction(at: targetPosition)
+    }
+
+    private func tearDownActiveInteraction() {
+        // Cancel the pan gesture so that panningEnd(with:velocity:) is called
+        panGestureRecognizer.isEnabled = false
+        panGestureRecognizer.isEnabled = true
+    }
+
+    private func startAnimation(to targetPosition: FloatingPanelPosition, at distance: CGFloat, with velocity: CGPoint) {
+        log.debug("startAnimation to \(targetPosition) -- distance = \(distance), velocity = \(velocity.y)")
+        guard let vc = viewcontroller else { return }
+
+        isDecelerating = true
+
+        vc.delegate?.floatingPanelWillBeginDecelerating(vc)
+
+        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: abs(velocity.y)/distance) : .zero
+        let animator = behavior.interactionAnimator(vc, to: targetPosition, with: velocityVector)
+        animator.addAnimations { [weak self] in
+            guard let `self` = self, let vc = self.viewcontroller else { return }
+            self.state = targetPosition
+            if animator.isInterruptible {
+                switch vc.contentMode {
+                case .fitToBounds:
+                    UIView.performWithLinear(startTime: 0.0, relativeDuration: 0.75) {
+                        self.layoutAdapter.activateFixedLayout()
+                        self.surfaceView.superview!.layoutIfNeeded()
+                    }
+                case .static:
+                    self.layoutAdapter.activateFixedLayout()
+                }
+            } else {
+                self.layoutAdapter.activateFixedLayout()
+            }
+            self.layoutAdapter.activateInteractiveLayout(of: targetPosition)
+        }
+        animator.addCompletion { [weak self] pos in
+            // Prevent calling `finishAnimation(at:)` by the old animator whose `isInterruptive` is false
+            // when a new animator has been started after the old one is interrupted.
+            guard let `self` = self, self.animator == animator else { return }
+            log.debug("finishAnimation to \(targetPosition)")
+            self.endAnimation(pos == .end)
+        }
+        self.animator = animator
+        animator.startAnimation()
+    }
+
+    private func endAnimation(_ finished: Bool) {
+        self.isDecelerating = false
+        self.animator = nil
+
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidEndDecelerating(vc)
+        }
+
+        if let scrollView = scrollView {
+            log.debug("finishAnimation -- scroll offset = \(scrollView.contentOffset)")
+        }
+
+        stopScrollDeceleration = false
+
+        log.debug("finishAnimation -- state = \(state) surface.minY = \(surfaceView.presentationFrame.minY) topY = \(layoutAdapter.topY)")
+        if finished, state == layoutAdapter.topMostState, abs(surfaceView.presentationFrame.minY - layoutAdapter.topY) <= 1.0 {
+            unlockScrollView()
+        }
+    }
+
+    private func distance(to targetPosition: FloatingPanelPosition) -> CGFloat {
+        let currentY = surfaceView.frame.minY
+        let targetY = layoutAdapter.positionY(for: targetPosition)
+        return CGFloat(abs(currentY - targetY))
+    }
+
+    // Distance travelled after decelerating to zero velocity at a constant rate.
+    // Refer to the slides p176 of [Designing Fluid Interfaces](https://developer.apple.com/videos/play/wwdc2018/803/)
+    private func project(initialVelocity: CGFloat, decelerationRate: CGFloat) -> CGFloat {
+        return (initialVelocity / 1000.0) * decelerationRate / (1.0 - decelerationRate)
+    }
+
+    func targetPosition(from currentY: CGFloat, with velocity: CGPoint) -> (FloatingPanelPosition) {
+        guard let vc = viewcontroller else { return state }
+        let supportedPositions = layoutAdapter.supportedPositions
+
+        guard supportedPositions.count > 1 else {
+            return state
+        }
+
+        let sortedPositions = Array(supportedPositions).sorted(by: { $0.rawValue < $1.rawValue })
+
+        // Projection
+        let decelerationRate = behavior.momentumProjectionRate(vc)
+        let baseY = abs(layoutAdapter.positionY(for: layoutAdapter.bottomMostState) - layoutAdapter.positionY(for: layoutAdapter.topMostState))
+        let vecY = velocity.y / baseY
+        var pY = project(initialVelocity: vecY, decelerationRate: decelerationRate) * baseY + currentY
+
+        let forwardY = velocity.y == 0 ? (currentY - layoutAdapter.positionY(for: state) > 0) : velocity.y > 0
+
+        let segment = layoutAdapter.segument(at: pY, forward: forwardY)
+
+        var fromPos: FloatingPanelPosition
+        var toPos: FloatingPanelPosition
+
+        let (lowerPos, upperPos) = (segment.lower ?? sortedPositions.first!, segment.upper ?? sortedPositions.last!)
+        (fromPos, toPos) = forwardY ? (lowerPos, upperPos) : (upperPos, lowerPos)
+
+        if behavior.shouldProjectMomentum(vc, for: toPos) == false {
+            let segment = layoutAdapter.segument(at: currentY, forward: forwardY)
+            var (lowerPos, upperPos) = (segment.lower ?? sortedPositions.first!, segment.upper ?? sortedPositions.last!)
+            // Equate the segment out of {top,bottom} most state to the {top,bottom} most segment
+            if lowerPos == upperPos {
+                if forwardY {
+                    upperPos = lowerPos.next(in: sortedPositions)
+                } else {
+                    lowerPos = upperPos.pre(in: sortedPositions)
+                }
+            }
+            (fromPos, toPos) = forwardY ? (lowerPos, upperPos) : (upperPos, lowerPos)
+            // Block a projection to a segment over the next from the current segment
+            // (= Trim pY with the current segment)
+            if forwardY {
+                pY = max(min(pY, layoutAdapter.positionY(for: toPos.next(in: sortedPositions))), layoutAdapter.positionY(for: fromPos))
+            } else {
+                pY = max(min(pY, layoutAdapter.positionY(for: fromPos)), layoutAdapter.positionY(for: toPos.pre(in: sortedPositions)))
+            }
+        }
+
+        // Redirection
+        let redirectionalProgress = max(min(behavior.redirectionalProgress(vc, from: fromPos, to: toPos), 1.0), 0.0)
+        let progress = abs(pY - layoutAdapter.positionY(for: fromPos)) / abs(layoutAdapter.positionY(for: fromPos) - layoutAdapter.positionY(for: toPos))
+        return progress > redirectionalProgress ? toPos : fromPos
+    }
+
+    // MARK: - ScrollView handling
+
+    private func lockScrollView() {
+        guard let scrollView = scrollView else { return }
+
+        if scrollView.isLocked {
+            log.debug("Already scroll locked.")
+            return
+        }
+        log.debug("lock scroll view")
+
+        scrollBouncable = scrollView.bounces
+        scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
+
+        scrollView.isDirectionalLockEnabled = true
+        scrollView.bounces = false
+        scrollView.showsVerticalScrollIndicator = false
+    }
+
+    private func unlockScrollView() {
+        guard let scrollView = scrollView, scrollView.isLocked else { return }
+        log.debug("unlock scroll view")
+
+        scrollView.isDirectionalLockEnabled = false
+        scrollView.bounces = scrollBouncable
+        scrollView.showsVerticalScrollIndicator = scrollIndictorVisible
+    }
+
+    private func stopScrollingWithDeceleration(at contentOffset: CGPoint) {
+        // Must use setContentOffset(_:animated) to force-stop deceleration
+        scrollView?.setContentOffset(contentOffset, animated: false)
+    }
+
+    private func contentOrigin(of scrollView: UIScrollView) -> CGPoint {
+        if let vc = viewcontroller, let origin = vc.delegate?.floatingPanel(vc, contentOffsetForPinning: scrollView) {
+            return origin
+        }
+        return CGPoint(x: 0.0, y: 0.0 - scrollView.contentInset.top)
+    }
+
+    private func allowScrollPanGesture(for scrollView: UIScrollView) -> Bool {
+        let contentOffset = scrollView.contentOffset - contentOrigin(of: scrollView)
+        if state == layoutAdapter.topMostState {
+            return contentOffset.y <= -30.0 || contentOffset.y > 0
+        }
+        return false
+    }
+}
+
+class FloatingPanelPanGestureRecognizer: UIPanGestureRecognizer {
+    fileprivate weak var floatingPanel: FloatingPanelCore?
+    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
+        super.touchesBegan(touches, with: event)
+        if floatingPanel?.animator != nil {
+            self.state = .began
+        }
+    }
+    override weak var delegate: UIGestureRecognizerDelegate? {
+        get {
+            return super.delegate
+        }
+        set {
+            guard newValue is FloatingPanelCore else {
+                let exception = NSException(name: .invalidArgumentException,
+                                            reason: "FloatingPanelController's built-in pan gesture recognizer must have its controller as its delegate.",
+                                            userInfo: nil)
+                exception.raise()
+                return
+            }
+            super.delegate = newValue
+        }
+    }
+}

Framework/Sources/FloatingPanelLayout.swift

@@ -5,23 +5,81 @@
 
 import UIKit
 
+/// FloatingPanelFullScreenLayout
+///
+/// Use the layout protocol if you configure full, half and tip insets from the superview, not the safe area.
+/// It can't be used with FloatingPanelIntrinsicLayout.
+public protocol FloatingPanelFullScreenLayout: FloatingPanelLayout { }
+
+public extension FloatingPanelFullScreenLayout {
+    var positionReference: FloatingPanelLayoutReference {
+        return .fromSuperview
+    }
+}
+
+/// FloatingPanelIntrinsicLayout
+///
+/// Use the layout protocol if you want to layout a panel using the intrinsic height.
+/// It can't be used with `FloatingPanelFullScreenLayout`.
+///
+/// - Attention:
+///     `insetFor(position:)` must return `nil` for the full position. Because
+///     the inset is determined automatically by the intrinsic height.
+///     You can customize insets only for the half, tip and hidden positions.
+///
+/// - Note:
+///     By default, the `positionReference` is set to `.fromSafeArea`.
+public protocol FloatingPanelIntrinsicLayout: FloatingPanelLayout { }
+
+public extension FloatingPanelIntrinsicLayout {
+    var initialPosition: FloatingPanelPosition {
+        return .full
+    }
+
+    var supportedPositions: Set<FloatingPanelPosition> {
+        return [.full]
+    }
+
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        return nil
+    }
+
+    var positionReference: FloatingPanelLayoutReference {
+        return .fromSafeArea
+    }
+}
+
+public enum FloatingPanelLayoutReference: Int {
+    case fromSafeArea = 0
+    case fromSuperview = 1
+}
+
 public protocol FloatingPanelLayout: class {
     /// Returns the initial position of a floating panel.
     var initialPosition: FloatingPanelPosition { get }
 
-    /// Returns a set of FloatingPanelPosition objects to tell the applicable positions of the floating panel controller. Default is all of them.
+    /// Returns a set of FloatingPanelPosition objects to tell the applicable
+    /// positions of the floating panel controller.
+    ///
+    /// By default, it returns full, half and tip positions.
     var supportedPositions: Set<FloatingPanelPosition> { get }
 
     /// Return the interaction buffer to the top from the top position. Default is 6.0.
     var topInteractionBuffer: CGFloat { get }
 
     /// Return the interaction buffer to the bottom from the bottom position. Default is 6.0.
+    ///
+    /// - Important:
+    /// The specified buffer is ignored when `FloatingPanelController.isRemovalInteractionEnabled` is set to true.
     var bottomInteractionBuffer: CGFloat { get }
 
-    /// Returns a CGFloat value to determine a floating panel height for each position(full, half and tip).
-    /// A value for full position indicates a top inset from a safe area.
-    /// On the other hand, values for half and tip positions indicate bottom insets from a safe area.
-    /// If a position doesn't contain the supported positions, return nil.
+    /// Returns a CGFloat value to determine a Y coordinate of a floating panel for each position(full, half, tip and hidden).
+    ///
+    /// Its returning value indicates a different inset for each position.
+    /// For full position, a top inset from a safe area in `FloatingPanelController.view`.
+    /// For half or tip position, a bottom inset from the safe area.
+    /// For hidden position, a bottom inset from `FloatingPanelController.view`.
+    /// If a position isn't supported or the default value is used, return nil.
     func insetFor(position: FloatingPanelPosition) -> CGFloat?
 
     /// Returns X-axis and width layout constraints of the surface view of a floating panel.
@@ -34,6 +92,9 @@ public protocol FloatingPanelLayout: class {
     ///
     /// Default is 0.3 at full position, otherwise 0.0.
     func backdropAlphaFor(position: FloatingPanelPosition) -> CGFloat
+
+    var positionReference: FloatingPanelLayoutReference { get }
+
 }
 
 public extension FloatingPanelLayout {
@@ -41,9 +102,9 @@ public extension FloatingPanelLayout {
     var bottomInteractionBuffer: CGFloat { return 6.0 }
 
     var supportedPositions: Set<FloatingPanelPosition> {
-        return Set(FloatingPanelPosition.allCases)
+        return Set([.full, .half, .tip])
     }
-    
+
     func prepareLayout(surfaceView: UIView, in view: UIView) -> [NSLayoutConstraint] {
         return [
             surfaceView.leftAnchor.constraint(equalTo: view.sideLayoutGuide.leftAnchor, constant: 0.0),
@@ -54,9 +115,15 @@ public extension FloatingPanelLayout {
     func backdropAlphaFor(position: FloatingPanelPosition) -> CGFloat {
         return position == .full ? 0.3 : 0.0
     }
+
+    var positionReference: FloatingPanelLayoutReference {
+        return .fromSafeArea
+    }
 }
 
 public class FloatingPanelDefaultLayout: FloatingPanelLayout {
+    public init() { }
+
     public var initialPosition: FloatingPanelPosition {
         return .half
     }
@@ -66,11 +133,14 @@ public class FloatingPanelDefaultLayout: FloatingPanelLayout {
         case .full: return 18.0
         case .half: return 262.0
         case .tip: return 69.0
+        case .hidden: return nil
         }
     }
 }
 
 public class FloatingPanelDefaultLandscapeLayout: FloatingPanelLayout {
+    public init() { }
+
     public var initialPosition: FloatingPanelPosition {
         return .tip
     }
@@ -87,9 +157,13 @@ public class FloatingPanelDefaultLandscapeLayout: FloatingPanelLayout {
     }
 }
 
+struct LayoutSegment {
+    let lower: FloatingPanelPosition?
+    let upper: FloatingPanelPosition?
+}
 
 class FloatingPanelLayoutAdapter {
-    private weak var parent: UIViewController!
+    weak var vc: FloatingPanelController!
     private weak var surfaceView: FloatingPanelSurfaceView!
     private weak var backdropView: FloatingPanelBackdropView!
 
@@ -99,24 +173,29 @@ class FloatingPanelLayoutAdapter {
         }
     }
 
-    var safeAreaInsets: UIEdgeInsets = .zero {
-        didSet {
-            updateHeight()
-            checkLayoutConsistance()
-        }
+    private var safeAreaInsets: UIEdgeInsets {
+        return vc?.layoutInsets ?? .zero
     }
 
-    private var parentHeight: CGFloat = 0.0
-    private var heightBuffer: CGFloat = 88.0 // For bounce
+    private var initialConst: CGFloat = 0.0
+
     private var fixedConstraints: [NSLayoutConstraint] = []
     private var fullConstraints: [NSLayoutConstraint] = []
     private var halfConstraints: [NSLayoutConstraint] = []
     private var tipConstraints: [NSLayoutConstraint] = []
     private var offConstraints: [NSLayoutConstraint] = []
-    private var heightConstraints: [NSLayoutConstraint] = []
+    private var interactiveTopConstraint: NSLayoutConstraint?
+    private var bottomConstraint: NSLayoutConstraint?
+
+
+    private var heightConstraint: NSLayoutConstraint?
 
     private var fullInset: CGFloat {
-        return layout.insetFor(position: .full) ?? 0.0
+        if layout is FloatingPanelIntrinsicLayout {
+            return intrinsicHeight
+        } else {
+            return layout.insetFor(position: .full) ?? 0.0
+        }
     }
     private var halfInset: CGFloat {
         return layout.insetFor(position: .half) ?? 0.0
@@ -124,29 +203,36 @@ class FloatingPanelLayoutAdapter {
     private var tipInset: CGFloat {
         return layout.insetFor(position: .tip) ?? 0.0
     }
-
-    var topY: CGFloat {
-        if layout.supportedPositions.contains(.full) {
-            return (safeAreaInsets.top + fullInset)
-        } else {
-            return middleY
-        }
+    private var hiddenInset: CGFloat {
+        return layout.insetFor(position: .hidden) ?? 0.0
     }
 
-    var middleY: CGFloat {
-        return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + halfInset)
+    var supportedPositions: Set<FloatingPanelPosition> {
+        return layout.supportedPositions
+    }
+
+    var topMostState: FloatingPanelPosition {
+        return supportedPositions.sorted(by: { $0.rawValue < $1.rawValue }).first ?? .hidden
+    }
+
+    var bottomMostState: FloatingPanelPosition {
+        return supportedPositions.sorted(by: { $0.rawValue < $1.rawValue }).last ?? .hidden
+    }
+
+    var topY: CGFloat {
+        return positionY(for: topMostState)
     }
 
     var bottomY: CGFloat {
-        if layout.supportedPositions.contains(.tip) {
-            return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + tipInset)
-        } else {
-            return middleY
-        }
+        return positionY(for: bottomMostState)
     }
 
-    var safeAreaBottomY: CGFloat {
-        return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom)
+    var topMaxY: CGFloat {
+        return topY - layout.topInteractionBuffer
+    }
+
+    var bottomMaxY: CGFloat {
+        return bottomY + layout.bottomInteractionBuffer
     }
 
     var adjustedContentInsets: UIEdgeInsets {
@@ -159,141 +245,372 @@ class FloatingPanelLayoutAdapter {
     func positionY(for pos: FloatingPanelPosition) -> CGFloat {
         switch pos {
         case .full:
-            return topY
+            if layout is FloatingPanelIntrinsicLayout {
+                return surfaceView.superview!.bounds.height - surfaceView.bounds.height
+            }
+            switch layout.positionReference {
+            case .fromSafeArea:
+                return (safeAreaInsets.top + fullInset)
+            case .fromSuperview:
+                return fullInset
+            }
         case .half:
-            return middleY
+            switch layout.positionReference {
+            case .fromSafeArea:
+                return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + halfInset)
+            case .fromSuperview:
+                return surfaceView.superview!.bounds.height - halfInset
+            }
         case .tip:
-            return bottomY
+            switch layout.positionReference {
+            case .fromSafeArea:
+                return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + tipInset)
+            case .fromSuperview:
+                return surfaceView.superview!.bounds.height - tipInset
+            }
+        case .hidden:
+            return surfaceView.superview!.bounds.height - hiddenInset
         }
     }
 
+    var intrinsicHeight: CGFloat = 0.0
+
     init(surfaceView: FloatingPanelSurfaceView, backdropView: FloatingPanelBackdropView, layout: FloatingPanelLayout) {
         self.layout = layout
         self.surfaceView = surfaceView
         self.backdropView = backdropView
     }
 
-    func prepareLayout(toParent parent: UIViewController) {
-        self.parent = parent
+    func updateIntrinsicHeight() {
+        #if swift(>=4.2)
+        let fittingSize = UIView.layoutFittingCompressedSize
+        #else
+        let fittingSize = UILayoutFittingCompressedSize
+        #endif
+        var intrinsicHeight = surfaceView.contentView?.systemLayoutSizeFitting(fittingSize).height ?? 0.0
+        var safeAreaBottom: CGFloat = 0.0
+        if #available(iOS 11.0, *) {
+            safeAreaBottom = surfaceView.contentView?.safeAreaInsets.bottom ?? 0.0
+            if safeAreaBottom > 0 {
+                intrinsicHeight -= safeAreaInsets.bottom
+            }
+        }
+        self.intrinsicHeight = max(intrinsicHeight, 0.0)
+
+        log.debug("Update intrinsic height =", intrinsicHeight,
+                  ", surface(height) =", surfaceView.frame.height,
+                  ", content(height) =", surfaceView.contentView?.frame.height ?? 0.0,
+                  ", content safe area(bottom) =", safeAreaBottom)
+    }
+
+    func prepareLayout(in vc: FloatingPanelController) {
+        self.vc = vc
+
+        NSLayoutConstraint.deactivate(fixedConstraints + fullConstraints + halfConstraints + tipConstraints + offConstraints)
+        NSLayoutConstraint.deactivate(constraint: self.heightConstraint)
+        self.heightConstraint = nil
+        NSLayoutConstraint.deactivate(constraint: self.bottomConstraint)
+        self.bottomConstraint = nil
 
         surfaceView.translatesAutoresizingMaskIntoConstraints = false
         backdropView.translatesAutoresizingMaskIntoConstraints = false
 
-        NSLayoutConstraint.deactivate(fixedConstraints + fullConstraints + halfConstraints + tipConstraints + offConstraints)
-
         // Fixed constraints of surface and backdrop views
-        let surfaceConstraints = layout.prepareLayout(surfaceView: surfaceView, in: parent.view!)
+        let surfaceConstraints = layout.prepareLayout(surfaceView: surfaceView, in: vc.view!)
         let backdropConstraints = [
-            backdropView.topAnchor.constraint(equalTo: parent.view.topAnchor,
-                                              constant: 0.0),
-            backdropView.leftAnchor.constraint(equalTo: parent.view.leftAnchor,
-                                               constant: 0.0),
-            backdropView.rightAnchor.constraint(equalTo: parent.view.rightAnchor,
-                                                constant: 0.0),
-            backdropView.bottomAnchor.constraint(equalTo: parent.view.bottomAnchor,
-                                                 constant: 0.0),
+            backdropView.topAnchor.constraint(equalTo: vc.view.topAnchor, constant: 0.0),
+            backdropView.leftAnchor.constraint(equalTo: vc.view.leftAnchor,constant: 0.0),
+            backdropView.rightAnchor.constraint(equalTo: vc.view.rightAnchor, constant: 0.0),
+            backdropView.bottomAnchor.constraint(equalTo: vc.view.bottomAnchor, constant: 0.0),
             ]
+
         fixedConstraints = surfaceConstraints + backdropConstraints
 
-        // Flexible surface constarints for full, half, tip and off
-        fullConstraints = [
-            surfaceView.topAnchor.constraint(equalTo: parent.layoutGuide.topAnchor,
-                                             constant: fullInset),
-        ]
+        if vc.contentMode == .fitToBounds {
+            bottomConstraint = surfaceView.bottomAnchor.constraint(equalTo: vc.view.bottomAnchor,
+                                                                   constant: 0.0)
+        }
+
+        // Flexible surface constraints for full, half, tip and off
+        let topAnchor: NSLayoutYAxisAnchor = {
+            if layout.positionReference == .fromSuperview {
+                return vc.view.topAnchor
+            } else {
+                return vc.layoutGuide.topAnchor
+            }
+        }()
+
+        switch layout {
+        case is FloatingPanelIntrinsicLayout:
+            // Set up on updateHeight()
+            break
+        default:
+            fullConstraints = [
+                surfaceView.topAnchor.constraint(equalTo: topAnchor,
+                                                 constant: fullInset),
+            ]
+        }
+
+        let bottomAnchor: NSLayoutYAxisAnchor = {
+            if layout.positionReference == .fromSuperview {
+                return vc.view.bottomAnchor
+            } else {
+                return vc.layoutGuide.bottomAnchor
+            }
+        }()
+
         halfConstraints = [
-            surfaceView.topAnchor.constraint(equalTo: parent.layoutGuide.bottomAnchor,
+            surfaceView.topAnchor.constraint(equalTo: bottomAnchor,
                                              constant: -halfInset),
         ]
         tipConstraints = [
-            surfaceView.topAnchor.constraint(equalTo: parent.layoutGuide.bottomAnchor,
+            surfaceView.topAnchor.constraint(equalTo: bottomAnchor,
                                              constant: -tipInset),
         ]
+
         offConstraints = [
-            surfaceView.topAnchor.constraint(equalTo: parent.view.bottomAnchor, constant: 0.0),
+            surfaceView.topAnchor.constraint(equalTo:vc.view.bottomAnchor,
+                                             constant: -hiddenInset),
         ]
     }
 
+    func startInteraction(at state: FloatingPanelPosition, offset: CGPoint = .zero) {
+        guard self.interactiveTopConstraint == nil else { return }
+        NSLayoutConstraint.deactivate(fullConstraints + halfConstraints + tipConstraints + offConstraints)
+
+        let interactiveTopConstraint: NSLayoutConstraint
+        switch layout.positionReference {
+        case .fromSafeArea:
+            initialConst = surfaceView.frame.minY - safeAreaInsets.top + offset.y
+            interactiveTopConstraint = surfaceView.topAnchor.constraint(equalTo: vc.layoutGuide.topAnchor,
+                                                                        constant: initialConst)
+        case .fromSuperview:
+            initialConst = surfaceView.frame.minY + offset.y
+            interactiveTopConstraint = surfaceView.topAnchor.constraint(equalTo: vc.view.topAnchor,
+                                                                        constant: initialConst)
+        }
+        NSLayoutConstraint.activate([interactiveTopConstraint])
+        self.interactiveTopConstraint = interactiveTopConstraint
+    }
+
+    func endInteraction(at state: FloatingPanelPosition) {
+        // Don't deactivate `interactiveTopConstraint` here because it leads to
+        // unsatisfiable constraints
+
+        if self.interactiveTopConstraint == nil {
+            // Actiavate `interactiveTopConstraint` for `fitToBounds` mode.
+            // It goes throught this path when the pan gesture state jumps
+            // from .begin to .end.
+            startInteraction(at: state)
+        }
+    }
+
     // The method is separated from prepareLayout(to:) for the rotation support
     // It must be called in FloatingPanelController.traitCollectionDidChange(_:)
     func updateHeight() {
+        guard let vc = vc else { return }
+        NSLayoutConstraint.deactivate(constraint: heightConstraint)
+        heightConstraint = nil
+
+        if layout is FloatingPanelIntrinsicLayout {
+            updateIntrinsicHeight()
+        }
         defer {
-            UIView.performWithoutAnimation {
-                surfaceView.superview!.layoutIfNeeded()
+            if layout is FloatingPanelIntrinsicLayout {
+                NSLayoutConstraint.deactivate(fullConstraints)
+                fullConstraints = [
+                    surfaceView.topAnchor.constraint(equalTo: vc.layoutGuide.bottomAnchor,
+                                                     constant: -fullInset),
+                ]
             }
         }
 
-        NSLayoutConstraint.deactivate(heightConstraints)
-        // Must use the parent height, not the screen height because safe area insets
-        // of the parent are relative values. For example, a view controller in
-        // Navigation controller's safe area insets and frame can be changed whether
-        // the navigation bar is translucent or not.
-        let height = self.parent.view.bounds.height - (safeAreaInsets.top + fullInset)
-        heightConstraints = [
-            surfaceView.heightAnchor.constraint(equalToConstant: height)
-        ]
-        NSLayoutConstraint.activate(heightConstraints)
-        surfaceView.set(bottomOverflow: heightBuffer)
+        guard vc.contentMode != .fitToBounds else { return }
+
+        switch layout {
+        case is FloatingPanelIntrinsicLayout:
+            heightConstraint = surfaceView.heightAnchor.constraint(equalToConstant: intrinsicHeight + safeAreaInsets.bottom)
+        default:
+            let const = -(positionY(for: topMostState))
+            heightConstraint =  surfaceView.heightAnchor.constraint(equalTo: vc.view.heightAnchor,
+                                                                    constant: const)
+        }
+        NSLayoutConstraint.activate(constraint: heightConstraint)
+
+        surfaceView.bottomOverflow = vc.view.bounds.height + layout.topInteractionBuffer
     }
 
-    func activateLayout(of state: FloatingPanelPosition?) {
+    func updateInteractiveTopConstraint(diff: CGFloat, allowsTopBuffer: Bool, with behavior: FloatingPanelBehavior) {
         defer {
-            surfaceView.superview!.layoutIfNeeded()
+            layoutSurfaceIfNeeded() // MUST be called to update `surfaceView.frame`
         }
-        setBackdropAlpha(of: state)
+
+        let topMostConst: CGFloat = {
+            var ret: CGFloat = 0.0
+            switch layout.positionReference {
+            case .fromSafeArea:
+                ret = topY - safeAreaInsets.top
+            case .fromSuperview:
+                ret = topY
+            }
+            return max(ret, 0.0) // The top boundary is equal to the related topAnchor.
+        }()
+        let bottomMostConst: CGFloat = {
+            var ret: CGFloat = 0.0
+            let _bottomY = vc.isRemovalInteractionEnabled ? positionY(for: .hidden) : bottomY
+            switch layout.positionReference {
+            case .fromSafeArea:
+                ret = _bottomY - safeAreaInsets.top
+            case .fromSuperview:
+                ret = _bottomY
+            }
+            return min(ret, surfaceView.superview!.bounds.height)
+        }()
+        let minConst = allowsTopBuffer ? topMostConst - layout.topInteractionBuffer : topMostConst
+        let maxConst = bottomMostConst + layout.bottomInteractionBuffer
+
+        var const = initialConst + diff
+
+        // Rubberbanding top buffer
+        if behavior.allowsRubberBanding(for: .top), const < topMostConst {
+            let buffer = topMostConst - const
+            const = topMostConst - rubberbandEffect(for: buffer, base: vc.view.bounds.height)
+        }
+
+        // Rubberbanding bottom buffer
+        if behavior.allowsRubberBanding(for: .bottom), const > bottomMostConst {
+            let buffer = const - bottomMostConst
+            const = bottomMostConst + rubberbandEffect(for: buffer, base: vc.view.bounds.height)
+        }
+
+        interactiveTopConstraint?.constant = max(minConst, min(maxConst, const))
+    }
+
+    // According to @chpwn's tweet: https://twitter.com/chpwn/status/285540192096497664
+    // x = distance from the edge
+    // c = constant value, UIScrollView uses 0.55
+    // d = dimension, either width or height
+    private func rubberbandEffect(for buffer: CGFloat, base: CGFloat) -> CGFloat {
+        return (1.0 - (1.0 / ((buffer * 0.55 / base) + 1.0))) * base
+    }
+
+    func activateFixedLayout() {
+        // Must deactivate `interactiveTopConstraint` here
+        NSLayoutConstraint.deactivate(constraint: self.interactiveTopConstraint)
+        self.interactiveTopConstraint = nil
 
         NSLayoutConstraint.activate(fixedConstraints)
 
-        guard var state = state else {
-            NSLayoutConstraint.deactivate(fullConstraints + halfConstraints + tipConstraints)
-            NSLayoutConstraint.activate(offConstraints)
-            return
+        if vc.contentMode == .fitToBounds {
+            NSLayoutConstraint.activate(constraint: self.bottomConstraint)
+        }
+    }
+
+    func activateInteractiveLayout(of state: FloatingPanelPosition) {
+        defer {
+            layoutSurfaceIfNeeded()
+            log.debug("activateLayout -- surface.presentation = \(self.surfaceView.presentationFrame) surface.frame = \(self.surfaceView.frame)")
         }
 
-        if layout.supportedPositions.contains(state) == false {
+        var state = state
+
+        setBackdropAlpha(of: state)
+
+        if isValid(state) == false {
             state = layout.initialPosition
         }
 
         NSLayoutConstraint.deactivate(fullConstraints + halfConstraints + tipConstraints + offConstraints)
         switch state {
         case .full:
-            NSLayoutConstraint.deactivate(halfConstraints + tipConstraints + offConstraints)
             NSLayoutConstraint.activate(fullConstraints)
         case .half:
-            NSLayoutConstraint.deactivate(fullConstraints + tipConstraints + offConstraints)
             NSLayoutConstraint.activate(halfConstraints)
         case .tip:
-            NSLayoutConstraint.deactivate(fullConstraints + halfConstraints + offConstraints)
             NSLayoutConstraint.activate(tipConstraints)
+        case .hidden:
+            NSLayoutConstraint.activate(offConstraints)
         }
     }
 
-    func setBackdropAlpha(of target: FloatingPanelPosition?) {
-        if let target = target {
-            self.backdropView.alpha = layout.backdropAlphaFor(position: target)
-        } else {
+    func activateLayout(of state: FloatingPanelPosition) {
+        activateFixedLayout()
+        activateInteractiveLayout(of: state)
+    }
+
+    func isValid(_ state: FloatingPanelPosition) -> Bool {
+        return supportedPositions.union([.hidden]).contains(state)
+    }
+
+    private func layoutSurfaceIfNeeded() {
+        #if !TEST
+        guard surfaceView.window != nil else { return }
+        #endif
+        surfaceView.superview?.layoutIfNeeded()
+    }
+
+    private func setBackdropAlpha(of target: FloatingPanelPosition) {
+        if target == .hidden {
             self.backdropView.alpha = 0.0
+        } else {
+            self.backdropView.alpha = layout.backdropAlphaFor(position: target)
         }
     }
 
-    func checkLayoutConsistance() {
+    private func checkLayoutConsistance() {
         // Verify layout configurations
-        let supportedPositions = layout.supportedPositions
-
         assert(supportedPositions.count > 0)
         assert(supportedPositions.contains(layout.initialPosition),
-               "Does not include an initial potision(\(layout.initialPosition)) in supportedPositions(\(supportedPositions))")
+               "Does not include an initial position (\(layout.initialPosition)) in supportedPositions (\(supportedPositions))")
 
-        supportedPositions.forEach { pos in
-            assert(layout.insetFor(position: pos) != nil,
-                   "Undefined an inset for a pos(\(pos))")
+        if layout is FloatingPanelIntrinsicLayout {
+            assert(layout.insetFor(position: .full) == nil, "Return `nil` for full position on FloatingPanelIntrinsicLayout")
         }
 
         if halfInset > 0 {
             assert(halfInset > tipInset, "Invalid half and tip insets")
         }
-        if fullInset > 0 {
-            assert(middleY > topY, "Invalid insets")
-            assert(bottomY > topY, "Invalid insets")
+        // The verification isn't working on orientation change(portrait -> landscape)
+        // of a floating panel in tab bar. Because the `safeAreaInsets.bottom` is
+        // updated in delay so that it can be 83.0(not 53.0) even after the surface
+        // and the super view's frame is fit to landscape already.
+        /*if fullInset > 0 {
+            assert(middleY > topY, "Invalid insets { topY: \(topY), middleY: \(middleY) }")
+            assert(bottomY > topY, "Invalid insets { topY: \(topY), bottomY: \(bottomY) }")
+         }*/
+    }
+
+    func segument(at posY: CGFloat, forward: Bool) -> LayoutSegment {
+        /// ----------------------->Y
+        /// --> forward                <-- backward
+        /// |-------|===o===|-------|  |-------|-------|===o===|
+        /// |-------|-------x=======|  |-------|=======x-------|
+        /// |-------|-------|===o===|  |-------|===o===|-------|
+        /// pos: o/x, seguement: =
+        let sortedPositions = supportedPositions.sorted(by: { $0.rawValue < $1.rawValue })
+
+        let upperIndex: Int?
+        if forward {
+            #if swift(>=4.2)
+            upperIndex = sortedPositions.firstIndex(where: { posY < positionY(for: $0) })
+            #else
+            upperIndex = sortedPositions.index(where: { posY < positionY(for: $0) })
+            #endif
+        } else {
+            #if swift(>=4.2)
+            upperIndex = sortedPositions.firstIndex(where: { posY <= positionY(for: $0) })
+            #else
+            upperIndex = sortedPositions.index(where: { posY <= positionY(for: $0) })
+            #endif
+        }
+
+        switch upperIndex {
+        case 0:
+            return LayoutSegment(lower: nil, upper: sortedPositions.first)
+        case let upperIndex?:
+            return LayoutSegment(lower: sortedPositions[upperIndex - 1], upper: sortedPositions[upperIndex])
+        default:
+            return LayoutSegment(lower: sortedPositions[sortedPositions.endIndex - 1], upper: nil)
         }
     }
 }

Framework/Sources/FloatingPanelSurfaceView.swift

@@ -5,24 +5,46 @@
 
 import UIKit
 
-class FloatingPanelSurfaceContentView: UIView {}
-
 /// A view that presents a surface interface in a floating panel.
 public class FloatingPanelSurfaceView: UIView {
 
-    /// A GrabberHandleView object displayed at the top of the surface view
-    public var grabberHandle: GrabberHandleView!
+    /// A GrabberHandleView object displayed at the top of the surface view.
+    ///
+    /// To use a custom grabber handle, hide this and then add the custom one
+    /// to the surface view at appropriate coordinates.
+    public let grabberHandle: GrabberHandleView = GrabberHandleView()
+
+    /// Offset of the grabber handle from the top
+    public var grabberTopPadding: CGFloat = 6.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }
 
     /// The height of the grabber bar area
-    public static var topGrabberBarHeight: CGFloat {
-        return Default.grabberTopPadding * 2 + GrabberHandleView.Default.height // 17.0
+    public var topGrabberBarHeight: CGFloat {
+        return grabberTopPadding * 2 + grabberHandleHeight
     }
 
-    /// A UIView object that can have the surface view added to it.
-    public var contentView: UIView!
+    /// Grabber view width and height
+    public var grabberHandleWidth: CGFloat = 36.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }
+    public var grabberHandleHeight: CGFloat = 5.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }
+
+    /// A root view of a content view controller
+    public weak var contentView: UIView!
+
+    /// The content insets specifying the insets around the content view.
+    public var contentInsets: UIEdgeInsets = .zero {
+        didSet {
+            // Needs update constraints
+            self.setNeedsUpdateConstraints()
+        }
+    }
 
     private var color: UIColor? = .white { didSet { setNeedsLayout() } }
-    private var bottomOverflow: CGFloat = 0.0 // Must not call setNeedsLayout()
+    var bottomOverflow: CGFloat = 0.0 // Must not call setNeedsLayout()
 
     public override var backgroundColor: UIColor? {
         get { return color }
@@ -33,7 +55,10 @@ public class FloatingPanelSurfaceView: UIView {
     ///
     /// `self.contentView` is masked with the top rounded corners automatically on iOS 11 and later.
     /// On iOS 10, they are not automatically masked because of a UIVisualEffectView issue. See https://forums.developer.apple.com/thread/50854
-    public var cornerRadius: CGFloat = 0.0 { didSet { setNeedsLayout() } }
+    public var cornerRadius: CGFloat {
+        set { containerView.layer.cornerRadius = newValue; setNeedsLayout() }
+        get { return containerView.layer.cornerRadius }
+    }
 
     /// A Boolean indicating whether the surface shadow is displayed.
     public var shadowHidden: Bool = false  { didSet { setNeedsLayout() } }
@@ -56,120 +81,162 @@ public class FloatingPanelSurfaceView: UIView {
     /// The color of the surface border.
     public var borderWidth: CGFloat = 0.0  { didSet { setNeedsLayout() } }
 
-    private var backgroundLayer: CAShapeLayer!  { didSet { setNeedsLayout() } }
+    /// The margins to use when laying out the container view wrapping content.
+    public var containerMargins: UIEdgeInsets = .zero { didSet {
+        setNeedsUpdateConstraints()
+    } }
 
-    private struct Default {
-        public static let grabberTopPadding: CGFloat = 6.0
-    }
+    /// The view presents an actual surface shape.
+    ///
+    /// It renders the background color, border line and top rounded corners,
+    /// specified by other properties. The reason why they're not be applied to
+    /// a content view directly is because it avoids any side-effects to the
+    /// content view.
+    public let containerView: UIView = UIView()
+
+    @available(*, unavailable, renamed: "containerView")
+    public var backgroundView: UIView!
+
+    private lazy var containerViewTopConstraint = containerView.topAnchor.constraint(equalTo: topAnchor, constant: containerMargins.top)
+    private lazy var containerViewHeightConstraint = containerView.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 1.0)
+    private lazy var containerViewLeftConstraint = containerView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0)
+    private lazy var containerViewRightConstraint = containerView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0)
+
+    /// The content view top constraint
+    private var contentViewTopConstraint: NSLayoutConstraint?
+    /// The content view left constraint
+    private var contentViewLeftConstraint: NSLayoutConstraint?
+    /// The content right constraint
+    private var contentViewRightConstraint: NSLayoutConstraint?
+    /// The content height constraint
+    private var contentViewHeightConstraint: NSLayoutConstraint?
+
+    private lazy var grabberHandleWidthConstraint = grabberHandle.widthAnchor.constraint(equalToConstant: grabberHandleWidth)
+    private lazy var grabberHandleHeightConstraint = grabberHandle.heightAnchor.constraint(equalToConstant: grabberHandleHeight)
+    private lazy var grabberHandleTopConstraint = grabberHandle.topAnchor.constraint(equalTo: topAnchor, constant: grabberTopPadding)
+
+    public override class var requiresConstraintBasedLayout: Bool { return true }
 
     override init(frame: CGRect) {
         super.init(frame: frame)
-        render()
+        addSubViews()
     }
 
-    required init?(coder aDecoder: NSCoder) {
+    required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
-        render()
+        addSubViews()
     }
 
-    private func render() {
+    private func addSubViews() {
         super.backgroundColor = .clear
         self.clipsToBounds = false
 
-        let backgroundLayer = CAShapeLayer()
-        layer.insertSublayer(backgroundLayer, at: 0)
-        self.backgroundLayer = backgroundLayer
-
-        let contentView = FloatingPanelSurfaceContentView()
-        addSubview(contentView)
-        self.contentView = contentView as UIView
-        contentView.backgroundColor = color
-        contentView.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(containerView)
+        containerView.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
-            contentView.topAnchor.constraint(equalTo: topAnchor, constant: 0.0),
-            contentView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0),
-            contentView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0),
-            contentView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 0.0),
+            containerViewTopConstraint,
+            containerViewLeftConstraint,
+            containerViewRightConstraint,
+            containerViewHeightConstraint,
             ])
 
-        let grabberHandle = GrabberHandleView()
         addSubview(grabberHandle)
-        self.grabberHandle = grabberHandle
-
         grabberHandle.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
-            grabberHandle.topAnchor.constraint(equalTo: topAnchor, constant: Default.grabberTopPadding),
-            grabberHandle.widthAnchor.constraint(equalToConstant: grabberHandle.frame.width),
-            grabberHandle.heightAnchor.constraint(equalToConstant: grabberHandle.frame.height),
+            grabberHandleWidthConstraint,
+            grabberHandleHeightConstraint,
+            grabberHandleTopConstraint,
             grabberHandle.centerXAnchor.constraint(equalTo: centerXAnchor),
             ])
     }
 
+    public override func updateConstraints() {
+        containerViewTopConstraint.constant = containerMargins.top
+        containerViewLeftConstraint.constant = containerMargins.left
+        containerViewRightConstraint.constant = -containerMargins.right
+        containerViewHeightConstraint.constant = (containerMargins.bottom == 0) ? bottomOverflow : -(containerMargins.top + containerMargins.bottom)
+
+        contentViewTopConstraint?.constant = containerMargins.top + contentInsets.top
+        contentViewLeftConstraint?.constant = containerMargins.left + contentInsets.left
+        contentViewRightConstraint?.constant = containerMargins.right + contentInsets.right
+        contentViewHeightConstraint?.constant = -(containerMargins.top + containerMargins.bottom + contentInsets.top + contentInsets.bottom)
+
+        grabberHandleTopConstraint.constant = grabberTopPadding
+        grabberHandleWidthConstraint.constant = grabberHandleWidth
+        grabberHandleHeightConstraint.constant = grabberHandleHeight
+
+        super.updateConstraints()
+    }
+
     public override func layoutSubviews() {
         super.layoutSubviews()
+        log.debug("surface view frame = \(frame)")
 
-        updateLayers()
-        updateContentViewMask()
+        containerView.backgroundColor = color
 
-        contentView.layer.borderColor = borderColor?.cgColor
-        contentView.layer.borderWidth = borderWidth
-        contentView.backgroundColor = color
+        updateShadow()
+        updateCornerRadius()
+        updateBorder()
     }
 
-    private func updateLayers() {
-        log.debug("SurfaceView bounds", bounds)
-        
-        var rect = bounds
-        rect.size.height += bottomOverflow // Expand the height for overflow buffer
-        let path = UIBezierPath(roundedRect: rect,
-                                byRoundingCorners: [.topLeft, .topRight],
-                                cornerRadii: CGSize(width: cornerRadius, height: cornerRadius))
-        backgroundLayer.path = path.cgPath
-        backgroundLayer.fillColor = color?.cgColor
-		
+    private func updateShadow() {
         if shadowHidden == false {
-            layer.shadowColor = shadowColor.cgColor
-            layer.shadowOffset = shadowOffset
-            layer.shadowOpacity = shadowOpacity
-            layer.shadowRadius = shadowRadius
+            if #available(iOS 11, *) {
+                // For clear background. See also, https://github.com/SCENEE/FloatingPanel/pull/51.
+                layer.shadowColor = shadowColor.cgColor
+                layer.shadowOffset = shadowOffset
+                layer.shadowOpacity = shadowOpacity
+                layer.shadowRadius = shadowRadius
+            } else {
+                // Can't update `layer.shadow*` directly because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
+                // Instead, a user should display shadow appropriately.
+            }
         }
     }
 
-    private func updateContentViewMask() {
+    private func updateCornerRadius() {
+        guard containerView.layer.cornerRadius != 0.0 else {
+            containerView.layer.masksToBounds = false
+            return
+        }
+        containerView.layer.masksToBounds = true
+        guard containerMargins.bottom == 0 else { return }
         if #available(iOS 11, *) {
             // Don't use `contentView.clipToBounds` because it prevents content view from expanding the height of a subview of it
-            // for the bottom overflow like Auto Layout settings of UIVisualEffectView in Main.storyborad of Example/Maps.
+            // for the bottom overflow like Auto Layout settings of UIVisualEffectView in Main.storyboard of Example/Maps.
             // Because the bottom of contentView must be fit to the bottom of a screen to work the `safeLayoutGuide` of a content VC.
-            let maskLayer = CAShapeLayer()
-            var rect = bounds
-            rect.size.height += bottomOverflow
-            let path = UIBezierPath(roundedRect: rect,
-                                    byRoundingCorners: [.topLeft, .topRight],
-                                    cornerRadii: CGSize(width: cornerRadius, height: cornerRadius))
-            maskLayer.path = path.cgPath
-            contentView.layer.mask = maskLayer
+            containerView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
         } else {
-            // Don't use `contentView.layer.mask` because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
-            // Instead, a user can mask the content view manually in an application.
+            // Can't use `containerView.layer.mask` because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
+            // Instead, a user should display rounding corners appropriately.
         }
     }
 
-    func set(bottomOverflow: CGFloat) {
-        self.bottomOverflow = bottomOverflow
-        updateLayers()
-        updateContentViewMask()
+    private func updateBorder() {
+        containerView.layer.borderColor = borderColor?.cgColor
+        containerView.layer.borderWidth = borderWidth
     }
 
+    func add(contentView: UIView) {
+        containerView.addSubview(contentView)
+        self.contentView = contentView
+        /* contentView.frame = bounds */ // MUST NOT: Because the top safe area inset of a content VC will be incorrect.
+        contentView.translatesAutoresizingMaskIntoConstraints = false
 
-    func add(childView: UIView) {
-        contentView.addSubview(childView)
-        childView.frame = contentView.bounds
-        childView.translatesAutoresizingMaskIntoConstraints = false
+        let topConstraint = contentView.topAnchor.constraint(equalTo: topAnchor, constant: containerMargins.top + contentInsets.top)
+        let leftConstraint = contentView.leftAnchor.constraint(equalTo: leftAnchor, constant: containerMargins.left + contentInsets.left)
+        let rightConstraint = rightAnchor.constraint(equalTo: contentView.rightAnchor, constant: containerMargins.right + contentInsets.right)
+        let heightPadding = containerMargins.top + containerMargins.bottom + contentInsets.top + contentInsets.bottom
+        let heightConstraint = contentView.heightAnchor.constraint(equalTo: heightAnchor, constant: -heightPadding)
         NSLayoutConstraint.activate([
-            childView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 0.0),
-            childView.leftAnchor.constraint(equalTo: contentView.leftAnchor, constant: 0.0),
-            childView.rightAnchor.constraint(equalTo: contentView.rightAnchor, constant: 0.0),
-            childView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: 0.0),
+            topConstraint,
+            leftConstraint,
+            rightConstraint,
+            heightConstraint,
             ])
+        self.contentViewTopConstraint = topConstraint
+        self.contentViewLeftConstraint = leftConstraint
+        self.contentViewRightConstraint = rightConstraint
+        self.contentViewHeightConstraint = heightConstraint
     }
 }

Framework/Sources/FloatingPanelTransitioning.swift

@@ -0,0 +1,122 @@
+//
+//  Created by Shin Yamamoto on 2018/11/21.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import UIKit
+
+class FloatingPanelModalTransition: NSObject, UIViewControllerTransitioningDelegate {
+    func animationController(forPresented presented: UIViewController,
+                             presenting: UIViewController,
+                             source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
+        return FloatingPanelModalPresentTransition()
+    }
+
+    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
+        return FloatingPanelModalDismissTransition()
+    }
+
+    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
+        return FloatingPanelPresentationController(presentedViewController: presented, presenting: presenting)
+    }
+}
+
+class FloatingPanelPresentationController: UIPresentationController {
+    override func presentationTransitionWillBegin() {
+        // Must call here even if duplicating on in containerViewWillLayoutSubviews()
+        // Because it let the floating panel present correctly with the presentation animation
+        addFloatingPanel()
+    }
+
+    override func presentationTransitionDidEnd(_ completed: Bool) {
+        // For non-animated presentation
+        if let fpc = presentedViewController as? FloatingPanelController, fpc.position == .hidden {
+            fpc.show(animated: false, completion: nil)
+        }
+    }
+
+    override func dismissalTransitionDidEnd(_ completed: Bool) {
+        if let fpc = presentedViewController as? FloatingPanelController {
+            // For non-animated dismissal
+            if fpc.position != .hidden {
+                fpc.hide(animated: false, completion: nil)
+            }
+            fpc.view.removeFromSuperview()
+        }
+    }
+
+    override func containerViewWillLayoutSubviews() {
+        guard
+            let fpc = presentedViewController as? FloatingPanelController
+            else { fatalError() }
+
+        /*
+         * Layout the views managed by `FloatingPanelController` here for the
+         * sake of the presentation and dismissal modally from the controller.
+         */
+        addFloatingPanel()
+
+        // Forward touch events to the presenting view controller
+        (fpc.view as? FloatingPanelPassThroughView)?.eventForwardingView = presentingViewController.view
+
+        fpc.backdropView.dismissalTapGestureRecognizer.isEnabled = true
+    }
+
+    @objc func handleBackdrop(tapGesture: UITapGestureRecognizer) {
+        presentedViewController.dismiss(animated: true, completion: nil)
+    }
+
+    private func addFloatingPanel() {
+        guard
+            let containerView = self.containerView,
+            let fpc = presentedViewController as? FloatingPanelController
+            else { fatalError() }
+
+        containerView.addSubview(fpc.view)
+        fpc.view.frame = containerView.bounds
+        fpc.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+    }
+}
+
+class FloatingPanelModalPresentTransition: NSObject, UIViewControllerAnimatedTransitioning {
+    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
+        guard
+            let fpc = transitionContext?.viewController(forKey: .to) as? FloatingPanelController
+        else { fatalError()}
+
+        let animator = fpc.behavior.addAnimator(fpc, to: fpc.layout.initialPosition)
+        return TimeInterval(animator.duration)
+    }
+
+    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
+        guard
+            let fpc = transitionContext.viewController(forKey: .to) as? FloatingPanelController
+        else { fatalError() }
+
+        fpc.show(animated: true) {
+            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
+        }
+    }
+}
+
+class FloatingPanelModalDismissTransition: NSObject, UIViewControllerAnimatedTransitioning {
+    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
+        guard
+            let fpc = transitionContext?.viewController(forKey: .from) as? FloatingPanelController
+        else { fatalError()}
+
+        let animator = fpc.behavior.removeAnimator(fpc, from: fpc.position)
+        return TimeInterval(animator.duration)
+    }
+
+    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
+        guard
+            let fpc = transitionContext.viewController(forKey: .from) as? FloatingPanelController
+        else { fatalError() }
+
+        fpc.hide(animated: true) {
+            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
+        }
+    }
+}
+

Framework/Sources/FloatingPanelView.swift

@@ -0,0 +1,19 @@
+//
+//  Created by Shin Yamamoto on 2018/11/21.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import UIKit
+
+class FloatingPanelPassThroughView: UIView {
+    public weak var eventForwardingView: UIView?
+    public override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
+        let hitView = super.hitTest(point, with: event)
+        switch hitView {
+        case self:
+            return eventForwardingView?.hitTest(self.convert(point, to: eventForwardingView), with: event)
+        default:
+            return hitView
+        }
+    }
+}

Framework/Sources/GrabberHandleView.swift

@@ -6,32 +6,30 @@
 import UIKit
 
 public class GrabberHandleView: UIView {
-    public struct Default {
-        public static let width: CGFloat = 36.0
-        public static let height: CGFloat = 5.0
-        public static let barColor = UIColor(displayP3Red: 0.76, green: 0.77, blue: 0.76, alpha: 1.0)
-    }
 
-    required init?(coder aDecoder: NSCoder) {
+    public var barColor = UIColor(displayP3Red: 0.76, green: 0.77, blue: 0.76, alpha: 1.0) { didSet { backgroundColor = barColor } }
+
+    required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
-        render()
     }
 
     init() {
-        let size = CGSize(width: Default.width,
-                          height: Default.height)
-        super.init(frame: CGRect(origin: .zero, size: size))
-        self.backgroundColor = Default.barColor
-        render()
+        super.init(frame: .zero)
+        backgroundColor = barColor
     }
 
-    private func render() {
-        self.layer.masksToBounds = true
-        self.layer.cornerRadius = frame.size.height * 0.5
+    public override func layoutSubviews() {
+        super.layoutSubviews()
+        render()
     }
 
     public override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
         let view = super.hitTest(point, with: event)
         return view == self ? nil : view
     }
+
+    private func render() {
+        self.layer.masksToBounds = true
+        self.layer.cornerRadius = frame.size.height * 0.5
+    }
 }

Framework/Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.1.0</string>
+	<string>1.7.3</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 </dict>

Framework/Sources/Logger.swift

@@ -19,29 +19,17 @@ struct Logger {
         case info = 1
         case warning = 2
         case error = 3
-        case fault = 4
 
-        var name: String {
-            switch self {
-            case .debug: return "DEBUG"
-            case .info: return "INFO"
-            case .warning: return "WARNING"
-            case .error: return "ERROR"
-            case .fault: return "FAULT"
-            }
-        }
-        var shortName: String {
+        var displayName: String {
             switch self {
             case .debug:
                 return "D/"
             case .info:
                 return "I/"
             case .warning:
-                return "W/"
+                return "Warning:"
             case .error:
-                return "E/"
-            case .fault:
-                return "F/"
+                return "Error:"
             }
         }
         @available(iOS 10.0, *)
@@ -49,31 +37,40 @@ struct Logger {
             switch self {
             case .debug: return .debug
             case .info: return .info
-            case .warning: return .info
+            case .warning: return .default
             case .error: return .error
-            case .fault: return .fault
             }
         }
 
-        public static func < (lhs: Logger.Level, rhs: Logger.Level) -> Bool {
+        static func < (lhs: Logger.Level, rhs: Logger.Level) -> Bool {
             return lhs.rawValue < rhs.rawValue
         }
     }
 
-    init() {
+    typealias Hook = ((String, Level) -> Void)
+    var hook: Hook?
+
+    fileprivate init() {
         osLog = OSLog(subsystem: "com.scenee.FloatingPanel", category: "FloatingPanel")
     }
 
     private func log(_ level: Level, _ message: Any, _ arguments: [Any], function: String, line: UInt) {
-        #if __FP_LOG
         _ = s.wait(timeout: .now() + 0.033)
         defer { s.signal() }
 
         let extraMessage: String = arguments.map({ String(describing: $0) }).joined(separator: " ")
-        let log = "\(level.shortName) \(message) \(extraMessage) (\(function):\(line))"
+        let log: String = {
+            switch level {
+            case .debug:
+                return "\(level.displayName) \(message) \(extraMessage) (\(function):\(line))"
+            default:
+                return "\(level.displayName) \(message) \(extraMessage)"
+            }
+        }()
+
+        hook?(log, level)
 
         os_log("%@", log: osLog, type: level.osLogType, log)
-        #endif
     }
 
     private func getPrettyFunction(_ function: String, _ file: String) -> String {
@@ -85,7 +82,9 @@ struct Logger {
     }
 
     func debug(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
+        #if __FP_LOG
         self.log(.debug, log, arguments, function: getPrettyFunction(function, file), line: line)
+        #endif
     }
 
     func info(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
@@ -99,8 +98,4 @@ struct Logger {
     func error(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
         self.log(.error, log, arguments, function: getPrettyFunction(function, file), line: line)
     }
-
-    func fault(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
-        self.log(.fault, log, arguments, function: getPrettyFunction(function, file), line: line)
-    }
 }

Framework/Sources/UIExtensions.swift

@@ -21,7 +21,7 @@ class CustomLayoutGuide: LayoutGuideProvider {
 }
 
 extension UIViewController {
-    var layoutInsets: UIEdgeInsets {
+    @objc var layoutInsets: UIEdgeInsets {
         if #available(iOS 11.0, *) {
             return view.safeAreaInsets
         } else {
@@ -60,24 +60,62 @@ extension UIView {
             return self
         }
     }
-}
 
-extension UIGestureRecognizer.State: CustomDebugStringConvertible {
-    public var debugDescription: String {
-        switch self {
-        case .began: return "Began"
-        case .changed: return "Changed"
-        case .failed: return "Failed"
-        case .cancelled: return "Cancelled"
-        case .ended: return "Endeded"
-        case .possible: return "Possible"
-        }
+    var presentationFrame: CGRect {
+        return layer.presentation()?.frame ?? frame
     }
 }
 
+extension UIView {
+    func disableAutoLayout() {
+        let frame = self.frame
+        translatesAutoresizingMaskIntoConstraints = true
+        self.frame = frame
+    }
+    func enableAutoLayout() {
+        translatesAutoresizingMaskIntoConstraints = false
+    }
+
+    static func performWithLinear(startTime: Double = 0.0, relativeDuration: Double = 1.0, _ animations: @escaping (() -> Void)) {
+        UIView.animateKeyframes(withDuration: 0.0, delay: 0.0, options: [.calculationModeCubic], animations: {
+            UIView.addKeyframe(withRelativeStartTime: startTime, relativeDuration: relativeDuration, animations: animations)
+        }, completion: nil)
+    }
+}
+
+#if __FP_LOG
+#if swift(>=4.2)
+extension UIGestureRecognizer.State: CustomDebugStringConvertible {
+    public var debugDescription: String {
+        switch self {
+        case .began: return "began"
+        case .changed: return "changed"
+        case .failed: return "failed"
+        case .cancelled: return "cancelled"
+        case .ended: return "endeded"
+        case .possible: return "possible"
+        }
+    }
+}
+#else
+extension UIGestureRecognizerState: CustomDebugStringConvertible {
+    public var debugDescription: String {
+        switch self {
+        case .began: return "began"
+        case .changed: return "changed"
+        case .failed: return "failed"
+        case .cancelled: return "cancelled"
+        case .ended: return "endeded"
+        case .possible: return "possible"
+        }
+    }
+}
+#endif
+#endif
+
 extension UIScrollView {
-    var contentOffsetZero: CGPoint {
-        return CGPoint(x: 0.0, y: 0.0 - contentInset.top)
+    var isLocked: Bool {
+        return !showsVerticalScrollIndicator && !bounces &&  isDirectionalLockEnabled
     }
 }
 
@@ -89,3 +127,32 @@ extension UISpringTimingParameters {
         self.init(mass: mass, stiffness: stiffness, damping: damp, initialVelocity: initialVelocity)
     }
 }
+
+extension CGPoint {
+    static var nan: CGPoint {
+        return CGPoint(x: CGFloat.nan, y: CGFloat.nan)
+    }
+    static func - (left: CGPoint, right: CGPoint) -> CGPoint {
+        return CGPoint(x: left.x - right.x, y: left.y - right.y)
+    }
+}
+
+extension UITraitCollection {
+    func shouldUpdateLayout(from previous: UITraitCollection) -> Bool {
+        return previous.horizontalSizeClass != horizontalSizeClass
+            || previous.verticalSizeClass != verticalSizeClass
+            || previous.preferredContentSizeCategory != preferredContentSizeCategory
+            || previous.layoutDirection != layoutDirection
+    }
+}
+
+extension NSLayoutConstraint {
+    static func activate(constraint: NSLayoutConstraint?) {
+        guard let constraint = constraint else { return }
+        self.activate([constraint])
+    }
+    static func deactivate(constraint: NSLayoutConstraint?) {
+        guard let constraint = constraint else { return }
+        self.deactivate([constraint])
+    }
+}

Framework/TestingApp/AppDelegate.swift

@@ -0,0 +1,22 @@
+//
+//  Created by Shin Yamamoto on 2018/11/01.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import UIKit
+@UIApplicationMain
+class AppDelegate: UIResponder, UIApplicationDelegate {
+    var window: UIWindow?
+
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
+        let rootVC = UIViewController(nibName: nil, bundle: nil)
+        rootVC.view.backgroundColor = .gray
+
+        let window = UIWindow()
+        window.rootViewController = rootVC
+        window.makeKeyAndVisible()
+        self.window = window
+
+        return true
+    }
+}

Framework/TestingApp/Info.plist

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

Framework/TestingApp/LaunchScreen.storyboard

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="13142" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12042"/>
+        <capability name="Constraints with non-1.0 multipliers" minToolsVersion="5.1"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Copyright © 2019 scenee. All rights reserved." textAlignment="center" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" minimumFontSize="9" translatesAutoresizingMaskIntoConstraints="NO" id="obG-Y5-kRd">
+                                <rect key="frame" x="0.0" y="626.5" width="375" height="20.5"/>
+                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                            <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="TestingApp" textAlignment="center" lineBreakMode="middleTruncation" baselineAdjustment="alignBaselines" minimumFontSize="18" translatesAutoresizingMaskIntoConstraints="NO" id="GJd-Yh-RWb">
+                                <rect key="frame" x="0.0" y="202" width="375" height="43"/>
+                                <fontDescription key="fontDescription" type="boldSystem" pointSize="36"/>
+                                <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                        </subviews>
+                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                        <constraints>
+                            <constraint firstItem="Bcu-3y-fUS" firstAttribute="centerX" secondItem="obG-Y5-kRd" secondAttribute="centerX" id="5cz-MP-9tL"/>
+                            <constraint firstItem="Bcu-3y-fUS" firstAttribute="centerX" secondItem="GJd-Yh-RWb" secondAttribute="centerX" id="Q3B-4B-g5h"/>
+                            <constraint firstItem="obG-Y5-kRd" firstAttribute="leading" secondItem="Bcu-3y-fUS" secondAttribute="leading" constant="20" symbolic="YES" id="SfN-ll-jLj"/>
+                            <constraint firstAttribute="bottom" secondItem="obG-Y5-kRd" secondAttribute="bottom" constant="20" id="Y44-ml-fuU"/>
+                            <constraint firstItem="GJd-Yh-RWb" firstAttribute="centerY" secondItem="Ze5-6b-2t3" secondAttribute="bottom" multiplier="1/3" constant="1" id="moa-c2-u7t"/>
+                            <constraint firstItem="GJd-Yh-RWb" firstAttribute="leading" secondItem="Bcu-3y-fUS" secondAttribute="leading" constant="20" symbolic="YES" id="x7j-FC-K8j"/>
+                        </constraints>
+                        <viewLayoutGuide key="safeArea" id="Bcu-3y-fUS"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>

Framework/Tests/FloatingPanelControllerTests.swift

@@ -0,0 +1,188 @@
+//
+//  Created by Shin Yamamoto on 2018/09/18.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelControllerTests: XCTestCase {
+    override func setUp() {}
+    override func tearDown() {}
+
+    func test_warningRetainCycle() {
+        let myVC = MyZombieViewController(nibName: nil, bundle: nil)
+        let exp = expectation(description: "Warning retain cycle")
+        exp.expectedFulfillmentCount = 2 // For layout & behavior logs
+        log.hook = {(log, level) in
+            if log.contains("A memory leak will occur by a retain cycle because") {
+                XCTAssert(level == .warning)
+                exp.fulfill()
+            }
+        }
+        myVC.loadViewIfNeeded()
+        wait(for: [exp], timeout: 10)
+    }
+
+    func test_addPanel() {
+        guard let rootVC = UIApplication.shared.keyWindow?.rootViewController else { fatalError() }
+        let fpc = FloatingPanelController()
+        fpc.addPanel(toParent: rootVC)
+        XCTAssert(fpc.surfaceView.frame.minY ==  (fpc.view.bounds.height - fpc.layoutInsets.bottom) - fpc.layout.insetFor(position: .half)!)
+        fpc.move(to: .tip, animated: false)
+        XCTAssert(fpc.surfaceView.frame.minY == (fpc.view.bounds.height - fpc.layoutInsets.bottom) - fpc.layout.insetFor(position: .tip)!)
+    }
+
+    @available(iOS 12.0, *)
+    func test_updateLayout_willTransition() {
+        class MyDelegate: FloatingPanelControllerDelegate {
+            func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+                if newCollection.userInterfaceStyle == .dark {
+                    XCTFail()
+                }
+                return nil
+            }
+        }
+        let myDelegate = MyDelegate()
+        let fpc = FloatingPanelController(delegate: myDelegate)
+        let traitCollection = UITraitCollection(traitsFrom: [fpc.traitCollection,
+                                                             UITraitCollection(userInterfaceStyle: .dark)])
+        XCTAssertEqual(traitCollection.userInterfaceStyle, .dark)
+        fpc.prepare(for: traitCollection)
+    }
+
+    func test_moveTo() {
+        let delegate = FloatingPanelTestDelegate()
+        let fpc = FloatingPanelController(delegate: delegate)
+        XCTAssertEqual(delegate.position, .hidden)
+        fpc.showForTest()
+        XCTAssertEqual(delegate.position, .half)
+
+        fpc.hide()
+        XCTAssertEqual(delegate.position, .hidden)
+        
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.position, .full)
+        XCTAssertEqual(delegate.position, .full)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .full))
+
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(delegate.position, .half)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .half))
+
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(fpc.position, .tip)
+        XCTAssertEqual(delegate.position, .tip)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .tip))
+
+        fpc.move(to: .hidden, animated: false)
+        XCTAssertEqual(fpc.position, .hidden)
+        XCTAssertEqual(delegate.position, .hidden)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .hidden))
+
+        fpc.move(to: .full, animated: true)
+        XCTAssertEqual(fpc.position, .full)
+        XCTAssertEqual(delegate.position, .full)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .full))
+
+        fpc.move(to: .half, animated: true)
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(delegate.position, .half)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .half))
+
+        fpc.move(to: .tip, animated: true)
+        XCTAssertEqual(fpc.position, .tip)
+        XCTAssertEqual(delegate.position, .tip)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .tip))
+
+        fpc.move(to: .hidden, animated: true)
+        XCTAssertEqual(fpc.position, .hidden)
+        XCTAssertEqual(delegate.position, .hidden)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .hidden))
+    }
+    
+    func test_moveWithNearbyPosition() {
+        let delegate = FloatingPanelTestDelegate()
+        let fpc = FloatingPanelController(delegate: delegate)
+        XCTAssertEqual(delegate.position, .hidden)
+        fpc.showForTest()
+        
+        XCTAssertEqual(fpc.nearbyPosition, .half)
+        
+        fpc.hide()
+        XCTAssertEqual(fpc.nearbyPosition, .tip)
+        
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.nearbyPosition, .full)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .full))
+    }
+
+    func test_originSurfaceY() {
+        let fpc = FloatingPanelController(delegate: nil)
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+        fpc.show(animated: false, completion: nil)
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .full))
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .half))
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .tip))
+        fpc.move(to: .hidden, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.minY, fpc.originYOfSurface(for: .hidden))
+    }
+
+    func test_contentMode() {
+        let fpc = FloatingPanelController(delegate: nil)
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+        fpc.show(animated: false, completion: nil)
+
+        fpc.contentMode = .static
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .full))
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .full))
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .full))
+
+        fpc.contentMode = .fitToBounds
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .full))
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .half))
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(fpc.surfaceView.frame.height, fpc.view.bounds.height - fpc.originYOfSurface(for: .tip))
+    }
+}
+
+private class MyZombieViewController: UIViewController, FloatingPanelLayout, FloatingPanelBehavior, FloatingPanelControllerDelegate {
+    var fpc: FloatingPanelController?
+    override func viewDidLoad() {
+        fpc = FloatingPanelController(delegate: self)
+        fpc?.addPanel(toParent: self)
+    }
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return self
+    }
+
+    func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
+        return self
+    }
+    var initialPosition: FloatingPanelPosition {
+        return .half
+    }
+
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .full: return UIScreen.main.bounds.height == 667.0 ? 18.0 : 16.0
+        case .half: return 262.0
+        case .tip: return 69.0
+        case .hidden: return nil
+        }
+    }
+}

Framework/Tests/FloatingPanelLayoutTests.swift

@@ -0,0 +1,254 @@
+//
+//  Created by Shin Yamamoto on 2019/06/27.
+//  Copyright © 2019 scenee. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelLayoutTests: XCTestCase {
+    var fpc: FloatingPanelController!
+    override func setUp() {
+        fpc = FloatingPanelController(delegate: nil)
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+    }
+    override func tearDown() {}
+
+    func test_layoutAdapter_topAndBottomMostState() {
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .tip)
+
+        class FloatingPanelLayoutWithHidden: FloatingPanelLayout {
+            func insetFor(position: FloatingPanelPosition) -> CGFloat? { return nil }
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .half, .full]
+        }
+        class FloatingPanelLayout2Positions: FloatingPanelLayout {
+            func insetFor(position: FloatingPanelPosition) -> CGFloat? { return nil }
+            let initialPosition: FloatingPanelPosition = .tip
+            let supportedPositions: Set<FloatingPanelPosition> = [.tip, .half]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayoutWithHidden()
+        fpc.delegate = delegate
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .hidden)
+
+        delegate.layout = FloatingPanelLayout2Positions()
+        fpc.delegate = delegate
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .half)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .tip)
+    }
+
+    func test_layoutSegment_3position() {
+        class FloatingPanelLayout3Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .half
+            let supportedPositions: Set<FloatingPanelPosition> = [.tip, .half, .full]
+        }
+
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        fpc.delegate = delegate
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+
+        let minPos = CGFloat.leastNormalMagnitude
+        let maxPos = CGFloat.greatestFiniteMagnitude
+
+        assertLayoutSegment(fpc.floatingPanel, with: [
+            (#line, pos: minPos, forwardY: true, lower: nil, upper: .full),
+            (#line, pos: minPos, forwardY: false, lower: nil, upper: .full),
+            (#line, pos: fullPos, forwardY: true, lower: .full, upper: .half),
+            (#line, pos: fullPos, forwardY: false, lower: nil,  upper: .full),
+            (#line, pos: halfPos, forwardY: true, lower: .half, upper: .tip),
+            (#line, pos: halfPos, forwardY: false, lower: .full,  upper: .half),
+            (#line, pos: tipPos, forwardY: true, lower: .tip, upper: nil),
+            (#line, pos: tipPos, forwardY: false, lower: .half,  upper: .tip),
+            (#line, pos: maxPos, forwardY: true, lower: .tip, upper: nil),
+            (#line, pos: maxPos, forwardY: false, lower: .tip, upper: nil),
+            ])
+    }
+
+    func test_layoutSegment_2positions() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .half
+            let supportedPositions: Set<FloatingPanelPosition> = [.half, .full]
+        }
+
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+        fpc.delegate = delegate
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+
+        let minPos = CGFloat.leastNormalMagnitude
+        let maxPos = CGFloat.greatestFiniteMagnitude
+
+        assertLayoutSegment(fpc.floatingPanel, with: [
+            (#line, pos: minPos, forwardY: true, lower: nil, upper: .full),
+            (#line, pos: minPos, forwardY: false, lower: nil, upper: .full),
+            (#line, pos: fullPos, forwardY: true, lower: .full, upper: .half),
+            (#line, pos: fullPos, forwardY: false, lower: nil,  upper: .full),
+            (#line, pos: halfPos, forwardY: true, lower: .half, upper: nil),
+            (#line, pos: halfPos, forwardY: false, lower: .full,  upper: .half),
+            (#line, pos: maxPos, forwardY: true, lower: .half, upper: nil),
+            (#line, pos: maxPos, forwardY: false, lower: .half, upper: nil),
+            ])
+    }
+
+    func test_layoutSegment_1positions() {
+        class FloatingPanelLayout1Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .full
+            let supportedPositions: Set<FloatingPanelPosition> = [.full]
+        }
+
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout1Positions()
+        fpc.delegate = delegate
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+
+        let minPos = CGFloat.leastNormalMagnitude
+        let maxPos = CGFloat.greatestFiniteMagnitude
+
+        assertLayoutSegment(fpc.floatingPanel, with: [
+            (#line, pos: minPos, forwardY: true, lower: nil, upper: .full),
+            (#line, pos: minPos, forwardY: false, lower: nil, upper: .full),
+            (#line, pos: fullPos, forwardY: true, lower: .full, upper: nil),
+            (#line, pos: fullPos, forwardY: false, lower: nil,  upper: .full),
+            (#line, pos: maxPos, forwardY: true, lower: .full, upper: nil),
+            (#line, pos: maxPos, forwardY: false, lower: .full, upper: nil),
+            ])
+    }
+
+    func test_updateInteractiveTopConstraint() {
+        fpc.showForTest()
+        fpc.move(to: .full, animated: false)
+
+        fpc.floatingPanel.layoutAdapter.startInteraction(at: fpc.position)
+        fpc.floatingPanel.layoutAdapter.startInteraction(at: fpc.position) // Should be ignore
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+
+        var pre: CGFloat
+        var next: CGFloat
+        pre = fpc.surfaceView.frame.minY
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: -100.0, allowsTopBuffer: false, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, pre)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: -100.0, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, fullPos - fpc.layout.topInteractionBuffer)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: 100.0, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, fullPos + 100.0)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: tipPos - fullPos, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, tipPos)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: tipPos - fullPos + 100.0, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, tipPos + fpc.layout.bottomInteractionBuffer)
+
+        fpc.floatingPanel.layoutAdapter.endInteraction(at: fpc.position)
+    }
+
+    func test_updateInteractiveTopConstraintWithHidden() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+        fpc.delegate = delegate
+        fpc.showForTest()
+        fpc.move(to: .full, animated: false)
+
+        fpc.floatingPanel.layoutAdapter.startInteraction(at: fpc.position)
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let hiddenPos = fpc.originYOfSurface(for: .hidden)
+
+        var pre: CGFloat
+        var next: CGFloat
+        pre = fpc.surfaceView.frame.minY
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: -100.0, allowsTopBuffer: false, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, pre)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: -100.0, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, fullPos - fpc.layout.topInteractionBuffer)
+
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: hiddenPos - fullPos + 100.0, allowsTopBuffer: true, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, hiddenPos + fpc.layout.bottomInteractionBuffer)
+
+        fpc.floatingPanel.layoutAdapter.endInteraction(at: fpc.position)
+    }
+
+    func test_positionReference() {
+        fpc = CustomSafeAreaFloatingPanelController()
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+
+        class MyFloatingPanelFullLayout: FloatingPanelTestLayout {
+            var initialPosition: FloatingPanelPosition = .half
+            var positionReference: FloatingPanelLayoutReference {
+                return .fromSuperview
+            }
+        }
+        class MyFloatingPanelSafeAreaLayout: FloatingPanelTestLayout {
+            var initialPosition: FloatingPanelPosition = .half
+            var positionReference: FloatingPanelLayoutReference {
+                return .fromSafeArea
+            }
+        }
+        let fullLayout = MyFloatingPanelFullLayout()
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = fullLayout
+        fpc.delegate = delegate
+        fpc.showForTest()
+
+        XCTAssertEqual(fpc.layout.positionReference, .fromSuperview)
+        XCTAssertEqual(fpc.originYOfSurface(for: .full), fullLayout.insetFor(position: .full))
+        XCTAssertEqual(fpc.originYOfSurface(for: .half), fpc.view!.frame.height - fullLayout.insetFor(position: .half)!)
+        XCTAssertEqual(fpc.originYOfSurface(for: .tip), fpc.view!.frame.height - fullLayout.insetFor(position: .tip)!)
+
+        let safeAreaLayout = MyFloatingPanelSafeAreaLayout()
+        delegate.layout = safeAreaLayout
+        fpc.delegate = delegate
+
+        XCTAssertEqual(fpc.layout.positionReference, .fromSafeArea)
+        XCTAssertEqual(fpc.originYOfSurface(for: .full),
+                       fullLayout.insetFor(position: .full)! + fpc.layoutInsets.top)
+        XCTAssertEqual(fpc.originYOfSurface(for: .half),
+                       fpc.view!.frame.height - (fullLayout.insetFor(position: .half)! +  fpc.layoutInsets.bottom))
+        XCTAssertEqual(fpc.originYOfSurface(for: .tip),
+                       fpc.view!.frame.height - (fullLayout.insetFor(position: .tip)! +  fpc.layoutInsets.bottom))
+    }
+}
+
+private typealias LayoutSegmentTestParameter = (UInt, pos: CGFloat, forwardY: Bool, lower: FloatingPanelPosition?, upper: FloatingPanelPosition?)
+private func assertLayoutSegment(_ floatingPanel: FloatingPanelCore, with params: [LayoutSegmentTestParameter]) {
+    params.forEach { (line, pos, forwardY, lowr, upper) in
+        let segument = floatingPanel.layoutAdapter.segument(at: pos, forward: forwardY)
+        XCTAssertEqual(segument.lower, lowr, line: line)
+        XCTAssertEqual(segument.upper, upper, line: line)
+    }
+}
+
+private class CustomSafeAreaFloatingPanelController: FloatingPanelController { }
+extension CustomSafeAreaFloatingPanelController {
+    override var layoutInsets: UIEdgeInsets {
+        return UIEdgeInsets(top: 64.0, left: 0.0, bottom: 0.0, right: 34.0)
+    }
+}

Framework/Tests/FloatingPanelPositionTests.swift

@@ -0,0 +1,27 @@
+//
+//  Created by Shin Yamamoto on 2019/07/05.
+//  Copyright © 2019 scenee. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelPositionTests: XCTestCase {
+    override func setUp() { }
+    override func tearDown() { }
+
+    func test_nextAndPre() {
+        var positions: [FloatingPanelPosition]
+        positions = [.full, .half, .tip, .hidden]
+        XCTAssertEqual(FloatingPanelPosition.full.next(in: positions),  .half)
+        XCTAssertEqual(FloatingPanelPosition.full.pre(in: positions),  .full)
+        XCTAssertEqual(FloatingPanelPosition.hidden.next(in: positions), .hidden)
+        XCTAssertEqual(FloatingPanelPosition.hidden.pre(in: positions), .tip)
+
+        positions = [.full, .hidden]
+        XCTAssertEqual(FloatingPanelPosition.full.next(in: positions),  .hidden)
+        XCTAssertEqual(FloatingPanelPosition.full.pre(in: positions),  .full)
+        XCTAssertEqual(FloatingPanelPosition.hidden.next(in: positions), .hidden)
+        XCTAssertEqual(FloatingPanelPosition.hidden.pre(in: positions), .full)
+    }
+}

Framework/Tests/FloatingPanelSurfaceViewTests.swift

@@ -0,0 +1,118 @@
+//
+//  Created by Shin Yamamoto on 2019/05/23.
+//  Copyright © 2019 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelSurfaceViewTests: XCTestCase {
+    override func setUp() {}
+    override func tearDown() {}
+
+    func test_surfaceView() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssertTrue(FloatingPanelSurfaceView.requiresConstraintBasedLayout)
+        XCTAssert(surface.contentView == nil)
+        surface.layoutIfNeeded()
+        XCTAssert(surface.grabberHandle.frame.minY == 6.0)
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth)
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight)
+        surface.backgroundColor = .red
+        surface.layoutIfNeeded()
+        XCTAssert(surface.backgroundColor == surface.containerView.backgroundColor)
+    }
+
+    func test_surfaceView_grabberHandle() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.contentView == nil)
+        surface.layoutIfNeeded()
+        XCTAssert(surface.grabberHandle.frame.minY == 6.0)
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth)
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight)
+
+        surface.grabberHandleWidth = 44.0
+        surface.grabberHandleHeight = 12.0
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth, "\(surface.grabberHandle.frame.width) == \(surface.grabberHandleWidth)")
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight, "\(surface.grabberHandle.frame.height) == \(surface.grabberHandleHeight)")
+    }
+
+    func test_surfaceView_containerMargins() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.containerView.frame, surface.bounds)
+        surface.containerMargins = UIEdgeInsets(top: 16.0, left: 16.0, bottom: 16.0, right: 16.0)
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.containerView.frame, surface.bounds.inset(by: surface.containerMargins))
+    }
+
+    func test_surfaceView_contentInsets() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        let contentView = UIView()
+        surface.add(contentView: contentView)
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.contentView.frame, surface.bounds)
+        surface.contentInsets = UIEdgeInsets(top: 16.0, left: 16.0, bottom: 16.0, right: 16.0)
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.contentView.frame, surface.bounds.inset(by: surface.contentInsets))
+    }
+
+    func test_surfaceView_containerMargins_and_contentInsets() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        let contentView = UIView()
+        surface.add(contentView: contentView)
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.contentView.frame, surface.bounds)
+        surface.containerMargins = UIEdgeInsets(top: 16.0, left: 16.0, bottom: 16.0, right: 16.0)
+        surface.contentInsets = UIEdgeInsets(top: 16.0, left: 16.0, bottom: 16.0, right: 16.0)
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssertEqual(surface.containerView.frame, surface.bounds.inset(by: surface.containerMargins))
+        XCTAssertEqual(surface.contentView.frame, surface.containerView.bounds.inset(by: surface.contentInsets))
+    }
+
+    func test_surfaceView_cornderRaduis() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == false)
+
+        surface.cornerRadius = 10.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 10.0)
+        XCTAssert(surface.containerView.layer.cornerRadius == 10.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+
+        surface.containerView.layer.cornerRadius = 12.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 12.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+
+        surface.cornerRadius = 0.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == false)
+
+        surface.containerView.layer.cornerRadius = 12.0
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 12.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+    }
+
+    func test_surfaceView_border() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.borderColor == nil)
+        XCTAssert(surface.borderWidth == 0.0)
+
+        surface.borderColor = .red
+        surface.borderWidth = 3.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.containerView.layer.borderColor == UIColor.red.cgColor)
+        XCTAssert(surface.containerView.layer.borderWidth == 3.0)
+    }
+}

Framework/Tests/FloatingPanelTests.swift

@@ -0,0 +1,537 @@
+//
+//  Created by Shin Yamamoto on 2019/05/23.
+//  Copyright © 2019 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelTests: XCTestCase {
+    override func setUp() {}
+    override func tearDown() {}
+
+    func test_scrolllock() {
+        let fpc = FloatingPanelController()
+
+        let contentVC1 = UITableViewController(nibName: nil, bundle: nil)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC1.tableView.bounces, true)
+        fpc.set(contentViewController: contentVC1)
+        fpc.track(scrollView: contentVC1.tableView)
+        fpc.showForTest()
+
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC1.tableView.bounces, false)
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC1.tableView.bounces, true)
+
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC1.tableView.bounces, false)
+
+        let exp1 = expectation(description: "move to full with animation")
+        fpc.move(to: .full, animated: true) {
+            XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+            XCTAssertEqual(contentVC1.tableView.bounces, true)
+            exp1.fulfill()
+        }
+        wait(for: [exp1], timeout: 1.0)
+
+        let exp2 = expectation(description: "move to tip with animation")
+        fpc.move(to: .tip, animated: false) {
+            XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+            XCTAssertEqual(contentVC1.tableView.bounces, false)
+            exp2.fulfill()
+        }
+        wait(for: [exp2], timeout: 1.0)
+
+        // Reset the content vc
+        let contentVC2 = UITableViewController(nibName: nil, bundle: nil)
+        XCTAssertEqual(contentVC2.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC2.tableView.bounces, true)
+        fpc.set(contentViewController: contentVC2)
+        fpc.track(scrollView: contentVC2.tableView)
+        fpc.show(animated: false, completion: nil)
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(contentVC2.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC2.tableView.bounces, false)
+    }
+
+    func test_getBackdropAlpha_1positions() {
+        class FloatingPanelLayout1Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .full
+            let supportedPositions: Set<FloatingPanelPosition> = [.full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout1Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos - 100.0, with: CGPoint(x: 0.0, y: -100.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: 0.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos + 100.0, with: CGPoint(x: 0.0, y: 100.0)), 0.3) // ok??
+    }
+
+    func test_getBackdropAlpha_2positions() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .half
+            let supportedPositions: Set<FloatingPanelPosition> = [.half, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let distance1 = abs(halfPos - fullPos)
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: 0.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos + distance1 * 0.5, with: CGPoint(x: 0.0, y: distance1 * 0.5)), 0.3 * 0.5)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos, with: CGPoint(x: 0.0, y: distance1)), 0.0)
+
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos, with: CGPoint(x: 0.0, y: 0.0)), 0.0)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos + distance1 * 0.5, with: CGPoint(x: 0.0, y: -0.5 * distance1)), 0.3 * 0.5)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: -1 * distance1)), 0.3)
+    }
+
+    func test_getBackdropAlpha_2positionsWithHidden() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let hiddenPos = fpc.originYOfSurface(for: .hidden)
+
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos - 100.0, with: CGPoint(x: 0.0, y: -100.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: 0.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: hiddenPos, with: CGPoint(x: 0.0, y: 100.0)), 0.0)
+    }
+
+    func test_getBackdropAlpha_3positions() {
+        let fpc = FloatingPanelController()
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+        let distance1 = abs(halfPos - fullPos)
+        let distance2 = abs(tipPos - halfPos)
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: 0.0)), 0.3)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos + distance1 * 0.5, with: CGPoint(x: 0.0, y: distance1 * 0.5)), 0.3 * 0.5)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos, with: CGPoint(x: 0.0, y: distance1)), 0.0)
+
+        fpc.move(to: .half, animated: false)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos, with: CGPoint(x: 0.0, y: 0.0)), 0.0)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos + distance1 * 0.5, with: CGPoint(x: 0.0, y: -0.5 * distance1)), 0.3 * 0.5)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: fullPos, with: CGPoint(x: 0.0, y: -1 * distance1)), 0.3)
+
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: tipPos, with: CGPoint(x: 0.0, y: 0.0)), 0.0)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos + distance2 * 0.5, with: CGPoint(x: 0.0, y: -0.5 * distance2)), 0.0)
+        XCTAssertEqual(fpc.floatingPanel.getBackdropAlpha(at: halfPos, with: CGPoint(x: 0.0, y: -1 * distance2)), 0.0)
+    }
+
+    func test_targetPosition_1positions() {
+        class FloatingPanelLayout1Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .full
+            let supportedPositions: Set<FloatingPanelPosition> = [.full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout1Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .full), // redirect
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            ])
+    }
+
+    func test_targetPosition_2positions() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .half
+            let supportedPositions: Set<FloatingPanelPosition> = [.half, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 1000.0), .half), // project to half
+            (#line, fullPos, CGPoint(x: 0.0, y: -1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .half), // project to half
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, halfPos - 10.0, CGPoint(x: 0.0, y: -100.0), .half), // redirect
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full),  // project to full
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .half), // redirect
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: -1000.0), .full), // project to full
+            ])
+        fpc.move(to: .half, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 1000.0), .half), // project to half
+            (#line, fullPos, CGPoint(x: 0.0, y: -1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .half), // project to half
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, halfPos - 10.0, CGPoint(x: 0.0, y: -100.0), .half), // redirect
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full),  // project to full
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .half), // redirect
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: -1000.0), .full), // project to full
+            ])
+    }
+
+    func test_targetPosition_2positionsWithHidden() {
+        class FloatingPanelLayout2Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout2Positions()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let hiddenPos = fpc.originYOfSurface(for: .hidden)
+
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 1000.0), .hidden), // project to hidden
+            (#line, fullPos, CGPoint(x: 0.0, y: -1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .hidden), // project to hidden
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, hiddenPos - 10.0, CGPoint(x: 0.0, y: -100.0), .hidden), // redirect
+            (#line, hiddenPos, CGPoint(x: 0.0, y: -1000.0), .full),  // project to full
+            (#line, hiddenPos, CGPoint(x: 0.0, y: -100.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 0.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 100.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 1000.0), .hidden), // redirect
+            (#line, hiddenPos + 10.0, CGPoint(x: 0.0, y: -1000.0), .full), // project to full
+            ])
+        fpc.move(to: .hidden, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 1000.0), .hidden), // project to hidden
+            (#line, fullPos, CGPoint(x: 0.0, y: -1000.0), .full), // redirect
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .hidden), // project to hidden
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, hiddenPos - 10.0, CGPoint(x: 0.0, y: -100.0), .hidden), // redirect
+            (#line, hiddenPos, CGPoint(x: 0.0, y: -1000.0), .full),  // project to full
+            (#line, hiddenPos, CGPoint(x: 0.0, y: -100.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 0.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 100.0), .hidden),
+            (#line, hiddenPos, CGPoint(x: 0.0, y: 1000.0), .hidden), // redirect
+            (#line, hiddenPos + 10.0, CGPoint(x: 0.0, y: -1000.0), .full), // project to full
+            ])
+    }
+
+    func test_targetPosition_2positionsFromFull() {
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+        // From .full
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: -100.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 0.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 100.0), .full), // far from topMostState
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 3000.0), .half), // block projecting to tip at half
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 500.0), .half), // project to half
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .half), // block projecting to tip at half
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .half), // block projecting to tip at half
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, halfPos - 10.0, CGPoint(x: 0.0, y: -100.0), .half), // redirect
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full), //project to full
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .tip), // project to tip
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: 100.0), .half), // redirect
+            (#line, tipPos - 10.0, CGPoint(x: 0.0, y: -100.0), .tip), // redirect
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -500.0), .half), // project to half
+            (#line, tipPos, CGPoint(x: 0.0, y: -100.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 0.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 100.0), .tip),
+            (#line, tipPos + 10.0, CGPoint(x: 0.0, y: -3000.0), .half), // block projecting to full at half
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: -100.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 0.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 100.0), .tip), // far from bottomMostState
+            ])
+    }
+
+    func test_targetPosition_3positionsFromHalf() {
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+        // From .half
+        fpc.move(to: .half, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: -100.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 0.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 100.0), .full), // far from topMostState
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 500.0), .half), // project to half
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .half), // block projecting to tip at half
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .half), // block projecting to tip at half
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, halfPos - 10.0, CGPoint(x: 0.0, y: -100.0), .half), // redirect
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full),// project to full
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .tip), // project to tip
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: 100.0), .half), // redirect
+            (#line, tipPos - 10.0, CGPoint(x: 0.0, y: -100.0), .tip), // redirect
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -500.0), .half), // project to half
+            (#line, tipPos, CGPoint(x: 0.0, y: -100.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 0.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 100.0), .tip),
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: -100.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 0.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 100.0), .tip), // far from bottomMostState
+            ])
+    }
+
+    func test_targetPosition_3positionsFromTip() {
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+
+        // From .tip
+        fpc.move(to: .tip, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: -100.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 0.0), .full), // far from topMostState
+            (#line, fullPos - 500.0, CGPoint(x: 0.0, y: 100.0), .full), // far from topMostState
+            (#line, fullPos, CGPoint(x: 0.0, y: -100.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 0.0), .full),
+            (#line, fullPos, CGPoint(x: 0.0, y: 500.0), .half), // project to half
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .half), // block projecting to tip at half
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .half), // block projecting to tip at half
+            (#line, fullPos + 10.0, CGPoint(x: 0.0, y: 100.0), .full), // redirect
+            (#line, halfPos - 10.0, CGPoint(x: 0.0, y: -100.0), .half), // redirect
+            (#line, halfPos, CGPoint(x: 0.0, y: -3000.0), .full), // project to full
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .tip), // project to tip
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: 100.0), .half), // redirect
+            (#line, tipPos - 10.0, CGPoint(x: 0.0, y: -100.0), .tip), // redirect
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .half), // block projecting to full at half
+            (#line, tipPos, CGPoint(x: 0.0, y: -500.0), .half), // project to half
+            (#line, tipPos, CGPoint(x: 0.0, y: -100.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 0.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 100.0), .tip),
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: -100.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 0.0), .tip), // far from bottomMostState
+            (#line, tipPos + 500.0, CGPoint(x: 0.0, y: 100.0), .tip), // far from bottomMostState
+            ])
+    }
+
+    func test_targetPosition_3positionsAllProjection() {
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        delegate.behavior = FloatingPanelProjectionalBehavior()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+
+        // From .full
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 3000.0), .tip),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .tip),
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .tip),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .tip),
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full),
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .full),
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .full),
+            (#line, tipPos + 10.0, CGPoint(x: 0.0, y: -3000.0), .full),
+            ])
+
+        // From .half
+        fpc.move(to: .tip, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .tip),
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .full),
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .full),
+            ])
+
+        // From .tip
+        fpc.move(to: .tip, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fullPos - 10.0, CGPoint(x: 0.0, y: 3000.0), .tip),
+            (#line, fullPos, CGPoint(x: 0.0, y: 1000.0), .tip),
+            (#line, fullPos, CGPoint(x: 0.0, y: 3000.0), .tip),
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .tip),
+            (#line, halfPos, CGPoint(x: 0.0, y: -1000.0), .full),
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .full),
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .full),
+            (#line, tipPos + 10.0, CGPoint(x: 0.0, y: -3000.0), .full),
+            ])
+    }
+
+    func test_targetPosition_3positionsWithHidden() {
+        class FloatingPanelLayout3PositionsWithHidden: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .half, .full]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3PositionsWithHidden()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+        XCTAssertEqual(fpc.position, .hidden)
+
+        fpc.move(to: .full, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fpc.surfaceView.frame.minY, CGPoint(x: 0.0, y: 1000.0), .half),
+            ])
+        fpc.move(to: .half, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, fpc.surfaceView.frame.minY, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, fpc.surfaceView.frame.minY, CGPoint(x: 0.0, y: -1000.0), .full),
+            (#line, fpc.surfaceView.frame.minY, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, fpc.surfaceView.frame.minY, CGPoint(x: 0.0, y: 1000.0), .hidden),
+            ])
+    }
+
+    func test_targetPosition_3positionsWithHiddenWithoutFull() {
+        class FloatingPanelLayout3Positions: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .tip, .half]
+        }
+
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayout3Positions()
+        delegate.behavior = FloatingPanelProjectionalBehavior()
+
+        let fpc = FloatingPanelController(delegate: delegate)
+        fpc.showForTest()
+        XCTAssertEqual(fpc.position, .hidden)
+
+        let halfPos = fpc.originYOfSurface(for: .half)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+        //let hiddenPos = fpc.originYOfSurface(for: .hidden)
+
+        fpc.move(to: .half, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, halfPos, CGPoint(x: 0.0, y: -100.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 0.0), .half),
+            (#line, halfPos, CGPoint(x: 0.0, y: 385.0), .tip), // projection
+            (#line, halfPos, CGPoint(x: 0.0, y: 1000.0), .hidden), // projection
+            (#line, halfPos + 10.0, CGPoint(x: 0.0, y: 100.0), .half), // redirection
+            (#line, tipPos - 10.0, CGPoint(x: 0.0, y: -100.0), .tip), // redirection
+            (#line, tipPos, CGPoint(x: 0.0, y: -3000.0), .half), //projection
+            (#line, tipPos, CGPoint(x: 0.0, y: -10.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 0.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 10.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 1000.0), .hidden), //projection
+            (#line, tipPos + 10.0, CGPoint(x: 0.0, y: 10.0), .tip), // redirection
+            (#line, tipPos - 10.0, CGPoint(x: 0.0, y: 10.0), .tip), // redirection
+            ])
+        fpc.move(to: .tip, animated: false)
+        assertTargetPosition(fpc.floatingPanel, with: [
+            (#line, tipPos, CGPoint(x: 0.0, y: -100.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: -1000.0), .half),
+            (#line, tipPos, CGPoint(x: 0.0, y: 0.0), .tip),
+            (#line, tipPos, CGPoint(x: 0.0, y: 1000.0), .hidden),
+            ])
+    }
+}
+
+private class FloatingPanelLayout3Positions: FloatingPanelTestLayout {
+    let initialPosition: FloatingPanelPosition = .tip
+    let supportedPositions: Set<FloatingPanelPosition> = [.tip, .half, .full]
+}
+
+private typealias TestParameter = (UInt, CGFloat,CGPoint, FloatingPanelPosition)
+private func assertTargetPosition(_ floatingPanel: FloatingPanelCore, with params: [TestParameter]) {
+    params.forEach { (line, pos, velocity, result) in
+        floatingPanel.surfaceView.frame.origin.y = pos
+        XCTAssertEqual(floatingPanel.targetPosition(from: pos, with: velocity), result, line: line)
+    }
+}
+
+private class FloatingPanelProjectionalBehavior: FloatingPanelBehavior {
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
+        return true
+    }
+}

Framework/Tests/Utils.swift

@@ -0,0 +1,46 @@
+//
+//  Created by Shin Yamamoto on 2019/06/27.
+//  Copyright © 2019 scenee. All rights reserved.
+//
+
+import Foundation
+@testable import FloatingPanel
+
+func waitRunLoop(secs: TimeInterval = 0) {
+    RunLoop.main.run(until: Date(timeIntervalSinceNow: secs))
+}
+
+extension FloatingPanelController {
+    func showForTest() {
+        loadViewIfNeeded()
+        view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+        show(animated: false, completion: nil)
+    }
+}
+
+class FloatingPanelTestDelegate: FloatingPanelControllerDelegate {
+    var layout: FloatingPanelLayout?
+    var behavior: FloatingPanelBehavior?
+    var position: FloatingPanelPosition = .hidden
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return layout
+    }
+    func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
+        return behavior
+    }
+    func floatingPanelDidChangePosition(_ vc: FloatingPanelController) {
+        position = vc.position
+    }
+}
+
+protocol FloatingPanelTestLayout: FloatingPanelFullScreenLayout {}
+extension FloatingPanelTestLayout {
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .full: return 20.0
+        case .half: return 250.0
+        case .tip: return 60.0
+        default: return nil
+        }
+    }
+}

Framework/Tests/ViewTests.swift

@@ -1,14 +0,0 @@
-//
-//  Created by Shin Yamamoto on 2018/09/18.
-//  Copyright © 2018 Shin Yamamoto. All rights reserved.
-//
-
-import XCTest
-@testable import FloatingPanelController
-
-class ViewTests: XCTestCase {
-
-    override func setUp() {}
-
-    override func tearDown() {}
-}

Package.swift

@@ -0,0 +1,27 @@
+// swift-tools-version:5.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "FloatingPanel",
+    platforms: [
+        .iOS(.v10)
+    ],
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "FloatingPanel",
+            targets: ["FloatingPanel"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(name: "FloatingPanel", path: "Framework/Sources"),
+    ],
+    swiftLanguageVersions: [.version("5")]
+)

README.md

@@ -2,10 +2,12 @@
 [![Version](https://img.shields.io/cocoapods/v/FloatingPanel.svg)](https://cocoapods.org/pods/FloatingPanel)
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)
 [![Platform](https://img.shields.io/cocoapods/p/FloatingPanel.svg)](https://cocoapods.org/pods/FloatingPanel)
+[![Swift 4.1](https://img.shields.io/badge/Swift-4.1-orange.svg?style=flat)](https://swift.org/)
 [![Swift 4.2](https://img.shields.io/badge/Swift-4.2-orange.svg?style=flat)](https://swift.org/)
+[![Swift 5.0](https://img.shields.io/badge/Swift-5.0-orange.svg?style=flat)](https://swift.org/)
+[![Swift 5.1](https://img.shields.io/badge/Swift-5.1-orange.svg?style=flat)](https://swift.org/)
 
-#  FloatingPanel
-
+# FloatingPanel
 
 FloatingPanel is a simple and easy-to-use UI component for a new interface introduced in Apple Maps, Shortcuts and Stocks app.
 The new interface displays the related contents and utilities in parallel as a user wants.
@@ -22,20 +24,37 @@ The new interface displays the related contents and utilities in parallel as a u
 - [Installation](#installation)
   - [CocoaPods](#cocoapods)
   - [Carthage](#carthage)
+  - [Swift Package Manager with Xcode 11](#swift-package-manager-with-xcode-11)
 - [Getting Started](#getting-started)
+  - [Add a floating panel as a child view controller](#add-a-floating-panel-as-a-child-view-controller)
+  - [Present a floating panel as a modality](#present-a-floating-panel-as-a-modality)
+- [View hierarchy](#view-hierarchy)
 - [Usage](#usage)
+  - [Show/Hide a floating panel in a view with your view hierarchy](#showhide-a-floating-panel-in-a-view-with-your-view-hierarchy)
+  - [Scale the content view when the surface position changes](#scale-the-content-view-when-the-surface-position-changes)
   - [Customize the layout with `FloatingPanelLayout` protocol](#customize-the-layout-with-floatingpanellayout-protocol)
     - [Change the initial position and height](#change-the-initial-position-and-height)
     - [Support your landscape layout](#support-your-landscape-layout)
+    - [Use Intrinsic height layout](#use-intrinsic-height-layout)
+    - [Specify position insets from the frame of `FloatingPanelController.view`, not the SafeArea](#specify-position-insets-from-the-frame-of-floatingpanelcontrollerview-not-the-safearea)
   - [Customize the behavior with `FloatingPanelBehavior` protocol](#customize-the-behavior-with-floatingpanelbehavior-protocol)
     - [Modify your floating panel's interaction](#modify-your-floating-panels-interaction)
-  - [Use a custom grabber handle](#use-a-custom-grabber-handle)
-  - [Add tap gestures to the surface or backdrop views](#add-tap-gestures-to-the-surface-or-backdrop-views)
+    - [Activate the rubber-band effect on the top/bottom edges](#activate-the-rubber-band-effect-on-the-topbottom-edges)
+    - [Manage the projection of a pan gesture momentum](#manage-the-projection-of-a-pan-gesture-momentum)
+  - [Customize the surface design](#customize-the-surface-design)
+    - [Use a custom grabber handle](#use-a-custom-grabber-handle)
+    - [Customize layout of the grabber handle](#customize-layout-of-the-grabber-handle)
+    - [Customize content padding from surface edges](#customize-content-padding-from-surface-edges)
+    - [Customize margins of the surface edges](#customize-margins-of-the-surface-edges)
+  - [Customize gestures](#customize-gestures)
+    - [Suppress the panel interaction](#suppress-the-panel-interaction)
+    - [Add tap gestures to the surface or backdrop views](#add-tap-gestures-to-the-surface-or-backdrop-views)
   - [Create an additional floating panel for a detail](#create-an-additional-floating-panel-for-a-detail)
   - [Move a position with an animation](#move-a-position-with-an-animation)
   - [Work your contents together with a floating panel behavior](#work-your-contents-together-with-a-floating-panel-behavior)
 - [Notes](#notes)
   - ['Show' or 'Show Detail' Segues from `FloatingPanelController`'s content view controller](#show-or-show-detail-segues-from-floatingpanelcontrollers-content-view-controller)
+  - [UISearchController issue](#uisearchcontroller-issue)
   - [FloatingPanelSurfaceView's issue on iOS 10](#floatingpanelsurfaceviews-issue-on-ios-10)
 - [Author](#author)
 - [License](#license)
@@ -52,6 +71,7 @@ The new interface displays the related contents and utilities in parallel as a u
 - [x] Layout customization for all trait environments(i.e. Landscape orientation support)
 - [x] Behavior customization
 - [x] Free from common issues of Auto Layout and gesture handling
+- [x] Modal presentation
 
 Examples are here.
 
@@ -60,7 +80,9 @@ Examples are here.
 
 ## Requirements
 
-FloatingPanel is written in Swift 4.2. Compatible with iOS 10.0+
+FloatingPanel is written in Swift 4.0+. It can be built by Xcode 9.4.1 or later. Compatible with iOS 10.0+.
+
+✏️ The default Swift version is 4.0 because it avoids build errors with Carthage on each Xcode version from the source compatibility between Swift 4.0, 4.2 and 5.0.
 
 ## Installation
 
@@ -73,6 +95,8 @@ it, simply add the following line to your Podfile:
 pod 'FloatingPanel'
 ```
 
+✏️FloatingPanel v1.7.0 or later requires CocoaPods v1.7.0+ for `swift_versions` support.
+
 ### Carthage
 
 For [Carthage](https://github.com/Carthage/Carthage), add the following to your `Cartfile`:
@@ -81,9 +105,14 @@ For [Carthage](https://github.com/Carthage/Carthage), add the following to your
 github "scenee/FloatingPanel"
 ```
 
+### Swift Package Manager with Xcode 11
+
+Follow [this doc](https://developer.apple.com/documentation/swift_packages/adding_package_dependencies_to_your_app).
 
 ## Getting Started
 
+### Add a floating panel as a child view controller
+
 ```swift
 import UIKit
 import FloatingPanel
@@ -112,15 +141,113 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
 
     override func viewWillDisappear(_ animated: Bool) {
         super.viewWillDisappear(animated)
+
         // Remove the views managed by the `FloatingPanelController` object from self.view.
         fpc.removePanelFromParent()
     }
-    ...
 }
 ```
 
+### Present a floating panel as a modality
+
+```swift
+let fpc = FloatingPanelController()
+let contentVC = ...
+fpc.set(contentViewController: contentVC)
+
+fpc.isRemovalInteractionEnabled = true // Optional: Let it removable by a swipe-down
+
+self.present(fpc, animated: true, completion: nil)
+```
+
+You can show a floating panel over UINavigationController from the container view controllers as a modality of `.overCurrentContext` style.
+
+✏️ FloatingPanelController has the custom presentation controller. If you would like to customize the presentation/dismissal, please see [FloatingPanelTransitioning](https://github.com/SCENEE/FloatingPanel/blob/master/Framework/Sources/FloatingPanelTransitioning.swift).
+
+## View hierarchy
+
+`FloatingPanelController` manages the views as the following view hierarchy.
+
+```
+FloatingPanelController.view (FloatingPanelPassThroughView)
+ ├─ .backdropView (FloatingPanelBackdropView)
+ └─ .surfaceView (FloatingPanelSurfaceView)
+    ├─ .containerView (UIView)
+    │  └─ .contentView (FloatingPanelController.contentViewController.view)
+    └─ .grabberHandle (GrabberHandleView)
+```
+
 ## Usage
 
+### Show/Hide a floating panel in a view with your view hierarchy
+
+If you need more control over showing and hiding the floating panel, you can forgo the `addPanel` and `removePanelFromParent` methods. These methods are a convenience wrapper for **FloatingPanel**'s `show` and `hide` methods along with some required setup.
+
+There are two ways to work with the `FloatingPanelController`:
+1. Add it to the hierarchy once and then call `show` and `hide` methods to make it appear/disappear.
+2. Add it to the hierarchy when needed and remove afterwards.
+
+The following example shows how to add the controller to your `UIViewController` and how to remove it. Make sure that you never add the same `FloatingPanelController` to the hierarchy before removing it.
+
+**NOTE**: `self.` prefix is not required, nor recommended. It's used here to make it clearer where do the functions used come from. `self` is an instance of a custom UIViewController in your code.
+
+```swift
+// Add the floating panel view to the controller's view on top of other views.
+self.view.addSubview(fpc.view)
+
+// REQUIRED. It makes the floating panel view have the same size as the controller's view.
+fpc.view.frame = self.view.bounds
+
+// In addition, Auto Layout constraints are highly recommended.
+// Constraint the fpc.view to all four edges of your controller's view.
+// It makes the layout more robust on trait collection change.
+fpc.view.translatesAutoresizingMaskIntoConstraints = false
+NSLayoutConstraint.activate([
+  fpc.view.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 0.0),
+  fpc.view.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 0.0),
+  fpc.view.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: 0.0),
+  fpc.view.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: 0.0),
+])
+
+// Add the floating panel controller to the controller hierarchy.
+self.addChild(fpc)
+
+// Show the floating panel at the initial position defined in your `FloatingPanelLayout` object.
+fpc.show(animated: true) {
+    // Inform the floating panel controller that the transition to the controller hierarchy has completed.
+    fpc.didMove(toParent: self)
+}
+```
+
+After you add the `FloatingPanelController` as seen above, you can call `fpc.show(animated: true) { }` to show the panel and `fpc.hide(animated: true) { }` to hide it.
+
+To remove the `FloatingPanelController` from the hierarchy, follow the example below.
+
+```swift
+// Inform the panel controller that it will be removed from the hierarchy.
+fpc.willMove(toParent: nil)
+    
+// Hide the floating panel.
+fpc.hide(animated: true) {
+    // Remove the floating panel view from your controller's view.
+    fpc.view.removeFromSuperview()
+    // Remove the floating panel controller from the controller hierarchy.
+    fpc.removeFromParent()
+}
+```
+
+### Scale the content view when the surface position changes
+
+Specify the `contentMode` to `.fitToBounds` if the surface height fits the bounds of `FloatingPanelController.view` when the surface position changes
+
+```swift
+fpc.contentMode = .fitToBounds
+```
+
+Otherwise, `FloatingPanelController` fixes the content by the height of the top most position.
+
+✏️ In `.fitToBounds` mode, the surface height changes as following a user interaction so that you have a responsibility to configure Auto Layout constrains not to break the layout of a content view by the elastic surface height.
+
 ### Customize the layout with `FloatingPanelLayout` protocol
 
 #### Change the initial position and height
@@ -131,7 +258,6 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
     func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
         return MyFloatingPanelLayout()
     }
-    ...
 }
 
 class MyFloatingPanelLayout: FloatingPanelLayout {
@@ -144,6 +270,7 @@ class MyFloatingPanelLayout: FloatingPanelLayout {
             case .full: return 16.0 // A top inset from safe area
             case .half: return 216.0 // A bottom inset from the safe area
             case .tip: return 44.0 // A bottom inset from the safe area
+            default: return nil // Or `case .hidden: return nil`
         }
     }
 }
@@ -157,7 +284,6 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
     func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
         return (newCollection.verticalSizeClass == .compact) ? FloatingPanelLandscapeLayout() : nil // Returning nil indicates to use the default layout
     }
-    ...
 }
 
 class FloatingPanelLandscapeLayout: FloatingPanelLayout {
@@ -178,13 +304,61 @@ class FloatingPanelLandscapeLayout: FloatingPanelLayout {
 
     public func prepareLayout(surfaceView: UIView, in view: UIView) -> [NSLayoutConstraint] {
         return [
-            surfaceView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuid.leftAnchor, constant: 8.0),
+            surfaceView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor, constant: 8.0),
             surfaceView.widthAnchor.constraint(equalToConstant: 291),
         ]
     }
 }
 ```
 
+#### Use Intrinsic height layout
+
+1. Lay out your content View with the intrinsic height size. For example, see "Detail View Controller scene"/"Intrinsic View Controller scene" of [Main.storyboard](https://github.com/SCENEE/FloatingPanel/blob/master/Examples/Samples/Sources/Base.lproj/Main.storyboard). The 'Stack View.bottom' constraint determines the intrinsic height.
+2. Create a layout that adopts and conforms to `FloatingPanelIntrinsicLayout` and use it.
+
+```swift
+class ViewController: UIViewController, FloatingPanelControllerDelegate {
+    ...
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return RemovablePanelLayout()
+    }
+}
+
+class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
+    var supportedPositions: Set<FloatingPanelPosition> {
+        return [.full, .half]
+    }
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .half: return 130.0
+        default: return nil  // Must return nil for .full
+        }
+    }
+    ...
+}
+```
+
+#### Specify position insets from the frame of `FloatingPanelController.view`, not the SafeArea
+
+There are 2 ways. One is returning `.fromSuperview` for `FloatingPanelLayout.positionReference` in your layout.
+
+```swift
+class MyFullScreenLayout: FloatingPanelLayout {
+    ...
+    var positionReference: FloatingPanelLayoutReference {
+        return .fromSuperview
+    }
+}
+```
+
+Another is using `FloatingPanelFullScreenLayout` protocol.
+
+```swift
+class MyFullScreenLayout: FloatingPanelFullScreenLayout {
+    ...
+}
+```
+
 ### Customize the behavior with `FloatingPanelBehavior` protocol
 
 #### Modify your floating panel's interaction
@@ -195,90 +369,136 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
     func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
         return FloatingPanelStocksBehavior()
     }
-    ...
 }
-...
 
 class FloatingPanelStocksBehavior: FloatingPanelBehavior {
-    var velocityThreshold: CGFloat {
-        return 15.0
-    }
-
+    ...
     func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
         let damping = self.damping(with: velocity)
         let springTiming = UISpringTimingParameters(dampingRatio: damping, initialVelocity: velocity)
         return UIViewPropertyAnimator(duration: 0.5, timingParameters: springTiming)
     }
-    ...
 }
 ```
 
-### Use a custom grabber handle
+#### Activate the rubber-band effect on the top/bottom edges
 
 ```swift
-class ViewController: UIViewController {
+class FloatingPanelBehavior: FloatingPanelBehavior {
     ...
-    override func viewDidLoad() {
-        ...
-        let myGrabberHandleView = MyGrabberHandleView()
-        fpc.surfaceView.grabberHandle.isHidden = true
-        fpc.surfaceView.addSubview(myGrabberHandleView)
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
+        return true
     }
-    ...
 }
 ```
 
-### Add tap gestures to the surface or backdrop views
+#### Manage the projection of a pan gesture momentum
+
+This allows full projectional panel behavior. For example, a user can swipe up a panel from tip to full nearby the tip position.
 
 ```swift
-class ViewController: UIViewController, FloatingPanelControllerDelegate {
+class FloatingPanelBehavior: FloatingPanelBehavior {
     ...
-    override func viewDidLoad() {
-        ...
-        surfaceTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSurface(tapGesture:)))
-        fpc.surfaceView.addGestureRecognizer(surfaceTapGesture)
-
-        backdropTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
-        fpc.backdropView.addGestureRecognizer(backdropTapGesture)
-
-        surfaceTapGesture.isEnabled = (fpc.position == .tip)
-        ...
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
+        return true
     }
+}
+```
+
+### Customize the surface design
+
+#### Use a custom grabber handle
+
+```swift
+let myGrabberHandleView = MyGrabberHandleView()
+fpc.surfaceView.grabberHandle.isHidden = true
+fpc.surfaceView.addSubview(myGrabberHandleView)
+```
+
+#### Customize layout of the grabber handle
+
+```swift
+fpc.surfaceView.grabberTopPadding = 10.0
+fpc.surfaceView.grabberHandleWidth = 44.0
+fpc.surfaceView.grabberHandleHeight = 12.0
+```
+
+#### Customize content padding from surface edges
+
+```swift
+fpc.surfaceView.contentInsets = .init(top: 20, left: 20, bottom: 20, right: 20)
+```
+
+#### Customize margins of the surface edges
+
+```swift
+fpc.surfaceView.containerMargins = .init(top: 20.0, left: 16.0, bottom: 16.0, right: 16.0)
+```
+
+The feature can be used for these 2 kind panels
+
+* Facebook/Slack-like panel whose surface top edge is separated from the grabber handle.
+* iOS native panel to display AirPods information, for example.
+
+### Customize gestures
+
+#### Suppress the panel interaction
+
+You can disable the pan gesture recognizer directly
+
+```swift
+fpc.panGestureRecognizer.isEnable = false
+```
+
+Or use this `FloatingPanelControllerDelegate` method.
+
+```swift
+func floatingPanelShouldBeginDragging(_ vc: FloatingPanelController) -> Bool {
+    return aCondition ?  false : true
+}
+```
+
+#### Add tap gestures to the surface or backdrop views
+
+```swift
+override func viewDidLoad() {
     ...
-    // Enable `surfaceTapGesture` only at `tip` position
-    func floatingPanelDidChangePosition(_ vc: FloatingPanelController) {
-        surfaceTapGesture.isEnabled = (vc.position == .tip)
-    }
+    surfaceTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSurface(tapGesture:)))
+    fpc.surfaceView.addGestureRecognizer(surfaceTapGesture)
+
+    backdropTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
+    fpc.backdropView.addGestureRecognizer(backdropTapGesture)
+
+    surfaceTapGesture.isEnabled = (fpc.position == .tip)
+}
+
+// Enable `surfaceTapGesture` only at `tip` position
+func floatingPanelDidChangePosition(_ vc: FloatingPanelController) {
+    surfaceTapGesture.isEnabled = (vc.position == .tip)
 }
 ```
 
 ### Create an additional floating panel for a detail
 
 ```swift
-class ViewController: UIViewController, FloatingPanelControllerDelegate {
-    var searchPanelVC: FloatingPanelController!
-    var detailPanelVC: FloatingPanelController!
+override func viewDidLoad() {
+    // Setup Search panel
+    self.searchPanelVC = FloatingPanelController()
 
-    override func viewDidLoad() {
-        // Setup Search panel
-        self.searchPanelVC = FloatingPanelController()
+    let searchVC = SearchViewController()
+    self.searchPanelVC.set(contentViewController: searchVC)
+    self.searchPanelVC.track(scrollView: contentVC.tableView)
 
-        let searchVC = SearchViewController()
-        self.searchPanelVC.set(contentViewController: searchVC)
-        self.searchPanelVC.track(scrollView: contentVC.tableView)
+    self.searchPanelVC.addPanel(toParent: self)
 
-        self.searchPanelVC.addPanel(toParent: self)
+    // Setup Detail panel
+    self.detailPanelVC = FloatingPanelController()
 
-        // Setup Detail panel
-        self.detailPanelVC = FloatingPanelController()
+    let contentVC = ContentViewController()
+    self.detailPanelVC.set(contentViewController: contentVC)
+    self.detailPanelVC.track(scrollView: contentVC.scrollView)
 
-        let contentVC = ContentViewController()
-        self.detailPanelVC.set(contentViewController: contentVC)
-        self.detailPanelVC.track(scrollView: contentVC.scrollView)
-
-        self.detailPanelVC.addPanel(toParent: self)
-    }
-    ...
+    self.detailPanelVC.addPanel(toParent: self)
 }
 ```
 
@@ -287,15 +507,15 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
 In the following example, I move a floating panel to full or half position while opening or closing a search bar like Apple Maps.
 
 ```swift
-    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
-        ...
-        fpc.move(to: .half, animated: true)
-    }
+func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
+    ...
+    fpc.move(to: .half, animated: true)
+}
 
-    func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
-        ...
-        fpc.move(to: .full, animated: true)
-    }
+func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
+    ...
+    fpc.move(to: .full, animated: true)
+}
 ```
 
 ### Work your contents together with a floating panel behavior
@@ -315,7 +535,6 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
             searchVC.hideHeader()
         }
     }
-    ...
 }
 ```
 
@@ -323,7 +542,7 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
 
 ### 'Show' or 'Show Detail' Segues from `FloatingPanelController`'s content view controller
 
-'Show' or 'Show Detail' segues from a content view controller will be managed by a view controller(hereinafter called 'master VC') adding a floating panel. Because a floating panel is just a subview of the master VC.
+'Show' or 'Show Detail' segues from a content view controller will be managed by a view controller(hereinafter called 'master VC') adding a floating panel. Because a floating panel is just a subview of the master VC(except for modality).
 
 `FloatingPanelController` has no way to manage a stack of view controllers like `UINavigationController`. If so, it would be so complicated and the interface will become `UINavigationController`. This component should not have the responsibility to manage the stack.
 
@@ -346,17 +565,22 @@ class ViewController: UIViewController {
 
         secondFpc.addPanel(toParent: self)
     }
-    ...
 }
 ```
 
-A `FloatingPanelController` object proxies an action for `show(_:sender)` to the master VC. That's why the master VC can handle a destination view controller of a 'Show' or 'Show Detail' segue and you can hook `show(_:sender)` to show a secondally floating panel set the destination view controller to the content.
+A `FloatingPanelController` object proxies an action for `show(_:sender)` to the master VC. That's why the master VC can handle a destination view controller of a 'Show' or 'Show Detail' segue and you can hook `show(_:sender)` to show a secondary floating panel set the destination view controller to the content.
 
 It's a great way to decouple between a floating panel and the content VC.
 
+### UISearchController issue
+
+`UISearchController` isn't able to be used with `FloatingPanelController` by the system design.
+
+Because `UISearchController` automatically presents itself modally when a user interacts with the search bar, and then it swaps the superview of the search bar to the view managed by itself while it displays. As a result, `FloatingPanelController` can't control the search bar when it's active, as you can see from [the screen shot](https://github.com/SCENEE/FloatingPanel/issues/248#issuecomment-521263831).
+
 ### FloatingPanelSurfaceView's issue on iOS 10
 
-* On iOS 10,   `FloatingPanelSurfaceView.cornerRadius` isn't not automatically masked with the top rounded corners  because of UIVisualEffectView issue. See https://forums.developer.apple.com/thread/50854. 
+* On iOS 10, `FloatingPanelSurfaceView.cornerRadius` isn't not automatically masked with the top rounded corners  because of `UIVisualEffectView` issue. See https://forums.developer.apple.com/thread/50854. 
 So you need to draw top rounding corners of your content.  Here is an example in Examples/Maps.
 ```swift
 override func viewDidLayoutSubviews() {
@@ -367,11 +591,11 @@ override func viewDidLayoutSubviews() {
     }
 }
 ```
-* If you sets clear color to `FloatingPanelSurfaceView.backgroundColor`, please note the bottom overflow of your content on bouncing at full position. To prevent it, you need to expand your content. For example, See Example/Maps's Auto Layout settings of UIVisualEffectView in Main.storyborad.
+* If you sets clear color to `FloatingPanelSurfaceView.backgroundColor`, please note the bottom overflow of your content on bouncing at full position. To prevent it, you need to expand your content. For example, See Example/Maps App's Auto Layout settings of `UIVisualEffectView` in Main.storyboard.
 
 ## Author
 
-Shin Yamamoto <shin@scenee.com>
+Shin Yamamoto <shin@scenee.com> | [@scenee](https://twitter.com/scenee)
 
 ## License