ignore .swiftpm/ folder (#324)

fixes floatingPanel(_ vc: FloatingPanelController, contentOffsetForPinning) name

.github/ISSUE_TEMPLATE.md

@@ -2,7 +2,7 @@
 >
 > Please remove this line and everything above it before submitting.
 
-### Short description
+### Description
 
 ### Expected behavior
 
@@ -12,16 +12,29 @@
 
 **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
-- [ ] Git submodules
-
+* CocoaPods
+* Carthage
+* Swift Package Manager
+ 
 **iOS version(s)**
 
+
 **Xcode version**
+

.gitignore

@@ -30,6 +30,9 @@ xcuserdata/
 *.dSYM.zip
 *.dSYM
 
+## Swift Package Manager Specific
+.swiftpm/
+
 ## Playgrounds
 timeline.xctimeline
 playground.xcworkspace

.travis.yml

@@ -22,22 +22,40 @@ jobs:
     osx_image: xcode10
     name: "Swift 4.2"
   - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.0 clean build
-    osx_image: xcode10.2
+    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: xcode10.2
+    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: xcode10.2
+    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: xcode10.2
+    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: xcode10.2
+    osx_image: xcode11
     before_install:
     - brew update
     - brew outdated carthage || brew upgrade carthage
@@ -45,18 +63,9 @@ jobs:
     - carthage build --no-skip-current
 
   - stage: CocoaPods
-    osx_image: xcode10.2
+    osx_image: xcode11
+    before_install: 
+    - gem install cocoapods
     script:
-    - pod spec lint
-    - pod lib lint
-
-  - stage: Build examples
-    osx_image: xcode10.2
-    script: xcodebuild -scheme Maps -sdk iphonesimulator clean build
-    name: "Maps"
-  - script: xcodebuild -scheme Stocks -sdk iphonesimulator clean build
-    osx_image: xcode10.2
-    name: "Stocks"
-  - script: xcodebuild -scheme Samples -sdk iphonesimulator clean build
-    osx_image: xcode10.2
-    name: "Samples"
+    - 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>";
 		};

Examples/Maps/Maps/ViewController.swift

@@ -107,6 +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) {
@@ -148,11 +149,9 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl
         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() {
@@ -179,7 +178,7 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl
     }
 
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return 2
+        return 100
     }
 
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
@@ -190,12 +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
@@ -274,3 +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 */
@@ -169,7 +161,7 @@
 				545DB9E621511E6300CA77B8 /* Sources */,
 				545DB9E721511E6300CA77B8 /* Frameworks */,
 				545DB9E821511E6300CA77B8 /* Resources */,
-				54B5111C216C3B300033A6F3 /* Embed Frameworks */,
+				549D23CD233C7779008EF4D7 /* Embed Frameworks */,
 			);
 			buildRules = (
 			);
@@ -302,7 +294,7 @@
 			);
 			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";
+			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 */
 

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="retina5_9" 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>
@@ -13,7 +11,7 @@
         <!--Navigation Controller-->
         <scene sceneID="Cjh-iX-VQw">
             <objects>
-                <navigationController id="RoN-h0-uBD" sceneMemberID="viewController">
+                <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"/>
@@ -35,18 +33,18 @@
                         <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="778"/>
+                                <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="43.666666666666664"/>
+                                            <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="43.666666666666664"/>
+                                                    <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"/>
@@ -62,7 +60,7 @@
                         <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="39L-Nq-qfp" secondAttribute="leading" id="Z6Y-Dc-cei"/>
-                            <constraint firstItem="7IS-PU-x0P" firstAttribute="bottom" secondItem="39L-Nq-qfp" secondAttribute="bottom" id="fNW-DP-lhV"/>
+                            <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="39L-Nq-qfp"/>
@@ -87,35 +85,35 @@
             <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="197.33000000000001"/>
+                        <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="147.33333333333334"/>
+                                <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="17"/>
+                                        <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="33" width="130" height="20.333333333333329"/>
+                                        <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="69.333333333333329" width="264.33333333333326" height="31"/>
+                                        <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="5.3333333333333428" width="89.333333333333329" height="20.333333333333332"/>
+                                                <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="215.33333333333334" y="0.0" width="51.000000000000028" height="31"/>
+                                                <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>
@@ -123,16 +121,16 @@
                                         </subviews>
                                     </stackView>
                                     <stackView opaque="NO" contentMode="scaleToFill" spacing="126" translatesAutoresizingMaskIntoConstraints="NO" id="ZtZ-Dz-4cC">
-                                        <rect key="frame" x="23.333333333333343" y="116.33333333333334" width="264.66666666666663" height="31"/>
+                                        <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="31"/>
+                                                <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="31"/>
+                                                <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>
@@ -309,22 +307,22 @@
             <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="778"/>
+                        <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="744" width="375" height="34"/>
+                                <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="44" 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="139.66666666666666" y="132" 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"/>
@@ -347,8 +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"/>
@@ -517,7 +522,7 @@
                                 </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="700"/>
+                                <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">
@@ -530,6 +535,23 @@
                                     <action selector="closeWithSender:" destination="YC8-ae-15L" eventType="touchUpInside" id="Z2v-19-S5k"/>
                                 </connections>
                             </button>
+                            <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="130.66666666666666" y="132" width="114" height="134"/>
                                 <subviews>
@@ -570,9 +592,11 @@
                             <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="aOK-7l-cA6"/>
                         <connections>
@@ -584,6 +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>
@@ -604,7 +630,7 @@
                     </connections>
                 </pongPressGestureRecognizer>
             </objects>
-            <point key="canvasLocation" x="655" y="734"/>
+            <point key="canvasLocation" x="653.60000000000002" y="733.74384236453204"/>
         </scene>
         <!--Debug Text View Controller-->
         <scene sceneID="Bkq-O7-q4A">

Examples/Samples/Sources/ViewController.swift

@@ -17,13 +17,17 @@ class SampleListViewController: UIViewController {
         case trackingTextView
         case showDetail
         case showModal
-        case showFloatingPanelModal
+        case showPanelModal
+        case showMultiPanelModal
         case showTabBar
         case showPageView
+        case showPageContentView
         case showNestedScrollView
         case showRemovablePanel
         case showIntrinsicView
         case showContentInset
+        case showContainerMargins
+        case showNavigationController
 
         var name: String {
             switch self {
@@ -31,13 +35,17 @@ class SampleListViewController: UIViewController {
             case .trackingTextView: return "Scroll tracking(TextView)"
             case .showDetail: return "Show Detail Panel"
             case .showModal: return "Show Modal"
-            case .showFloatingPanelModal: return "Show Floating Panel Modal"
+            case .showPanelModal: return "Show Panel Modal"
+            case .showMultiPanelModal: return "Show Multi Panel Modal"
             case .showTabBar: return "Show Tab Bar"
             case .showPageView: return "Show Page View"
+            case .showPageContentView: return "Show Page Content View"
             case .showNestedScrollView: return "Show Nested ScrollView"
             case .showRemovablePanel: return "Show Removable Panel"
             case .showIntrinsicView: return "Show Intrinsic View"
             case .showContentInset: return "Show with ContentInset"
+            case .showContainerMargins: return "Show with ContainerMargins"
+            case .showNavigationController: return "Show Navigation Controller"
             }
         }
 
@@ -47,13 +55,17 @@ class SampleListViewController: UIViewController {
             case .trackingTextView: return "ConsoleViewController"
             case .showDetail: return "DetailViewController"
             case .showModal: return "ModalViewController"
-            case .showFloatingPanelModal: return nil
+            case .showMultiPanelModal: return nil
+            case .showPanelModal: return nil
             case .showTabBar: return "TabBarViewController"
             case .showPageView: return nil
+            case .showPageContentView: return nil
             case .showNestedScrollView: return "NestedScrollViewController"
             case .showRemovablePanel: return "DetailViewController"
             case .showIntrinsicView: return "IntrinsicViewController"
             case .showContentInset: return nil
+            case .showContainerMargins: return nil
+            case .showNavigationController: return "RootNavigationController"
             }
         }
     }
@@ -67,24 +79,14 @@ class SampleListViewController: UIViewController {
     var mainPanelObserves: [NSKeyValueObservation] = []
     var settingsObserves: [NSKeyValueObservation] = []
 
-    lazy var pages: [UIViewController] = {
-        let page1 = FloatingPanelController(delegate: self)
-        page1.view.backgroundColor = .blue
-        page1.show()
-        let page2 = FloatingPanelController(delegate: self)
-        page2.view.backgroundColor = .red
-        page2.show()
-        let page3 = FloatingPanelController(delegate: self)
-        page3.view.backgroundColor = .green
-        page3.show()
-        return [page1, page2, page3]
-    }()
+    var pages: [UIViewController] = []
 
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.dataSource = self
         tableView.delegate = self
         tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
+        automaticallyAdjustsScrollViewInsets = false
 
         let searchController = UISearchController(searchResultsController: nil)
         if #available(iOS 11.0, *) {
@@ -97,11 +99,14 @@ class SampleListViewController: UIViewController {
 
         let contentVC = DebugTableViewController()
         addMainPanel(with: contentVC)
+
+        var insets = UIEdgeInsets.zero
+        insets.bottom += 69.0
+        tableView.contentInset = insets
     }
 
     override func viewDidAppear(_ animated: Bool) {
         super.viewDidAppear(animated)
-
         if #available(iOS 11.0, *) {
             if let observation = navigationController?.navigationBar.observe(\.prefersLargeTitles, changeHandler: { (bar, _) in
                 self.tableView.reloadData()
@@ -119,15 +124,15 @@ class SampleListViewController: UIViewController {
     func addMainPanel(with contentVC: UIViewController) {
         mainPanelObserves.removeAll()
 
-        // Initialize FloatingPanelController
+        let oldMainPanelVC = mainPanelVC
+
         mainPanelVC = FloatingPanelController()
         mainPanelVC.delegate = self
+        mainPanelVC.contentInsetAdjustmentBehavior = .always
 
-        // Initialize FloatingPanelController and add the view
         mainPanelVC.surfaceView.cornerRadius = 6.0
         mainPanelVC.surfaceView.shadowHidden = false
 
-        // Set a content view controller
         mainPanelVC.set(contentViewController: contentVC)
 
         // Enable tap-to-hide and removal interaction
@@ -137,11 +142,17 @@ class SampleListViewController: UIViewController {
             tapGesture.cancelsTouchesInView = false
             tapGesture.numberOfTapsRequired = 2
             mainPanelVC.surfaceView.addGestureRecognizer(tapGesture)
+        case .showPageContentView:
+            if let page = (mainPanelVC.contentViewController as? UIPageViewController)?.viewControllers?.first {
+                mainPanelVC.track(scrollView: (page as! DebugTableViewController).tableView)
+            }
         case .showRemovablePanel, .showIntrinsicView:
             mainPanelVC.isRemovalInteractionEnabled = true
 
             let backdropTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
             mainPanelVC.backdropView.addGestureRecognizer(backdropTapGesture)
+        case .showNavigationController:
+            mainPanelVC.contentInsetAdjustmentBehavior = .never
         default:
             break
         }
@@ -159,12 +170,23 @@ class SampleListViewController: UIViewController {
             mainPanelVC.track(scrollView: contentVC.tableView)
         case let contentVC as NestedScrollViewController:
             mainPanelVC.track(scrollView: contentVC.scrollView)
+        case let navVC as UINavigationController:
+            if let rootVC = (navVC.topViewController as? SampleListViewController) {
+                rootVC.loadViewIfNeeded()
+                mainPanelVC.track(scrollView: rootVC.tableView)
+            }
         default:
             break
         }
 
         //  Add FloatingPanel to self.view
-        mainPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
+        if let oldMainPanelVC = oldMainPanelVC {
+            oldMainPanelVC.removePanelFromParent(animated: true, completion: {
+                self.mainPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
+            })
+        } else {
+            mainPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
+        }
     }
 
     @objc
@@ -251,6 +273,8 @@ extension SampleListViewController: UITableViewDelegate {
         }()
 
         self.currentMenu = menu
+        detailPanelVC?.removePanelFromParent(animated: true, completion: nil)
+        detailPanelVC = nil
 
         switch menu {
         case .showDetail:
@@ -258,6 +282,7 @@ extension SampleListViewController: UITableViewDelegate {
 
             // Initialize FloatingPanelController
             detailPanelVC = FloatingPanelController()
+            detailPanelVC.delegate = self
 
             // Initialize FloatingPanelController and add the view
             detailPanelVC.surfaceView.cornerRadius = 6.0
@@ -266,13 +291,24 @@ extension SampleListViewController: UITableViewDelegate {
             // Set a content view controller
             detailPanelVC.set(contentViewController: contentVC)
 
+            detailPanelVC.contentMode = .fitToBounds
+            (contentVC as? DetailViewController)?.intrinsicHeightConstraint.priority = .defaultLow
+
             //  Add FloatingPanel to self.view
             detailPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
         case .showModal, .showTabBar:
             let modalVC = contentVC
+            modalVC.modalPresentationStyle = .fullScreen
             present(modalVC, animated: true, completion: nil)
 
         case .showPageView:
+            pages = [UIColor.blue, .red, .green].compactMap({ (color) -> UIViewController in
+                let page = FloatingPanelController(delegate: self)
+                page.view.backgroundColor = color
+                page.show()
+                return page
+            })
+
             let pageVC = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: [:])
             let closeButton = UIButton(type: .custom)
             pageVC.view.addSubview(closeButton)
@@ -285,11 +321,21 @@ extension SampleListViewController: UITableViewDelegate {
                 ])
             pageVC.dataSource = self
             pageVC.setViewControllers([pages[0]], direction: .forward, animated: false, completion: nil)
+            pageVC.modalPresentationStyle = .fullScreen
             present(pageVC, animated: true, completion: nil)
 
-        case .showFloatingPanelModal:
+        case .showPageContentView:
+            pages = [DebugTableViewController(), DebugTableViewController(), DebugTableViewController()]
+            let pageVC = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: [:])
+            pageVC.dataSource = self
+            pageVC.delegate = self
+            pageVC.setViewControllers([pages[0]], direction: .forward, animated: false, completion: nil)
+            self.addMainPanel(with: pageVC)
+        case .showPanelModal:
             let fpc = FloatingPanelController()
             let contentVC = self.storyboard!.instantiateViewController(withIdentifier: "DetailViewController")
+            contentVC.loadViewIfNeeded()
+            (contentVC as? DetailViewController)?.modeChangeView.isHidden = true
             fpc.set(contentViewController: contentVC)
             fpc.delegate = self
 
@@ -299,23 +345,39 @@ extension SampleListViewController: UITableViewDelegate {
             fpc.isRemovalInteractionEnabled = true
 
             self.present(fpc, animated: true, completion: nil)
-            
+
+        case .showMultiPanelModal:
+            let fpc = MultiPanelController()
+            self.present(fpc, animated: true, completion: nil)
+
         case .showContentInset:
             let contentViewController = UIViewController()
             contentViewController.view.backgroundColor = .green
-            
+
             let fpc = FloatingPanelController()
             fpc.set(contentViewController: contentViewController)
-            fpc.surfaceView.contentInsets = .init(top: 20, left: 20, bottom: 0, right: 20)
-            
+            fpc.surfaceView.contentInsets = .init(top: 20, left: 20, bottom: 20, right: 20)
+
+            fpc.delegate = self
+            fpc.isRemovalInteractionEnabled = true
+            self.present(fpc, animated: true, completion: nil)
+
+        case .showContainerMargins:
+            let fpc = FloatingPanelController()
+            fpc.surfaceView.cornerRadius = 38.5
+            fpc.surfaceView.backgroundColor = .red
+            fpc.surfaceView.containerMargins = .init(top: 24.0, left: 8.0, bottom: layoutInsets.bottom, right: 8.0)
+            #if swift(>=5.1) // Actually Xcode 11 or later
+            if #available(iOS 13.0, *) {
+                fpc.surfaceView.layer.cornerCurve = .continuous
+            }
+            #endif
+
             fpc.delegate = self
             fpc.isRemovalInteractionEnabled = true
             self.present(fpc, animated: true, completion: nil)
         default:
-            detailPanelVC?.removePanelFromParent(animated: true, completion: nil)
-            mainPanelVC?.removePanelFromParent(animated: true) {
-                self.addMainPanel(with: contentVC)
-            }
+            self.addMainPanel(with: contentVC)
         }
     }
 
@@ -325,6 +387,14 @@ extension SampleListViewController: UITableViewDelegate {
 }
 
 extension SampleListViewController: FloatingPanelControllerDelegate {
+    func floatingPanel(_ vc: FloatingPanelController, contentOffsetForPinning trackedScrollView: UIScrollView) -> CGPoint {
+        if currentMenu == .showNavigationController, #available(iOSApplicationExtension 11.0, *) {
+            // 148.0 is the SafeArea's top value for a navigation bar with a large title.
+            return CGPoint(x: 0.0, y: 0.0 - trackedScrollView.contentInset.top - 148.0)
+        }
+        return CGPoint(x: 0.0, y: 0.0 - trackedScrollView.contentInset.top)
+    }
+
     func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
         if vc == settingsPanelVC {
             return IntrinsicPanelLayout()
@@ -335,13 +405,15 @@ extension SampleListViewController: FloatingPanelControllerDelegate {
             return newCollection.verticalSizeClass == .compact ? RemovablePanelLandscapeLayout() :  RemovablePanelLayout()
         case .showIntrinsicView:
             return IntrinsicPanelLayout()
-        case .showFloatingPanelModal:
+        case .showPanelModal:
             if vc != mainPanelVC && vc != detailPanelVC {
                 return ModalPanelLayout()
             }
             fallthrough
+        case .showContentInset:
+            return NoInteractionBufferPanelLayout()
         default:
-            return (newCollection.verticalSizeClass == .compact) ? nil  : self
+            return (newCollection.verticalSizeClass == .compact) ? nil : self
         }
     }
 
@@ -403,9 +475,40 @@ extension SampleListViewController: UIPageViewControllerDataSource {
         return pages[index - 1]
     }
 }
+extension SampleListViewController: UIPageViewControllerDelegate {
+    // For showPageContent
+    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
+        if completed, let page = pageViewController.viewControllers?.first {
+            (pageViewController.parent as! FloatingPanelController).track(scrollView: (page as! DebugTableViewController).tableView)
+        }
+    }
+}
 
 class IntrinsicPanelLayout: FloatingPanelIntrinsicLayout { }
 
+class NoInteractionBufferPanelLayout: FloatingPanelLayout {
+    var initialPosition: FloatingPanelPosition {
+        return .full
+    }
+
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .full: return 0
+        case .half: return 216
+        case .tip: return 60
+        case .hidden: return nil
+        }
+    }
+
+    var topInteractionBuffer: CGFloat {
+        return 0.0
+    }
+
+    var bottomInteractionBuffer: CGFloat {
+        return 0.0
+    }
+}
+
 class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
     var supportedPositions: Set<FloatingPanelPosition> {
         return [.full, .half]
@@ -560,7 +663,8 @@ class InspectableViewController: UIViewController {
 }
 
 class DebugTableViewController: InspectableViewController {
-    weak var tableView: UITableView!
+    lazy var tableView = UITableView(frame: .zero, style: .plain)
+    lazy var buttonStackView = UIStackView()
     var items: [String] = []
     var itemHeight: CGFloat = 66.0
 
@@ -574,8 +678,6 @@ class DebugTableViewController: InspectableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
 
-        let tableView = UITableView(frame: .zero,
-                                    style: .plain)
         view.addSubview(tableView)
         tableView.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
@@ -586,18 +688,17 @@ class DebugTableViewController: InspectableViewController {
             ])
         tableView.dataSource = self
         tableView.delegate = self
-        self.tableView = tableView
+        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
 
-        let stackView = UIStackView()
-        view.addSubview(stackView)
-        stackView.axis = .vertical
-        stackView.distribution = .fillEqually
-        stackView.alignment = .trailing
-        stackView.spacing = 10.0
-        stackView.translatesAutoresizingMaskIntoConstraints = false
+        view.addSubview(buttonStackView)
+        buttonStackView.axis = .vertical
+        buttonStackView.distribution = .fillEqually
+        buttonStackView.alignment = .trailing
+        buttonStackView.spacing = 10.0
+        buttonStackView.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
-            stackView.topAnchor.constraint(equalTo: view.topAnchor, constant: 22.0),
-            stackView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -22.0),
+            buttonStackView.topAnchor.constraint(equalTo: view.topAnchor, constant: 22.0),
+            buttonStackView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -22.0),
             ])
 
         for menu in Menu.allCases {
@@ -613,13 +714,12 @@ class DebugTableViewController: InspectableViewController {
                 button.addTarget(self, action: #selector(reorderItems), for: .touchUpInside)
                 reorderButton = button
             }
-            stackView.addArrangedSubview(button)
+            buttonStackView.addArrangedSubview(button)
         }
 
         for i in 0...100 {
             items.append("Items \(i)")
         }
-        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
     }
 
     @objc func animateScroll() {
@@ -677,6 +777,10 @@ class DebugTableViewController: InspectableViewController {
         //  Remove FloatingPanel from a view
         (self.parent as! FloatingPanelController).removePanelFromParent(animated: true, completion: nil)
     }
+
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        print("TableView --- ", scrollView.contentOffset, scrollView.contentInset)
+    }
 }
 
 extension DebugTableViewController: UITableViewDataSource {
@@ -719,6 +823,8 @@ extension DebugTableViewController: UITableViewDelegate {
 }
 
 class DetailViewController: InspectableViewController {
+    @IBOutlet weak var modeChangeView: UIStackView!
+    @IBOutlet weak var intrinsicHeightConstraint: NSLayoutConstraint!
     @IBOutlet weak var closeButton: UIButton!
     @IBAction func close(sender: UIButton) {
         // (self.parent as? FloatingPanelController)?.removePanelFromParent(animated: true, completion: nil)
@@ -735,6 +841,10 @@ class DetailViewController: InspectableViewController {
             break
         }
     }
+    @IBAction func modeChanged(_ sender: Any) {
+        guard let fpc = parent as? FloatingPanelController else { return }
+        fpc.contentMode = (fpc.contentMode == .static) ? .fitToBounds : .static
+    }
 
     @IBAction func tapped(_ sender: Any) {
         print("Detail panel is tapped!")
@@ -795,7 +905,9 @@ class ModalViewController: UIViewController, FloatingPanelControllerDelegate {
     @IBAction func moveToTip(sender: UIButton) {
         fpc.move(to: .tip, animated: true)
     }
-
+    @IBAction func moveToHidden(sender: UIButton) {
+        fpc.move(to: .hidden, animated: true)
+    }
     @IBAction func updateLayout(_ sender: Any) {
         isNewlayout = !isNewlayout
         UIView.animate(withDuration: 0.5) {
@@ -933,7 +1045,7 @@ extension TabBarContentViewController: UITextViewDelegate {
         // Using KVO of `scrollView.contentOffset`). Because it can lead to an
         // infinite loop if a user also resets a content offset as below and,
         // in the situation, a user has to modify the library.
-        if fpc.position != .full, fpc.surfaceView.frame.minY < fpc.originYOfSurface(for: .full) {
+        if fpc.position != .full, fpc.surfaceView.frame.minY > fpc.originYOfSurface(for: .full) {
             scrollView.contentOffset = .zero
         }
     }
@@ -1102,8 +1214,8 @@ class TwoTabBarPanelLayout: FloatingPanelLayout {
 }
 
 class TwoTabBarPanelBehavior: FloatingPanelBehavior {
-    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
-        return (edge == .bottom || edge == .top)
+    func allowsRubberBanding(for edges: UIRectEdge) -> Bool {
+        return [UIRectEdge.top, UIRectEdge.bottom].contains(edges)
     }
 }
 
@@ -1182,3 +1294,72 @@ class SettingsViewController: InspectableViewController {
         navigationController?.navigationBar.isTranslucent = sender.isOn
     }
 }
+
+// MARK -: Multi Panel
+
+import WebKit
+final class MultiPanelController: FloatingPanelController, FloatingPanelControllerDelegate {
+
+    private final class FirstPanelContentViewController: UIViewController {
+
+        lazy var webView: WKWebView = WKWebView()
+
+        override func viewDidLoad() {
+            super.viewDidLoad()
+            view.addSubview(webView)
+            webView.frame = view.bounds
+            webView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+            webView.load(URLRequest(url: URL(string: "https://www.apple.com")!))
+
+            let vc = MultiSecondPanelController()
+            vc.setUpContent()
+            vc.addPanel(toParent: self)
+        }
+    }
+
+    private final class MultiSecondPanelController: FloatingPanelController {
+
+        private final class SecondPanelContentViewController: DebugTableViewController {}
+
+        func setUpContent() {
+            contentInsetAdjustmentBehavior = .never
+            let vc = SecondPanelContentViewController()
+            vc.loadViewIfNeeded()
+            vc.title = "Second Panel"
+            vc.buttonStackView.isHidden = true
+            let navigationController = UINavigationController(rootViewController: vc)
+            navigationController.navigationBar.barTintColor = .white
+            navigationController.navigationBar.titleTextAttributes = [
+                .foregroundColor: UIColor.black
+            ]
+            set(contentViewController: navigationController)
+            self.track(scrollView: vc.tableView)
+            surfaceView.containerMargins = .init(top: 24.0, left: 0.0, bottom: layoutInsets.bottom, right: 0.0)
+        }
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        delegate = self
+        isRemovalInteractionEnabled = true
+
+        let vc = FirstPanelContentViewController()
+        set(contentViewController: vc)
+        track(scrollView: vc.webView.scrollView)
+    }
+
+    private final class FirstViewLayout: FloatingPanelLayout {
+        let initialPosition: FloatingPanelPosition = .full
+        let supportedPositions: Set<FloatingPanelPosition> = [.full]
+        func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+            switch position {
+            case .full: return 40.0
+            default: return nil
+            }
+        }
+    }
+
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return FirstViewLayout()
+    }
+}

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 */,
 			);

FloatingPanel.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name                = "FloatingPanel"
-  s.version             = "1.6.2"
+  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.
@@ -13,7 +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       = "4.0"
+  s.swift_versions      = ["4.0", "4.2", "5.0"]
 
   s.framework           = "UIKit"
 

Framework/FloatingPanel.xcodeproj/project.pbxproj

@@ -8,7 +8,6 @@
 
 /* Begin PBXBuildFile section */
 		542753C622C49A6E00D17955 /* FloatingPanelLayoutTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */; };
-		542753C822C49A8F00D17955 /* Utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C722C49A8F00D17955 /* Utils.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 */; };
@@ -18,6 +17,8 @@
 		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 */; };
@@ -25,7 +26,7 @@
 		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 */
 
@@ -61,6 +62,7 @@
 		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>"; };
@@ -68,7 +70,7 @@
 		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>"; };
@@ -127,7 +129,7 @@
 				545DB9C42151169500CA77B8 /* FloatingPanel.h */,
 				545DB9DF21511AC100CA77B8 /* FloatingPanelController.swift */,
 				54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */,
-				54CFBFC4215CD09C006B5735 /* FloatingPanel.swift */,
+				54CFBFC4215CD09C006B5735 /* FloatingPanelCore.swift */,
 				54CFBFC2215CD045006B5735 /* FloatingPanelLayout.swift */,
 				5450EEE321646DF500135936 /* FloatingPanelBehavior.swift */,
 				54352E9721A521CA00CBCA08 /* FloatingPanelView.swift */,
@@ -144,9 +146,10 @@
 			isa = PBXGroup;
 			children = (
 				54A6B6B022968B530077F348 /* FloatingPanelTests.swift */,
+				545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */,
 				542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */,
 				54A6B6B72296A8520077F348 /* FloatingPanelSurfaceViewTests.swift */,
-				545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */,
+				549E944422CF295D0050AECF /* FloatingPanelPositionTests.swift */,
 				542753C722C49A8F00D17955 /* Utils.swift */,
 				545DB9D12151169500CA77B8 /* Info.plist */,
 			);
@@ -308,14 +311,13 @@
 				54CFBFC3215CD045006B5735 /* FloatingPanelLayout.swift in Sources */,
 				54CDC5D5215B6D8D007D205C /* FloatingPanelBackdropView.swift in Sources */,
 				54352E9821A521CA00CBCA08 /* FloatingPanelView.swift in Sources */,
-				54CFBFC5215CD09C006B5735 /* FloatingPanel.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 */,
-				542753C822C49A8F00D17955 /* Utils.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -325,8 +327,10 @@
 			files = (
 				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;
 		};
@@ -480,6 +484,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				APPLICATION_EXTENSION_API_ONLY = YES;
+				BUILD_LIBRARY_FOR_DISTRIBUTION = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -510,6 +515,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				APPLICATION_EXTENSION_API_ONLY = YES;
+				BUILD_LIBRARY_FOR_DISTRIBUTION = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -698,7 +704,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanel;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
-				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "DEBUG __FP_LOG";
+				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "TEST DEBUG __FP_LOG";
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 4.0;

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

@@ -23,6 +23,11 @@ public protocol FloatingPanelBehavior {
     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.
@@ -67,14 +72,7 @@ public protocol FloatingPanelBehavior {
 
 public extension FloatingPanelBehavior {
     func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
-        switch (fpc.position, proposedTargetPosition) {
-        case (.full, .tip):
-            return false
-        case (.tip,  .full):
-            return false
-        default:
-            return true
-        }
+        return false
     }
 
     func momentumProjectionRate(_ fpc: FloatingPanelController) -> CGFloat {
@@ -134,7 +132,7 @@ public class FloatingPanelDefaultBehavior: FloatingPanelBehavior {
     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

@@ -12,7 +12,9 @@ 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)
 
     /// Asks the delegate if dragging should begin by the pan gesture recognizer.
     func floatingPanelShouldBeginDragging(_ vc: FloatingPanelController) -> Bool
@@ -35,6 +37,15 @@ public protocol FloatingPanelControllerDelegate: class {
     ///
     /// 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 {
@@ -60,6 +71,9 @@ public extension FloatingPanelControllerDelegate {
     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)
+    }
 }
 
 
@@ -72,18 +86,56 @@ public enum FloatingPanelPosition: Int {
     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.
 ///
-open 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?{
         didSet{
@@ -147,9 +199,23 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         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(set) var floatingPanel: FloatingPanel!
+    private(set) var floatingPanel: FloatingPanelCore!
     private var preSafeAreaInsets: UIEdgeInsets = .zero // Capture the latest one
     private var safeAreaInsetsObservation: NSKeyValueObservation?
     private let modalTransition = FloatingPanelModalTransition()
@@ -172,7 +238,7 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         modalPresentationStyle = .custom
         transitioningDelegate = modalTransition
 
-        floatingPanel = FloatingPanel(self,
+        floatingPanel = FloatingPanelCore(self,
                                       layout: fetchLayout(for: self.traitCollection),
                                       behavior: fetchBehavior(for: self.traitCollection))
     }
@@ -181,7 +247,7 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
         floatingPanel.behavior = fetchBehavior(for: self.traitCollection)
     }
-    
+
     // MARK:- Overrides
 
     /// Creates the view that the controller manages.
@@ -205,7 +271,8 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         if #available(iOS 11.0, *) {}
         else {
             // Because {top,bottom}LayoutGuide is managed as a view
-            if preSafeAreaInsets != layoutInsets {
+            if preSafeAreaInsets != layoutInsets,
+                floatingPanel.isDecelerating == false {
                 self.update(safeAreaInsets: layoutInsets)
             }
         }
@@ -230,6 +297,41 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         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 }
@@ -256,8 +358,7 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
 
     private func update(safeAreaInsets: UIEdgeInsets) {
         guard
-            preSafeAreaInsets != safeAreaInsets,
-            self.floatingPanel.isDecelerating == false
+            preSafeAreaInsets != safeAreaInsets
             else { return }
 
         log.debug("Update safeAreaInsets", safeAreaInsets)
@@ -278,7 +379,6 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
 
     private func reloadLayout(for traitCollection: UITraitCollection) {
         floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
-        floatingPanel.layoutAdapter.prepareLayout(in: self)
 
         if let parent = self.parent {
             if let layout = layout as? UIViewController, layout == parent {
@@ -291,13 +391,20 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
     }
 
     private func activateLayout() {
-        // preserve the current content offset
-        let contentOffset = scrollView?.contentOffset
+        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)
 
-        scrollView?.contentOffset = contentOffset ?? .zero
+        if let contentOffset = contentOffset {
+            scrollView?.contentOffset = contentOffset
+        }
     }
 
     // MARK: - Container view controller interface
@@ -331,7 +438,6 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
 
     /// Hides the surface view to the hidden position
     public func hide(animated: Bool = false, completion: (() -> Void)? = nil) {
-        safeAreaInsetsObservation = nil
         move(to: .hidden,
              animated: animated,
              completion: completion)
@@ -377,9 +483,9 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
         show(animated: animated) { [weak self] in
             guard let `self` = self else { return }
             #if swift(>=4.2)
-            self.didMove(toParent: self)
+            self.didMove(toParent: parent)
             #else
-            self.didMove(toParentViewController: self)
+            self.didMove(toParentViewController: parent)
             #endif
         }
     }
@@ -526,16 +632,7 @@ open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGe
 
     /// 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
-        case .hidden:
-            return floatingPanel.layoutAdapter.hiddenY
-        }
+        return floatingPanel.layoutAdapter.positionY(for: pos)
     }
 }
 

Framework/Sources/FloatingPanelCore.swift

@@ -8,7 +8,7 @@ import UIKit.UIGestureRecognizerSubclass // For Xcode 9.4.1
 ///
 /// FloatingPanel presentation model
 ///
-class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
+class FloatingPanelCore: NSObject, UIGestureRecognizerDelegate {
     // MUST be a weak reference to prevent UI freeze on the presentation modally
     weak var viewcontroller: FloatingPanelController?
 
@@ -19,8 +19,8 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
     weak var scrollView: UIScrollView? {
         didSet {
-            guard let scrollView = scrollView else { return }
-            scrollView.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
+            oldValue?.panGestureRecognizer.removeTarget(self, action: nil)
+            scrollView?.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
         }
     }
 
@@ -51,7 +51,6 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
     // Scroll handling
     private var initialScrollOffset: CGPoint = .zero
-    private var initialScrollFrame: CGRect = .zero
     private var stopScrollDeceleration: Bool = false
     private var scrollBouncable = false
     private var scrollIndictorVisible = false
@@ -82,10 +81,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         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) {
@@ -93,6 +97,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     }
 
     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
@@ -146,14 +151,19 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     // MARK: - Layout update
 
     private func updateLayout(to target: FloatingPanelPosition) {
-        self.layoutAdapter.activateLayout(of: target)
+        self.layoutAdapter.activateFixedLayout()
+        self.layoutAdapter.activateInteractiveLayout(of: target)
     }
 
-    private func getBackdropAlpha(with translation: CGPoint) -> CGFloat {
-        let currentY = surfaceView.frame.minY
+    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 next = directionalPosition(at: currentY, with: translation)
-        let pre = redirectionalPosition(at: currentY, with: translation)
         let nextY = layoutAdapter.positionY(for: next)
         let preY = layoutAdapter.positionY(for: pre)
 
@@ -181,6 +191,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         }
 
         switch otherGestureRecognizer {
+        case is FloatingPanelPanGestureRecognizer:
+            // All visiable panels' pan gesture should be recognized simultaneously.
+            return true
         case is UIPanGestureRecognizer,
              is UISwipeGestureRecognizer,
              is UIRotationGestureRecognizer,
@@ -192,13 +205,22 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         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
-            return surfaceFrame.minY == layoutAdapter.positionY(for: state)
+            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 {
-        guard gestureRecognizer == panGestureRecognizer else { return false }
         /* 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
     }
 
@@ -219,7 +241,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             // the panel's pan gesture if not returns false
             if let scrollGestureRecognizers = scrollView.gestureRecognizers,
                 scrollGestureRecognizers.contains(otherGestureRecognizer) {
-                return false
+                switch otherGestureRecognizer {
+                case scrollView.panGestureRecognizer:
+                    if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+                        return false
+                    }
+                    return allowScrollPanGesture(for: scrollView)
+                default:
+                    return false
+                }
             }
         }
 
@@ -229,6 +259,13 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         }
 
         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,
@@ -251,6 +288,14 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     }
 
     // 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)
 
@@ -260,14 +305,17 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
             let location = panGesture.location(in: surfaceView)
 
-            let belowTop = surfaceView.frame.minY > layoutAdapter.topY
-
+            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 {
@@ -284,22 +332,43 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
                     scrollView.setContentOffset(initialScrollOffset, animated: false)
                 }
 
-                // Always hide a scroll indicator at the non-top.
+                // Hide a scroll indicator at the non-top in dragging.
                 if interactionInProgress {
                     lockScrollView()
-                }
-            } else {
-                let offset = scrollView.contentOffset.y - scrollView.contentOffsetZero.y
-                // Always show a scroll indicator at the top.
-                if interactionInProgress {
-                    if offset > 0 {
+                } 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 {
-                    // Hide a scroll indicator just before starting an interaction by swiping a panel down.
-                    if state == layoutAdapter.topMostState,
-                        offset < 0, velocity.y > 0 {
-                        lockScrollView()
+                    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)
+                        }
                     }
                 }
             }
@@ -310,24 +379,26 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             log.debug("panel gesture(\(state):\(panGesture.state)) --",
                 "translation =  \(translation.y), location = \(location.y), velocity = \(velocity.y)")
 
-            if let animator = self.animator {
-                log.debug("panel animation interrupted!!!")
-                if animator.isInterruptible {
-                    animator.stopAnimation(false)
-                    animator.finishAnimation(at: .current)
-                }
-                self.animator = nil
-
-                // A user can stop a panel at the nearest Y of a target position
-                if abs(surfaceView.frame.minY - layoutAdapter.topY) < 1.0 {
-                    surfaceView.frame.origin.y = layoutAdapter.topY
-                }
+            if interactionInProgress == false, isDecelerating == false,
+                let vc = viewcontroller, vc.delegate?.floatingPanelShouldBeginDragging(vc) == false {
+                return
             }
 
-            if interactionInProgress == 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 {
@@ -346,6 +417,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
                 }
                 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
@@ -384,14 +464,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             return true
         }
 
+        let scrollViewFrame = scrollView.convert(scrollView.bounds, to: surfaceView)
         guard
-            scrollView.frame.contains(initialLocation), // When initialLocation not in scrollView, don't scroll.
+            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 - scrollView.contentOffsetZero.y
+        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 {
@@ -413,30 +494,31 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         // 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 let scrollView = scrollView {
-                initialScrollFrame = scrollView.frame
-            }
-        } else {
-            if let scrollView = scrollView {
+            if grabberAreaFrame.contains(location) {
                 initialScrollOffset = scrollView.contentOffset
             }
+        } else {
+            initialScrollOffset = scrollView.contentOffset
         }
     }
 
     private func panningChange(with translation: CGPoint) {
         log.debug("panningChange -- translation = \(translation.y)")
-        let pre = surfaceView.frame.minY
+        let preY = surfaceView.frame.minY
         let dy = translation.y - initialTranslationY
 
         layoutAdapter.updateInteractiveTopConstraint(diff: dy,
                                                      allowsTopBuffer: allowsTopBuffer(for: dy),
                                                      with: behavior)
 
-        backdropView.alpha = getBackdropAlpha(with: translation)
+        let currentY = surfaceView.frame.minY
+        backdropView.alpha = getBackdropAlpha(at: currentY, with: translation)
         preserveContentVCLayoutIfNeeded()
 
-        let didMove = (pre != surfaceView.frame.minY)
+        let didMove = (preY != currentY)
         guard didMove else { return }
 
         if let vc = viewcontroller {
@@ -456,21 +538,27 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     }
 
     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
                     }
@@ -479,7 +567,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             disabledBottomAutoLayout = true
         } else {
             if disabledBottomAutoLayout {
-                vc.contentViewController?.view?.constraints.forEach({ (const) in
+                disabledAutoLayoutItems.forEach({ (const) in
                     switch vc.contentViewController?.layoutGuide.bottomAnchor {
                     case const.firstAnchor:
                         (const.secondItem as? UIView)?.enableAutoLayout()
@@ -491,6 +579,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
                         break
                     }
                 })
+                disabledAutoLayoutItems.removeAll()
             }
             disabledBottomAutoLayout = false
         }
@@ -504,7 +593,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             return
         }
 
-        stopScrollDeceleration = (surfaceView.frame.minY > layoutAdapter.topY) // Projecting the dragging to the scroll dragging or not
+        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 }
@@ -512,24 +601,37 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             }
         }
 
-        let targetPosition = self.targetPosition(with: velocity)
+        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(abs(velocity.y)/distance, behavior.removalVelocity)) : .zero
-
+            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)
-                startRemovalAnimation(vc, with: velocityVector) { [weak self] in
+                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)
         }
@@ -552,12 +654,12 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     private func shouldStartRemovalAnimation(with velocityVector: CGVector) -> Bool {
         let posY = layoutAdapter.positionY(for: state)
         let currentY = surfaceView.frame.minY
-        let bottomMaxY = layoutAdapter.bottomMaxY
+        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 = (bottomMaxY - posY)
+        let den = (hiddenY - posY)
 
         guard num >= 0, den != 0, (num / den >= pth || velocityVector.dy == vth)
         else { return false }
@@ -569,6 +671,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         let animator = behavior.removalInteractionAnimator(vc, with: velocityVector)
 
         animator.addAnimations { [weak self] in
+            self?.state = .hidden
             self?.updateLayout(to: .hidden)
         }
         animator.addCompletion({ _ in
@@ -591,14 +694,19 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         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 {
-                fitToBounds(scrollView: scrollView)
-                settle(scrollView: scrollView)
-                initialScrollOffset = scrollView.contentOffsetZero
+                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)
         }
@@ -609,9 +717,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             vc.delegate?.floatingPanelWillBeginDragging(vc)
         }
 
-        layoutAdapter.startInteraction(at: state)
+        layoutAdapter.startInteraction(at: state, offset: offset)
 
         interactionInProgress = true
+
+        lockScrollView()
     }
 
     private func endInteraction(for targetPosition: FloatingPanelPosition) {
@@ -624,7 +734,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         interactionInProgress = false
 
         // Prevent to keep a scroll view indicator visible at the half/tip position
-        if state != layoutAdapter.topMostState {
+        if targetPosition != layoutAdapter.topMostState {
             lockScrollView()
         }
 
@@ -645,24 +755,38 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
         vc.delegate?.floatingPanelWillBeginDecelerating(vc)
 
-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(abs(velocity.y)/distance, 30.0)) : .zero
+        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 else { return }
+            guard let `self` = self, let vc = self.viewcontroller else { return }
             self.state = targetPosition
-            self.updateLayout(to: 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
-            guard let `self` = self else { return }
-            self.finishAnimation(at: targetPosition)
+            // 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 finishAnimation(at targetPosition: FloatingPanelPosition) {
-        log.debug("finishAnimation to \(targetPosition)")
-
+    private func endAnimation(_ finished: Bool) {
         self.isDecelerating = false
         self.animator = nil
 
@@ -675,8 +799,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         }
 
         stopScrollDeceleration = false
-        // Don't unlock scroll view in animating view when presentation layer != model layer
-        if state == layoutAdapter.topMostState {
+
+        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()
         }
     }
@@ -687,187 +812,63 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         return CGFloat(abs(currentY - targetY))
     }
 
-    private func directionalPosition(at currentY: CGFloat, with translation: CGPoint) -> FloatingPanelPosition {
-        return getPosition(at: currentY, with: translation, directional: true)
-    }
-
-    private func redirectionalPosition(at currentY: CGFloat, with translation: CGPoint) -> FloatingPanelPosition {
-        return getPosition(at: currentY, with: translation, directional: false)
-    }
-
-    private func getPosition(at currentY: CGFloat, with translation: CGPoint, directional: Bool) -> FloatingPanelPosition {
-        let supportedPositions: Set = layoutAdapter.supportedPositions
-        if supportedPositions.count == 1 {
-            return state
-        }
-        let isForwardYAxis = (translation.y >= 0)
-        switch supportedPositions {
-        case [.full, .half]:
-            return (isForwardYAxis == directional) ? .half : .full
-        case [.half, .tip]:
-            return (isForwardYAxis == directional) ? .tip : .half
-        case [.full, .tip]:
-            return (isForwardYAxis == directional) ? .tip : .full
-        default:
-            let middleY = layoutAdapter.middleY
-            if currentY > middleY {
-                return (isForwardYAxis == directional) ? .tip : .half
-            } else {
-                return (isForwardYAxis == directional) ? .half : .full
-            }
-        }
-    }
-
     // 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)
     }
 
-    private func targetPosition(with velocity: CGPoint) -> (FloatingPanelPosition) {
+    func targetPosition(from currentY: CGFloat, with velocity: CGPoint) -> (FloatingPanelPosition) {
         guard let vc = viewcontroller else { return state }
-        let currentY = surfaceView.frame.minY
         let supportedPositions = layoutAdapter.supportedPositions
 
-        if supportedPositions.count == 1 {
+        guard supportedPositions.count > 1 else {
             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 nextState: FloatingPanelPosition
-            let forwardYDirection: Bool
-
-            /*
-             full <-> half <-> tip
-             */
-            switch state {
-            case .full:
-                nextState = .half
-                forwardYDirection = true
-            case .half:
-                nextState = (currentY > middleY) ? .tip : .full
-                forwardYDirection = (currentY > middleY)
-            case .tip:
-                nextState = .half
-                forwardYDirection = false
-            case .hidden:
-                fatalError("Now .hidden must not be used for a user interaction")
-            }
-
-            let redirectionalProgress = max(min(behavior.redirectionalProgress(vc, from: state, to: nextState), 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
-            }
-
-            let decelerationRate = behavior.momentumProjectionRate(vc)
-
-            let baseY = abs(bottomY - topY)
-            let vecY = velocity.y / baseY
-            let pY = project(initialVelocity: vecY, decelerationRate: decelerationRate) * baseY + currentY
-
-            switch currentY {
-            case ..<th1:
-                switch pY {
-                case bottomY...:
-                    return behavior.shouldProjectMomentum(vc, for: .tip) ? .tip : .half
-                case middleY...:
-                    return .half
-                case topY...:
-                    return .full
-                default:
-                    return .full
-                }
-            case ...middleY:
-                switch pY {
-                case bottomY...:
-                    return behavior.shouldProjectMomentum(vc, for: .tip) ? .tip : .half
-                case middleY...:
-                    return .half
-                case topY...:
-                    return .half
-                default:
-                    return .full
-                }
-            case ..<th2:
-                switch pY {
-                case bottomY...:
-                    return .tip
-                case middleY...:
-                    return .half
-                case topY...:
-                    return .half
-                default:
-                    return behavior.shouldProjectMomentum(vc, for: .full) ? .full : .half
-                }
-            default:
-                switch pY {
-                case bottomY...:
-                    return .tip
-                case middleY...:
-                    return .tip
-                case topY...:
-                    return .half
-                default:
-                    return behavior.shouldProjectMomentum(vc, for: .full) ? .full : .half
-                }
-            }
-        }
-    }
-
-    private func targetPosition(from positions: [FloatingPanelPosition], at currentY: CGFloat, velocity: CGPoint) -> FloatingPanelPosition {
-        guard let vc = viewcontroller else { return state }
-        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(vc, from: state, to: target), 1.0), 0.0)
-
-        let th = topY + (bottomY - topY) * redirectionalProgress
+        let sortedPositions = Array(supportedPositions).sorted(by: { $0.rawValue < $1.rawValue })
 
+        // Projection
         let decelerationRate = behavior.momentumProjectionRate(vc)
-        let pY = project(initialVelocity: velocity.y, decelerationRate: decelerationRate) + currentY
+        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
 
-        switch currentY {
-        case ..<th:
-            if pY >= bottomY {
-                return bottom
-            } else {
-                return top
+        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)
+                }
             }
-        default:
-            if pY <= topY {
-                return top
+            (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 {
-                return bottom
+                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
@@ -879,6 +880,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             log.debug("Already scroll locked.")
             return
         }
+        log.debug("lock scroll view")
 
         scrollBouncable = scrollView.bounces
         scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
@@ -890,44 +892,36 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
     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 fitToBounds(scrollView: UIScrollView) {
-        log.debug("fit scroll view to bounds -- scroll offset =", scrollView.contentOffset.y)
-
-        surfaceView.frame.origin.y = layoutAdapter.topY - scrollView.contentOffset.y
-        scrollView.transform = CGAffineTransform.identity.translatedBy(x: 0.0,
-                                                                       y: scrollView.contentOffset.y)
-        scrollView.scrollIndicatorInsets = UIEdgeInsets(top: -scrollView.contentOffset.y,
-                                                        left: 0.0,
-                                                        bottom: 0.0,
-                                                        right: 0.0)
-    }
-
-    private func settle(scrollView: UIScrollView) {
-        log.debug("settle scroll view")
-        let frame = surfaceView.layer.presentation()?.frame ?? surfaceView.frame
-        surfaceView.transform = .identity
-        surfaceView.frame = frame
-        scrollView.transform = .identity
-        scrollView.frame = initialScrollFrame
-        scrollView.contentOffset = scrollView.contentOffsetZero
-        scrollView.scrollIndicatorInsets = .zero
-    }
-
-
     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: FloatingPanel?
+    fileprivate weak var floatingPanel: FloatingPanelCore?
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
         super.touchesBegan(touches, with: event)
         if floatingPanel?.animator != nil {
@@ -939,7 +933,7 @@ class FloatingPanelPanGestureRecognizer: UIPanGestureRecognizer {
             return super.delegate
         }
         set {
-            guard newValue is FloatingPanel else {
+            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)

Framework/Sources/FloatingPanelLayout.swift

@@ -11,15 +11,24 @@ import UIKit
 /// 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.
+/// 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 {
@@ -34,6 +43,15 @@ public extension FloatingPanelIntrinsicLayout {
     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 {
@@ -43,14 +61,16 @@ public protocol FloatingPanelLayout: class {
     /// Returns a set of FloatingPanelPosition objects to tell the applicable
     /// positions of the floating panel controller.
     ///
-    /// By default, it returns all position except for `hidden` position. Because
-    /// it's always supported by `FloatingPanelController` so you don't need to return it.
+    /// 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 Y coordinate of a floating panel for each position(full, half, tip and hidden).
@@ -72,6 +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 {
@@ -92,6 +115,10 @@ public extension FloatingPanelLayout {
     func backdropAlphaFor(position: FloatingPanelPosition) -> CGFloat {
         return position == .full ? 0.3 : 0.0
     }
+
+    var positionReference: FloatingPanelLayoutReference {
+        return .fromSafeArea
+    }
 }
 
 public class FloatingPanelDefaultLayout: FloatingPanelLayout {
@@ -130,9 +157,13 @@ public class FloatingPanelDefaultLandscapeLayout: FloatingPanelLayout {
     }
 }
 
+struct LayoutSegment {
+    let lower: FloatingPanelPosition?
+    let upper: FloatingPanelPosition?
+}
 
 class FloatingPanelLayoutAdapter {
-    weak var vc: UIViewController!
+    weak var vc: FloatingPanelController!
     private weak var surfaceView: FloatingPanelSurfaceView!
     private weak var backdropView: FloatingPanelBackdropView!
 
@@ -154,6 +185,8 @@ class FloatingPanelLayoutAdapter {
     private var tipConstraints: [NSLayoutConstraint] = []
     private var offConstraints: [NSLayoutConstraint] = []
     private var interactiveTopConstraint: NSLayoutConstraint?
+    private var bottomConstraint: NSLayoutConstraint?
+
 
     private var heightConstraint: NSLayoutConstraint?
 
@@ -175,9 +208,7 @@ class FloatingPanelLayoutAdapter {
     }
 
     var supportedPositions: Set<FloatingPanelPosition> {
-        var supportedPositions = layout.supportedPositions
-        supportedPositions.remove(.hidden)
-        return supportedPositions
+        return layout.supportedPositions
     }
 
     var topMostState: FloatingPanelPosition {
@@ -189,54 +220,19 @@ class FloatingPanelLayoutAdapter {
     }
 
     var topY: CGFloat {
-        if supportedPositions.contains(.full) {
-            switch layout {
-            case is FloatingPanelIntrinsicLayout:
-                return surfaceView.superview!.bounds.height - surfaceView.bounds.height
-            case is FloatingPanelFullScreenLayout:
-                return fullInset
-            default:
-                return (safeAreaInsets.top + fullInset)
-            }
-        } else {
-            return middleY
-        }
-    }
-
-    var middleY: CGFloat {
-        if layout is FloatingPanelFullScreenLayout {
-            return surfaceView.superview!.bounds.height - halfInset
-        } else{
-            return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + halfInset)
-        }
+        return positionY(for: topMostState)
     }
 
     var bottomY: CGFloat {
-        if supportedPositions.contains(.tip) {
-            if layout is FloatingPanelFullScreenLayout {
-                return surfaceView.superview!.bounds.height - tipInset
-            } else{
-                return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + tipInset)
-            }
-        } else {
-            return middleY
-        }
-    }
-
-    var hiddenY: CGFloat {
-        return surfaceView.superview!.bounds.height
+        return positionY(for: bottomMostState)
     }
 
     var topMaxY: CGFloat {
-        return layout is FloatingPanelFullScreenLayout ? 0.0 : safeAreaInsets.top
+        return topY - layout.topInteractionBuffer
     }
 
     var bottomMaxY: CGFloat {
-        if layout is FloatingPanelFullScreenLayout{
-            return surfaceView.superview!.bounds.height - hiddenInset
-        } else {
-            return surfaceView.superview!.bounds.height - (safeAreaInsets.bottom + hiddenInset)
-        }
+        return bottomY + layout.bottomInteractionBuffer
     }
 
     var adjustedContentInsets: UIEdgeInsets {
@@ -249,13 +245,31 @@ 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 hiddenY
+            return surfaceView.superview!.bounds.height - hiddenInset
         }
     }
 
@@ -289,10 +303,14 @@ class FloatingPanelLayoutAdapter {
                   ", content safe area(bottom) =", safeAreaBottom)
     }
 
-    func prepareLayout(in vc: UIViewController) {
+    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
@@ -308,9 +326,14 @@ class FloatingPanelLayoutAdapter {
 
         fixedConstraints = surfaceConstraints + backdropConstraints
 
+        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 is FloatingPanelFullScreenLayout {
+            if layout.positionReference == .fromSuperview {
                 return vc.view.topAnchor
             } else {
                 return vc.layoutGuide.topAnchor
@@ -329,7 +352,7 @@ class FloatingPanelLayoutAdapter {
         }
 
         let bottomAnchor: NSLayoutYAxisAnchor = {
-            if layout is FloatingPanelFullScreenLayout {
+            if layout.positionReference == .fromSuperview {
                 return vc.view.bottomAnchor
             } else {
                 return vc.layoutGuide.bottomAnchor
@@ -351,20 +374,20 @@ class FloatingPanelLayoutAdapter {
         ]
     }
 
-    func startInteraction(at state: FloatingPanelPosition) {
+    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 {
-        case is FloatingPanelIntrinsicLayout,
-             is FloatingPanelFullScreenLayout:
-            initialConst = surfaceView.frame.minY
-            interactiveTopConstraint = surfaceView.topAnchor.constraint(equalTo: vc.view.topAnchor,
-                                                                        constant: initialConst)
-        default:
-            initialConst = surfaceView.frame.minY - safeAreaInsets.top
+        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
@@ -373,67 +396,75 @@ class FloatingPanelLayoutAdapter {
     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 let const = self.heightConstraint {
-            NSLayoutConstraint.deactivate([const])
+        if layout is FloatingPanelIntrinsicLayout {
+            updateIntrinsicHeight()
+        }
+        defer {
+            if layout is FloatingPanelIntrinsicLayout {
+                NSLayoutConstraint.deactivate(fullConstraints)
+                fullConstraints = [
+                    surfaceView.topAnchor.constraint(equalTo: vc.layoutGuide.bottomAnchor,
+                                                     constant: -fullInset),
+                ]
+            }
         }
 
-        let heightConstraint: NSLayoutConstraint
+        guard vc.contentMode != .fitToBounds else { return }
 
         switch layout {
         case is FloatingPanelIntrinsicLayout:
-            updateIntrinsicHeight()
             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([heightConstraint])
-        self.heightConstraint = heightConstraint
+        NSLayoutConstraint.activate(constraint: heightConstraint)
 
         surfaceView.bottomOverflow = vc.view.bounds.height + layout.topInteractionBuffer
-
-        if layout is FloatingPanelIntrinsicLayout {
-            NSLayoutConstraint.deactivate(fullConstraints)
-            fullConstraints = [
-                surfaceView.topAnchor.constraint(equalTo: vc.layoutGuide.bottomAnchor,
-                                                 constant: -fullInset),
-            ]
-        }
     }
 
     func updateInteractiveTopConstraint(diff: CGFloat, allowsTopBuffer: Bool, with behavior: FloatingPanelBehavior) {
         defer {
-            surfaceView.superview!.layoutIfNeeded() // MUST call here to update `surfaceView.frame`
+            layoutSurfaceIfNeeded() // MUST be called to update `surfaceView.frame`
         }
 
         let topMostConst: CGFloat = {
             var ret: CGFloat = 0.0
-            switch layout {
-            case is FloatingPanelIntrinsicLayout, is FloatingPanelFullScreenLayout:
-                ret = topY
-            default:
+            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
-            switch layout {
-            case is FloatingPanelIntrinsicLayout, is FloatingPanelFullScreenLayout:
-                ret = bottomY
-            default:
-                ret = bottomY - safeAreaInsets.top
+            let _bottomY = vc.isRemovalInteractionEnabled ? positionY(for: .hidden) : bottomY
+            switch layout.positionReference {
+            case .fromSafeArea:
+                ret = _bottomY - safeAreaInsets.top
+            case .fromSuperview:
+                ret = _bottomY
             }
-            return min(ret, bottomMaxY)
+            return min(ret, surfaceView.superview!.bounds.height)
         }()
         let minConst = allowsTopBuffer ? topMostConst - layout.topInteractionBuffer : topMostConst
         let maxConst = bottomMostConst + layout.bottomInteractionBuffer
@@ -463,23 +494,29 @@ class FloatingPanelLayoutAdapter {
         return (1.0 - (1.0 / ((buffer * 0.55 / base) + 1.0))) * base
     }
 
-    func activateLayout(of state: FloatingPanelPosition) {
+    func activateFixedLayout() {
+        // Must deactivate `interactiveTopConstraint` here
+        NSLayoutConstraint.deactivate(constraint: self.interactiveTopConstraint)
+        self.interactiveTopConstraint = nil
+
+        NSLayoutConstraint.activate(fixedConstraints)
+
+        if vc.contentMode == .fitToBounds {
+            NSLayoutConstraint.activate(constraint: self.bottomConstraint)
+        }
+    }
+
+    func activateInteractiveLayout(of state: FloatingPanelPosition) {
         defer {
-            surfaceView.superview!.layoutIfNeeded()
+            layoutSurfaceIfNeeded()
+            log.debug("activateLayout -- surface.presentation = \(self.surfaceView.presentationFrame) surface.frame = \(self.surfaceView.frame)")
         }
 
         var state = state
 
         setBackdropAlpha(of: state)
 
-        // Must deactivate `interactiveTopConstraint` here
-        if let interactiveTopConstraint = interactiveTopConstraint {
-            NSLayoutConstraint.deactivate([interactiveTopConstraint])
-            self.interactiveTopConstraint = nil
-        }
-        NSLayoutConstraint.activate(fixedConstraints)
-
-        if supportedPositions.union([.hidden]).contains(state) == false {
+        if isValid(state) == false {
             state = layout.initialPosition
         }
 
@@ -496,6 +533,22 @@ class FloatingPanelLayoutAdapter {
         }
     }
 
+    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
@@ -507,7 +560,7 @@ class FloatingPanelLayoutAdapter {
     private func checkLayoutConsistance() {
         // Verify layout configurations
         assert(supportedPositions.count > 0)
-        assert(supportedPositions.union([.hidden]).contains(layout.initialPosition),
+        assert(supportedPositions.contains(layout.initialPosition),
                "Does not include an initial position (\(layout.initialPosition)) in supportedPositions (\(supportedPositions))")
 
         if layout is FloatingPanelIntrinsicLayout {
@@ -526,4 +579,38 @@ class FloatingPanelLayoutAdapter {
             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

@@ -34,10 +34,8 @@ public class FloatingPanelSurfaceView: UIView {
 
     /// A root view of a content view controller
     public weak var contentView: UIView!
-    
+
     /// The content insets specifying the insets around the content view.
-    ///
-    /// - important: Currently the `bottom` inset is ignored.
     public var contentInsets: UIEdgeInsets = .zero {
         didSet {
             // Needs update constraints
@@ -83,8 +81,8 @@ public class FloatingPanelSurfaceView: UIView {
     /// The color of the surface border.
     public var borderWidth: CGFloat = 0.0  { didSet { setNeedsLayout() } }
 
-    /// Offset of the container view from the top
-    public var containerTopInset: CGFloat = 0.0 { didSet {
+    /// The margins to use when laying out the container view wrapping content.
+    public var containerMargins: UIEdgeInsets = .zero { didSet {
         setNeedsUpdateConstraints()
     } }
 
@@ -99,9 +97,11 @@ public class FloatingPanelSurfaceView: UIView {
     @available(*, unavailable, renamed: "containerView")
     public var backgroundView: UIView!
 
-    private lazy var containerViewTopInsetConstraint: NSLayoutConstraint = containerView.topAnchor.constraint(equalTo: topAnchor, constant: containerTopInset)
-    private lazy var containerViewHeightConstraint: NSLayoutConstraint = containerView.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 1.0)
-    
+    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
@@ -111,9 +111,11 @@ public class FloatingPanelSurfaceView: UIView {
     /// The content height constraint
     private var contentViewHeightConstraint: NSLayoutConstraint?
 
-    private lazy var grabberHandleWidthConstraint: NSLayoutConstraint = grabberHandle.widthAnchor.constraint(equalToConstant: grabberHandleWidth)
-    private lazy var grabberHandleHeightConstraint: NSLayoutConstraint = grabberHandle.heightAnchor.constraint(equalToConstant: grabberHandleHeight)
-    private lazy var grabberHandleTopConstraint: NSLayoutConstraint = grabberHandle.topAnchor.constraint(equalTo: topAnchor, constant: grabberTopPadding)
+    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)
@@ -132,9 +134,9 @@ public class FloatingPanelSurfaceView: UIView {
         addSubview(containerView)
         containerView.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
-            containerViewTopInsetConstraint,
-            containerView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0),
-            containerView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0),
+            containerViewTopConstraint,
+            containerViewLeftConstraint,
+            containerViewRightConstraint,
             containerViewHeightConstraint,
             ])
 
@@ -149,13 +151,15 @@ public class FloatingPanelSurfaceView: UIView {
     }
 
     public override func updateConstraints() {
-        containerViewTopInsetConstraint.constant = containerTopInset
-        containerViewHeightConstraint.constant = bottomOverflow
+        containerViewTopConstraint.constant = containerMargins.top
+        containerViewLeftConstraint.constant = containerMargins.left
+        containerViewRightConstraint.constant = -containerMargins.right
+        containerViewHeightConstraint.constant = (containerMargins.bottom == 0) ? bottomOverflow : -(containerMargins.top + containerMargins.bottom)
 
-        contentViewTopConstraint?.constant = contentInsets.top
-        contentViewLeftConstraint?.constant = contentInsets.left
-        contentViewRightConstraint?.constant = contentInsets.right
-        contentViewHeightConstraint?.constant = -containerTopInset
+        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
@@ -196,6 +200,7 @@ public class FloatingPanelSurfaceView: UIView {
             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.storyboard of Example/Maps.
@@ -218,10 +223,11 @@ public class FloatingPanelSurfaceView: UIView {
         /* contentView.frame = bounds */ // MUST NOT: Because the top safe area inset of a content VC will be incorrect.
         contentView.translatesAutoresizingMaskIntoConstraints = false
 
-        let topConstraint = contentView.topAnchor.constraint(equalTo: topAnchor, constant: contentInsets.top)
-        let leftConstraint = contentView.leftAnchor.constraint(equalTo: leftAnchor, constant: contentInsets.left)
-        let rightConstraint = rightAnchor.constraint(equalTo: contentView.rightAnchor, constant: contentInsets.right)
-        let heightConstraint = contentView.heightAnchor.constraint(equalTo: heightAnchor, constant: -containerTopInset)
+        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([
             topConstraint,
             leftConstraint,

Framework/Sources/FloatingPanelTransitioning.swift

@@ -59,9 +59,7 @@ class FloatingPanelPresentationController: UIPresentationController {
         // Forward touch events to the presenting view controller
         (fpc.view as? FloatingPanelPassThroughView)?.eventForwardingView = presentingViewController.view
 
-        // Set tap-to-dismiss in the backdrop view
-        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
-        fpc.backdropView.addGestureRecognizer(tapGesture)
+        fpc.backdropView.dismissalTapGestureRecognizer.isEnabled = true
     }
 
     @objc func handleBackdrop(tapGesture: UITapGestureRecognizer) {

Framework/Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.6.2</string>
+	<string>1.7.3</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 </dict>

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 {
@@ -60,6 +60,10 @@ extension UIView {
             return self
         }
     }
+
+    var presentationFrame: CGRect {
+        return layer.presentation()?.frame ?? frame
+    }
 }
 
 extension UIView {
@@ -71,6 +75,12 @@ extension UIView {
     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
@@ -104,9 +114,6 @@ extension UIGestureRecognizerState: CustomDebugStringConvertible {
 #endif
 
 extension UIScrollView {
-    var contentOffsetZero: CGPoint {
-        return CGPoint(x: 0.0, y: 0.0 - contentInset.top)
-    }
     var isLocked: Bool {
         return !showsVerticalScrollIndicator && !bounces &&  isDirectionalLockEnabled
     }
@@ -123,8 +130,10 @@ extension UISpringTimingParameters {
 
 extension CGPoint {
     static var nan: CGPoint {
-        return CGPoint(x: CGFloat.nan,
-                       y: CGFloat.nan)
+        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)
     }
 }
 
@@ -136,3 +145,14 @@ extension UITraitCollection {
             || 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/Tests/FloatingPanelControllerTests.swift

@@ -7,9 +7,7 @@ import XCTest
 @testable import FloatingPanel
 
 class FloatingPanelControllerTests: XCTestCase {
-
     override func setUp() {}
-
     override func tearDown() {}
 
     func test_warningRetainCycle() {
@@ -52,6 +50,114 @@ class FloatingPanelControllerTests: XCTestCase {
         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 {

Framework/Tests/FloatingPanelLayoutTests.swift

@@ -7,13 +7,15 @@ import XCTest
 @testable import FloatingPanel
 
 class FloatingPanelLayoutTests: XCTestCase {
-    override func setUp() {}
+    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() {
-        let fpc = FloatingPanelController(delegate: nil)
-        fpc.loadViewIfNeeded()
-        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
         XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
         XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .tip)
 
@@ -31,11 +33,222 @@ class FloatingPanelLayoutTests: XCTestCase {
         delegate.layout = FloatingPanelLayoutWithHidden()
         fpc.delegate = delegate
         XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
-        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .half) // Will fixed on fix-hidden-position branch
+        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

@@ -8,11 +8,11 @@ import XCTest
 
 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)
@@ -23,11 +23,8 @@ class FloatingPanelSurfaceViewTests: XCTestCase {
         XCTAssert(surface.backgroundColor == surface.containerView.backgroundColor)
     }
 
-    func test_surfaceView_constraintsUpdate() {
-        let window = UIWindow()
+    func test_surfaceView_grabberHandle() {
         let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
-        window.addSubview(surface)
-        window.makeKeyAndVisible()
         XCTAssert(surface.contentView == nil)
         surface.layoutIfNeeded()
         XCTAssert(surface.grabberHandle.frame.minY == 6.0)
@@ -36,11 +33,46 @@ class FloatingPanelSurfaceViewTests: XCTestCase {
 
         surface.grabberHandleWidth = 44.0
         surface.grabberHandleHeight = 12.0
+        surface.setNeedsLayout()
         surface.layoutIfNeeded()
-        waitRunLoop(secs: 0.000_001)
         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)")
-        window.resignKey()
+    }
+
+    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() {

Framework/Tests/FloatingPanelTests.swift

@@ -7,22 +7,19 @@ import XCTest
 @testable import FloatingPanel
 
 class FloatingPanelTests: XCTestCase {
-
     override func setUp() {}
-
     override func tearDown() {}
 
     func test_scrolllock() {
         let fpc = FloatingPanelController()
-        fpc.loadViewIfNeeded()
-        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+
         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.show(animated: false, completion: nil) // half
+        fpc.showForTest()
+
         XCTAssertEqual(fpc.position, .half)
         XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
         XCTAssertEqual(contentVC1.tableView.bounces, false)
@@ -63,16 +60,478 @@ class FloatingPanelTests: XCTestCase {
         XCTAssertEqual(contentVC2.tableView.bounces, false)
     }
 
-}
-
-private protocol FloatingPanelTestLayout: FloatingPanelLayout {}
-private extension FloatingPanelTestLayout {
-    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
-        switch position {
-        case .full: return 18.0
-        case .half: return 262.0
-        case .tip: return 69.0
-        default: return nil
+    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

@@ -10,9 +10,37 @@ 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
+        }
+    }
 }

README.md

@@ -5,9 +5,9 @@
 [![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.
@@ -24,25 +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)
@@ -83,7 +95,7 @@ it, simply add the following line to your Podfile:
 pod 'FloatingPanel'
 ```
 
-✏️ To suppress "Swift Conversion" warnings in Xcode, please set a Swift version to `SWIFT_VERSION` for the project in your Podfile. It will be resolved in CocoaPods v1.7.0.
+✏️FloatingPanel v1.7.0 or later requires CocoaPods v1.7.0+ for `swift_versions` support.
 
 ### Carthage
 
@@ -93,6 +105,10 @@ 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
@@ -165,41 +181,72 @@ FloatingPanelController.view (FloatingPanelPassThroughView)
 
 ### 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 controller and the managed views to a view controller.
-// From the second time, just call `show(animated:completion)`.
-view.addSubview(fpc.view)
+// 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
 
-fpc.view.frame = view.bounds // MUST
 // In addition, Auto Layout constraints are highly recommended.
-// Because it makes the layout more robust on trait collection change.
-//
-//     fpc.view.translatesAutoresizingMaskIntoConstraints = false
-//     NSLayoutConstraint.activate([...])
-// 
+// 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),
+])
 
-parent.addChild(fpc)
+// Add the floating panel controller to the controller hierarchy.
+self.addChild(fpc)
 
-// Show a floating panel to the initial position defined in your `FloatingPanelLayout` object.
+// Show the floating panel at the initial position defined in your `FloatingPanelLayout` object.
 fpc.show(animated: true) {
-
-    // Only for the first time
-    self.didMove(toParent: self)
-}
-
-...
-
-// Hide it
-fpc.hide(animated: true) {
-
-    // Remove it if needed
-    self.willMove(toParent: nil)
-    self.view.removeFromSuperview()
-    self.removeFromParent()
+    // Inform the floating panel controller that the transition to the controller hierarchy has completed.
+    fpc.didMove(toParent: self)
 }
 ```
 
-NOTE: `FloatingPanelController` wraps `show`/`hide` with `addPanel`/`removePanelFromParent` for easy-to-use. But `show`/`hide` are more convenience for your app.
+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
 
@@ -291,6 +338,27 @@ class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
 }
 ```
 
+#### 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
@@ -313,7 +381,33 @@ class FloatingPanelStocksBehavior: FloatingPanelBehavior {
 }
 ```
 
-### Use a custom grabber handle
+#### Activate the rubber-band effect on the top/bottom edges
+
+```swift
+class FloatingPanelBehavior: FloatingPanelBehavior {
+    ...
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
+        return true
+    }
+}
+```
+
+#### 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 FloatingPanelBehavior: FloatingPanelBehavior {
+    ...
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
+        return true
+    }
+}
+```
+
+### Customize the surface design
+
+#### Use a custom grabber handle
 
 ```swift
 let myGrabberHandleView = MyGrabberHandleView()
@@ -321,7 +415,50 @@ fpc.surfaceView.grabberHandle.isHidden = true
 fpc.surfaceView.addSubview(myGrabberHandleView)
 ```
 
-### Add tap gestures to the surface or backdrop views
+#### 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() {
@@ -435,6 +572,12 @@ A `FloatingPanelController` object proxies an action for `show(_:sender)` to the
 
 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.