Release 1.7.5

* Add "Show Panel in Sheet Modal" sample
* Fix the behavior in a sheet modal

.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

Examples/Maps/Maps.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	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 */; };
@@ -31,6 +32,7 @@
 /* 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>"; };
@@ -46,6 +48,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				543844BD23D2BE2000D5EDE4 /* MapKit.framework in Frameworks */,
 				549D23D2233C77D5008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -53,12 +56,21 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		543844BB23D2BE1F00D5EDE4 /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				543844BC23D2BE2000D5EDE4 /* MapKit.framework */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 		54B5111D216C3D840033A6F3 = {
 			isa = PBXGroup;
 			children = (
 				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) {
@@ -177,7 +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 {
@@ -188,12 +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
@@ -275,12 +274,12 @@ class SearchHeaderView: UIView {
 
 extension UISearchBar {
     func setSearchText(fontSize: CGFloat) {
-        #if swift(>=5.1) // Xcode 11 or later
+        if #available(iOS 13, *) {
             let font = searchTextField.font
             searchTextField.font = font?.withSize(fontSize)
-        #else
+        } else {
             let textField = value(forKey: "_searchField") as! UITextField
             textField.font = textField.font?.withSize(fontSize)
-        #endif
+        }
     }
 }

Examples/Samples/Samples.xcodeproj/project.pbxproj

@@ -294,7 +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="14490.70" 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="14490.49"/>
+        <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"/>

Examples/Samples/Sources/ViewController.swift

@@ -18,6 +18,8 @@ class SampleListViewController: UIViewController {
         case showDetail
         case showModal
         case showPanelModal
+        case showMultiPanelModal
+        case showPanelInSheetModal
         case showTabBar
         case showPageView
         case showPageContentView
@@ -26,6 +28,7 @@ class SampleListViewController: UIViewController {
         case showIntrinsicView
         case showContentInset
         case showContainerMargins
+        case showNavigationController
 
         var name: String {
             switch self {
@@ -34,6 +37,8 @@ class SampleListViewController: UIViewController {
             case .showDetail: return "Show Detail Panel"
             case .showModal: return "Show Modal"
             case .showPanelModal: return "Show Panel Modal"
+            case .showMultiPanelModal: return "Show Multi Panel Modal"
+            case .showPanelInSheetModal: return "Show Panel in Sheet Modal"
             case .showTabBar: return "Show Tab Bar"
             case .showPageView: return "Show Page View"
             case .showPageContentView: return "Show Page Content View"
@@ -42,6 +47,7 @@ class SampleListViewController: UIViewController {
             case .showIntrinsicView: return "Show Intrinsic View"
             case .showContentInset: return "Show with ContentInset"
             case .showContainerMargins: return "Show with ContainerMargins"
+            case .showNavigationController: return "Show Navigation Controller"
             }
         }
 
@@ -51,6 +57,8 @@ class SampleListViewController: UIViewController {
             case .trackingTextView: return "ConsoleViewController"
             case .showDetail: return "DetailViewController"
             case .showModal: return "ModalViewController"
+            case .showMultiPanelModal: return nil
+            case .showPanelInSheetModal: return nil
             case .showPanelModal: return nil
             case .showTabBar: return "TabBarViewController"
             case .showPageView: return nil
@@ -60,6 +68,7 @@ class SampleListViewController: UIViewController {
             case .showIntrinsicView: return "IntrinsicViewController"
             case .showContentInset: return nil
             case .showContainerMargins: return nil
+            case .showNavigationController: return "RootNavigationController"
             }
         }
     }
@@ -80,6 +89,7 @@ class SampleListViewController: UIViewController {
         tableView.dataSource = self
         tableView.delegate = self
         tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
+        automaticallyAdjustsScrollViewInsets = false
 
         let searchController = UISearchController(searchResultsController: nil)
         if #available(iOS 11.0, *) {
@@ -92,11 +102,14 @@ 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()
@@ -116,15 +129,13 @@ class SampleListViewController: UIViewController {
 
         let oldMainPanelVC = mainPanelVC
 
-        // Initialize FloatingPanelController
         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
@@ -143,6 +154,8 @@ class SampleListViewController: UIViewController {
 
             let backdropTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
             mainPanelVC.backdropView.addGestureRecognizer(backdropTapGesture)
+        case .showNavigationController:
+            mainPanelVC.contentInsetAdjustmentBehavior = .never
         default:
             break
         }
@@ -160,6 +173,11 @@ 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
         }
@@ -331,6 +349,24 @@ extension SampleListViewController: UITableViewDelegate {
 
             self.present(fpc, animated: true, completion: nil)
 
+        case .showMultiPanelModal:
+            let fpc = MultiPanelController()
+            self.present(fpc, animated: true, completion: nil)
+
+        case .showPanelInSheetModal:
+            let fpc = FloatingPanelController()
+            let contentVC = UIViewController()
+            fpc.set(contentViewController: contentVC)
+            fpc.delegate = self
+
+            fpc.surfaceView.cornerRadius = 38.5
+            fpc.surfaceView.shadowHidden = false
+            fpc.isRemovalInteractionEnabled = true
+
+            let mvc = UIViewController()
+            mvc.view.backgroundColor = UIColor(displayP3Red: 2/255, green: 184/255, blue: 117/255, alpha: 1.0)
+            fpc.addPanel(toParent: mvc)
+            self.present(mvc, animated: true, completion: nil)
         case .showContentInset:
             let contentViewController = UIViewController()
             contentViewController.view.backgroundColor = .green
@@ -368,6 +404,14 @@ 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()
@@ -636,7 +680,8 @@ 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
 
@@ -650,8 +695,6 @@ class DebugTableViewController: InspectableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
 
-        let tableView = UITableView(frame: .zero,
-                                    style: .plain)
         view.addSubview(tableView)
         tableView.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
@@ -662,18 +705,17 @@ 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 {
@@ -689,13 +731,12 @@ 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() {
@@ -841,8 +882,7 @@ class ModalViewController: UIViewController, FloatingPanelControllerDelegate {
 
     var isNewlayout: Bool = false
 
-    override func viewWillAppear(_ animated: Bool) {
-        super.viewWillAppear(animated)
+    override func viewDidLoad() {
         // Initialize FloatingPanelController
         fpc = FloatingPanelController()
         fpc.delegate = self
@@ -862,8 +902,8 @@ class ModalViewController: UIViewController, FloatingPanelControllerDelegate {
         fpc.addPanel(toParent: self, belowView: safeAreaView)
     }
 
-    override func viewWillDisappear(_ animated: Bool) {
-        super.viewWillDisappear(animated)
+    override func viewDidDisappear(_ animated: Bool) {
+        super.viewDidDisappear(animated)
         //  Remove FloatingPanel from a view
         fpc.removePanelFromParent(animated: false)
     }
@@ -924,20 +964,15 @@ class TabBarContentViewController: UIViewController {
             }
         }
     }
-    var fpc: FloatingPanelController!
+    lazy var fpc = FloatingPanelController()
     var consoleVC: DebugTextViewController!
 
     var threeLayout: ThreeTabBarPanelLayout!
     var tab3Mode: Tab3Mode = .changeAutoLayout
     var switcherLabel: UILabel!
 
-    override func viewWillAppear(_ animated: Bool) {
-        super.viewWillAppear(animated)
-        // Initialize FloatingPanelController
-        fpc = FloatingPanelController()
+    override func viewDidLoad() {
         fpc.delegate = self
-
-        // Initialize FloatingPanelController and add the view
         fpc.surfaceView.cornerRadius = 6.0
         fpc.surfaceView.shadowHidden = false
 
@@ -987,12 +1022,6 @@ class TabBarContentViewController: UIViewController {
         fpc.updateLayout()
     }
 
-    override func viewWillDisappear(_ animated: Bool) {
-        super.viewWillDisappear(animated)
-        //  Remove FloatingPanel from a view
-        fpc.removePanelFromParent(animated: false)
-    }
-
     // MARK: - Action
 
     @IBAction func close(sender: UIButton) {
@@ -1270,3 +1299,72 @@ 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()
+    }
+}

FloatingPanel.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name                = "FloatingPanel"
-  s.version             = "1.7.0"
+  s.version             = "1.7.5"
   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.

Framework/FloatingPanel.xcodeproj/project.pbxproj

@@ -26,7 +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 */
 
@@ -70,7 +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>"; };
@@ -129,7 +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 */,
@@ -311,7 +311,7 @@
 				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 */,
@@ -484,6 +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;
@@ -514,6 +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;

Framework/Sources/FloatingPanelController.swift

@@ -37,6 +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 {
@@ -62,6 +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)
+    }
 }
 
 
@@ -187,7 +199,13 @@ open class FloatingPanelController: UIViewController {
         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 }
@@ -197,7 +215,7 @@ open class FloatingPanelController: UIViewController {
 
     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()
@@ -220,7 +238,7 @@ open class FloatingPanelController: UIViewController {
         modalPresentationStyle = .custom
         transitioningDelegate = modalTransition
 
-        floatingPanel = FloatingPanel(self,
+        floatingPanel = FloatingPanelCore(self,
                                       layout: fetchLayout(for: self.traitCollection),
                                       behavior: fetchBehavior(for: self.traitCollection))
     }
@@ -229,7 +247,7 @@ open class FloatingPanelController: UIViewController {
         floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
         floatingPanel.behavior = fetchBehavior(for: self.traitCollection)
     }
-    
+
     // MARK:- Overrides
 
     /// Creates the view that the controller manages.
@@ -279,6 +297,41 @@ open class FloatingPanelController: UIViewController {
         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 }
@@ -318,7 +371,6 @@ open class FloatingPanelController: UIViewController {
         switch contentInsetAdjustmentBehavior {
         case .always:
             scrollView?.contentInset = adjustedContentInsets
-            scrollView?.scrollIndicatorInsets = adjustedContentInsets
         default:
             break
         }
@@ -340,13 +392,18 @@ open class FloatingPanelController: UIViewController {
     private func activateLayout() {
         floatingPanel.layoutAdapter.prepareLayout(in: self)
 
-        // preserve the current content offset
-        let contentOffset = scrollView?.contentOffset
+        // 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
@@ -364,9 +421,11 @@ open class FloatingPanelController: UIViewController {
             // inset's update expectedly.
             // 2. The safe area top inset can be variable on the large title navigation bar(iOS11+).
             // That's why it needs the observation to keep `adjustedContentInsets` correct.
-            safeAreaInsetsObservation = self.observe(\.view.safeAreaInsets, options: [.initial, .new, .old]) { [weak self] (vc, change) in
-                guard change.oldValue != change.newValue else { return }
-                self?.update(safeAreaInsets: vc.layoutInsets)
+            safeAreaInsetsObservation = self.view.observe(\.safeAreaInsets, options: [.initial, .new, .old]) { [weak self] (_, change) in
+                // Use `self.view.safeAreaInsets` becauese `change.newValue` can be nil in particular case when
+                // is reported in https://github.com/SCENEE/FloatingPanel/issues/330
+                guard let `self` = self, change.oldValue != self.view.safeAreaInsets else { return }
+                self.update(safeAreaInsets: self.view.safeAreaInsets)
             }
         } else {
             // KVOs for topLayoutGuide & bottomLayoutGuide are not effective.
@@ -425,9 +484,9 @@ open class FloatingPanelController: UIViewController {
         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
         }
     }
@@ -611,7 +670,8 @@ public extension UIViewController {
         }
         // Call dismiss(animated:completion:) to FloatingPanelController directly
         if let fpc = self as? FloatingPanelController {
-            if fpc.presentingViewController != nil {
+            // When a panel is presented modally and it's not a child view controller of the presented view controller.
+            if fpc.presentingViewController != nil, fpc.parent == nil {
                 self.fp_original_dismiss(animated: flag, completion: completion)
             } else {
                 fpc.removePanelFromParent(animated: flag, completion: completion)

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?
 
@@ -81,7 +81,6 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         super.init()
 
         panGestureRecognizer.floatingPanel = self
-
         surfaceView.addGestureRecognizer(panGestureRecognizer)
         panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
         panGestureRecognizer.delegate = self
@@ -98,7 +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")
+        assert(layoutAdapter.validPositions.contains(to), "Can't move to '\(to)' position because it's not valid in the layout")
         guard let vc = viewcontroller else {
             completion?()
             return
@@ -192,6 +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,
@@ -203,13 +205,27 @@ 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
+            }
+        }
+        if #available(iOS 11.0, *),
+            otherGestureRecognizer.name == "_UISheetInteractionBackgroundDismissRecognizer" {
+            // The dismiss gesture of a sheet modal should not begin until the pan gesture fails.
+            return true
+        }
         return false
     }
 
@@ -230,7 +246,15 @@ 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
+                }
             }
         }
 
@@ -240,11 +264,23 @@ 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,
              is UIScreenEdgePanGestureRecognizer,
              is UIPinchGestureRecognizer:
+            if #available(iOS 11.0, *),
+                otherGestureRecognizer.name == "_UISheetInteractionBackgroundDismissRecognizer" {
+                // Should begin the pan gesture without waiting the dismiss gesture of a sheet modal.
+                return false
+            }
             // Do not begin the pan gesture until these gestures fail
             return true
         default:
@@ -279,15 +315,16 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
             let location = panGesture.location(in: surfaceView)
 
-            let belowTop = surfaceView.presentationFrame.minY > layoutAdapter.topY
-            let offset = scrollView.contentOffset.y - scrollView.contentOffsetZero.y
-
+            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 = \(offset),",
+                "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
@@ -330,11 +367,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
                 } else {
                     if state == layoutAdapter.topMostState {
                         // Hide a scroll indicator just before starting an interaction by swiping a panel down.
-                        if offset < 0, velocity.y > 0 {
+                        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 offset > 0, velocity.y < 0 {
+                        if velocity.y < 0, allowScrollPanGesture(for: scrollView) {
                             unlockScrollView()
                         }
 
@@ -370,7 +407,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
                     }
                     animator.finishAnimation(at: .current)
                 } else {
-                    self.animator = nil
+                    self.endAnimation(false) // Must call it manually
                 }
             }
 
@@ -437,14 +474,15 @@ 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 {
@@ -565,7 +603,7 @@ 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 }
@@ -592,19 +630,22 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             }
         }
 
-        if let vc = viewcontroller {
-            vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: velocity, targetPosition: targetPosition)
-        }
-
         if scrollView != nil, !stopScrollDeceleration,
             surfaceView.frame.minY == layoutAdapter.topY,
             targetPosition == layoutAdapter.topMostState {
             self.state = targetPosition
             self.updateLayout(to: targetPosition)
             self.unlockScrollView()
+            if let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: .zero, targetPosition: targetPosition)
+            }
             return
         }
 
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: velocity, targetPosition: targetPosition)
+        }
+
         // Workaround: Disable a tracking scroll to prevent bouncing a scroll content in a panel animating
         let isScrollEnabled = scrollView?.isScrollEnabled
         if let scrollView = scrollView, targetPosition != .full {
@@ -670,9 +711,12 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             if grabberAreaFrame.contains(location) {
                 initialScrollOffset = scrollView.contentOffset
             } else {
+                initialScrollOffset = contentOrigin(of: scrollView)
                 // Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
-                offset = CGPoint(x: -scrollView.contentOffset.x, y: -scrollView.contentOffset.y)
-                initialScrollOffset = scrollView.contentOffsetZero
+                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)
         }
@@ -721,7 +765,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
 
         vc.delegate?.floatingPanelWillBeginDecelerating(vc)
 
-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: abs(velocity.y)/distance) : .zero
+        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: velocity.y / distance) : .zero
         let animator = behavior.interactionAnimator(vc, to: targetPosition, with: velocityVector)
         animator.addAnimations { [weak self] in
             guard let `self` = self, let vc = self.viewcontroller else { return }
@@ -745,15 +789,14 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
             // 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 }
-            self.finishAnimation(at: targetPosition)
+            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
 
@@ -768,7 +811,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         stopScrollDeceleration = false
 
         log.debug("finishAnimation -- state = \(state) surface.minY = \(surfaceView.presentationFrame.minY) topY = \(layoutAdapter.topY)")
-        if state == layoutAdapter.topMostState, abs(surfaceView.presentationFrame.minY - layoutAdapter.topY) <= 1.0 {
+        if finished, state == layoutAdapter.topMostState, abs(surfaceView.presentationFrame.minY - layoutAdapter.topY) <= 1.0 {
             unlockScrollView()
         }
     }
@@ -776,7 +819,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
     private func distance(to targetPosition: FloatingPanelPosition) -> CGFloat {
         let currentY = surfaceView.frame.minY
         let targetY = layoutAdapter.positionY(for: targetPosition)
-        return CGFloat(abs(currentY - targetY))
+        return CGFloat(targetY - currentY)
     }
 
     // Distance travelled after decelerating to zero velocity at a constant rate.
@@ -870,10 +913,25 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
         // 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 {
@@ -885,7 +943,7 @@ 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

@@ -94,6 +94,7 @@ public protocol FloatingPanelLayout: class {
     func backdropAlphaFor(position: FloatingPanelPosition) -> CGFloat
 
     var positionReference: FloatingPanelLayoutReference { get }
+
 }
 
 public extension FloatingPanelLayout {
@@ -210,6 +211,10 @@ class FloatingPanelLayoutAdapter {
         return layout.supportedPositions
     }
 
+    var validPositions: Set<FloatingPanelPosition> {
+        return supportedPositions.union([.hidden])
+    }
+
     var topMostState: FloatingPanelPosition {
         return supportedPositions.sorted(by: { $0.rawValue < $1.rawValue }).first ?? .hidden
     }
@@ -452,7 +457,7 @@ class FloatingPanelLayoutAdapter {
             case .fromSuperview:
                 ret = topY
             }
-            return max(ret, 0.0) // The top boundary is equal to the related topAnchor.
+            return ret
         }()
         let bottomMostConst: CGFloat = {
             var ret: CGFloat = 0.0
@@ -463,7 +468,7 @@ class FloatingPanelLayoutAdapter {
             case .fromSuperview:
                 ret = _bottomY
             }
-            return min(ret, surfaceView.superview!.bounds.height)
+            return ret
         }()
         let minConst = allowsTopBuffer ? topMostConst - layout.topInteractionBuffer : topMostConst
         let maxConst = bottomMostConst + layout.bottomInteractionBuffer
@@ -515,7 +520,7 @@ class FloatingPanelLayoutAdapter {
 
         setBackdropAlpha(of: state)
 
-        if isValid(state) == false {
+        if validPositions.contains(state) == false {
             state = layout.initialPosition
         }
 
@@ -537,10 +542,6 @@ class FloatingPanelLayoutAdapter {
         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 }
@@ -559,8 +560,8 @@ class FloatingPanelLayoutAdapter {
     private func checkLayoutConsistance() {
         // Verify layout configurations
         assert(supportedPositions.count > 0)
-        assert(supportedPositions.contains(layout.initialPosition),
-               "Does not include an initial position (\(layout.initialPosition)) in supportedPositions (\(supportedPositions))")
+        assert(validPositions.contains(layout.initialPosition),
+               "Does not include an initial position (\(layout.initialPosition)) in (\(validPositions))")
 
         if layout is FloatingPanelIntrinsicLayout {
             assert(layout.insetFor(position: .full) == nil, "Return `nil` for full position on FloatingPanelIntrinsicLayout")

Framework/Sources/FloatingPanelSurfaceView.swift

@@ -34,7 +34,7 @@ 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.
     public var contentInsets: UIEdgeInsets = .zero {
         didSet {
@@ -101,7 +101,7 @@ public class FloatingPanelSurfaceView: UIView {
     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
@@ -228,6 +228,7 @@ public class FloatingPanelSurfaceView: UIView {
         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)
+        heightConstraint.priority = UILayoutPriority(999)
         NSLayoutConstraint.activate([
             topConstraint,
             leftConstraint,

Framework/Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.7.0</string>
+	<string>1.7.5</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 </dict>

Framework/Sources/UIExtensions.swift

@@ -114,9 +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
     }
@@ -133,8 +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)
     }
 }
 

Framework/Tests/FloatingPanelControllerTests.swift

@@ -101,6 +101,22 @@ class FloatingPanelControllerTests: XCTestCase {
         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)

Framework/Tests/FloatingPanelLayoutTests.swift

@@ -195,6 +195,43 @@ class FloatingPanelLayoutTests: XCTestCase {
         fpc.floatingPanel.layoutAdapter.endInteraction(at: fpc.position)
     }
 
+    func test_updateInteractiveTopConstraintWithMinusInsets() {
+        class FloatingPanelLayoutMinusInsets: FloatingPanelTestLayout {
+            let initialPosition: FloatingPanelPosition = .full
+            let supportedPositions: Set<FloatingPanelPosition> = [.tip, .full]
+            func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+                switch position {
+                case .full, .tip: return -200
+                default: return nil
+                }
+            }
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayoutMinusInsets()
+        fpc.delegate = delegate
+        fpc.showForTest()
+        fpc.floatingPanel.layoutAdapter.startInteraction(at: fpc.position)
+
+        let fullPos = fpc.originYOfSurface(for: .full)
+        let tipPos = fpc.originYOfSurface(for: .tip)
+        let current = fpc.surfaceView.frame.minY
+
+        var next: CGFloat
+        fpc.floatingPanel.layoutAdapter.updateInteractiveTopConstraint(diff: -100.0, allowsTopBuffer: false, with: fpc.behavior)
+        next = fpc.surfaceView.frame.minY
+        XCTAssertEqual(next, current)
+
+        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: 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_positionReference() {
         fpc = CustomSafeAreaFloatingPanelController()
         fpc.loadViewIfNeeded()
@@ -238,7 +275,7 @@ class FloatingPanelLayoutTests: XCTestCase {
 }
 
 private typealias LayoutSegmentTestParameter = (UInt, pos: CGFloat, forwardY: Bool, lower: FloatingPanelPosition?, upper: FloatingPanelPosition?)
-private func assertLayoutSegment(_ floatingPanel: FloatingPanel, with params: [LayoutSegmentTestParameter]) {
+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)

Framework/Tests/FloatingPanelTests.swift

@@ -523,7 +523,7 @@ private class FloatingPanelLayout3Positions: FloatingPanelTestLayout {
 }
 
 private typealias TestParameter = (UInt, CGFloat,CGPoint, FloatingPanelPosition)
-private func assertTargetPosition(_ floatingPanel: FloatingPanel, with params: [TestParameter]) {
+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)

README.md

@@ -36,7 +36,7 @@ The new interface displays the related contents and utilities in parallel as a u
     - [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 `FloatingPanelContrller.view`, not the SafeArea](#specify-position-insets-from-the-frame-of-floatingpanelcontrllerview-not-the-safearea)
+    - [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)
     - [Activate the rubber-band effect on the top/bottom edges](#activate-the-rubber-band-effect-on-the-topbottom-edges)
@@ -181,41 +181,60 @@ 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
 
@@ -227,6 +246,8 @@ fpc.contentMode = .fitToBounds
 
 Otherwise, `FloatingPanelController` fixes the content by the height of the top most position.
 
+✏️ In `.fitToBounds` mode, the surface height changes as following a user interaction so that you have a responsibility to configure Auto Layout constrains not to break the layout of a content view by the elastic surface height.
+
 ### Customize the layout with `FloatingPanelLayout` protocol
 
 #### Change the initial position and height
@@ -317,7 +338,7 @@ class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
 }
 ```
 
-#### Specify position insets from the frame of `FloatingPanelContrller.view`, not the SafeArea
+#### 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.
 
@@ -378,7 +399,7 @@ This allows full projectional panel behavior. For example, a user can swipe up a
 ```swift
 class FloatingPanelBehavior: FloatingPanelBehavior {
     ...
-    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool
+    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
         return true
     }
 }