Fix the scroll tracking of WKWebView on iOS 17.4

Examples/Samples/Samples.xcodeproj/project.pbxproj

@@ -32,6 +32,8 @@
 		54CDC5D8215BBE23007D205C /* SupplementaryViews.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CDC5D7215BBE23007D205C /* SupplementaryViews.swift */; };
 		54EAD35B263A75EB006A36EA /* PanelLayouts.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54EAD35A263A75EB006A36EA /* PanelLayouts.swift */; };
 		54EAD365263A765F006A36EA /* PagePanelController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54EAD364263A765F006A36EA /* PagePanelController.swift */; };
+		54F185822BF4AD0000916F57 /* DebugListCollectionViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54F185812BF4AD0000916F57 /* DebugListCollectionViewController.swift */; };
+		54F185842BF4B82E00916F57 /* UnavailableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54F185832BF4B82E00916F57 /* UnavailableViewController.swift */; };
 		5D82A6AD28D1843C006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6AC28D18438006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
@@ -76,6 +78,8 @@
 		54CDC5D7215BBE23007D205C /* SupplementaryViews.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SupplementaryViews.swift; sourceTree = "<group>"; };
 		54EAD35A263A75EB006A36EA /* PanelLayouts.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PanelLayouts.swift; sourceTree = "<group>"; };
 		54EAD364263A765F006A36EA /* PagePanelController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PagePanelController.swift; sourceTree = "<group>"; };
+		54F185812BF4AD0000916F57 /* DebugListCollectionViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DebugListCollectionViewController.swift; sourceTree = "<group>"; };
+		54F185832BF4B82E00916F57 /* UnavailableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UnavailableViewController.swift; sourceTree = "<group>"; };
 		5D82A6AC28D18438006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
@@ -97,6 +101,7 @@
 			children = (
 				5442E23F25FC533800A26F43 /* DebugTableViewController.swift */,
 				5442E24925FC53C100A26F43 /* DebugTextViewController.swift */,
+				54F185812BF4AD0000916F57 /* DebugListCollectionViewController.swift */,
 				5442E23325FC528400A26F43 /* DetailViewController.swift */,
 				5442E24325FC538200A26F43 /* InspectorViewController.swift */,
 				5442E22325FC51AF00A26F43 /* ImageViewController.swift */,
@@ -106,6 +111,7 @@
 				5442E22B25FC521F00A26F43 /* SettingsViewController.swift */,
 				5442E22F25FC525200A26F43 /* TabBarViewController.swift */,
 				544BC56726CC918200D0A436 /* AdaptiveLayoutTestViewController.swift */,
+				54F185832BF4B82E00916F57 /* UnavailableViewController.swift */,
 			);
 			path = ContentViewControllers;
 			sourceTree = "<group>";
@@ -247,6 +253,7 @@
 				5442E23A25FC52CD00A26F43 /* ModalViewController.swift in Sources */,
 				5442E22425FC51AF00A26F43 /* ImageViewController.swift in Sources */,
 				5442E24025FC533800A26F43 /* DebugTableViewController.swift in Sources */,
+				54F185822BF4AD0000916F57 /* DebugListCollectionViewController.swift in Sources */,
 				5442E25225FC541700A26F43 /* NestedScrollViewController.swift in Sources */,
 				5442E22825FC51E200A26F43 /* MultiPanelController.swift in Sources */,
 				546341A125C6415100CA0596 /* UseCase.swift in Sources */,
@@ -257,6 +264,7 @@
 				54EAD365263A765F006A36EA /* PagePanelController.swift in Sources */,
 				5442E24425FC538200A26F43 /* InspectorViewController.swift in Sources */,
 				5442E22C25FC521F00A26F43 /* SettingsViewController.swift in Sources */,
+				54F185842BF4B82E00916F57 /* UnavailableViewController.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Examples/Samples/Sources/ContentViewControllers/DebugListCollectionViewController.swift

@@ -0,0 +1,77 @@
+// Copyright 2018 the FloatingPanel authors. All rights reserved. MIT license.
+
+import UIKit
+
+@available(iOS 14, *)
+class DebugListCollectionViewController: UIViewController {
+
+    enum Section {
+        case main
+    }
+
+    var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil
+    var collectionView: UICollectionView! = nil
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        navigationItem.title = "List"
+        configureHierarchy()
+        configureDataSource()
+    }
+}
+
+@available(iOS 14, *)
+extension DebugListCollectionViewController {
+    /// - Tag: List
+    private func createLayout() -> UICollectionViewLayout {
+        var config = UICollectionLayoutListConfiguration(appearance: .insetGrouped)
+        config.trailingSwipeActionsConfigurationProvider =  { indexPath -> UISwipeActionsConfiguration? in
+            return UISwipeActionsConfiguration(
+                actions: [UIContextualAction(
+                    style: .destructive,
+                    title: "Delete",
+                    handler: { _, _, completion in
+                        // Do nothing now
+                    }
+                )]
+            )
+        }
+        return UICollectionViewCompositionalLayout.list(using: config)
+    }
+}
+
+@available(iOS 14, *)
+extension DebugListCollectionViewController {
+    private func configureHierarchy() {
+        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout())
+        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        view.addSubview(collectionView)
+        collectionView.delegate = self
+    }
+    private func configureDataSource() {
+
+        let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { (cell, indexPath, item) in
+            var content = cell.defaultContentConfiguration()
+            content.text = "\(item)"
+            cell.contentConfiguration = content
+        }
+
+        dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: collectionView) {
+            (collectionView: UICollectionView, indexPath: IndexPath, identifier: Int) -> UICollectionViewCell? in
+
+            return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: identifier)
+        }
+
+        var snapshot = NSDiffableDataSourceSnapshot<Section, Int>()
+        snapshot.appendSections([.main])
+        snapshot.appendItems(Array(0..<94))
+        dataSource.apply(snapshot, animatingDifferences: false)
+    }
+}
+
+@available(iOS 14, *)
+extension DebugListCollectionViewController: UICollectionViewDelegate {
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
+        collectionView.deselectItem(at: indexPath, animated: true)
+    }
+}

Examples/Samples/Sources/ContentViewControllers/UnavailableViewController.swift

@@ -0,0 +1,24 @@
+// Copyright 2018 the FloatingPanel authors. All rights reserved. MIT license.
+
+import UIKit
+
+class UnavailableViewController: UIViewController {
+    weak var label: UILabel!
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        let label = UILabel()
+        label.text = "Unavailable content"
+        label.numberOfLines = 0
+        label.textAlignment = .center
+        label.frame = view.bounds
+        label.autoresizingMask = [
+            .flexibleTopMargin,
+            .flexibleLeftMargin,
+            .flexibleBottomMargin,
+            .flexibleRightMargin
+        ]
+        view.addSubview(label)
+        self.label = label
+    }
+}

Examples/Samples/Sources/UseCases/UseCase.swift

@@ -5,6 +5,7 @@ import UIKit
 enum UseCase: Int, CaseIterable {
     case trackingTableView
     case trackingTextView
+    case trackingCollectionViewList
     case showDetail
     case showModal
     case showPanelModal
@@ -31,6 +32,7 @@ extension UseCase {
     var name: String {
         switch self {
         case .trackingTableView: return "Scroll tracking(TableView)"
+        case .trackingCollectionViewList: return "Scroll tracking(List CollectionView)"
         case .trackingTextView: return "Scroll tracking(TextView)"
         case .showDetail: return "Show Detail Panel"
         case .showModal: return "Show Modal"
@@ -65,6 +67,15 @@ extension UseCase {
     private var content: Content {
         switch self {
         case .trackingTableView: return .viewController(DebugTableViewController())
+        case .trackingCollectionViewList:
+            if #available(iOS 14, *) {
+                return .viewController(DebugListCollectionViewController())
+            } else {
+                let vc = UnavailableViewController()
+                vc.loadViewIfNeeded()
+                vc.label.text = "UICollectionLayoutListConfiguration is unavailable.\nBuild this app on iOS 14 and later."
+                return .viewController(vc)
+            }
         case .trackingTextView: return .storyboard("ConsoleViewController") // Storyboard only
         case .showDetail: return .storyboard(String(describing: DetailViewController.self))
         case .showModal: return .storyboard(String(describing: ModalViewController.self))

Examples/Samples/Sources/UseCases/UseCaseController.swift

@@ -52,6 +52,30 @@ extension UseCaseController {
             fpc.ext_trackScrollView(in: contentVC)
             addMain(panel: fpc)
 
+         case .trackingCollectionViewList:
+            let fpc = FloatingPanelController()
+            fpc.delegate = self
+            fpc.contentInsetAdjustmentBehavior = .always
+            fpc.surfaceView.appearance = {
+                let appearance = SurfaceAppearance()
+                appearance.cornerRadius = 6.0
+                return appearance
+            }()
+
+            let tapGesture = UITapGestureRecognizer(target: self, action: #selector(UseCaseController.handleSurface(tapGesture:)))
+            tapGesture.cancelsTouchesInView = false
+            tapGesture.numberOfTapsRequired = 2
+            // Prevents a delay to response a tap in menus of DebugTableViewController.
+            tapGesture.delaysTouchesEnded = false
+            fpc.surfaceView.addGestureRecognizer(tapGesture)
+
+            fpc.set(contentViewController: contentVC)
+            if #available(iOS 14, *),
+                let scrollView = (fpc.contentViewController as? DebugListCollectionViewController)?.collectionView {
+                    fpc.track(scrollView: scrollView)
+            }
+            addMain(panel: fpc)
+
         case .trackingTextView:
             let fpc = FloatingPanelController()
             fpc.delegate = self

Sources/Core.swift

@@ -588,11 +588,16 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         // When no scrollView, nothing to handle.
         guard let scrollView = scrollView, scrollView.frame.contains(initialLocation) else { return false }
 
-        // For _UISwipeActionPanGestureRecognizer
-        if let scrollGestureRecognizers = scrollView.gestureRecognizers {
+        // Prevents moving a panel on swipe actions using _UISwipeActionPanGestureRecognizer.
+        // [Warning] Do not apply this to WKWebView. Since iOS 17.4, WKWebView has an additional pan
+        // gesture recognizer besides UIScrollViewPanGestureRecognizer. Applying this to WKWebView
+        // will block panel movements because another pan gesture isn't `scrollView.panGestureRecognizer`.
+        if let scrollGestureRecognizers = scrollView.gestureRecognizers,
+            scrollView is UITableView || scrollView is UICollectionView {
             for gesture in scrollGestureRecognizers {
-                guard gesture.state == .began || gesture.state == .changed
-                else { continue }
+                guard gesture.state == .began || gesture.state == .changed else {
+                    continue
+                }
 
                 if gesture != scrollView.panGestureRecognizer {
                     return true