Replace FilePreviewScreen with InteractiveQuickLook. (#1187)

* Replace FilePreviewScreen with InteractiveQuickLook. - Allows full screen presentation. - Allows dismiss gesture to work. - Presentation looks much better on macOS.
2026-11-03 06:55:59 +00:00 · 2023-06-28 15:32:16 +01:00
parent 908b368680
commit afbb0a8260
14 changed files with 147 additions and 363 deletions
@@ -0,0 +1,130 @@
+//
+// Copyright 2022 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import QuickLook
+import SwiftUI
+
+extension View {
+    /// Preview a media file using a QuickLook Preview Controller. The preview is interactive with
+    /// the dismiss gesture working as expected if it was presented from UIKit.
+    func interactiveQuickLook(item: Binding<MediaPreviewItem?>) -> some View {
+        modifier(InteractiveQuickLookModifier(item: item))
+    }
+}
+
+private struct InteractiveQuickLookModifier: ViewModifier {
+    @Binding var item: MediaPreviewItem?
+    
+    func body(content: Content) -> some View {
+        content.background {
+            if let item {
+                MediaPreviewViewController(previewItem: item) { self.item = nil }
+            }
+        }
+    }
+}
+
+private struct MediaPreviewViewController: UIViewControllerRepresentable {
+    let previewItem: MediaPreviewItem
+    let onDismiss: () -> Void
+
+    func makeUIViewController(context: Context) -> PreviewHostingController {
+        PreviewHostingController(previewItem: previewItem, onDismiss: onDismiss)
+    }
+
+    func updateUIViewController(_ uiViewController: PreviewHostingController, context: Context) { }
+    
+    /// A view controller that hosts the QuickLook preview.
+    ///
+    /// This wrapper somehow allows the preview controller to do presentation/dismissal
+    /// animations and interactions which don't work if you represent it directly to SwiftUI 🤷‍♂️
+    class PreviewHostingController: UIViewController, QLPreviewControllerDataSource, QLPreviewControllerDelegate {
+        let previewItem: MediaPreviewItem
+        let onDismiss: () -> Void
+        
+        var previewController: QLPreviewController?
+
+        init(previewItem: MediaPreviewItem, onDismiss: @escaping () -> Void) {
+            self.previewItem = previewItem
+            self.onDismiss = onDismiss
+            
+            super.init(nibName: nil, bundle: nil)
+        }
+        
+        @available(*, unavailable)
+        required init?(coder: NSCoder) {
+            fatalError("init(coder:) has not been implemented")
+        }
+        
+        override func viewDidLoad() {
+            view.backgroundColor = .clear
+        }
+        
+        override func viewWillAppear(_ animated: Bool) {
+            super.viewWillAppear(animated)
+            
+            guard self.previewController == nil else { return }
+            
+            let previewController = QLPreviewController()
+            previewController.dataSource = self
+            previewController.delegate = self
+            present(previewController, animated: true)
+            
+            self.previewController = previewController
+        }
+        
+        // MARK: QLPreviewControllerDataSource
+        
+        func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
+            1
+        }
+
+        func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
+            previewItem
+        }
+        
+        // MARK: QLPreviewControllerDelegate
+        
+        func previewControllerDidDismiss(_ controller: QLPreviewController) {
+            onDismiss()
+        }
+    }
+}
+
+/// Wraps a media file and title to be previewed with QuickLook.
+class MediaPreviewItem: NSObject, QLPreviewItem {
+    let file: MediaFileHandleProxy
+    
+    var previewItemURL: URL? { file.url }
+    let previewItemTitle: String?
+
+    init(file: MediaFileHandleProxy, title: String?) {
+        self.file = file
+        previewItemTitle = title
+    }
+}
+
+// MARK: - Previews
+
+struct PreviewView_Previews: PreviewProvider {
+    static let previewURL = URL(staticString: "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf")
+    static let previewItem = MediaPreviewItem(file: .unmanaged(url: previewURL),
+                                              title: "Important Document")
+    
+    static var previews: some View {
+        MediaPreviewViewController(previewItem: previewItem) { }
+    }
+}