QuickLook swipe down and less message motion when coming back from GiveBackMyFirstResponder

deltachat-ios/Chat/ChatViewController.swift

@@ -202,6 +202,9 @@ class ChatViewController: UITableViewController, UITableViewDropDelegate {
         set { _bag = newValue }
     }
 
+    private var previewControllerTargetSnapshot: UIView?
+    private var previewControllerTargetHiddenOriginal: UIView?
+
     init(dcContext: DcContext, chatId: Int, highlightedMsg: Int? = nil) {
         self.dcContext = dcContext
         self.chatId = chatId
@@ -258,7 +261,29 @@ class ChatViewController: UITableViewController, UITableViewDropDelegate {
 
         // Binding to the tableView will enable interactive dismissal
         keyboardManager?.bind(to: tableView)
-        keyboardManager?.on(event: .willShow) { [tableView = tableView!] notification in
+        var shouldDebounceWillShow = false
+        var willShowDebounceTimer: Timer?
+        keyboardManager?.on(event: .didHide) { [weak self] _ in
+            // Debounce when input accessory view was completely hidden because when it comes
+            // back there is a chance that we first need to make ChatViewController firstResponder,
+            // and then the text field. This would cause two scroll view inset updates.
+            shouldDebounceWillShow = shouldDebounceWillShow || !(self?.canBecomeFirstResponder ?? true)
+        }
+        keyboardManager?.on(event: .willShow) { [weak self, tableView = tableView!] notification in
+            // Don't react to first responder changes in presented view controllers
+            guard self?.canBecomeFirstResponder == true else { return }
+            willShowDebounceTimer?.invalidate()
+            if shouldDebounceWillShow {
+                willShowDebounceTimer = Timer.scheduledTimer(withTimeInterval: 0.5, repeats: false) { _ in
+                    animateTableViewInset(notification: notification, tableView: tableView)
+                }
+            } else {
+                animateTableViewInset(notification: notification, tableView: tableView)
+            }
+        }
+        func animateTableViewInset(notification: KeyboardNotification, tableView: UITableView) {
+            shouldDebounceWillShow = false
+            willShowDebounceTimer = nil
             // Using superview instead of window here because in iOS 13+ a modal can change
             // the frame of the vc it is presented over which causes this calculation to be off.
             let globalTableViewFrame = tableView.convert(tableView.bounds, to: tableView.superview)
@@ -1998,8 +2023,9 @@ extension ChatViewController {
     func showMediaGalleryFor(message: DcMsg) {
         let msgIds = dcContext.getChatMedia(chatId: chatId, messageType: Int32(message.type), messageType2: 0, messageType3: 0)
         let index = msgIds.firstIndex(of: message.id) ?? 0
-
-        navigationController?.pushViewController(PreviewController(dcContext: dcContext, type: .multi(msgIds, index)), animated: true)
+        let previewController = PreviewController(dcContext: dcContext, type: .multi(msgIds: msgIds, index: index))
+        previewController.delegate = self
+        present(previewController, animated: true)
     }
 
     private func didTapAsm(msg: DcMsg, orgText: String) {
@@ -2395,7 +2421,7 @@ extension ChatViewController: DraftPreviewDelegate {
                     previewController.setEditing(true, animated: true)
                     previewController.delegate = self
                 }
-                navigationController?.pushViewController(previewController, animated: true)
+                present(previewController, animated: true)
             }
         }
     }
@@ -2543,15 +2569,78 @@ extension ChatViewController: ChatContactRequestDelegate {
 // MARK: - QLPreviewControllerDelegate
 extension ChatViewController: QLPreviewControllerDelegate {
     func previewController(_ controller: QLPreviewController, editingModeFor previewItem: QLPreviewItem) -> QLPreviewItemEditingMode {
-        return .updateContents
+        if isDraftPreviewItem(previewItem) {
+            return .updateContents
+        } else {
+            return .disabled
+        }
     }
 
     func previewController(_ controller: QLPreviewController, didUpdateContentsOf previewItem: QLPreviewItem) {
-        DispatchQueue.main.async { [weak self] in
-            guard let self else { return }
-            self.draftArea.reload(draft: self.draft)
+        if isDraftPreviewItem(previewItem) {
+            DispatchQueue.main.async { [weak self] in
+                guard let self else { return }
+                self.draftArea.reload(draft: self.draft)
+            }
+        }
+    }
+
+    /// Since iOS 16 we can't just return a frame anymore so we return a view.
+    /// Since tableView is flipped we add a snapshot to the superview which we later remove.
+    func previewController(_ controller: QLPreviewController, transitionViewFor item: any QLPreviewItem) -> UIView? {
+        guard let item = item as? PreviewItem else { return nil }
+
+        if isDraftPreviewItem(item) {
+            let snapshot = UIImageView(image: draftArea.mediaPreview.contentImageView.image)
+            snapshot.layer.opacity = 0
+            snapshot.frame = draftArea.mediaPreview.contentImageView.convert(
+                draftArea.mediaPreview.contentImageView.frame,
+                to: draftArea.mainContentView
+            )
+            // Place the snapshot below the tableView, outside of the screen so the
+            // preview controller animates towards where the inputAccessoryView will
+            // pop back in from, when firstResponder is returned.
+            snapshot.frame.origin.y = (tableView.superview ?? tableView).frame.maxY
+            tableView.superview?.addSubview(snapshot)
+            previewControllerTargetSnapshot?.removeFromSuperview()
+            previewControllerTargetSnapshot = snapshot
+            return snapshot
+        } else if let msgId = item.messageId, let row = messageIds.firstIndex(of: msgId) {
+            previewControllerTargetHiddenOriginal?.layer.opacity = 1
+            previewControllerTargetSnapshot?.removeFromSuperview()
+            // Scroll to the message that will be dismissed
+            let indexPath = IndexPath(row: row, section: 0)
+            if tableView.indexPathsForVisibleRows?.contains(indexPath) == false {
+                tableView.scrollToRow(at: indexPath, at: .none, animated: false)
+            }
+            if let cell = tableView.cellForRow(at: indexPath) as? BaseMessageCell,
+               let snapshot = cell.messageBackgroundContainer.snapshotView(afterScreenUpdates: true) {
+                if cell is ImageTextCell { // hide cell while transitioning
+                    cell.layer.opacity = 0
+                }
+                snapshot.layer.opacity = 0
+                snapshot.clipsToBounds = true
+                snapshot.frame = cell.messageBackgroundContainer.globalFrame
+                tableView.superview?.addSubview(snapshot)
+                previewControllerTargetSnapshot = snapshot
+                previewControllerTargetHiddenOriginal = cell
+                return snapshot
+            }
         }
+        return nil
     }
+
+    func previewControllerDidDismiss(_ controller: QLPreviewController) {
+        previewControllerTargetSnapshot?.removeFromSuperview()
+        previewControllerTargetSnapshot = nil
+        previewControllerTargetHiddenOriginal?.layer.opacity = 1
+        previewControllerTargetHiddenOriginal = nil
+    }
+
+    private func isDraftPreviewItem(_ item: QLPreviewItem) -> Bool {
+        item.previewItemURL?.path == draft.attachment && item.previewItemURL != nil
+    }
+
 }
 
 // MARK: - AudioControllerDelegate
@@ -2677,3 +2766,10 @@ extension ChatViewController: BackButtonUpdateable {
         }
     }
 }
+
+// TODO: Move
+extension UIView {
+    var globalFrame: CGRect {
+        return self.convert(bounds, to: nil)
+    }
+}

deltachat-ios/Controller/FilesViewController.swift

@@ -261,7 +261,7 @@ extension FilesViewController {
         guard let index = fileMessageIds.firstIndex(of: msgId) else {
             return
         }
-        let previewController = PreviewController(dcContext: dcContext, type: .multi(fileMessageIds, index))
+        let previewController = PreviewController(dcContext: dcContext, type: .multi(msgIds: fileMessageIds, index: index))
         navigationController?.pushViewController(previewController, animated: true)
     }
 

deltachat-ios/Controller/GalleryViewController.swift

@@ -199,7 +199,7 @@ extension GalleryViewController: UICollectionViewDataSource, UICollectionViewDel
     }
 
     func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
-        let previewController = PreviewController(dcContext: dcContext, type: .multi(mediaMessageIds, indexPath.row))
+        let previewController = PreviewController(dcContext: dcContext, type: .multi(msgIds: mediaMessageIds, index: indexPath.row))
         previewController.delegate = self
         navigationController?.pushViewController(previewController, animated: true)
 

deltachat-ios/Controller/PreviewController.swift

@@ -5,7 +5,7 @@ import DcCore
 class PreviewController: QLPreviewController {
     enum PreviewType {
         case single(URL)
-        case multi([Int], Int) // msgIds, index
+        case multi(msgIds: [Int], index: Int)
     }
 
     let previewType: PreviewType
@@ -49,7 +49,7 @@ extension PreviewController: QLPreviewControllerDataSource {
             return PreviewItem(url: url, title: self.customTitle)
         case .multi(let msgIds, _):
             let msg = dcContext.getMessage(id: msgIds[index])
-            return PreviewItem(url: msg.fileURL, title: self.customTitle)
+            return PreviewItem(url: msg.fileURL, title: self.customTitle, messageId: msg.id)
         }
     }
 }
@@ -58,9 +58,11 @@ extension PreviewController: QLPreviewControllerDataSource {
 class PreviewItem: NSObject, QLPreviewItem {
     var previewItemURL: URL?
     var previewItemTitle: String?
+    var messageId: Int?
 
-    init(url: URL?, title: String?) {
+    init(url: URL?, title: String?, messageId: Int? = nil) {
         self.previewItemURL = url
         self.previewItemTitle = title ?? ""
+        self.messageId = messageId
     }
 }

deltachat-ios/Helper/GiveBackMyFirstResponder.swift

@@ -1,4 +1,5 @@
 import UIKit
+import QuickLook
 
 /// https://gist.github.com/Amzd/223979ef5a06d98ef17d2d78dbd96e22
 extension UIViewController {
@@ -31,6 +32,14 @@ extension UIViewController {
         }
     }
 
+    /// QLPreviewController causes issues when dismissed using the swipe gesture if there was a first responder active when it was presented.
+    /// Issues range from freezing the previous first responder to crashing the app.
+    public func present(_ previewController: QLPreviewController, animated: Bool, completion: (() -> Void)? = nil) {
+        // QLPreviewController can not be used as child because it would not do its custom transitions
+        let vc = GiveBackMyFirstResponder.asChild(of: previewController)
+        present(vc, animated: animated, completion: completion)
+    }
+
     /// In iOS 16 and below and iOS 18 the UIImagePickerController does not give back the first responder when search was used.
     /// This function fixes that by making the previous first responder, first responder again when the image picker is dismissed.
     public func present(_ imagePicker: UIImagePickerController, animated: Bool, completion: (() -> Void)? = nil) {
@@ -64,6 +73,17 @@ private class GiveBackMyFirstResponder<VC: UIViewController>: FirstResponderRetu
         view.addSubview(culprit.view)
         culprit.didMove(toParent: self)
     }
+
+    /// Returns a type erased version of the culprit view controller with a FirstResponderReturningViewController as child.
+    /// The type erasure prevents infinite recursion in UIViewController.present.
+    static func asChild(of culprit: VC) -> UIViewController {
+        let vc = FirstResponderReturningViewController()
+        culprit.addChild(vc)
+        culprit.view.addSubview(vc.view)
+        vc.view.isUserInteractionEnabled = false
+        vc.didMove(toParent: culprit)
+        return culprit
+    }
 }
 
 private class FirstResponderReturningViewController: UIViewController {

deltachat-ios/Helper/MediaPicker.swift

@@ -158,13 +158,30 @@ class MediaPicker: NSObject, UINavigationControllerDelegate {
 extension MediaPicker: UIImagePickerControllerDelegate {
 
     func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
+        // This async basically makes sure the "Downloading from iCloud" alert is closed and
+        // the keyboard is opened again if the search bar was active. This edge case causes a crash
+        // in the KeyInput layer and prevents the keyboard from being opened until next launch (tested on iOS 16).
+        // To test this:
+        // - Remove this asyncAfter
+        // - Open Chat
+        // - Select text field so keyboard is open
+        // - Attach
+        // - Gallery
+        // - Tap search bar in image picker
+        // - Select an image that needs to be downloaded from iCloud
+        // - Keyboard should come up but it does not (on iOS 16)
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
+            self.handleImagePickerController(picker, didFinishPickingMediaWithInfo: info)
+        }
+    }
 
+    private func handleImagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
         if let type = info[.mediaType] as? String, let mediaType = PickerMediaType(rawValue: type) {
 
             switch mediaType {
             case .video:
                 if let videoUrl = info[.mediaURL] as? URL {
-                    handleVideoUrl(url: videoUrl)
+                    self.handleVideoUrl(url: videoUrl)
                 }
             case .image:
                 if let image = info[.editedImage] as? UIImage {