feat: Show download progress on shared media

Assisted-by: ClaudeCode:claude-opus-5.5
Signed-off-by: Marcel Müller <marcel-mueller@gmx.de>

Author: SystemKeeper

NextcloudTalk/Chat/ChatFileDownloadObserver.swift

@@ -0,0 +1,48 @@
+//
+// SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+import Foundation
+
+/// Follows the download of one file through the notifications NCChatFileController posts
+class ChatFileDownloadObserver {
+
+    enum Change {
+        case isDownloading(Bool)
+        /// nil while the size of the download is unknown
+        case progress(Float?)
+    }
+
+    var fileParameter: NCMessageFileParameter?
+
+    private let onChange: (Change) -> Void
+    private var observers: [NSObjectProtocol] = []
+
+    init(onChange: @escaping (Change) -> Void) {
+        self.onChange = onChange
+
+        // Download progress can be reported off the main queue
+        self.observers.append(NotificationCenter.default.addObserver(forName: .NCChatFileControllerDidChangeIsDownloading, object: nil, queue: .main) { [weak self] notification in
+            guard let status = self?.status(from: notification) else { return }
+
+            self?.onChange(.isDownloading(status.isDownloading))
+        })
+
+        self.observers.append(NotificationCenter.default.addObserver(forName: .NCChatFileControllerDidChangeDownloadProgress, object: nil, queue: .main) { [weak self] notification in
+            guard let status = self?.status(from: notification) else { return }
+
+            self?.onChange(.progress(status.canReportProgress ? Float(status.downloadProgress) : nil))
+        })
+    }
+
+    deinit {
+        self.observers.forEach { NotificationCenter.default.removeObserver($0) }
+    }
+
+    private func status(from notification: Notification) -> NCChatFileStatus? {
+        guard let fileParameter = self.fileParameter else { return nil }
+
+        return NCChatFileStatus.getStatus(from: notification, for: fileParameter)
+    }
+}

NextcloudTalk/Media Viewer/NCMediaViewerPageViewController.swift

@@ -157,6 +157,10 @@ import SwiftyGif
         return videoPlayButton
     }()
 
+    private lazy var downloadObserver = ChatFileDownloadObserver { [weak self] change in
+        self?.downloadDidChange(change)
+    }
+
     init(message: NCChatMessage, account: TalkAccount) {
         self.message = message
         self.account = account
@@ -193,7 +197,7 @@ import SwiftyGif
 
         self.navigationItem.title = self.message.file()?.name
 
-        NotificationCenter.default.addObserver(self, selector: #selector(didChangeDownloadProgress(notification:)), name: NSNotification.Name.NCChatFileControllerDidChangeDownloadProgress, object: nil)
+        self.downloadObserver.fileParameter = self.message.file()
 
         self.startLoading()
 
@@ -662,17 +666,12 @@ import SwiftyGif
         }
     }
 
-    func didChangeDownloadProgress(notification: Notification) {
-        DispatchQueue.main.async {
-            guard let fileParameter = self.message.file(),
-                  let receivedStatus = NCChatFileStatus.getStatus(from: notification, for: fileParameter),
-                  receivedStatus.canReportProgress
-            else { return }
+    private func downloadDidChange(_ change: ChatFileDownloadObserver.Change) {
+        guard case .progress(let progress?) = change else { return }
 
-            self.activityIndicator.indicatorMode = .determinate
-            self.activityIndicator.setProgress(Float(receivedStatus.downloadProgress), animated: true)
-            self.downloadIndicator.setProgress(Float(receivedStatus.downloadProgress))
-        }
+        self.activityIndicator.indicatorMode = .determinate
+        self.activityIndicator.setProgress(progress, animated: true)
+        self.downloadIndicator.setProgress(progress)
     }
 
     // MARK: - NCChatFileController delegate

NextcloudTalk/Rooms/SharedItemCells.swift

@@ -9,9 +9,17 @@ import SDWebImage
 
 class SharedItemTableViewCell: UITableViewCell {
 
-    var fileParameter: NCMessageFileParameter?
+    var fileParameter: NCMessageFileParameter? {
+        get { self.downloadObserver.fileParameter }
+        set { self.downloadObserver.fileParameter = newValue }
+    }
+
     private var activityIndicator: NCActivityIndicator?
 
+    private lazy var downloadObserver = ChatFileDownloadObserver { [weak self] change in
+        self?.downloadDidChange(change)
+    }
+
     let titleLabel: UILabel = {
         let label = UILabel()
         label.font = .preferredFont(forTextStyle: .body)
@@ -32,9 +40,6 @@ class SharedItemTableViewCell: UITableViewCell {
 
     override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
         super.init(style: style, reuseIdentifier: reuseIdentifier)
-
-        NotificationCenter.default.addObserver(self, selector: #selector(didChangeIsDownloading(notification:)), name: NSNotification.Name.NCChatFileControllerDidChangeIsDownloading, object: nil)
-        NotificationCenter.default.addObserver(self, selector: #selector(didChangeDownloadProgress(notification:)), name: NSNotification.Name.NCChatFileControllerDidChangeDownloadProgress, object: nil)
     }
 
     required init?(coder: NSCoder) {
@@ -61,35 +66,24 @@ class SharedItemTableViewCell: UITableViewCell {
         return parts.joined(separator: " ⸱ ")
     }
 
-    @objc private func didChangeIsDownloading(notification: Notification) {
-        DispatchQueue.main.async {
-            guard let fileParameter = self.fileParameter,
-                  let receivedStatus = NCChatFileStatus.getStatus(from: notification, for: fileParameter)
-            else { return }
-
-            if receivedStatus.isDownloading, self.activityIndicator == nil {
-                self.addActivityIndicator(with: 0)
-            } else if !receivedStatus.isDownloading, self.activityIndicator != nil {
-                self.accessoryView = nil
-                self.activityIndicator = nil
-            }
-        }
-    }
-
-    @objc private func didChangeDownloadProgress(notification: Notification) {
-        DispatchQueue.main.async {
-            guard let fileParameter = self.fileParameter,
-                  let receivedStatus = NCChatFileStatus.getStatus(from: notification, for: fileParameter)
-            else { return }
-
+    private func downloadDidChange(_ change: ChatFileDownloadObserver.Change) {
+        switch change {
+        case .isDownloading(true) where self.activityIndicator == nil:
+            self.addActivityIndicator(with: 0)
+        case .isDownloading(false):
+            self.accessoryView = nil
+            self.activityIndicator = nil
+        case .progress(let progress):
             if let activityIndicator = self.activityIndicator {
-                if receivedStatus.canReportProgress {
+                if let progress {
                     activityIndicator.indicatorMode = .determinate
-                    activityIndicator.setProgress(Float(receivedStatus.downloadProgress), animated: true)
+                    activityIndicator.setProgress(progress, animated: true)
                 }
             } else {
-                self.addActivityIndicator(with: Float(receivedStatus.downloadProgress))
+                self.addActivityIndicator(with: progress ?? 0)
             }
+        default:
+            break
         }
     }
 

NextcloudTalk/Rooms/SharedMediaCell.swift

@@ -15,6 +15,17 @@ class SharedMediaCell: UICollectionViewCell {
 
     private var fileId: String?
     private var previewRequest: SDWebImageCombinedOperation?
+    private var isVideo = false
+
+    private lazy var downloadObserver = ChatFileDownloadObserver { [weak self] change in
+        self?.downloadDidChange(change)
+    }
+
+    private let downloadIndicator: MediaDownloadIndicatorView = {
+        let downloadIndicator = MediaDownloadIndicatorView(frame: .zero)
+        downloadIndicator.isHidden = true
+        return downloadIndicator
+    }()
 
     private let imageView: UIImageView = {
         let imageView = UIImageView()
@@ -68,6 +79,7 @@ class SharedMediaCell: UICollectionViewCell {
         self.contentView.addSubview(self.fileIconView)
         self.contentView.addSubview(self.playIconView)
         self.contentView.addSubview(self.captionView)
+        self.contentView.addSubview(self.downloadIndicator)
         self.captionView.addSubview(self.actorLabel)
 
         for view in [self.imageView, self.fileIconView, self.playIconView, self.captionView, self.actorLabel] {
@@ -90,6 +102,9 @@ class SharedMediaCell: UICollectionViewCell {
             self.playIconView.widthAnchor.constraint(equalToConstant: 44),
             self.playIconView.heightAnchor.constraint(equalToConstant: 44),
 
+            self.downloadIndicator.centerXAnchor.constraint(equalTo: self.contentView.centerXAnchor),
+            self.downloadIndicator.centerYAnchor.constraint(equalTo: self.contentView.centerYAnchor),
+
             self.captionView.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor),
             self.captionView.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor),
             self.captionView.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor),
@@ -128,6 +143,8 @@ class SharedMediaCell: UICollectionViewCell {
         self.fileId = nil
         self.imageView.image = nil
         self.fileIconView.isHidden = true
+        self.downloadObserver.fileParameter = nil
+        self.showsDownload(false)
     }
 
     func configure(with message: NCChatMessage, aspectRatio: CGFloat, showsServerPreview: Bool, account: TalkAccount) {
@@ -137,7 +154,10 @@ class SharedMediaCell: UICollectionViewCell {
         self.fileId = file?.parameterId
         self.actorLabel.text = actorDisplayName
         self.captionView.isHidden = actorDisplayName.isEmpty
-        self.playIconView.isHidden = !NCUtils.isVideo(fileType: file?.mimetype ?? "")
+        self.isVideo = NCUtils.isVideo(fileType: file?.mimetype ?? "")
+        self.downloadObserver.fileParameter = file
+        // A download started before this cell showed the file only reports its next change
+        self.showsDownload(file.flatMap { ChatFileDownloader.shared.downloadStatus(forFileId: $0.parameterId)?.isDownloading } ?? false)
         self.accessibilityLabel = [file?.name ?? "", actorDisplayName].filter { !$0.isEmpty }.joined(separator: ", ")
 
         guard let file, file.previewAvailable else {
@@ -170,6 +190,30 @@ class SharedMediaCell: UICollectionViewCell {
         }
     }
 
+    private func downloadDidChange(_ change: ChatFileDownloadObserver.Change) {
+        switch change {
+        case .isDownloading(let isDownloading):
+            self.showsDownload(isDownloading)
+        case .progress(let progress):
+            self.showsDownload(true)
+
+            if let progress {
+                self.downloadIndicator.setProgress(progress)
+            }
+        }
+    }
+
+    private func showsDownload(_ showsDownload: Bool) {
+        if showsDownload, self.downloadIndicator.isHidden {
+            self.downloadIndicator.showProgress()
+        } else if !showsDownload {
+            self.downloadIndicator.stopAnimating()
+        }
+
+        self.downloadIndicator.isHidden = !showsDownload
+        self.playIconView.isHidden = showsDownload || !self.isVideo
+    }
+
     private func showFileIcon(for file: NCMessageFileParameter?) {
         self.imageView.image = nil
         self.fileIconView.image = UIImage(named: NCUtils.previewImage(forMimeType: file?.mimetype))