Multi file uploads (#4358)

* Allow MediaPickerScreen users to select the media selection mode (single or multiple)

* Fix cancellation

* Add support for multiple media URLs on the MediaUploadPreviewScreen.

* Support processing more URLs on the `MediaUploadingPreprocessor` and sending more on the `MediaUploadPreviewScreen`

* Add feature flag for `multipleAttachmentUploadEnabled`

* Add a label showing the current preview item index in the MediaUploadPreviewScreen

* Add support for dragging and dropping or pasting multiple items at the same time.

* Support sharing more than one file through the share extension.

* Limit the number of items that can be shared in one go to 5.

* Fix unit tests

* Fix incorrect fatal error when dealing with single selection media pickers.

* Document the `multipleAttachmentUploadEnabled` usage in the context of the MediaPicker.

* Use a task group for processing selected media in the photo library picker.

* Use a task group for processing multiple selected media in the MediaUploadingPreprocessor

* Switch the maximum number of items that can be shared to 10.

* Allow multiple items to be pasted at the same time.

ElementX/Sources/Screens/Timeline/TimelineInteractionHandler.swift

@@ -14,7 +14,7 @@ enum TimelineInteractionHandlerAction {
     case displayEmojiPicker(itemID: TimelineItemIdentifier, selectedEmojis: Set<String>)
     case displayReportContent(itemID: TimelineItemIdentifier, senderID: String)
     case displayMessageForwarding(itemID: TimelineItemIdentifier)
-    case displayMediaUploadPreviewScreen(url: URL)
+    case displayMediaUploadPreviewScreen(mediaURLs: [URL])
     case displayPollForm(mode: PollFormMode)
     
     case showActionMenu(TimelineItemActionMenuInfo)
@@ -277,7 +277,7 @@ class TimelineInteractionHandler {
     
     // MARK: Pasting and dropping
     
-    func handlePasteOrDrop(_ provider: NSItemProvider) {
+    func handlePasteOrDrop(_ providers: [NSItemProvider]) {
         Task {
             let loadingIndicatorIdentifier = UUID().uuidString
             self.userIndicatorController.submitIndicator(UserIndicator(id: loadingIndicatorIdentifier, type: .modal, title: L10n.commonLoading, persistent: true))
@@ -285,13 +285,19 @@ class TimelineInteractionHandler {
                 self.userIndicatorController.retractIndicatorWithId(loadingIndicatorIdentifier)
             }
             
-            guard let fileURL = await provider.storeData() else {
-                MXLog.error("Failed storing NSItemProvider data \(provider)")
-                self.actionsSubject.send(.displayErrorToast(L10n.screenRoomErrorFailedProcessingMedia))
-                return
+            var mediaURLs = [URL]()
+            for provider in providers {
+                if let fileURL = await provider.storeData() {
+                    mediaURLs.append(fileURL)
+                } else {
+                    MXLog.error("Failed storing NSItemProvider data \(provider)")
+                    self.actionsSubject.send(.displayErrorToast(L10n.screenRoomErrorFailedProcessingMedia))
+                }
             }
             
-            self.actionsSubject.send(.displayMediaUploadPreviewScreen(url: fileURL))
+            if !mediaURLs.isEmpty {
+                self.actionsSubject.send(.displayMediaUploadPreviewScreen(mediaURLs: mediaURLs))
+            }
         }
     }
     

ElementX/Sources/Screens/Timeline/TimelineModels.swift

@@ -18,7 +18,7 @@ enum TimelineViewModelAction {
     case displayDocumentPicker
     case displayLocationPicker
     case displayPollForm(mode: PollFormMode)
-    case displayMediaUploadPreviewScreen(url: URL)
+    case displayMediaUploadPreviewScreen(mediaURLs: [URL])
     case displaySenderDetails(userID: String)
     case displayMessageForwarding(forwardingItem: MessageForwardingItem)
     case displayMediaPreview(TimelineMediaPreviewViewModel)
@@ -63,7 +63,7 @@ enum TimelineViewAction {
     case displayReadReceipts(itemID: TimelineItemIdentifier)
     case displayThread(itemID: TimelineItemIdentifier)
     
-    case handlePasteOrDrop(provider: NSItemProvider)
+    case handlePasteOrDrop(providers: [NSItemProvider])
     case handlePollAction(TimelineViewPollAction)
     case handleAudioPlayerAction(TimelineAudioPlayerAction)
     

ElementX/Sources/Screens/Timeline/TimelineViewModel.swift

@@ -192,8 +192,8 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
             displayReadReceipts(for: itemID)
         case .displayThread(let itemID):
             actionsSubject.send(.displayThread(itemID: itemID))
-        case .handlePasteOrDrop(let provider):
-            timelineInteractionHandler.handlePasteOrDrop(provider)
+        case .handlePasteOrDrop(let providers):
+            timelineInteractionHandler.handlePasteOrDrop(providers)
         case .handlePollAction(let pollAction):
             handlePollAction(pollAction)
         case .handleAudioPlayerAction(let audioPlayerAction):
@@ -231,8 +231,8 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
             editLastMessage()
         case .attach(let attachment):
             attach(attachment)
-        case .handlePasteOrDrop(let provider):
-            timelineInteractionHandler.handlePasteOrDrop(provider)
+        case .handlePasteOrDrop(let providers):
+            timelineInteractionHandler.handlePasteOrDrop(providers)
         case .composerModeChanged(mode: let mode):
             trackComposerMode(mode)
         case .composerFocusedChanged(isFocused: let isFocused):
@@ -480,8 +480,8 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
                     actionsSubject.send(.displayPollForm(mode: mode))
                 case .displayReportContent(let itemID, let senderID):
                     actionsSubject.send(.displayReportContent(itemID: itemID, senderID: senderID))
-                case .displayMediaUploadPreviewScreen(let url):
-                    actionsSubject.send(.displayMediaUploadPreviewScreen(url: url))
+                case .displayMediaUploadPreviewScreen(let mediaURLs):
+                    actionsSubject.send(.displayMediaUploadPreviewScreen(mediaURLs: mediaURLs))
                 case .showActionMenu(let actionMenuInfo):
                     self.state.bindings.actionMenuInfo = actionMenuInfo
                 case .showDebugInfo(let debugInfo):

ElementX/Sources/Screens/Timeline/View/TimelineView.swift

@@ -55,12 +55,13 @@ struct TimelineView: View {
                     .environmentObject(timelineContext)
             }
             .onDrop(of: ["public.item", "public.file-url"], isTargeted: $dragOver) { providers -> Bool in
-                guard let provider = providers.first,
-                      provider.isSupportedForPasteOrDrop else {
+                let supportedProviders = providers.filter(\.isSupportedForPasteOrDrop)
+                
+                guard !supportedProviders.isEmpty else {
                     return false
                 }
                 
-                timelineContext.send(viewAction: .handlePasteOrDrop(provider: provider))
+                timelineContext.send(viewAction: .handlePasteOrDrop(providers: supportedProviders))
                 return true
             }
     }