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.

ShareExtension/Sources/ShareExtensionViewController.swift

@@ -63,23 +63,32 @@ class ShareExtensionViewController: UIViewController {
     // MARK: - Private
     
     private func prepareSharePayload() async -> ShareExtensionPayload? {
-        guard let extensionItem = extensionContext?.inputItems.first as? NSExtensionItem,
-              let itemProvider = extensionItem.attachments?.first else {
+        guard let extensionContext,
+              let extensionItem = extensionContext.inputItems.first as? NSExtensionItem,
+              let itemProviders = extensionItem.attachments else {
             return nil
         }
         
-        let roomID = (extensionContext?.intent as? INSendMessageIntent)?.conversationIdentifier
+        let roomID = (extensionContext.intent as? INSendMessageIntent)?.conversationIdentifier
         
-        if let fileURL = await itemProvider.storeData(withinAppGroupContainer: true) {
-            return .mediaFile(roomID: roomID, mediaFile: .init(url: fileURL, suggestedName: fileURL.lastPathComponent))
-        } else if let url = await itemProvider.loadTransferable(type: URL.self) {
-            return .text(roomID: roomID, text: url.absoluteString)
-        } else if let string = await itemProvider.loadString() {
-            return .text(roomID: roomID, text: string)
-        } else {
-            MXLog.error("Failed loading NSItemProvider data: \(itemProvider)")
-            return nil
+        var mediaFiles = [ShareExtensionMediaFile]()
+        for itemProvider in itemProviders {
+            if let fileURL = await itemProvider.storeData(withinAppGroupContainer: true) {
+                mediaFiles.append(.init(url: fileURL, suggestedName: fileURL.lastPathComponent))
+            } else if let url = await itemProvider.loadTransferable(type: URL.self) {
+                return .text(roomID: roomID, text: url.absoluteString)
+            } else if let string = await itemProvider.loadString() {
+                return .text(roomID: roomID, text: string)
+            } else {
+                MXLog.error("Failed loading NSItemProvider data: \(itemProvider)")
+            }
         }
+        
+        if !mediaFiles.isEmpty {
+            return .mediaFiles(roomID: roomID, mediaFiles: mediaFiles)
+        }
+        
+        return nil
     }
     
     private func openMainApp(payload: ShareExtensionPayload) async {

ShareExtension/SupportingFiles/Info.plist

@@ -31,15 +31,15 @@
 			<key>NSExtensionActivationRule</key>
 			<dict>
 				<key>NSExtensionActivationSupportsFileWithMaxCount</key>
-				<integer>1</integer>
+				<integer>10</integer>
 				<key>NSExtensionActivationSupportsImageWithMaxCount</key>
-				<integer>1</integer>
+				<integer>10</integer>
 				<key>NSExtensionActivationSupportsMovieWithMaxCount</key>
-				<integer>1</integer>
+				<integer>10</integer>
 				<key>NSExtensionActivationSupportsText</key>
 				<true/>
 				<key>NSExtensionActivationSupportsWebURLWithMaxCount</key>
-				<integer>1</integer>
+				<integer>10</integer>
 			</dict>
 		</dict>
 		<key>NSExtensionPointIdentifier</key>

ShareExtension/SupportingFiles/target.yml

@@ -53,11 +53,11 @@ targets:
           NSExtensionAttributes:
             IntentsSupported: [INSendMessageIntent]
             NSExtensionActivationRule:
-              NSExtensionActivationSupportsFileWithMaxCount: 1
-              NSExtensionActivationSupportsImageWithMaxCount: 1
-              NSExtensionActivationSupportsMovieWithMaxCount: 1
+              NSExtensionActivationSupportsFileWithMaxCount: 10
+              NSExtensionActivationSupportsImageWithMaxCount: 10
+              NSExtensionActivationSupportsMovieWithMaxCount: 10
               NSExtensionActivationSupportsText: true
-              NSExtensionActivationSupportsWebURLWithMaxCount: 1
+              NSExtensionActivationSupportsWebURLWithMaxCount: 10
 
     entitlements:
       path: ShareExtension.entitlements