Add support for adding/editing/removing media captions. (#3547)

* Add support for editing media captions.

* Add composer snapshots.

* PR comment.

ElementX/Sources/Services/Timeline/TimelineController/MockRoomTimelineController.swift

@@ -91,6 +91,13 @@ class MockRoomTimelineController: RoomTimelineControllerProtocol {
               html: String?,
               intentionalMentions: IntentionalMentions) async { }
     
+    func editCaption(_ eventOrTransactionID: EventOrTransactionId,
+                     message: String,
+                     html: String?,
+                     intentionalMentions: IntentionalMentions) async { }
+    
+    func removeCaption(_ eventOrTransactionID: EventOrTransactionId) async { }
+    
     func redact(_ eventOrTransactionID: EventOrTransactionId) async { }
     
     func pin(eventID: String) async { }

ElementX/Sources/Services/Timeline/TimelineController/RoomTimelineController.swift

@@ -238,7 +238,7 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
                                                                    html: html,
                                                                    intentionalMentions: intentionalMentions.toRustMentions())
         
-        switch await activeTimeline.edit(eventOrTransactionID, newContent: messageContent) {
+        switch await activeTimeline.edit(eventOrTransactionID, newContent: .roomMessage(content: messageContent)) {
         case .success:
             MXLog.info("Finished editing message by event")
         case let .failure(error):
@@ -246,6 +246,34 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
         }
     }
     
+    func editCaption(_ eventOrTransactionID: EventOrTransactionId,
+                     message: String,
+                     html: String?,
+                     intentionalMentions: IntentionalMentions) async {
+        // We're waiting on an API for including mentions: https://github.com/matrix-org/matrix-rust-sdk/issues/4302
+        MXLog.info("Editing timeline item caption: \(eventOrTransactionID) in \(roomID)")
+        
+        // When formattedCaption is nil, caption will be parsed as markdown and generate the HTML for us.
+        let newContent = createCaptionEdit(caption: message, formattedCaption: html.map { .init(format: .html, body: $0) })
+        switch await activeTimeline.edit(eventOrTransactionID, newContent: newContent) {
+        case .success:
+            MXLog.info("Finished editing caption")
+        case let .failure(error):
+            MXLog.error("Failed editing caption with error: \(error)")
+        }
+    }
+    
+    func removeCaption(_ eventOrTransactionID: EventOrTransactionId) async {
+        // Set a `nil` caption to remove it from the event.
+        let newContent = createCaptionEdit(caption: nil, formattedCaption: nil)
+        switch await activeTimeline.edit(eventOrTransactionID, newContent: newContent) {
+        case .success:
+            MXLog.info("Finished removing caption.")
+        case let .failure(error):
+            MXLog.error("Failed removing caption with error: \(error)")
+        }
+    }
+    
     func redact(_ eventOrTransactionID: EventOrTransactionId) async {
         MXLog.info("Send redaction in \(roomID)")
         

ElementX/Sources/Services/Timeline/TimelineController/RoomTimelineControllerProtocol.swift

@@ -56,6 +56,13 @@ protocol RoomTimelineControllerProtocol {
               html: String?,
               intentionalMentions: IntentionalMentions) async
     
+    func editCaption(_ eventOrTransactionID: EventOrTransactionId,
+                     message: String,
+                     html: String?,
+                     intentionalMentions: IntentionalMentions) async
+    
+    func removeCaption(_ eventOrTransactionID: EventOrTransactionId) async
+    
     func toggleReaction(_ reaction: String, to eventOrTransactionID: EventOrTransactionId) async
 
     func redact(_ eventOrTransactionID: EventOrTransactionId) async

ElementX/Sources/Services/Timeline/TimelineItems/EventBasedMessageTimelineItemProtocol.swift

@@ -26,6 +26,15 @@ protocol EventBasedMessageTimelineItemProtocol: EventBasedTimelineItemProtocol {
 }
 
 extension EventBasedMessageTimelineItemProtocol {
+    var supportsMediaCaption: Bool {
+        switch contentType {
+        case .audio, .file, .image, .video:
+            true
+        case .emote, .notice, .text, .location, .voice:
+            false
+        }
+    }
+    
     var hasMediaCaption: Bool {
         switch contentType {
         case .audio(let content):

ElementX/Sources/Services/Timeline/TimelineProxy.swift

@@ -164,9 +164,9 @@ final class TimelineProxy: TimelineProxyProtocol {
         }
     }
     
-    func edit(_ eventOrTransactionID: EventOrTransactionId, newContent: RoomMessageEventContentWithoutRelation) async -> Result<Void, TimelineProxyError> {
+    func edit(_ eventOrTransactionID: EventOrTransactionId, newContent: EditedContent) async -> Result<Void, TimelineProxyError> {
         do {
-            try await timeline.edit(eventOrTransactionId: eventOrTransactionID, newContent: .roomMessage(content: newContent))
+            try await timeline.edit(eventOrTransactionId: eventOrTransactionID, newContent: newContent)
             
             MXLog.info("Finished editing timeline item: \(eventOrTransactionID)")
 

ElementX/Sources/Services/Timeline/TimelineProxyProtocol.swift

@@ -38,7 +38,7 @@ protocol TimelineProxyProtocol {
     func paginateForwards(requestSize: UInt16) async -> Result<Void, TimelineProxyError>
     
     func edit(_ eventOrTransactionID: EventOrTransactionId,
-              newContent: RoomMessageEventContentWithoutRelation) async -> Result<Void, TimelineProxyError>
+              newContent: EditedContent) async -> Result<Void, TimelineProxyError>
     
     func redact(_ eventOrTransactionID: EventOrTransactionId,
                 reason: String?) async -> Result<Void, TimelineProxyError>