Allow the user to forward the same message to multiple rooms at once

This will send the item to the rooms in order they were chosen and only deep link
into the target room if single, otherwise it will just dismiss the forwarding screen
after sending.

ElementX/Sources/FlowCoordinators/PinnedEventsTimelineFlowCoordinator.swift

@@ -12,7 +12,7 @@ import Foundation
 enum PinnedEventsTimelineFlowCoordinatorAction {
     case finished
     case displayUser(userID: String)
-    case forwardedMessageToRoom(roomID: String)
+    case forwardedMessageToRooms(roomIDs: [String])
     case displayRoomScreenWithFocussedPin(eventID: String, threadRootEventID: String?)
 }
 
@@ -148,9 +148,9 @@ class PinnedEventsTimelineFlowCoordinator: FlowCoordinatorProtocol {
             switch action {
             case .dismiss:
                 navigationStackCoordinator.setSheetCoordinator(nil)
-            case .sent(let roomID):
+            case .sent(let roomIDs):
                 navigationStackCoordinator.setSheetCoordinator(nil)
-                actionsSubject.send(.forwardedMessageToRoom(roomID: roomID))
+                actionsSubject.send(.forwardedMessageToRooms(roomIDs: roomIDs))
             }
         }
         .store(in: &cancellables)

ElementX/Sources/FlowCoordinators/RoomFlowCoordinator.swift

@@ -1282,10 +1282,9 @@ class RoomFlowCoordinator: FlowCoordinatorProtocol {
             switch action {
             case .dismiss:
                 navigationStackCoordinator.setSheetCoordinator(nil)
-            case .sent(let roomID):
+            case .sent(let roomIDs):
                 navigationStackCoordinator.setSheetCoordinator(nil)
-                // Timelines are cached - the local echo will be visible when fetching the room by its ID.
-                stateMachine.tryEvent(.startChildFlow(roomID: roomID, via: [], entryPoint: .room))
+                processPostMessageForwardingTo(rooms: roomIDs)
             }
         }
         .store(in: &cancellables)
@@ -1524,6 +1523,15 @@ class RoomFlowCoordinator: FlowCoordinatorProtocol {
         }
     }
     
+    private func processPostMessageForwardingTo(rooms roomIDs: [String]) {
+        // Only open forwarding target room if single.
+        guard roomIDs.count == 1, let roomID = roomIDs.last else {
+            return
+        }
+        
+        stateMachine.tryEvent(.startChildFlow(roomID: roomID, via: [], entryPoint: .room))
+    }
+    
     // MARK: - Other flows
     
     private func startChildFlow(for roomID: String, via: [String], entryPoint: RoomFlowCoordinatorEntryPoint) {
@@ -1582,9 +1590,9 @@ class RoomFlowCoordinator: FlowCoordinatorProtocol {
             case .displayUser(let userID):
                 navigationStackCoordinator.setSheetCoordinator(nil)
                 stateMachine.tryEvent(.startMembersFlow(entryPoint: .roomMember(userID: userID)))
-            case .forwardedMessageToRoom(let roomID):
+            case .forwardedMessageToRooms(let roomIDs):
                 navigationStackCoordinator.setSheetCoordinator(nil)
-                stateMachine.tryEvent(.startChildFlow(roomID: roomID, via: [], entryPoint: .room))
+                processPostMessageForwardingTo(rooms: roomIDs)
             case .displayRoomScreenWithFocussedPin(let eventID, let threadRootEventID):
                 navigationStackCoordinator.setSheetCoordinator(nil)
                 if let threadRootEventID {

ElementX/Sources/Screens/MessageForwardingScreen/MessageForwardingScreenCoordinator.swift

@@ -18,7 +18,7 @@ struct MessageForwardingScreenCoordinatorParameters {
 
 enum MessageForwardingScreenCoordinatorAction {
     case dismiss
-    case sent(roomID: String)
+    case sent(roomIDs: [String])
 }
 
 final class MessageForwardingScreenCoordinator: CoordinatorProtocol {
@@ -42,8 +42,8 @@ final class MessageForwardingScreenCoordinator: CoordinatorProtocol {
             switch action {
             case .dismiss:
                 self?.actionsSubject.send(.dismiss)
-            case .sent(let roomID):
-                self?.actionsSubject.send(.sent(roomID: roomID))
+            case .sent(let roomIDs):
+                self?.actionsSubject.send(.sent(roomIDs: roomIDs))
             }
         }
         .store(in: &cancellables)

ElementX/Sources/Screens/MessageForwardingScreen/MessageForwardingScreenModels.swift

@@ -11,12 +11,12 @@ import MatrixRustSDK
 
 enum MessageForwardingScreenViewModelAction {
     case dismiss
-    case sent(roomID: String)
+    case sent(roomIDs: [String])
 }
 
 struct MessageForwardingScreenViewState: BindableState {
     var rooms: [MessageForwardingRoom] = []
-    var selectedRoomID: String?
+    var selectedRoomIDs = [String]()
     var bindings = MessageForwardingScreenViewStateBindings()
 }
 

ElementX/Sources/Screens/MessageForwardingScreen/MessageForwardingScreenViewModel.swift

@@ -63,7 +63,11 @@ class MessageForwardingScreenViewModel: MessageForwardingScreenViewModelType, Me
         case .send:
             Task { await forward() }
         case .selectRoom(let roomID):
-            state.selectedRoomID = roomID
+            if let index = state.selectedRoomIDs.firstIndex(of: roomID) {
+                state.selectedRoomIDs.remove(at: index)
+            } else {
+                state.selectedRoomIDs.append(roomID)
+            }
         case .reachedTop:
             updateVisibleRange(edge: .top)
         case .reachedBottom:
@@ -114,23 +118,30 @@ class MessageForwardingScreenViewModel: MessageForwardingScreenViewModelType, Me
     }
     
     private func forward() async {
-        guard let roomID = state.selectedRoomID else {
+        guard !state.selectedRoomIDs.isEmpty else {
             fatalError()
         }
         
-        guard case let .joined(targetRoomProxy) = await clientProxy.roomForIdentifier(roomID) else {
-            MXLog.error("Failed retrieving room to forward to with id: \(roomID)")
-            userIndicatorController.submitIndicator(UserIndicator(title: L10n.errorUnknown))
-            return
+        var succeededRoomIdentifiers = [String]()
+        
+        for roomID in state.selectedRoomIDs {
+            guard case let .joined(targetRoomProxy) = await clientProxy.roomForIdentifier(roomID) else {
+                MXLog.error("Failed retrieving room to forward to with id: \(roomID)")
+                userIndicatorController.submitIndicator(UserIndicator(title: L10n.errorUnknown))
+                continue
+            }
+            
+            if case .failure(let error) = await targetRoomProxy.timeline.sendMessageEventContent(forwardingItem.content) {
+                MXLog.error("Failed forwarding message with error: \(error)")
+                userIndicatorController.submitIndicator(UserIndicator(title: L10n.errorUnknown))
+                continue
+            }
+            
+            succeededRoomIdentifiers.append(roomID)
         }
         
-        if case .failure(let error) = await targetRoomProxy.timeline.sendMessageEventContent(forwardingItem.content) {
-            MXLog.error("Failed forwarding message with error: \(error)")
-            userIndicatorController.submitIndicator(UserIndicator(title: L10n.errorUnknown))
-            return
+        if !succeededRoomIdentifiers.isEmpty {
+            actionsSubject.send(.sent(roomIDs: succeededRoomIdentifiers))
         }
-        
-        // Timelines are cached - the local echo will be visible when fetching the room by its ID.
-        actionsSubject.send(.sent(roomID: roomID))
     }
 }

ElementX/Sources/Screens/MessageForwardingScreen/View/MessageForwardingScreen.swift

@@ -17,7 +17,7 @@ struct MessageForwardingScreen: View {
             Section {
                 ForEach(context.viewState.rooms) { room in
                     MessageForwardingListRow(room: room,
-                                             isSelected: context.viewState.selectedRoomID == room.id,
+                                             isSelected: context.viewState.selectedRoomIDs.contains(room.id),
                                              context: context)
                 }
                 // Replace these with ScrollView's `scrollPosition` when dropping iOS 16.
@@ -46,7 +46,7 @@ struct MessageForwardingScreen: View {
                 Button(L10n.actionSend) {
                     context.send(viewAction: .send)
                 }
-                .disabled(context.viewState.selectedRoomID == nil)
+                .disabled(context.viewState.selectedRoomIDs.isEmpty)
             }
         }
         .searchController(query: $context.searchQuery, showsCancelButton: false)