Refactor how drafts are handled on a coordinator level and add support for them on thread timelines.

Author: stefanceriu

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/ComposerToolbarModels.swift

@@ -39,6 +39,8 @@ enum ComposerToolbarViewModelAction {
 
 enum ComposerToolbarViewAction {
     case composerAppeared
+    case composerDisappeared
+    
     case sendMessage
     case editLastMessage
     case cancelReply

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/ComposerToolbarViewModel.swift

@@ -161,9 +161,22 @@ final class ComposerToolbarViewModel: ComposerToolbarViewModelType, ComposerTool
             }
         }
         .store(in: &cancellables)
+        
+        NotificationCenter.default.publisher(for: UIApplication.willResignActiveNotification).sink { [weak self] _ in
+            self?.saveDraft()
+        }
+        .store(in: &cancellables)
     }
 
     // MARK: - Public
+    
+    func start() {
+        Task { await loadDraft() }
+    }
+    
+    func stop() {
+        saveDraft()
+    }
 
     override func process(viewAction: ComposerToolbarViewAction) {
         switch viewAction {
@@ -172,6 +185,8 @@ final class ComposerToolbarViewModel: ComposerToolbarViewModelType, ComposerTool
                 hasAppeard = true
                 wysiwygViewModel.setup()
             }
+        case .composerDisappeared:
+            saveDraft()
         case .sendMessage:
             guard !state.sendButtonDisabled else { return }
 

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/ComposerToolbarViewModelProtocol.swift

@@ -13,8 +13,9 @@ import WysiwygComposer
 protocol ComposerToolbarViewModelProtocol {
     var actions: AnyPublisher<ComposerToolbarViewModelAction, Never> { get }
     var context: ComposerToolbarViewModelType.Context { get }
+    
+    func start()
+    func stop()
 
     func process(timelineAction: TimelineComposerAction)
-    func loadDraft() async
-    func saveDraft()
 }

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/View/ComposerToolbar.swift

@@ -181,6 +181,9 @@ struct ComposerToolbar: View {
         } onAppearAction: {
             context.send(viewAction: .composerAppeared)
         }
+        .onDisappear {
+            context.send(viewAction: .composerDisappeared)
+        }
         .environmentObject(context)
         .focused($composerFocused)
         .padding(.leading, context.composerFormattingEnabled ? 7 : 0)

ElementX/Sources/Screens/RoomScreen/RoomScreenCoordinator.swift

@@ -107,11 +107,6 @@ final class RoomScreenCoordinator: CoordinatorProtocol {
                                                          analyticsService: ServiceLocator.shared.analytics,
                                                          composerDraftService: parameters.composerDraftService)
         self.composerViewModel = composerViewModel
-        
-        NotificationCenter.default.publisher(for: UIApplication.willResignActiveNotification).sink { _ in
-            composerViewModel.saveDraft()
-        }
-        .store(in: &cancellables)
     }
 
     // MARK: - Public
@@ -193,8 +188,9 @@ final class RoomScreenCoordinator: CoordinatorProtocol {
             }
             .store(in: &cancellables)
 
-        // Loading the draft requires the subscriptions to be set up first otherwise the room won't be be able to propagate the information to the composer.
-        Task { await composerViewModel.loadDraft() }
+        // Loading the draft requires the subscriptions to be set up first otherwise
+        // the room won't be be able to propagate the information to the composer.
+        composerViewModel.start()
     }
 
     func focusOnEvent(_ focussedEvent: FocusEvent) {
@@ -212,7 +208,7 @@ final class RoomScreenCoordinator: CoordinatorProtocol {
     }
 
     func stop() {
-        composerViewModel.saveDraft()
+        composerViewModel.stop()
         roomViewModel.stop()
     }
 
@@ -221,10 +217,7 @@ final class RoomScreenCoordinator: CoordinatorProtocol {
 
         return AnyView(RoomScreen(context: roomViewModel.context,
                                   timelineContext: timelineViewModel.context,
-                                  composerToolbar: composerToolbar)
-                .onDisappear { [weak self] in
-                    self?.composerViewModel.saveDraft()
-                })
+                                  composerToolbar: composerToolbar))
     }
 }
 

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenCoordinator.swift

@@ -74,8 +74,6 @@ final class ThreadTimelineScreenCoordinator: CoordinatorProtocol {
                                                         maxExpandedHeight: ComposerConstant.maxHeight,
                                                         parserStyle: .elementX)
 
-        #warning("Drafts are not handled and they can't be without rust side changes")
-        
         composerViewModel = ComposerToolbarViewModel(initialText: nil,
                                                      roomProxy: parameters.roomProxy,
                                                      isInThread: true,
@@ -144,9 +142,14 @@ final class ThreadTimelineScreenCoordinator: CoordinatorProtocol {
                 timelineViewModel.process(composerAction: action)
             }
             .store(in: &cancellables)
+        
+        // Loading the draft requires the subscriptions to be set up first otherwise
+        // the room won't be be able to propagate the information to the composer.
+        composerViewModel.start()
     }
 
     func stop() {
+        composerViewModel.stop()
         viewModel.stop()
     }