Memory management (#503)

* Correctly tear down the user session on signing out

* Fix session verification <-> user session retain cycle, visible range debouncer leak

* Manually clean up coordinators retained within SwiftUI's NavigationStacks

* Slightly refactor the timeline content menu builder and prevent it from retaining the view model. Cleanup now unnecessarily optional RoomScreenCoordinator instance vars

* Move coordinator dismissal logic to the navigation modules

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

@@ -17,11 +17,17 @@
 import SwiftUI
 
 struct TimelineItemContextMenuActions {
-    static var empty: TimelineItemContextMenuActions { .init(actions: [], debugActions: []) }
-    
     let actions: [TimelineItemContextMenuAction]
     let debugActions: [TimelineItemContextMenuAction]
-    var isEmpty: Bool { actions.isEmpty && debugActions.isEmpty }
+    
+    init?(actions: [TimelineItemContextMenuAction], debugActions: [TimelineItemContextMenuAction]) {
+        if actions.isEmpty, debugActions.isEmpty {
+            return nil
+        }
+        
+        self.actions = actions
+        self.debugActions = debugActions
+    }
 }
 
 enum TimelineItemContextMenuAction: Identifiable, Hashable {
@@ -52,16 +58,11 @@ public struct TimelineItemContextMenu: View {
     let callback: (TimelineItemContextMenuAction) -> Void
     
     public var body: some View {
-        if contextMenuActions.isEmpty {
-            // When there are no actions make sure then menu isn't shown.
-            EmptyView()
-        } else {
-            viewsForActions(contextMenuActions.actions)
-            Menu {
-                viewsForActions(contextMenuActions.debugActions)
-            } label: {
-                Label("Developer", systemImage: "hammer")
-            }
+        viewsForActions(contextMenuActions.actions)
+        Menu {
+            viewsForActions(contextMenuActions.debugActions)
+        } label: {
+            Label("Developer", systemImage: "hammer")
         }
     }
     

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

@@ -72,7 +72,7 @@ class TimelineTableViewController: UIViewController {
         }
     }
         
-    var contextMenuBuilder: (@MainActor (_ itemId: String) -> TimelineItemContextMenu)?
+    var contextMenuActionProvider: (@MainActor (_ itemId: String) -> TimelineItemContextMenuActions?)?
     
     @Binding private var scrollToBottomButtonVisible: Bool
     
@@ -189,7 +189,7 @@ class TimelineTableViewController: UIViewController {
             // A local reference to avoid capturing self in the cell configuration.
             let coordinator = self.coordinator
             let opacity = self.opacity(for: timelineItem)
-            let contextMenuBuilder = self.contextMenuBuilder
+            let contextMenuActionProvider = self.contextMenuActionProvider
             
             cell.item = timelineItem
             cell.contentConfiguration = UIHostingConfiguration {
@@ -198,7 +198,11 @@ class TimelineTableViewController: UIViewController {
                     .frame(maxWidth: .infinity, alignment: .leading)
                     .opacity(opacity)
                     .contextMenu {
-                        contextMenuBuilder?(timelineItem.id)
+                        contextMenuActionProvider?(timelineItem.id).map { actions in
+                            TimelineItemContextMenu(contextMenuActions: actions) { action in
+                                coordinator.send(viewAction: .contextMenuAction(itemID: timelineItem.id, action: action))
+                            }
+                        }
                     }
                     .onAppear {
                         coordinator.send(viewAction: .itemAppeared(id: timelineItem.id))

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

@@ -70,7 +70,7 @@ struct TimelineView: UIViewControllerRepresentable {
             }
             
             // Doesn't have an equatable conformance :(
-            tableViewController.contextMenuBuilder = context.viewState.contextMenuBuilder
+            tableViewController.contextMenuActionProvider = context.viewState.contextMenuActionProvider
         }
         
         func send(viewAction: RoomScreenViewAction) {