Handle notifications properly when a call is happening. (#3276)

ElementX/Sources/Screens/CallScreen/CallScreenCoordinator.swift

@@ -17,8 +17,13 @@ struct CallScreenCoordinatorParameters {
 }
 
 enum CallScreenCoordinatorAction {
-    /// The call is still ongoing but the user wishes to navigate around the app.
-    case pictureInPictureStarted(AVPictureInPictureController)
+    /// The call is able to be minimised to picture in picture with the provided controller.
+    ///
+    /// **Note:** Manually starting the PiP will not trigger the action below as we don't want
+    /// to change the app's navigation when backgrounding the app with the call screen visible.
+    case pictureInPictureIsAvailable(AVPictureInPictureController)
+    /// The call is still ongoing but the user requested to navigate around the app.
+    case pictureInPictureStarted
     /// The call is hidden and the user wishes to return to it.
     case pictureInPictureStopped
     /// The call is finished and the screen is done with.
@@ -46,8 +51,10 @@ final class CallScreenCoordinator: CoordinatorProtocol {
             guard let self else { return }
             
             switch action {
-            case .pictureInPictureStarted(let controller):
-                actionsSubject.send(.pictureInPictureStarted(controller))
+            case .pictureInPictureIsAvailable(let controller):
+                actionsSubject.send(.pictureInPictureIsAvailable(controller))
+            case .pictureInPictureStarted:
+                actionsSubject.send(.pictureInPictureStarted)
             case .pictureInPictureStopped:
                 actionsSubject.send(.pictureInPictureStopped)
             case .dismiss:

ElementX/Sources/Screens/CallScreen/CallScreenModels.swift

@@ -9,7 +9,8 @@ import AVKit
 import Foundation
 
 enum CallScreenViewModelAction {
-    case pictureInPictureStarted(AVPictureInPictureController)
+    case pictureInPictureIsAvailable(AVPictureInPictureController)
+    case pictureInPictureStarted
     case pictureInPictureStopped
     case dismiss
 }
@@ -34,6 +35,7 @@ struct Bindings {
 
 enum CallScreenViewAction {
     case urlChanged(URL?)
+    case pictureInPictureIsAvailable(AVPictureInPictureController)
     case navigateBack
     case pictureInPictureWillStop
     case endCall

ElementX/Sources/Screens/CallScreen/CallScreenViewModel.swift

@@ -111,6 +111,8 @@ class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol
         case .urlChanged(let url):
             guard let url else { return }
             MXLog.info("URL changed to: \(url)")
+        case .pictureInPictureIsAvailable(let controller):
+            actionsSubject.send(.pictureInPictureIsAvailable(controller))
         case .navigateBack:
             Task { await handleBackwardsNavigation() }
         case .pictureInPictureWillStop:
@@ -188,7 +190,7 @@ class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol
         
         switch await requestPictureInPictureHandler() {
         case .success(let controller):
-            actionsSubject.send(.pictureInPictureStarted(controller))
+            actionsSubject.send(.pictureInPictureStarted)
         case .failure:
             actionsSubject.send(.dismiss)
         }

ElementX/Sources/Screens/CallScreen/View/CallScreen.swift

@@ -128,6 +128,7 @@ private struct CallView: UIViewRepresentable {
                                                                                                    contentViewController: pictureInPictureViewController))
                 pictureInPictureController.delegate = self
                 self.pictureInPictureController = pictureInPictureController
+                viewModelContext.send(viewAction: .pictureInPictureIsAvailable(pictureInPictureController))
             }
         }
         
@@ -222,6 +223,18 @@ private struct CallView: UIViewRepresentable {
             }
         }
         
+        nonisolated func pictureInPictureControllerDidStartPictureInPicture(_ pictureInPictureController: AVPictureInPictureController) {
+            Task { @MainActor in
+                // Double check that the controller is definitely showing a page that supports picture in picture.
+                // This is necessary as it doesn't get checked when backgrounding the app or tapping a notification.
+                guard case .success(true) = await webViewCanEnterPictureInPicture() else {
+                    MXLog.error("Picture in picture started on a webpage that doesn't support it. Ending the call.")
+                    viewModelContext?.send(viewAction: .endCall)
+                    return
+                }
+            }
+        }
+        
         nonisolated func pictureInPictureControllerWillStopPictureInPicture(_ pictureInPictureController: AVPictureInPictureController) {
             Task { await viewModelContext?.send(viewAction: .pictureInPictureWillStop) }
         }