fix(player): exit on phone back even with the chrome up (#1938)

4443b761 staged the system-back path (strip/fullscreen/hide/exit), so on
Android a back with the controls visible hid them instead of closing the
player. The PlayerNavigationCoordinator now takes an exitPlayerBeforeChrome
policy; the player enables it on mobile, restoring immediate exit on Back
while TV/desktop keep the staged chrome handling.

lib/screens/video_player_screen.dart

@@ -927,6 +927,11 @@ class VideoPlayerScreenState extends State<VideoPlayerScreen> with WidgetsBindin
       dismissPrompt: _dismissPlaybackPromptForBack,
       isChromePresented: () =>
           _isPlayerInitialized && player != null && _hasFirstFrame.value && _chromeController.controlsPresented,
+      // On phones a Back must exit the player even with the controls up
+      // (#1938); the staged chrome handling is TV/desktop behavior (#4443b761
+      // applied it to the phone system-back path too, so back stopped
+      // closing the player).
+      exitPlayerBeforeChrome: () => PlatformDetector.isMobile(context),
       exitFullscreenIfActive: FullscreenStateManager().exitFullscreenIfActive,
       // macOS fullscreen belongs to the app window, while HTPC-style player
       // navigation treats physical Escape as semantic Back. In both cases the

lib/widgets/video_controls/video_controls.dart

@@ -300,6 +300,7 @@ class PlayerNavigationCoordinator {
   final bool Function() isChromePresented;
   final Future<bool> Function() exitFullscreenIfActive;
   final bool Function() _physicalEscapeExitsFullscreen;
+  final bool Function() _exitPlayerBeforeChrome;
   final VoidCallback exitPlayer;
   final VoidCallback navigateHome;
   final bool Function() isActive;
@@ -313,14 +314,17 @@ class PlayerNavigationCoordinator {
     required this.isChromePresented,
     required this.exitFullscreenIfActive,
     bool Function()? physicalEscapeExitsFullscreen,
+    bool Function()? exitPlayerBeforeChrome,
     required this.exitPlayer,
     required this.navigateHome,
     bool Function()? isActive,
   }) : _physicalEscapeExitsFullscreen = physicalEscapeExitsFullscreen ?? _alwaysTrue,
+       _exitPlayerBeforeChrome = exitPlayerBeforeChrome ?? _alwaysFalse,
        isActive = isActive ?? _alwaysActive;
 
   static bool _alwaysActive() => true;
   static bool _alwaysTrue() => true;
+  static bool _alwaysFalse() => false;
 
   void handle(PlayerNavigationKey navigationKey) {
     if (navigationKey == PlayerNavigationKey.home) {
@@ -331,6 +335,12 @@ class PlayerNavigationCoordinator {
       dismissPrompt();
       return;
     }
+    if (navigationKey == PlayerNavigationKey.back && _exitPlayerBeforeChrome()) {
+      // Mobile Back exits even with the chrome up (#1938); the staged
+      // strip/fullscreen/hide/exit chain is TV and desktop behavior.
+      exitPlayer();
+      return;
+    }
     final disposition = resolvePlayerBackDisposition(
       navigationKey: navigationKey,
       contentStripVisible: chromeController.contentStripVisible,

test/widgets/video_controls_test.dart

@@ -570,6 +570,7 @@ void main() {
       Future<bool> Function()? exitFullscreenIfActive,
       bool physicalEscapeExitsFullscreen = true,
       bool Function()? physicalEscapeExitsFullscreenProvider,
+      bool Function()? exitPlayerBeforeChrome,
       VoidCallback? exitPlayer,
       VoidCallback? navigateHome,
       bool Function()? isActive,
@@ -581,6 +582,7 @@ void main() {
         isChromePresented: isChromePresented ?? () => chromeController.controlsPresented,
         exitFullscreenIfActive: exitFullscreenIfActive ?? () async => false,
         physicalEscapeExitsFullscreen: physicalEscapeExitsFullscreenProvider ?? () => physicalEscapeExitsFullscreen,
+        exitPlayerBeforeChrome: exitPlayerBeforeChrome,
         exitPlayer: exitPlayer ?? () {},
         navigateHome: navigateHome ?? () {},
         isActive: isActive,
@@ -635,6 +637,43 @@ void main() {
       expect(exits, 1);
     });
 
+    testWidgets('mobile Back exits on the first press even with the chrome up (#1938)', (tester) async {
+      final chromeController = PlayerChromeController();
+      addTearDown(chromeController.dispose);
+      var exits = 0;
+      final coordinator = coordinatorFor(
+        chromeController,
+        exitPlayerBeforeChrome: () => true,
+        exitPlayer: () => exits++,
+      );
+      await pumpNavigationFocus(tester, coordinator);
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.gameButtonB);
+
+      expect(exits, 1, reason: 'a phone back must close the player even while the controls are up');
+      expect(chromeController.controlsVisible, isTrue, reason: 'no staged hide: the player leaves directly');
+    });
+
+    testWidgets('mobile Back dismisses an open prompt before exiting', (tester) async {
+      final chromeController = PlayerChromeController();
+      addTearDown(chromeController.dispose);
+      var promptDismissals = 0;
+      var exits = 0;
+      final coordinator = coordinatorFor(
+        chromeController,
+        isPromptOpen: () => true,
+        dismissPrompt: () => promptDismissals++,
+        exitPlayerBeforeChrome: () => true,
+        exitPlayer: () => exits++,
+      );
+      await pumpNavigationFocus(tester, coordinator);
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.gameButtonB);
+
+      expect(promptDismissals, 1, reason: 'prompts keep priority over the mobile exit policy');
+      expect(exits, 0);
+    });
+
     testWidgets('Back exits on the first press when the route opened with no chrome', (tester) async {
       final chromeController = PlayerChromeController(initiallyVisible: false);
       addTearDown(chromeController.dispose);