lightbox: Toggle wakelock while video is playing

Fixes: #763

Author: rajveermalviya

lib/model/binding.dart

@@ -7,6 +7,7 @@ import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:image_picker/image_picker.dart' as image_picker;
 import 'package:package_info_plus/package_info_plus.dart' as package_info_plus;
 import 'package:url_launcher/url_launcher.dart' as url_launcher;
+import 'package:wakelock_plus/wakelock_plus.dart' as wakelock_plus;
 
 import '../host/android_notifications.dart';
 import '../log.dart';
@@ -174,6 +175,11 @@ abstract class ZulipBinding {
     required image_picker.ImageSource source,
     bool requestFullMetadata,
   });
+
+  /// Enables or disables screen wakelock, via package:wakelock_plus.
+  ///
+  /// This wraps [wakelock_plus.WakelockPlus.toggle].
+  Future<void> toggleWakelock({required bool enable});
 }
 
 /// Like [device_info_plus.BaseDeviceInfo], but without things we don't use.
@@ -433,4 +439,9 @@ class LiveZulipBinding extends ZulipBinding {
     return image_picker.ImagePicker()
       .pickImage(source: source, requestFullMetadata: requestFullMetadata);
   }
+
+  @override
+  Future<void> toggleWakelock({required bool enable}) async {
+    return wakelock_plus.WakelockPlus.toggle(enable: enable);
+  }
 }

lib/widgets/lightbox.dart

@@ -8,6 +8,7 @@ import 'package:video_player/video_player.dart';
 import '../api/core.dart';
 import '../api/model/model.dart';
 import '../log.dart';
+import '../model/binding.dart';
 import 'content.dart';
 import 'dialog.dart';
 import 'page.dart';
@@ -492,11 +493,24 @@ class _VideoLightboxPageState extends State<VideoLightboxPage> with PerAccountSt
     _controller?.removeListener(_handleVideoControllerUpdate);
     _controller?.dispose();
     _controller = null;
+    // The VideoController doesn't emit a pause event
+    // while disposing, so disable the wakelock here
+    // explicitly.
+    ZulipBinding.instance.toggleWakelock(enable: false);
     super.dispose();
   }
 
   void _handleVideoControllerUpdate() {
     setState(() {});
+    _updateWakelock();
+  }
+
+  Future<void> _updateWakelock() async {
+    if (_controller!.value.isPlaying) {
+      await ZulipBinding.instance.toggleWakelock(enable: true);
+    } else {
+      await ZulipBinding.instance.toggleWakelock(enable: false);
+    }
   }
 
   Widget? _buildBottomAppBar(BuildContext context, Color color, double elevation) {

test/model/binding.dart

@@ -74,6 +74,7 @@ class TestZulipBinding extends ZulipBinding {
     _resetNotifications();
     _resetPickFiles();
     _resetPickImage();
+    _resetWakelock();
   }
 
   /// The current global store offered to a [GlobalStoreWidget].
@@ -367,6 +368,20 @@ class TestZulipBinding extends ZulipBinding {
     (_pickImageCalls ??= []).add((source: source, requestFullMetadata: requestFullMetadata));
     return pickImageResult;
   }
+
+  /// Returns the current status of wakelock, which can be
+  /// changed via [toggleWakelock].
+  bool get wakelockEnabled => _wakelockEnabled;
+  bool _wakelockEnabled = false;
+
+  void _resetWakelock() {
+    _wakelockEnabled = false;
+  }
+
+  @override
+  Future<void> toggleWakelock({required bool enable}) async {
+    _wakelockEnabled = enable;
+  }
 }
 
 class FakeFirebaseMessaging extends Fake implements FirebaseMessaging {

test/widgets/lightbox_test.dart

@@ -409,6 +409,35 @@ void main() {
         expectedMessage: zulipLocalizations.errorVideoPlayerFailed)));
     });
 
+    testWidgets('toggles wakelock when playing state changes', (tester) async {
+      await setupPage(tester, videoSrc: Uri.parse(kTestVideoUrl));
+      check(platform.isPlaying).isTrue();
+      check(TestZulipBinding.instance.wakelockEnabled).isTrue();
+
+      await tester.tap(find.byIcon(Icons.pause_circle_rounded));
+      check(platform.isPlaying).isFalse();
+      check(TestZulipBinding.instance.wakelockEnabled).isFalse();
+
+      // re-render to update player controls
+      await tester.pump();
+
+      await tester.tap(find.byIcon(Icons.play_circle_rounded));
+      check(platform.isPlaying).isTrue();
+      check(TestZulipBinding.instance.wakelockEnabled).isTrue();
+    });
+
+    testWidgets('disables wakelock when disposed', (tester) async {
+      await setupPage(tester, videoSrc: Uri.parse(kTestVideoUrl));
+      check(platform.isPlaying).isTrue();
+      check(TestZulipBinding.instance.wakelockEnabled).isTrue();
+
+      // Replace current page with empty container,
+      // disposing the previous page.
+      await tester.pumpWidget(Container());
+
+      check(TestZulipBinding.instance.wakelockEnabled).isFalse();
+    });
+
     testWidgets('video advances over time and stops playing when it ends', (tester) async {
       await setupPage(tester, videoSrc: Uri.parse(kTestVideoUrl));
       check(platform.isPlaying).isTrue();