Replace RouteAware with FocusDetector

zanovis · Feb 7, 2024 · 7229f88 · 7229f88
1 parent d940420
commit 7229f88
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Showing 7 changed files with 224 additions and 151 deletions.
diff --git a/lib/src/utils/focus_detector.dart b/lib/src/utils/focus_detector.dart
@@ -0,0 +1,176 @@
+import 'package:flutter/widgets.dart';
+import 'package:visibility_detector/visibility_detector.dart';
+
+// code taken and adapted from
+// https://github.com/EdsonBueno/focus_detector
+
+/// Fires callbacks every time the widget appears or disappears from the screen.
+class FocusDetector extends StatefulWidget {
+  const FocusDetector({
+    required this.child,
+    this.onFocusGained,
+    this.onFocusRegained,
+    this.onFocusLost,
+    this.onVisibilityGained,
+    this.onVisibilityRegained,
+    this.onVisibilityLost,
+    this.onForegroundGained,
+    this.onForegroundLost,
+    super.key,
+  });
+
+  /// Called when the widget becomes visible or enters foreground while visible.
+  final VoidCallback? onFocusGained;
+
+  /// Called when the widget gains focus again (same as onFocusGained but does
+  /// not fires the first time).
+  final VoidCallback? onFocusRegained;
+
+  /// Called when the widget becomes invisible or enters background while visible.
+  final VoidCallback? onFocusLost;
+
+  /// Called when the widget becomes visible.
+  final VoidCallback? onVisibilityGained;
+
+  /// Called when the widget become visible again (same as onVisibilityGained but
+  /// does not fires the first time).
+  final VoidCallback? onVisibilityRegained;
+
+  /// Called when the widget becomes invisible.
+  final VoidCallback? onVisibilityLost;
+
+  /// Called when the app entered the foreground while the widget is visible.
+  final VoidCallback? onForegroundGained;
+
+  /// Called when the app is sent to background while the widget was visible.
+  final VoidCallback? onForegroundLost;
+
+  /// The widget below this widget in the tree.
+  final Widget child;
+
+  @override
+  _FocusDetectorState createState() => _FocusDetectorState();
+}
+
+class _FocusDetectorState extends State<FocusDetector>
+    with WidgetsBindingObserver {
+  final _visibilityDetectorKey = UniqueKey();
+
+  /// Counter to keep track of the visibility changes.
+  int _visibilityCounter = 0;
+
+  /// Whether this widget is currently visible within the app.
+  bool _isWidgetVisible = false;
+
+  /// Whether the app is in the foreground.
+  bool _isAppInForeground = true;
+
+  @override
+  void initState() {
+    WidgetsBinding.instance.addObserver(this);
+    super.initState();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    _notifyPlaneTransition(state);
+  }
+
+  /// Notifies app's transitions to/from the foreground.
+  void _notifyPlaneTransition(AppLifecycleState state) {
+    if (!_isWidgetVisible) {
+      return;
+    }
+
+    final isAppResumed = state == AppLifecycleState.resumed;
+    final wasResumed = _isAppInForeground;
+    if (isAppResumed && !wasResumed) {
+      _isAppInForeground = true;
+      _notifyFocusGain();
+      _notifyForegroundGain();
+      return;
+    }
+
+    final isAppPaused = state == AppLifecycleState.paused;
+    if (isAppPaused && wasResumed) {
+      _isAppInForeground = false;
+      _notifyFocusLoss();
+      _notifyForegroundLoss();
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) => VisibilityDetector(
+        key: _visibilityDetectorKey,
+        onVisibilityChanged: (visibilityInfo) {
+          final visibleFraction = visibilityInfo.visibleFraction;
+          _notifyVisibilityStatusChange(visibleFraction);
+        },
+        child: widget.child,
+      );
+
+  /// Notifies changes in the widget's visibility.
+  void _notifyVisibilityStatusChange(double newVisibleFraction) {
+    if (!_isAppInForeground) {
+      return;
+    }
+
+    final wasFullyVisible = _isWidgetVisible;
+    final isFullyVisible = newVisibleFraction == 1;
+    if (!wasFullyVisible && isFullyVisible) {
+      _isWidgetVisible = true;
+      _notifyFocusGain();
+      _notifyVisibilityGain();
+      _visibilityCounter++;
+    }
+
+    final isFullyInvisible = newVisibleFraction == 0;
+    if (wasFullyVisible && isFullyInvisible) {
+      _isWidgetVisible = false;
+      _notifyFocusLoss();
+      _notifyVisibilityLoss();
+    }
+  }
+
+  void _notifyFocusGain() {
+    widget.onFocusGained?.call();
+    if (_visibilityCounter > 0) {
+      widget.onFocusRegained?.call();
+    }
+  }
+
+  void _notifyFocusLoss() {
+    widget.onFocusLost?.call();
+  }
+
+  void _notifyVisibilityGain() {
+    widget.onVisibilityGained?.call();
+    if (_visibilityCounter > 0) {
+      widget.onVisibilityRegained?.call();
+    }
+  }
+
+  void _notifyVisibilityLoss() {
+    widget.onVisibilityLost?.call();
+  }
+
+  void _notifyForegroundGain() {
+    final onForegroundGained = widget.onForegroundGained;
+    if (onForegroundGained != null) {
+      onForegroundGained();
+    }
+  }
+
+  void _notifyForegroundLoss() {
+    final onForegroundLost = widget.onForegroundLost;
+    if (onForegroundLost != null) {
+      onForegroundLost();
+    }
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    super.dispose();
+  }
+}
diff --git a/lib/src/view/relation/relation_screen.dart b/lib/src/view/relation/relation_screen.dart
@@ -4,7 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:lichess_mobile/src/model/relation/relation_ctrl.dart';
 import 'package:lichess_mobile/src/model/user/user.dart';
-import 'package:lichess_mobile/src/navigation.dart';
+import 'package:lichess_mobile/src/utils/focus_detector.dart';
 import 'package:lichess_mobile/src/utils/l10n_context.dart';
 import 'package:lichess_mobile/src/utils/navigation.dart';
 import 'package:lichess_mobile/src/view/relation/following_screen.dart';
@@ -22,13 +22,22 @@ class RelationScreen extends ConsumerStatefulWidget {
   ConsumerState<RelationScreen> createState() => _RelationScreenState();
 }
 
-class _RelationScreenState extends ConsumerState<RelationScreen>
-    with RouteAware {
+class _RelationScreenState extends ConsumerState<RelationScreen> {
   @override
   Widget build(BuildContext context) {
-    return PlatformWidget(
-      androidBuilder: _androidBuilder,
-      iosBuilder: _iosBuilder,
+    return FocusDetector(
+      onFocusRegained: () {
+        ref.read(relationCtrlProvider.notifier).startWatchingFriends();
+      },
+      onFocusLost: () {
+        if (context.mounted) {
+          ref.read(relationCtrlProvider.notifier).stopWatchingFriends();
+        }
+      },
+      child: PlatformWidget(
+        androidBuilder: _androidBuilder,
+        iosBuilder: _iosBuilder,
+      ),
     );
   }
 
@@ -47,33 +56,6 @@ class _RelationScreenState extends ConsumerState<RelationScreen>
       child: _Body(),
     );
   }
-
-  @override
-  void didChangeDependencies() {
-    super.didChangeDependencies();
-    final route = ModalRoute.of(context);
-    if (route != null && route is PageRoute) {
-      homeRouteObserver.subscribe(this, route);
-    }
-  }
-
-  @override
-  void dispose() {
-    homeRouteObserver.unsubscribe(this);
-    super.dispose();
-  }
-
-  @override
-  void didPushNext() {
-    ref.read(relationCtrlProvider.notifier).stopWatchingFriends();
-    super.didPushNext();
-  }
-
-  @override
-  void didPopNext() {
-    ref.read(relationCtrlProvider.notifier).startWatchingFriends();
-    super.didPopNext();
-  }
 }
 
 class _Body extends StatelessWidget {

diff --git a/lib/src/view/watch/live_tv_channels_screen.dart b/lib/src/view/watch/live_tv_channels_screen.dart
@@ -4,30 +4,34 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:lichess_mobile/src/constants.dart';
 import 'package:lichess_mobile/src/model/tv/live_tv_channels.dart';
 import 'package:lichess_mobile/src/model/tv/tv_channel.dart';
-import 'package:lichess_mobile/src/navigation.dart';
 import 'package:lichess_mobile/src/styles/lichess_colors.dart';
 import 'package:lichess_mobile/src/styles/styles.dart';
 import 'package:lichess_mobile/src/utils/chessground_compat.dart';
+import 'package:lichess_mobile/src/utils/focus_detector.dart';
 import 'package:lichess_mobile/src/utils/navigation.dart';
 import 'package:lichess_mobile/src/view/watch/tv_screen.dart';
 import 'package:lichess_mobile/src/widgets/board_preview.dart';
 import 'package:lichess_mobile/src/widgets/platform.dart';
 import 'package:lichess_mobile/src/widgets/user_full_name.dart';
 
-class LiveTvChannelsScreen extends ConsumerStatefulWidget {
+class LiveTvChannelsScreen extends ConsumerWidget {
   const LiveTvChannelsScreen({super.key});
 
   @override
-  ConsumerState<LiveTvChannelsScreen> createState() => _TvChannelsScreenState();
-}
-
-class _TvChannelsScreenState extends ConsumerState<LiveTvChannelsScreen>
-    with RouteAware, WidgetsBindingObserver {
-  @override
-  Widget build(BuildContext context) {
-    return PlatformWidget(
-      androidBuilder: _androidBuilder,
-      iosBuilder: _iosBuilder,
+  Widget build(BuildContext context, WidgetRef ref) {
+    return FocusDetector(
+      onFocusRegained: () {
+        ref.read(liveTvChannelsProvider.notifier).startWatching();
+      },
+      onFocusLost: () {
+        if (context.mounted) {
+          ref.read(liveTvChannelsProvider.notifier).stopWatching();
+        }
+      },
+      child: PlatformWidget(
+        androidBuilder: _androidBuilder,
+        iosBuilder: _iosBuilder,
+      ),
     );
   }
 
@@ -52,55 +56,6 @@ class _TvChannelsScreenState extends ConsumerState<LiveTvChannelsScreen>
       child: _Body(),
     );
   }
-
-  @override
-  void initState() {
-    WidgetsBinding.instance.addObserver(this);
-    super.initState();
-  }
-
-  @override
-  void didChangeAppLifecycleState(AppLifecycleState state) {
-    if (state == AppLifecycleState.resumed) {
-      ref.read(liveTvChannelsProvider.notifier).startWatching();
-    } else {
-      ref.read(liveTvChannelsProvider.notifier).stopWatching();
-    }
-  }
-
-  @override
-  void didChangeDependencies() {
-    super.didChangeDependencies();
-    final route = ModalRoute.of(context);
-    if (route != null && route is PageRoute) {
-      rootNavPageRouteObserver.subscribe(this, route);
-    }
-  }
-
-  @override
-  void dispose() {
-    WidgetsBinding.instance.removeObserver(this);
-    rootNavPageRouteObserver.unsubscribe(this);
-    super.dispose();
-  }
-
-  @override
-  void didPushNext() {
-    ref.read(liveTvChannelsProvider.notifier).stopWatching();
-    super.didPushNext();
-  }
-
-  @override
-  void didPopNext() {
-    ref.read(liveTvChannelsProvider.notifier).startWatching();
-    super.didPopNext();
-  }
-
-  @override
-  void didPop() {
-    ref.read(liveTvChannelsProvider.notifier).stopWatching();
-    super.didPop();
-  }
 }
 
 class _Body extends ConsumerWidget {