overlay: favourite toggle highlight

lib/widgets/album/thumbnail_collection.dart

@@ -47,7 +47,7 @@ class ThumbnailCollection extends StatelessWidget {
             child: ValueListenableBuilder(
               valueListenable: _columnCountNotifier,
               builder: (context, columnCount, child) {
-                debugPrint('$runtimeType builder columnCount=$columnCount');
+                debugPrint('$runtimeType builder columnCount=$columnCount entries=${collection.entryCount}');
                 final scrollView = CustomScrollView(
                   key: _scrollableKey,
                   primary: true,

lib/widgets/common/fx/sweeper.dart

@@ -0,0 +1,133 @@
+import 'dart:math';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
+
+class Sweeper extends StatefulWidget {
+  final WidgetBuilder builder;
+  final double startAngle;
+  final double sweepAngle;
+  final Curve curve;
+  final ValueNotifier<bool> toggledNotifier;
+
+  const Sweeper({
+    Key key,
+    @required this.builder,
+    this.startAngle = -pi / 2,
+    this.sweepAngle = pi / 4,
+    this.curve = Curves.easeInOutCubic,
+    @required this.toggledNotifier,
+  }) : super(key: key);
+
+  @override
+  _SweeperState createState() => _SweeperState();
+}
+
+class _SweeperState extends State<Sweeper> with SingleTickerProviderStateMixin {
+  AnimationController _angleAnimationController;
+  Animation<double> _angle;
+  bool _isAppearing = false;
+
+  bool get isToggled => widget.toggledNotifier.value;
+
+  static const opacityAnimationDurationMillis = 150;
+  static const sweepingDurationMillis = 650;
+
+  @override
+  void initState() {
+    super.initState();
+    _angleAnimationController = AnimationController(
+      duration: const Duration(milliseconds: sweepingDurationMillis),
+      vsync: this,
+    );
+    _angle = Tween(
+      begin: widget.startAngle - widget.sweepAngle / 2,
+      end: widget.startAngle + pi * 2 - widget.sweepAngle / 2,
+    ).animate(CurvedAnimation(
+      parent: _angleAnimationController,
+      curve: widget.curve,
+    ));
+    _angleAnimationController.addStatusListener(_onAnimationStatusChange);
+    _registerWidget(widget);
+  }
+
+  @override
+  void didUpdateWidget(Sweeper oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    _unregisterWidget(oldWidget);
+    _registerWidget(widget);
+  }
+
+  @override
+  void dispose() {
+    _angleAnimationController.removeStatusListener(_onAnimationStatusChange);
+    _unregisterWidget(widget);
+    super.dispose();
+  }
+
+  void _registerWidget(Sweeper widget) {
+    widget.toggledNotifier.addListener(_onToggle);
+  }
+
+  void _unregisterWidget(Sweeper widget) {
+    widget.toggledNotifier.removeListener(_onToggle);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return IgnorePointer(
+      child: AnimatedOpacity(
+        opacity: isToggled && (_isAppearing || _angleAnimationController.status == AnimationStatus.forward) ? 1 : 0,
+        duration: const Duration(milliseconds: opacityAnimationDurationMillis),
+        child: ValueListenableBuilder<double>(
+            valueListenable: _angleAnimationController,
+            builder: (context, value, child) {
+              return ClipPath(
+                child: widget.builder(context),
+                clipper: _SweepClipPath(
+                  startAngle: _angle.value,
+                  sweepAngle: widget.sweepAngle,
+                ),
+              );
+            }),
+      ),
+    );
+  }
+
+  void _onAnimationStatusChange(AnimationStatus status) {
+    setState(() {});
+  }
+
+  Future<void> _onToggle() async {
+    if (isToggled) {
+      _isAppearing = true;
+      setState(() {});
+      await Future.delayed(Duration(milliseconds: (opacityAnimationDurationMillis * timeDilation).toInt()));
+      _isAppearing = false;
+      _angleAnimationController.forward();
+    } else {
+      await Future.delayed(Duration(milliseconds: (opacityAnimationDurationMillis * timeDilation).toInt()));
+      _angleAnimationController.reset();
+    }
+    setState(() {});
+  }
+}
+
+class _SweepClipPath extends CustomClipper<Path> {
+  final double startAngle;
+  final double sweepAngle;
+
+  const _SweepClipPath({@required this.startAngle, @required this.sweepAngle});
+
+  @override
+  Path getClip(Size size) {
+    Path path = Path();
+    path.moveTo(size.width / 2, size.height / 2);
+    path.addArc(Rect.fromLTWH(0, 0, size.width, size.height), startAngle, sweepAngle);
+    path.lineTo(size.width / 2, size.height / 2);
+    return path;
+  }
+
+  @override
+  bool shouldReclip(CustomClipper<Path> oldClipper) => true;
+}

lib/widgets/fullscreen/overlay/top.dart

@@ -1,4 +1,5 @@
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/widgets/common/fx/sweeper.dart';
 import 'package:aves/widgets/common/menu_row.dart';
 import 'package:aves/widgets/fullscreen/fullscreen_action_delegate.dart';
 import 'package:aves/widgets/fullscreen/overlay/common.dart';
@@ -42,11 +43,20 @@ class FullscreenTopOverlay extends StatelessWidget {
               scale: scale,
               child: ValueListenableBuilder(
                 valueListenable: entry.isFavouriteNotifier,
-                builder: (context, isFavourite, child) => IconButton(
-                  icon: Icon(isFavourite ? Icons.favorite : Icons.favorite_border),
+                builder: (context, isFavourite, child) => Stack(
+                  alignment: Alignment.center,
+                  children: [
+                    IconButton(
+                      icon: Icon(isFavourite ? OMIcons.favorite : OMIcons.favoriteBorder),
                       onPressed: () => onActionSelected?.call(FullscreenAction.toggleFavourite),
                       tooltip: isFavourite ? 'Remove favourite' : 'Add favourite',
                     ),
+                    Sweeper(
+                      builder: (context) => Icon(OMIcons.favoriteBorder, color: Colors.redAccent),
+                      toggledNotifier: entry.isFavouriteNotifier,
+                    ),
+                  ],
+                ),
               ),
             ),
             const SizedBox(width: 8),