fix(player): 恢复随机飘心粒子模型

lib/pages/player/widgets/player_double_tap_hearts.dart

@@ -1,56 +1,38 @@
 // Author: fruit.com.cn
 
+import 'dart:math';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import '../../../core/theme/app_colors.dart';
 
-const int _heartDurationMs = 1900;
-const int _lastHeartDelayMs = 260;
-const double _heartPopPortion = 0.12;
-const double _heartStartScale = 0.7;
-const double _heartHoldPortion = 0.45;
-
-const List<_HeartParticle> _hearts = [
-  _HeartParticle(
-    delay: 0,
-    travel: 120,
-    drift: 0,
-    size: 44,
-    color: AppColors.doubleTapHeartRed,
-  ),
-  _HeartParticle(
-    delay: 140,
-    travel: 120,
-    drift: -32,
-    size: 34,
-    color: AppColors.doubleTapHeartPink,
-  ),
-  _HeartParticle(
-    delay: _lastHeartDelayMs,
-    travel: 120,
-    drift: 30,
-    size: 38,
-    color: AppColors.doubleTapHeartRed,
-  ),
-];
-
 /// 双击点赞时，在点击位置飘出一小簇心。
 class PlayerDoubleTapHeartBurst extends StatefulWidget {
   const PlayerDoubleTapHeartBurst({
     super.key,
     required this.burstId,
     required this.onCompleted,
+    this.random,
   });
 
-  static const int particleCount = 3;
-  static const int singleHeartDurationMs = _heartDurationMs;
-  static const Duration animationDuration = Duration(
-    milliseconds: _lastHeartDelayMs + _heartDurationMs,
-  );
+  static const int minParticleCount = 4;
+  static const int maxParticleCount = 5;
 
   final int burstId;
   final VoidCallback onCompleted;
+  final Random? random;
+
+  @visibleForTesting
+  static double opacityForProgress(double progress) =>
+      1 - Curves.easeIn.transform(progress);
+
+  @visibleForTesting
+  static double scaleForProgress(double progress) {
+    return progress < 0.3
+        ? 0.55 + (1.15 - 0.55) * (progress / 0.3)
+        : 1.15 - (1.15 - 0.2) * ((progress - 0.3) / 0.7);
+  }
 
   @override
   State<PlayerDoubleTapHeartBurst> createState() =>
@@ -60,6 +42,7 @@ class PlayerDoubleTapHeartBurst extends StatefulWidget {
 class _PlayerDoubleTapHeartBurstState extends State<PlayerDoubleTapHeartBurst>
     with SingleTickerProviderStateMixin {
   late final AnimationController _controller;
+  late final List<_HeartParticle> _particles;
   final Stopwatch _lifetime = Stopwatch();
   bool _completed = false;
 
@@ -67,13 +50,39 @@ class _PlayerDoubleTapHeartBurstState extends State<PlayerDoubleTapHeartBurst>
   void initState() {
     super.initState();
     _lifetime.start();
+    final random = widget.random ?? Random();
+    var delay = 0;
+    _particles = List.generate(
+      PlayerDoubleTapHeartBurst.minParticleCount +
+          random.nextInt(
+            PlayerDoubleTapHeartBurst.maxParticleCount -
+                PlayerDoubleTapHeartBurst.minParticleCount +
+                1,
+          ),
+      (index) {
+        if (index > 0) delay += 40 + random.nextInt(21);
+        return _HeartParticle(
+          delay: delay,
+          duration: 900 + random.nextInt(201),
+          travel: 120 + random.nextInt(41),
+          drift: -30 + random.nextInt(61),
+          size: (22 + random.nextInt(13)).toDouble(),
+          color: random.nextBool()
+              ? AppColors.doubleTapHeartRed
+              : AppColors.doubleTapHeartPink,
+        );
+      },
+    );
+    final total = _particles
+        .map((particle) => particle.delay + particle.duration)
+        .reduce(max);
     if (kDebugMode) {
       debugPrint('[player] phase=heart-burst-init id=${widget.burstId}');
-      debugPrint('[player] phase=heart-burst-start id=${widget.burstId}');
+      debugPrint(
+        '[player] phase=heart-burst-start '
+        'id=${widget.burstId} count=${_particles.length}',
+      );
     }
-    final total = _hearts
-        .map((heart) => heart.delay + _heartDurationMs)
-        .reduce((left, right) => left > right ? left : right);
     _controller = AnimationController(
       vsync: this,
       duration: Duration(milliseconds: total),
@@ -122,8 +131,8 @@ class _PlayerDoubleTapHeartBurstState extends State<PlayerDoubleTapHeartBurst>
             return Stack(
               clipBehavior: Clip.none,
               children: [
-                for (var index = 0; index < _hearts.length; index++)
-                  _heart(_hearts[index], elapsed, index),
+                for (var index = 0; index < _particles.length; index++)
+                  _particle(_particles[index], elapsed, index),
               ],
             );
           },
@@ -132,35 +141,26 @@ class _PlayerDoubleTapHeartBurstState extends State<PlayerDoubleTapHeartBurst>
     );
   }
 
-  Widget _heart(_HeartParticle heart, double elapsed, int index) {
-    final progress = ((elapsed - heart.delay) / _heartDurationMs).clamp(
+  Widget _particle(_HeartParticle particle, double elapsed, int index) {
+    final progress = ((elapsed - particle.delay) / particle.duration).clamp(
       0.0,
       1.0,
     );
     if (progress <= 0) return const SizedBox.shrink();
-    final move = Curves.easeOutSine.transform(progress);
-    final scale = progress < _heartPopPortion
-        ? _heartStartScale +
-              (1 - _heartStartScale) * (progress / _heartPopPortion)
-        : 1.0;
-    final opacity = progress < _heartHoldPortion
-        ? 1.0
-        : 1 -
-              Curves.easeInOutSine.transform(
-                (progress - _heartHoldPortion) / (1 - _heartHoldPortion),
-              );
+    final move = Curves.easeOutCubic.transform(progress);
+    final scale = PlayerDoubleTapHeartBurst.scaleForProgress(progress);
     return Positioned(
-      left: heart.drift * move - heart.size / 2,
-      top: -heart.size / 2 - heart.travel * move,
+      left: particle.drift * move - particle.size / 2,
+      top: -particle.travel * move,
       child: Opacity(
-        opacity: opacity.clamp(0.0, 1.0),
+        opacity: PlayerDoubleTapHeartBurst.opacityForProgress(progress),
         child: Transform.scale(
           scale: scale,
           child: Icon(
             key: Key('double-tap-heart-$index'),
             Icons.favorite_rounded,
-            color: heart.color,
-            size: heart.size,
+            color: particle.color,
+            size: particle.size,
           ),
         ),
       ),
@@ -171,6 +171,7 @@ class _PlayerDoubleTapHeartBurstState extends State<PlayerDoubleTapHeartBurst>
 class _HeartParticle {
   const _HeartParticle({
     required this.delay,
+    required this.duration,
     required this.travel,
     required this.drift,
     required this.size,
@@ -178,8 +179,9 @@ class _HeartParticle {
   });
 
   final int delay;
-  final double travel;
-  final double drift;
+  final int duration;
+  final int travel;
+  final int drift;
   final double size;
   final Color color;
 }

lib/pages/player/widgets/player_tap_gesture_region.dart

@@ -171,10 +171,6 @@ class _PlayerTapGestureRegionState extends State<PlayerTapGestureRegion> {
       debugPrint(
         '[player] phase=double-tap-like episodeId=${widget.episodeId}',
       );
-      debugPrint(
-        '[player] phase=heart-burst '
-        'count=${PlayerDoubleTapHeartBurst.particleCount}',
-      );
     }
     widget.onDoubleTapLike?.call(position);
   }

test/player/player_double_tap_hearts_test.dart

@@ -1,26 +1,34 @@
 // Author: fruit.com.cn
 
+import 'dart:math';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:fruitshorts/pages/player/widgets/player_double_tap_hearts.dart';
 
 void main() {
-  testWidgets('should_show_three_medium_hearts_when_double_tap_burst_starts', (
+  testWidgets('should_show_randomized_heart_particles_when_burst_starts', (
     tester,
   ) async {
     await tester.pumpWidget(
-      const MaterialApp(
+      MaterialApp(
         home: Scaffold(
-          body: PlayerDoubleTapHeartBurst(burstId: 1, onCompleted: _noop),
+          body: PlayerDoubleTapHeartBurst(
+            burstId: 1,
+            onCompleted: _noop,
+            random: Random(42),
+          ),
         ),
       ),
     );
-    await tester.pump(const Duration(milliseconds: 300));
+    await tester.pump(const Duration(milliseconds: 400));
 
-    expect(find.byIcon(Icons.favorite_rounded), findsNWidgets(3));
-    expect(_size(tester, 0), 44);
-    expect(_size(tester, 1), 34);
-    expect(_size(tester, 2), 38);
+    final hearts = find.byIcon(Icons.favorite_rounded);
+    final count = hearts.evaluate().length;
+    expect(count, inInclusiveRange(4, 5));
+    for (var index = 0; index < count; index++) {
+      expect(_size(tester, index), inInclusiveRange(22, 34));
+    }
     expect(
       tester
           .widgetList<Stack>(
@@ -34,14 +42,16 @@ void main() {
     );
   });
 
-  test('heart burst stays long and sparse', () {
-    expect(PlayerDoubleTapHeartBurst.singleHeartDurationMs, 1900);
+  test('heart particles fade from the start and scale in two phases', () {
+    expect(PlayerDoubleTapHeartBurst.opacityForProgress(0.5), lessThan(0.7));
+    expect(PlayerDoubleTapHeartBurst.scaleForProgress(0), 0.55);
     expect(
-      PlayerDoubleTapHeartBurst.animationDuration,
-      greaterThanOrEqualTo(const Duration(milliseconds: 1800)),
+      PlayerDoubleTapHeartBurst.scaleForProgress(0.3),
+      closeTo(1.15, 1e-9),
     );
-    expect(PlayerDoubleTapHeartBurst.particleCount, lessThanOrEqualTo(4));
-    expect(PlayerDoubleTapHeartBurst.particleCount, 3);
+    expect(PlayerDoubleTapHeartBurst.scaleForProgress(1), closeTo(0.2, 1e-9));
+    expect(PlayerDoubleTapHeartBurst.minParticleCount, 4);
+    expect(PlayerDoubleTapHeartBurst.maxParticleCount, 5);
   });
 }