feat(player): 重做播放页信息层级与互动栏点击动效

lib/pages/player/widgets/interaction_rail_burst.dart

@@ -0,0 +1,88 @@
+// Author: fruit.com.cn
+// 职责：绘制收藏点赞周围的紧凑双向短线，无圆环或阴影，不参与手势。
+import 'dart:math' as math;
+
+import 'package:flutter/material.dart';
+
+const int _rayCount = 8;
+const double _startProgress = 0.1;
+const double _radiusStart = 0.34;
+const double _radiusTravel = 0.14;
+const double _rayLength = 0.07;
+const double _strokeFraction = 0.025;
+const double _rayAlpha = 0.65;
+const double _fullCircle = math.pi * 2;
+const double _rayRotation = math.pi / _rayCount;
+
+/// 收藏/点赞的装饰反馈：选中外扩，取消收束。
+class RailTapBurst extends StatelessWidget {
+  /// [progress] 来自按钮的点击动画，不创建独立计时器。
+  const RailTapBurst({
+    super.key,
+    required this.progress,
+    required this.color,
+    required this.contracting,
+  });
+
+  final double progress;
+  final Color color;
+  final bool contracting;
+
+  @override
+  Widget build(BuildContext context) => IgnorePointer(
+    child: CustomPaint(
+      painter: _RailBurstPainter(
+        progress: progress,
+        color: color,
+        contracting: contracting,
+      ),
+    ),
+  );
+}
+
+class _RailBurstPainter extends CustomPainter {
+  const _RailBurstPainter({
+    required this.progress,
+    required this.color,
+    required this.contracting,
+  });
+
+  final double progress;
+  final Color color;
+  final bool contracting;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final phase = ((progress - _startProgress) / (1 - _startProgress)).clamp(
+      0.0,
+      1.0,
+    );
+    if (phase == 0 || phase == 1) return;
+    final eased = Curves.easeOutCubic.transform(phase);
+    final travel = contracting ? 1 - eased : eased;
+    final base = size.shortestSide;
+    final radius = base * (_radiusStart + _radiusTravel * travel);
+    final alpha = math.sin(math.pi * phase);
+    final paint = Paint()
+      ..style = PaintingStyle.stroke
+      ..strokeCap = StrokeCap.round
+      ..strokeWidth = base * _strokeFraction
+      ..color = color.withValues(alpha: alpha * _rayAlpha);
+    final center = size.center(Offset.zero);
+    final length = base * _rayLength * (1 - phase);
+    for (var index = 0; index < _rayCount; index++) {
+      final angle = _fullCircle * index / _rayCount + _rayRotation;
+      canvas.drawLine(
+        center + Offset.fromDirection(angle, radius),
+        center + Offset.fromDirection(angle, radius + length),
+        paint,
+      );
+    }
+  }
+
+  @override
+  bool shouldRepaint(covariant _RailBurstPainter oldDelegate) =>
+      oldDelegate.progress != progress ||
+      oldDelegate.color != color ||
+      oldDelegate.contracting != contracting;
+}