更新睡眠报告

lib/pages/sleep_report/chart/GradientLine.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+
+class GradientLine extends StatelessWidget {
+  final double height;
+  final Color color;
+
+  const GradientLine({
+    Key? key,
+    this.height = 4.0,
+    required this.color,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        return CustomPaint(
+          size: Size(constraints.maxWidth, height),
+          painter: _GradientLinePainter(color: color),
+        );
+      },
+    );
+  }
+}
+
+class _GradientLinePainter extends CustomPainter {
+  final Color color;
+
+  _GradientLinePainter({required this.color});
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final Paint paint = Paint()
+      ..shader = LinearGradient(
+        colors: [
+          color.withOpacity(0.0), // 左端透明
+          color.withOpacity(1.0), // 中间最深
+          color.withOpacity(0.0), // 右端透明
+        ],
+        stops: [0.0, 0.5, 1.0],
+      ).createShader(Rect.fromLTWH(0, 0, size.width, size.height));
+
+    canvas.drawRect(Rect.fromLTWH(0, 0, size.width, size.height), paint);
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) => false;
+}