feat: 改进聊天弹窗和遮罩层交互，优化状态管理和绘制逻辑

lib/widgets/_hole_overlay.dart

@@ -1,46 +1,52 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/gestures.dart';
+import 'package:flutter/rendering.dart';
 
-/// 遮罩层，icon 区域挖洞可交互
+// 一个带洞的遮罩层，点击洞外区域触发onTap事件
 class HoleOverlay extends StatelessWidget {
   final Offset iconPosition;
   final double iconSize;
   final VoidCallback? onTap;
+  final Widget? child;
 
   const HoleOverlay({
     super.key,
     required this.iconPosition,
     required this.iconSize,
     this.onTap,
+    this.child,
   });
 
   @override
   Widget build(BuildContext context) {
-    return Listener(
-      behavior: HitTestBehavior.translucent,
-      onPointerDown: (PointerDownEvent event) {
-        final RenderBox box = context.findRenderObject() as RenderBox;
-        final Offset local = box.globalToLocal(event.position);
-        final iconRect = Rect.fromLTWH(
-          iconPosition.dx,
-          iconPosition.dy,
-          iconSize,
-          iconSize,
-        );
-        if (!iconRect.contains(local)) {
-          // 遮罩区域，拦截并关闭弹窗
-          if (onTap != null) {
-            onTap!();
+    debugPrint('🔧 HoleOverlay build: iconPosition=$iconPosition, iconSize=$iconSize');
+    
+    final holeRect = Rect.fromLTWH(
+      iconPosition.dx,
+      iconPosition.dy,
+      iconSize,
+      iconSize,
+    );
+    
+    return CustomPaint(
+      painter: _HolePainter(
+        iconPosition: iconPosition,
+        iconSize: iconSize,
+      ),
+      child: GestureDetector(
+        onTapDown: (details) {
+          final tapPosition = details.localPosition;
+          final isInHole = holeRect.contains(tapPosition);
+          debugPrint('🎯 HoleOverlay onTapDown: position=$tapPosition, holeRect=$holeRect, isInHole=$isInHole');
+          
+          if (!isInHole) {
+            debugPrint('🔥 HoleOverlay: 点击洞外，触发onTap');
+            onTap?.call();
+          } else {
+            debugPrint('🚫 HoleOverlay: 点击洞内，不触发onTap');
           }
-        }
-        // 如果点在icon区域，什么都不做，事件会传递到下层
-      },
-      child: CustomPaint(
-        size: Size.infinite,
-        painter: _HolePainter(
-          iconPosition: iconPosition,
-          iconSize: iconSize,
-        ),
+        },
+        child: child,
+        behavior: HitTestBehavior.translucent,
       ),
     );
   }
@@ -50,31 +56,51 @@ class _HolePainter extends CustomPainter {
   final Offset iconPosition;
   final double iconSize;
 
-  _HolePainter({required this.iconPosition, required this.iconSize});
+  _HolePainter({
+    required this.iconPosition,
+    required this.iconSize,
+  });
 
   @override
   void paint(Canvas canvas, Size size) {
-    final paint = Paint()
-      ..color = Colors.white.withOpacity(0.0)
-      ..blendMode = BlendMode.srcOver;
-
-    // 画全屏遮罩
-    canvas.drawRect(Offset.zero & size, paint);
-
-    // 挖洞
     final holeRect = Rect.fromLTWH(
       iconPosition.dx,
       iconPosition.dy,
       iconSize,
       iconSize,
     );
-    final holePath = Path()..addOval(holeRect);
-    paint.blendMode = BlendMode.clear;
-    canvas.drawPath(holePath, paint);
+    
+    debugPrint('🎨 HolePainter paint: size=$size, holeRect=$holeRect');
+    
+    // 使用 saveLayer 确保混合模式正确
+    canvas.saveLayer(Offset.zero & size, Paint());
+    
+    // 画半透明背景
+    final backgroundPaint = Paint()
+      ..color = Colors.black.withOpacity(0.3);
+    canvas.drawRect(Offset.zero & size, backgroundPaint);
+    debugPrint('🔲 HolePainter paint: 绘制背景完成');
+    
+    // 挖洞：使用 BlendMode.clear
+    final holePaint = Paint()
+      ..blendMode = BlendMode.clear;
+    canvas.drawOval(holeRect, holePaint);
+    debugPrint('⭕ HolePainter paint: 挖洞完成，holeRect=$holeRect');
+    
+    canvas.restore();
+    
+    // 调试：画红色边框显示洞的位置
+    final debugPaint = Paint()
+      ..color = Colors.red
+      ..style = PaintingStyle.stroke
+      ..strokeWidth = 2.0;
+    canvas.drawOval(holeRect, debugPaint);
+    debugPrint('🔴 HolePainter paint: 绘制调试边框完成');
   }
 
   @override
   bool shouldRepaint(covariant _HolePainter oldDelegate) {
-    return iconPosition != oldDelegate.iconPosition || iconSize != oldDelegate.iconSize;
+    return oldDelegate.iconPosition != iconPosition || 
+           oldDelegate.iconSize != iconSize;
   }
-}
+}