解决多指批注问题

making_school_asignment_app/lib/page/home_page/children/homework_review/components/question_paper_view.dart

@@ -283,6 +283,35 @@ class QuestionImageView extends HookWidget with EventBusMixin<BottomOperationBar
   // 定时器超时时间，单位为毫秒
   static const int timeoutDuration = 300;
 
+  void toTimer(ValueNotifier<List<dynamic>> vnHandWritings) {
+    timer?.cancel();
+    timer = Timer(const Duration(milliseconds: timeoutDuration), () {
+      if (_activePointers > 2) {
+        _activePointers = 0;
+        if (vnHandWritings.value.last != null) {
+          vnHandWritings.value.add(null); // 增加空点以分隔不同的线段
+          sateData.handwritings = vnHandWritings.value; // 添加笔迹数据
+        }
+      }
+    });
+  }
+
+  /// 获取最后一个点的坐标位置
+  Offset? getLastDrop(List<dynamic> vals, int index) {
+    Offset? lastDrop;
+    if (vals.isNotEmpty) {
+      lastDrop = vals[index] as Offset?;
+      // if (lastDrop == null) {
+      //   index -= 1;
+      //   if (index > -1) {
+      //     lastDrop = getLastDrop(vals, index);
+      //   }
+      // }
+    
+    }
+    return lastDrop;
+  }
+
   @override
   Widget build(BuildContext context) {
     final theMaxHeight = useState<double>(maxHeight);
@@ -431,16 +460,17 @@ class QuestionImageView extends HookWidget with EventBusMixin<BottomOperationBar
         // 处理单个触摸点按下的逻辑
         _activePointers = _activePointers + 1;
         print("+++进入：onPointerDown $_activePointers");
-        timer?.cancel();
+        toTimer(vnHandWritings);
-        timer = Timer(const Duration(milliseconds: timeoutDuration), () {
+        // timer?.cancel();
-          if (_activePointers > 0) {
+        // timer = Timer(const Duration(milliseconds: timeoutDuration), () {
-            _activePointers = 0;
+        //   if (_activePointers > 2) {
-            if (vnHandWritings.value.last != null) {
+        //     _activePointers = 0;
-              vnHandWritings.value.add(null); // 增加空点以分隔不同的线段
+        //     if (vnHandWritings.value.last != null) {
-              sateData.handwritings = vnHandWritings.value; // 添加笔迹数据
+        //       vnHandWritings.value.add(null); // 增加空点以分隔不同的线段
-            }
+        //       sateData.handwritings = vnHandWritings.value; // 添加笔迹数据
-          }
+        //     }
-        });
+        //   }
+        // });
         sateData.panQuestView = true;
       },
       onPointerUp: (PointerUpEvent details) {
@@ -460,7 +490,7 @@ class QuestionImageView extends HookWidget with EventBusMixin<BottomOperationBar
       onPointerMove: (PointerMoveEvent event) {
         print("进入：onPointerMove $_activePointers");
         if (_activePointers != 1) return;
-        timer?.cancel();
+        toTimer(vnHandWritings);
         if (!annotationState.pen.value) return;
 
         Offset localPosition = event.localPosition; // 相对
@@ -500,6 +530,12 @@ class QuestionImageView extends HookWidget with EventBusMixin<BottomOperationBar
           (dy - max(0, imageHeightOffsetStart) + ((zoomFile.imageHeightOffsetStart == null || zoomFile.imageHeightOffsetStart! <= 0.1) ? (sateData.zoomOffset?.dy.abs() ?? 0) : 0)) / theScale,
         );
 
+        /// 判断当前点和上一个点的距离 判断是否是多指
+        var lastDrop = getLastDrop(vnHandWritings.value, vnHandWritings.value.length-1);
+        if (lastDrop != null && ((lastDrop.dx - localPosition.dx).abs() > 40 || (lastDrop.dy - localPosition.dy).abs() > 40)) {
+          /// 当前X点和上一个x点相差 大于10判定为多个手指
+          return;
+        }
         // print("最终位置 ： $localPosition");
         vnHandWritings.value = List.from(vnHandWritings.value)..add(localPosition);
         sateData.handwritings = vnHandWritings.value;