perf(measure): 优化指针进出区域

lib/view/gesture/mouse_gesture.dart

@@ -18,6 +18,7 @@ class _MeasureMouseGesturePanelState extends State<MeasureMouseGesturePanel> {
 
   final mouseState = Get.put<IMouseState>(MouseState());
   late final application = Get.find<IApplication>();
+  bool ifShowCursor = false;
 
   @override
   void initState() {
@@ -63,9 +64,19 @@ class _MeasureMouseGesturePanelState extends State<MeasureMouseGesturePanel> {
             PointInfoType.mouseMove,
           );
         },
+        onEnter: (e) {
+          setState(() {
+            ifShowCursor = true;
+          });
+        },
+        onExit: (e) {
+          setState(() {
+            ifShowCursor = false;
+          });
+        },
         child: Stack(
-          children: const [
-            PositionedCursor(),
+          children: [
+            ifShowCursor ? const PositionedCursor() : Container(),
           ],
         ),
       ),