add hover detector to wrap a hovering widget

lib/hover_detector.dart

@@ -0,0 +1,25 @@
+import 'package:flutter/material.dart';
+
+class HoverDetector extends StatefulWidget {
+  const HoverDetector(
+      {Key? key, required this.defaultChild, required this.hoverChild})
+      : super(key: key);
+  final Widget defaultChild;
+  final Widget hoverChild;
+
+  @override
+  State<HoverDetector> createState() => _HoverDetectorState();
+}
+
+class _HoverDetectorState extends State<HoverDetector> {
+  bool amIHovering = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return MouseRegion(
+      child: amIHovering ? widget.hoverChild : widget.defaultChild,
+      onEnter: (PointerEvent details) => setState(() => amIHovering = true),
+      onExit: (PointerEvent details) => setState(() => amIHovering = false),
+    );
+  }
+}