hover_example.dart

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MouseRegionApp());
}

class MouseRegionApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  bool onFirst = false;
  bool onSecond = false;
  Offset exitFrom = Offset(0,0);

  MouseCursor _mouseCursor = SystemMouseCursors.basic;

  @override
  Widget build(BuildContext context) {
    return FocusableActionDetector(
      mouseCursor: _mouseCursor,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Container(height: 50, color: Colors.white,),
          Expanded(
            child: MouseRegion(
              onEnter: (PointerEvent details) => setState(() => onFirst = true),
              onExit: (PointerEvent details) =>  setState(() { 
                onFirst = false;
                exitFrom = details.position;
            }),
              child: Container(
                color: onFirst ? Colors.red : Colors.blue,
                child: Center(child: Text(onFirst ? "Look mom, I'm hovering" : "I last exited from $exitFrom"))
              ),
            ),
          ),
          Expanded(
            child: MouseRegion(
              onEnter: (PointerEvent details) => setState(() {
                onSecond = true;
                if (_mouseCursor == SystemMouseCursors.progress) {
                  _mouseCursor = SystemMouseCursors.basic;
                } else {
                  _mouseCursor = SystemMouseCursors.progress;
                }
              }),
              onExit: (PointerEvent details) =>
                  setState(() => onSecond = false),
              child: Container(
                color: onSecond ? Colors.red : Colors.green,
              ),
            ),
          ),
        ],
      ),
    );
  }
}