// 定义一个混入：可以飞行的能力
mixin FlyableMixin {
  void fly() {
    print("I can fly!");
  }
}

// 定义一个混入：可以游泳的能力
mixin SwimmableMixin {
  void swim() {
    print("I can swim!");
  }
}

// Bird 类使用 FlyableMixin
class Bird with FlyableMixin {
  String name;
  Bird(this.name);

  void chirp() {
    print("$name is chirping.");
  }
}

// Duck 类使用 FlyableMixin 和 SwimmableMixin
class Duck with FlyableMixin, SwimmableMixin {
  String name;
  Duck(this.name);

  void quack() {
    print("$name is quacking.");
  }
}

void main() {
  var eagle = Bird("Eagle");
  eagle.fly();   // 输出: I can fly!
  eagle.chirp(); // 输出: Eagle is chirping.

  var donald = Duck("Donald");
  donald.fly();   // 输出: I can fly!
  donald.swim();  // 输出: I can swim!
  donald.quack(); // 输出: Donald is quacking.
}

// 限制混入只能被 Animal 或其子类使用
mixin EaterMixin on Animal {
  void eatFood() {
    print("$name is eating food.");
  }
}

class Animal {
  String name;
  Animal(this.name);
}

class Dog extends Animal with EaterMixin {
  Dog(String name) : super(name);
}

// class Car with EaterMixin { // 错误：Car 不是 Animal 的子类
//   Car();
// }

void main() {
  var dog = Dog("Buddy");
  dog.eatFood(); // 输出: Buddy is eating food.
}

mixin A {
  void doSomething() {
    print("Do something from A");
  }
}

mixin B {
  void doSomething() {
    print("Do something from B");
  }
}

class MyClass with A, B {
  // MyClass 最终会使用 B 中的 doSomething 实现
}

class AnotherClass with B, A {
  // AnotherClass 最终会使用 A 中的 doSomething 实现
}

void main() {
  MyClass().doSomething();      // 输出: Do something from B
  AnotherClass().doSomething(); // 输出: Do something from A
}

import 'package:flutter/material.dart';

// 定义一个日志记录混入
mixin LoggerMixin<T extends StatefulWidget> on State<T> {
  void log(String message) {
    print('[${T.runtimeType}] $message');
  }

  @override
  void initState() {
    super.initState();
    log('initState called.');
  }

  @override
  void dispose() {
    log('dispose called.');
    super.dispose();
  }

  // 可以在这里添加更多的生命周期方法或自定义日志方法
}

// 示例 Widget 1：一个简单的计数器
class CounterWidget extends StatefulWidget {
  const CounterWidget({super.key});

  @override
  State<CounterWidget> createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State<CounterWidget> with LoggerMixin<CounterWidget> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
      log('Counter incremented to $_counter');
    });
  }

  @override
  Widget build(BuildContext context) {
    log('build called.');
    return Scaffold(
      appBar: AppBar(title: const Text('计数器')), 
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text('你点击了按钮这么多次:'),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

// 示例 Widget 2：一个简单的文本显示器
class TextViewWidget extends StatefulWidget {
  const TextViewWidget({super.key});

  @override
  State<TextViewWidget> createState() => _TextViewWidgetState();
}

class _TextViewWidgetState extends State<TextViewWidget> with LoggerMixin<TextViewWidget> {
  String _text = 'Hello Mixin!';

  @override
  Widget build(BuildContext context) {
    log('build called.');
    return Scaffold(
      appBar: AppBar(title: const Text('文本显示')), 
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              _text,
              style: const TextStyle(fontSize: 24),
            ),
            ElevatedButton(
              onPressed: () {
                setState(() {
                  _text = '文本已更新！';
                  log('Text updated.');
                });
              },
              child: const Text('更新文本'),
            ),
          ],
        ),
      ),
    );
  }
}

class MixinExampleScreen extends StatelessWidget {
  const MixinExampleScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Builder(
        builder: (context) {
          return Scaffold(
            appBar: AppBar(title: const Text('混入应用案例')), 
            body: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  ElevatedButton(
                    onPressed: () {
                      Navigator.of(context).push(MaterialPageRoute(builder: (context) => const CounterWidget()));
                    },
                    child: const Text('打开计数器'),
                  ),
                  const SizedBox(height: 20),
                  ElevatedButton(
                    onPressed: () {
                      Navigator.of(context).push(MaterialPageRoute(builder: (context) => const TextViewWidget()));
                    },
                    child: const Text('打开文本显示'),
                  ),
                ],
              ),
            ),
          );
        }
      ),
    );
  }
}

void main() {
  runApp(const MixinExampleScreen());
}