dart设计模式之适配器模式，桥接模式，装饰器模式

import 'run.dart';
//官方媒体播放接口
abstract class MediaPlayer {
  void play(String audioType, String fileName);
}
//自定义媒体播放接口
abstract class AdvancedMediaPlayer {
  void playVlc(String fileName);
  void playMp4(String fileName);
}
//创建实现了 AdvancedMediaPlayer 接口的实体类。
class VlcPlayer implements AdvancedMediaPlayer {
  @override
  void playMp4(String fileName) {}
  @override
  void playVlc(String fileName) {
    print("Playing vlc file. Name: " + fileName);
  }
}
class Mp4Player implements AdvancedMediaPlayer {
  @override
  void playVlc(String fileName) {
    //什么也不做
  }
  @override
  void playMp4(String fileName) {
    print("Playing mp4 file. Name: " + fileName);
  }
}
// 创建实现了 MediaPlayer 接口的适配器类。
class MediaAdapter implements MediaPlayer {
  AdvancedMediaPlayer advancedMusicPlayer;
  MediaAdapter(String audioType) {
    if (audioType == "vlc") {
      advancedMusicPlayer = new VlcPlayer();
    } else if (audioType == "mp4") {
      advancedMusicPlayer = new Mp4Player();
    }
  }
  @override
  void play(String audioType, String fileName) {
    if (audioType == "vlc") {
      advancedMusicPlayer.playVlc(fileName);
    } else if (audioType == "mp4") {
      advancedMusicPlayer.playMp4(fileName);
    }
  }
}
// 创建实现了 MediaPlayer 接口的实体类。
class AudioPlayer implements MediaPlayer {
  MediaAdapter mediaAdapter;
  @override
  void play(String audioType, String fileName) {
    //播放 mp3 音乐文件的内置支持
    if (audioType == "mp3") {
      print("Playing mp3 file. Name: " + fileName);
    }
    //mediaAdapter 提供了播放其他文件格式的支持
    else if (audioType == "vlc" || audioType == "mp4") {
      mediaAdapter = new MediaAdapter(audioType);
      mediaAdapter.play(audioType, fileName);
    } else {
      print("Invalid media. " + audioType + " format not supported");
    }
  }
}
class RunAdapter implements Run {
  @override
  main() {
    AudioPlayer audioPlayer = new AudioPlayer();
    audioPlayer.play("mp3", "beyond the horizon.mp3");
    audioPlayer.play("mp4", "alone.mp4");
    audioPlayer.play("vlc", "far far away.vlc");
    audioPlayer.play("avi", "mind me.avi");
  }
  @override
  String name = "适配器模式";
}
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//咖啡售卖系统中，容量作为抽象化（Abstraction），口味作为实现化（Implementor）
//创建口味接口
abstract class ICoffeeAdditives {
  void addSomething();
}
// 创建抽象化类
abstract class Coffee {
  ICoffeeAdditives additives;
  Coffee(this.additives);
  void orderCoffee(int count);
}
//修正抽象化类，增加品控方法
abstract class RefinedCoffee extends Coffee {
  RefinedCoffee(ICoffeeAdditives additives) : super(additives);
  checkQuality(int score) {
    print("添加" + score.toString() + "%");
  }
}
//创建实现化部分
class Milk implements ICoffeeAdditives {
  @override
  void addSomething() {
    print("加奶");
  }
}
class Sugar implements ICoffeeAdditives {
  @override
  void addSomething() {
    print("加糖");
  }
}
class LargeCoffee extends RefinedCoffee {
  LargeCoffee(ICoffeeAdditives additives) : super(additives);
  @override
  void orderCoffee(int count) {
    additives.addSomething();
    print("大杯咖啡" + count.toString() + "杯");
  }
}
class MidCoffee extends RefinedCoffee {
  MidCoffee(ICoffeeAdditives additives) : super(additives);
  @override
  void orderCoffee(int count) {
    additives.addSomething();
    print("中杯咖啡" + count.toString() + "杯");
  }
}
class RunBridge implements Run {
  @override
  String name = "桥接模式";
  @override
  main() {
    RefinedCoffee largeWithMilk = new LargeCoffee(Milk());
    largeWithMilk.orderCoffee(2);
    largeWithMilk.checkQuality(90);
    print("\n");
    RefinedCoffee largeWithSugar = new MidCoffee(Sugar());
    largeWithSugar.orderCoffee(1);
    largeWithSugar.checkQuality(100);
  }
}
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//创建接口
abstract class Shape {
  void draw();
}
//创建接口实体类
class Rectangle implements Shape {
  @override
  void draw() {
    print("shape: Rectangle");
  }
}
class Circle implements Shape {
  @override
  void draw() {
    print("shape: Circle");
  }
}
//创建实现了Shape接口的抽象类
class ShapeDecorator implements Shape {
  final Shape decoratedShape;
  ShapeDecorator(this.decoratedShape);
  @override
  void draw() {
    decoratedShape.draw();
  }
}
//创建扩展了 ShapeDecorator 类的实体装饰类。
class RedShapeDecorator extends ShapeDecorator {
  RedShapeDecorator(Shape decoratedShape) : super(decoratedShape);
  @override
  void draw() {
    decoratedShape.draw();
    _setRedBorder(decoratedShape);
  }
  void _setRedBorder(Shape decoratedShape) {
    print("Border Color: Red");
  }
}
//使用 RedShapeDecorator 来装饰 Shape 对象。
class RunDecorator implements Run {
  @override
  void main() {
    Shape circle = new Circle();
    // ShapeDecorator redCircle = new RedShapeDecorator(new Circle());
    // ShapeDecorator redRectangle = new RedShapeDecorator(new Rectangle());
    Shape redCircle = new RedShapeDecorator(new Circle());
    Shape redRectangle = new RedShapeDecorator(new Rectangle());
    print("Circle with normal border");
    circle.draw();
    print("\nCircle of red border");
    redCircle.draw();
    print("\nRectangle of red border");
    redRectangle.draw();
  }
  @override
  String name = "装饰器模式";
}