[装饰器设计模式详解]C/Java/JS/Go/Python/TS不同语言实现

// Shape.java 基础形状接口
public interface Shape {
   void draw(;
}

// Circle.java 具体形状实现了基础形状接口 public class Circle implements Shape { @Override public void draw( { System.out.println("Circle::draw("; } } // Square.java 具体形状实现了基础形状接口 public class Square implements Shape { @Override public void draw( { System.out.println("Square::draw("; } }

// ShapeDecorator.java 抽象装饰类，是否实现Shape可选 public abstract class ShapeDecorator implements Shape { // public abstract class ShapeDecorator { protected Shape decoratedShape; public ShapeDecorator(Shape decoratedShape { this.decoratedShape = decoratedShape; } public void draw( { decoratedShape.draw(; } }

// RedShapeDecorator.java 具体装饰器1 public class RedShapeDecorator extends ShapeDecorator { public RedShapeDecorator(Shape decoratedShape { super(decoratedShape; } @Override public void draw( { decoratedShape.draw(; setRedColor(decoratedShape; } private void setRedColor(Shape decoratedShape { System.out.println( "RedShapeDecorator::setRedColor( " + decoratedShape.getClass(.getName( ; } } // ShadowShapeDecorator.java 具体装饰器2 public class ShadowShapeDecorator extends ShapeDecorator { public ShadowShapeDecorator(Shape decoratedShape { super(decoratedShape; } @Override public void draw( { // decoratedShape.draw(; setShadow(decoratedShape; } private void setShadow(Shape decoratedShape { System.out.println( "ShadowShapeDecorator::setShadow( " + decoratedShape.getClass(.getName( ; } }

/** * 装饰器模式是将一个对象放到一个装饰器对象中，执行装饰器类里的方法时，对象的行为能力得到增强。 * 先声明具体对象，然后放到装饰器，得到一个带有装饰器的新对象，该对象具备了新的能力。 */ // 声明形状 Shape circle = new Circle(; Shape square = new Square(; // 增加红色装饰 ShapeDecorator redCircle = new RedShapeDecorator(circle; ShapeDecorator redSquare = new RedShapeDecorator(square; circle.draw(; redCircle.draw(; redSquare.draw(; // 增加影子装饰 ShadowShapeDecorator shadowCircle = new ShadowShapeDecorator(circle; ShadowShapeDecorator shadowSquare = new ShadowShapeDecorator(square; shadowCircle.draw(; shadowSquare.draw(;

// Shape.go 基础形状接口 type Shape interface { Draw( GetName( string }

// Circle.go 具体形状实现了基础形状接口 type Circle struct { } func (c *Circle Draw( { fmt.Println("Circle::Draw(" } func (c *Circle GetName( string { return "Circle" } // Square.go 具体形状实现了基础形状接口 type Square struct { } func (c *Square Draw( { fmt.Println("Square::Draw(" } func (c *Square GetName( string { return "Square" }

// ShapeDecorator.go 抽象装饰类，是否实现Shape可选 type ShapeDecorator interface { Draw( }

// RedShapeDecorator.go 具体装饰器1 type RedShapeDecorator struct { DecoratedShape Shape } func (r *RedShapeDecorator Draw( { r.DecoratedShape.Draw( r.SetRedColor(r.DecoratedShape } func (r *RedShapeDecorator SetRedColor(decoratedShape Shape { fmt.Println("RedShapeDecorator::setRedColor( " + decoratedShape.GetName( } // ShadowShapeDecorator.go 具体装饰器2 type ShadowShapeDecorator struct { DecoratedShape Shape } func (s *ShadowShapeDecorator Draw( { // 装饰器根据需要是否调用形状的Draw方法 // s.DecoratedShape.Draw( s.SetShadow(s.DecoratedShape } func (s *ShadowShapeDecorator SetShadow(decoratedShape Shape { fmt.Println("ShadowShapeDecorator::SetShadow( " + decoratedShape.GetName( }

/** * 装饰器模式是将一个对象放到一个装饰器对象中，执行装饰器类里的方法时，对象的行为能力得到增强。 * 先声明具体对象，然后放到装饰器，得到一个带有装饰器的新对象，该对象具备了新的能力。 */ // 声明形状 var circle = new(src.Circle var square = new(src.Square // 增加红色装饰 var redCircle = &src.RedShapeDecorator{ DecoratedShape: circle, } var redSquare = &src.RedShapeDecorator{ DecoratedShape: square, } circle.Draw( redCircle.Draw( redSquare.Draw( // 增加影子装饰 var shadowCircle = &src.ShadowShapeDecorator{ DecoratedShape: circle, } var shadowSquare = &src.ShadowShapeDecorator{ DecoratedShape: square, } shadowCircle.Draw( shadowSquare.Draw(