设计模式（九）合成

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类结构和对象结构：

1、抽象组件

public interface View {
	public void draw();
}

2、树叶组件

public class Circle implements View{

	@Override
	public void draw() {
		System.out.print("O");
	}

}

public class Square implements View{

	@Override
	public void draw() {
		System.out.println("口");
	}

}

3、树枝组件

import java.util.ArrayList;

public class LinearLayout implements View{
	
	public static final int HORIZONTAL=0;
	public static final int VERTICAL=1;
	
	private int orientation;
	private ArrayList<View> views=new ArrayList<View>();

	@Override
	public void draw() {
		if(orientation==HORIZONTAL){
			for(View view:views){
				view.draw();
			}
		}else{
			for(View view:views){
				System.out.print("\t");//制表，形成垂直布局的效果
				view.draw();
				System.out.print("\n");//换行
			}
		}
	}
	
	public void add(View view){
		views.add(view);
	}
	
	public void remove(View view){
		views.remove(view);
	}

	public void setOrientation(int orientation) {
		this.orientation = orientation;
	}

}	
	public static final int HORIZONTAL=0;
	public static final int VERTICAL=1;
	
	private int orientation;
	private ArrayList<View> views=new ArrayList<View>();

	@Override
	public void draw() {
		if(orientation==HORIZONTAL){
			for(View view:views){
				view.draw();
			}
		}else{
			for(View view:views){
				System.out.print("\t");//制表，形成垂直布局的效果
				view.draw();
				System.out.print("\n");//换行
			}
		}
	}
	
	public void add(View view){
		views.add(view);
	}
	
	public void remove(View view){
		views.remove(view);
	}

	public void setOrientation(int orientation) {
		this.orientation = orientation;
	}

}

4、消费者

public class Customer{

	public static void main(String[] args) {
		
		Circle circle=new Circle();
		Circle circle2=new Circle();
		Circle circle3=new Circle();
		
		Square square=new Square();
		Square square2=new Square();
		Square square3=new Square();
		
		LinearLayout layoutChild=new LinearLayout();//子布局
		layoutChild.setOrientation(LinearLayout.VERTICAL);//垂直布局
		layoutChild.add(square);
		layoutChild.add(square2);
		layoutChild.add(square3);
		
		LinearLayout layout=new LinearLayout();//父布局，默认水平布局
		layout.add(circle);
		layout.add(circle2);
		layout.add(circle3);
		layout.add(layoutChild);
		
		layout.draw();//绘制整个视图
		
		System.out.println("--------删除子布局的一个树叶节点后---------");
		
		layoutChild.remove(square2);
		layout.draw();//再次绘制整个视图
	}

}

5、运行结果