设计模式之桥接模式

1.引言

无意间，看到公司的人使用了桥接模式完成了一个功能模块，代码调理清晰，写的很不错。于是有了这篇梳理性文章。

2.正题

2.1 定义

桥接模式顾名思义，需要连接俩端。而且这俩端都需要进行拓展。例如RecycleView的布局，需要viewHolder和layoutManager 俩个维度。俩个维度相互搭配，形成不同的布局。这个时候就需要使用桥接模式。

2.2 UML图

image.png

interface1，interface2代表俩个维度的抽象。其下有很多实现类

2.3 实例

维度1: IViewHolder 获取不同类型的布局

public interface IViewHolder {
    public View onCreateViewHolder();
    public void bindViewHolder();
}

维度1 实现的俩个类:

public class TitleViewHolder implements IViewHolder {

    public ILayoutManager iLayoutManager;

    public TitleViewHolder(ILayoutManager iLayoutManagerImp) {
        this.iLayoutManager=iLayoutManagerImp;
    }

    @Override
    public View onCreateViewHolder() {

        System.out.println("占据的spansize: "+iLayoutManager.getSpanSize());
        return null;
    }

    @Override
    public void bindViewHolder() {

    }
}

public class ListViewViewHolder implements IViewHolder {
    public ILayoutManager iLayoutManager;

    public ListViewViewHolder(ILayoutManager iLayoutManagerImp) {
        this.iLayoutManager=iLayoutManagerImp;
    }


    @Override
    public View onCreateViewHolder() {
        return null;
    }

    @Override
    public void bindViewHolder() {

    }
}

维度2 接口

public interface ILayoutManager {
    
    public int getSpanSize();

    public void setWidth(int width);

    public void setHeight(int height);
}

实现类：

public class ListViewLayoutManager implements ILayoutManager {
    public int width = 0;
    public int height = 0;

    @Override
    public int getSpanSize() {
        return 20;
    }

    @Override
    public void setWidth(int width1) {

        width = width1;
    }

    @Override
    public void setHeight(int height1) {
        height = height1;
    }
}

public class TitleLayoutManager implements ILayoutManager {
    public int width = 0;
    public int height = 0;

    @Override
    public int getSpanSize() {
        return 20;//占据20个spanSize
    }

    @Override
    public void setWidth(int width1) {

        width = width1;
    }

    @Override
    public void setHeight(int height1) {
        height = height1;
    }
}

桥接类：

public class AdapterBridge {


    public static void main(String args[]){

        ILayoutManager manager=new TitleLayoutManager();
        IViewHolder mIViewHolder=new TitleViewHolder(manager);


        ILayoutManager manager1=new ListViewLayoutManager();
        IViewHolder mIViewHolder1=new ListViewViewHolder(manager);


        mIViewHolder.onCreateViewHolder();
    }
}