Android TV Leanback分析之Presenter（

Presenter是一个抽象类，和RecyclerView.Adapter中需要实现的方法相对应，onCreateViewHolder、onBindViewHolder、onUnbindViewHolder

ViewHolder 是持有子视图的root view。其子类可扩展具体的view。

public abstract class Presenter implements FacetProvider {
    
    //Facet用于item布局属性
    private Map<Class, Object> mFacets;

    public static class ViewHolder implements FacetProvider {
        public final View view;
        private Map<Class, Object> mFacets;

        public ViewHolder(View view) {
            this.view = view;
        }

    }
    public abstract ViewHolder onCreateViewHolder(ViewGroup parent);
    public abstract void onBindViewHolder(ViewHolder viewHolder, Object item);
    public abstract void onUnbindViewHolder(ViewHolder viewHolder);
    
    //...

}

PresenterSelector 也是一个抽象类，需要实现getPresenter

public abstract class PresenterSelector {
    //子类去实现不同item获取不同Presenter
    public abstract Presenter getPresenter(Object item);
    //Presenter列表
    Presenter[] getPresenters() {
        return null;
    }

}