瀑布流ListView

  1 package cn.bitlove.waterfalllistview.widget;
  2 
  3 import cn.bitlove.waterfalllistview.R;
  4 import android.content.Context;
  5 import android.util.AttributeSet;
  6 import android.view.LayoutInflater;
  7 import android.view.View;
  8 import android.view.ViewGroup;
  9 import android.widget.AbsListView;
 10 import android.widget.FrameLayout;
 11 import android.widget.AbsListView.OnScrollListener;
 12 import android.widget.ListView;
 13 
 14 /**
 15  * 瀑布流Listview
 16  * */
 17 public class WaterfallListview extends ListView implements OnScrollListener {
 18 
 19     final private String tag="WaterfallListView";
 20     private Context mContext;
 21     private LayoutInflater mInflater;        
 22     final int REFRESH_IDEL=0;        //空闲中
 23     final int REFRESH_PREPARE=1;    //准备刷新
 24     final int REFRESH_ING=2;        //刷新中
 25     final int REFRESH_End=3;        //刷新完成
 26     private int mRefreshState = REFRESH_IDEL;        //刷新状态
 27     private int mScrollState;        //滚动状态
 28 
 29     private FrameLayout mFooterLayout;    //ListView 的footer
 30     private View mListFoot;        //底部刷新区域
 31 
 32     private IOnRefresh mRefreshListener = null;    //刷新监听器
 33     public WaterfallListview(Context context) {
 34         super(context);
 35     }
 36     public  WaterfallListview(Context context, AttributeSet attrs) {
 37         super(context,attrs);
 38         init();
 39     }
 40     @Override
 41     public void onScrollStateChanged(AbsListView view, int scrollState) {
 42         mScrollState = scrollState;
 43     }
 44 
 45     @Override
 46     public void onScroll(AbsListView view, int firstVisibleItem,
 47             int visibleItemCount, int totalItemCount) {
 48         if(totalItemCount==0 || mScrollState==SCROLL_STATE_IDLE){
 49             return;
 50         }
 51         //最后一个item
 52         int lastItemCount = firstVisibleItem+visibleItemCount;
 53         if(lastItemCount==totalItemCount && mRefreshState==REFRESH_IDEL){
 54             prepareRefresh();
 55             doRefresh();
 56         }
 57     }
 58 
 59     private void init(){
 60         mCOntext= getContext();
 61         mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 62         initFooter();
 63         setOnScrollListener(this);
 64     }
 65     /**
 66      * 设置刷新器
 67      * */
 68     public void setRefreshListener(IOnRefresh refresher){
 69         mRefreshListener = refresher;
 70     }
 71 
 72     /**
 73      * 初始化底部刷新内容
 74      * */
 75     private void initFooter(){
 76         mListFoot = mInflater.inflate(R.layout.foot_waterfall_listview, null);
 77         mFooterLayout = new FrameLayout(mContext);
 78         addFooterView(mFooterLayout);
 79     }
 80     /**
 81      * 准备刷新
 82      * */
 83     private void prepareRefresh(){
 84         //Log.i(tag,"prepareRefresh");
 85         mRefreshState = REFRESH_PREPARE;
 86         ViewGroup vg = (ViewGroup) mListFoot.getParent();
 87         if(vg!=null){
 88             vg.removeView(mListFoot);
 89         }
 90 
 91         mFooterLayout.addView(mListFoot);
 92 
 93         if(mRefreshListener!=null){
 94             mRefreshListener.beforeRefresh();
 95         }
 96     }
 97     /**
 98      * 执行刷新
 99      * */
100     private void doRefresh(){
101         //Log.i(tag,"doRefresh");
102         mRefreshState=REFRESH_ING;
103 
104         if(mRefreshListener!=null){
105             mRefreshListener.doRefresh();
106         }
107 
108     }
109     /**
110      * 完成刷新
111      * */
112     public void completeRefresh(){
113         mRefreshState = REFRESH_IDEL;
114         mFooterLayout.removeAllViews();
115     }
116     
117     public interface IOnRefresh{
118         public void beforeRefresh();
119         /**
120          * 执行完doRefresh操作后，必须调用completeRefresh方法来清理刷新状态
121          * */
122         public void doRefresh();
123     }
124 }