package com.example.reflush;

import android.app.ListActivity;

import android.os.Bundle;

import android.util.Log;

import android.view.Gravity;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AbsListView;

import android.widget.BaseAdapter;

import android.widget.LinearLayout;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.TextView;

import android.widget.Toast;

import android.widget.AbsListView.OnScrollListener;

import android.widget.LinearLayout.LayoutParams;  

public class MainActivity extends ListActivity implements OnScrollListener{

    private static final String TAG = "MainActivity";

    private listViewAdapter adapter = new listViewAdapter();

    ListView listView ;

    private int lastItem = ;

    LinearLayout loadingLayout;

    /**

      * 设置布局显示属性

      */

        private LayoutParams mLayoutParams =new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);

        /**

      * 设置布局显示目标最大化属性

      */

        private LayoutParams FFlayoutParams =new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.FILL_PARENT);  

    private ProgressBar progressBar;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

      super.onCreate(savedInstanceState);

      Log.i(TAG, "onCreate(Bundle savedInstanceState)>>>>>>>>>>>>>>>" );

         //线性布局

      LinearLayout layout = new LinearLayout(this);

        //设置布局 水平方向

      layout.setOrientation(LinearLayout.HORIZONTAL);

       //进度条

      progressBar = new ProgressBar(this);

       //进度条显示位置

      progressBar.setPadding(, , , );

      //把进度条加入到layout中

      layout.addView(progressBar, mLayoutParams);

      //文本内容

      TextView textView = new TextView(this);

      textView.setText("加载中...");

      textView.setGravity(Gravity.CENTER_VERTICAL);

      //把文本加入到layout中

      layout.addView(textView, FFlayoutParams);

      //设置layout的重力方向，即对齐方式是

      layout.setGravity(Gravity.CENTER);  

      //设置ListView的页脚layout

      loadingLayout = new LinearLayout(this);

      loadingLayout.addView(layout, mLayoutParams);

      loadingLayout.setGravity(Gravity.CENTER);  

      //得到一个ListView用来显示条目

      listView = getListView();

      //添加到页脚显示

      listView.addFooterView(loadingLayout);

      //给ListView添加适配器

      setListAdapter(adapter);

      //给ListView注册滚动监听

      listView.setOnScrollListener(this);

    }

    @Override

    public void onScroll(AbsListView v, int firstVisibleItem,

       int visibleItemCount, int totalItemCount) {

      Log.i(TAG , "Scroll>>>first: " + firstVisibleItem + ", visible: " + visibleItemCount + ", total: " + totalItemCount);

      lastItem = firstVisibleItem + visibleItemCount - ;

      Log.i(TAG , "Scroll>>>lastItem:" + lastItem);

      //显示50条ListItem，即0-49，因为onScroll是在“滑动”执行过之后才触发，所以用adapter.count<=41作条件

      if (adapter.count<=) {

       if (firstVisibleItem+visibleItemCount==totalItemCount) {

        adapter.count += ;

        adapter.notifyDataSetChanged();

        listView.setSelection(lastItem);

        int currentPage=adapter.count/;

        Toast.makeText(getApplicationContext(), "第"+currentPage+"页", Toast.LENGTH_LONG).show();

       }

      }

      else {

        listView.removeFooterView(loadingLayout);

      }  

    }

    @Override

    public void onScrollStateChanged(AbsListView v, int state) {

      if (lastItem == adapter.count && state == OnScrollListener.SCROLL_STATE_IDLE) {

       Log.i(TAG,"ScrollStateChanged>>>state:"+state+"lastItem:" + lastItem);

       //显示50条ListItem，即0-49，因为onScrollStateChanged是在“拖动滑动”执行过之后才触发，所以用adapter.count<=41作条件

       if (adapter.count<=) {

        adapter.count += ;

        adapter.notifyDataSetChanged();

       }  

      }

    }

      /**

       * 要用用于生成显示数据

       * @author tomatos.to

       *

       */

    class listViewAdapter extends BaseAdapter {

      int count = ;

      public int getCount() {

       Log.i(TAG, "getCount>>>count:" + count);

       return count;

      }

      public Object getItem(int pos) {

       Log.i(TAG, "getItem>>>pos:" + pos);

       return pos;

      }

      public long getItemId(int pos) {

       Log.i(TAG, "getItemId>>>ItemId:" + pos);

       return pos;

      }

      public View getView(int pos, View v, ViewGroup p) {

       Log.i(TAG, "getView>>>pos:" + pos);

       TextView view;

       if (v==null) {

        view = new TextView(MainActivity.this);

       }

       else {

        view=(TextView)v;

       }

       view.setText("ListItem " + pos);

       view.setTextSize(20f);

       view.setGravity(Gravity.CENTER);

       view.setHeight();

       return view;

      }

    }  

}