GridViewページング(AbsListViewを正確にリスニングして下にスクロール)

import android.view.View;
import android.widget.AbsListView;
import android.widget.Toast;
import android.widget.AbsListView.OnScrollListener;

/** 
*  ，  
*/
public class AutoLoadListener implements OnScrollListener {

  public interface AutoLoadCallBack {
    void execute();
  }

  private int getLastVisiblePosition = 0, lastVisiblePositionY = 0;
  private AutoLoadCallBack mCallback;

  public AutoLoadListener(AutoLoadCallBack callback) {
    this.mCallback = callback;
  }

  public void onScrollStateChanged(AbsListView view, int scrollState) {

    if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) {
      //      
      if (view.getLastVisiblePosition() == (view.getCount() - 1)) {
        View v = (View) view.getChildAt(view.getChildCount() - 1);
        int[] location = new int[2];
        v.getLocationOnScreen(location);//      
        int y = location[1];

        MyLog.d("x" + location[0], "y" + location[1]);
        if (view.getLastVisiblePosition() != getLastVisiblePosition && lastVisiblePositionY != y)//      
        {
          Toast.makeText(view.getContext(), " ， ", 500).show();
          getLastVisiblePosition = view.getLastVisiblePosition();
          lastVisiblePositionY = y;
          return;
        } else if (view.getLastVisiblePosition() == getLastVisiblePosition && lastVisiblePositionY == y)//      
        {
          mCallback.execute();
        }
      }

      // ，      
      getLastVisiblePosition = 0;
      lastVisiblePositionY = 0;
    }
  }

  public void onScroll(AbsListView arg0, int arg1, int arg2, int arg3) {

  }
}