android gallery left,reight move tip

public OnClickListener arrow_listener = new OnClickListener(){

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

MotionEvent e1 = MotionEvent.obtain(

    SystemClock.uptimeMillis(), 

    SystemClock.uptimeMillis(),  

    MotionEvent.ACTION_DOWN, 89.333336f, 265.33334f, 0);

MotionEvent e2 = MotionEvent.obtain(

    SystemClock.uptimeMillis(), 

    SystemClock.uptimeMillis(), 

    MotionEvent.ACTION_UP, 300.0f, 238.00003f, 0);

switch(v.getId()){

case R.id.btn_map_arrow_left:

center_gallery.onFling(e1, e2, -800, 0);

break;

case R.id.btn_map_arrow_right:

center_gallery.onFling(e1, e2, 800, 0);

break;

}

}

};