title: How to show the PopupWindow alway above the button(view)?
body: <p>The Design requirements is，have a listview,in the items of listview,have a button,press the button, and then,to show a popupwindow above the button alway,not bottom.</p>
  
  <p>In Android,use "showAsDropDown",the Popupwindow default display on bottom of the button(View or anchor).
  But if the bottom not enougn to show,the Popupwindow will show on top of the button(View or anchor).</p>
  
  <pre><code>onTop = (displayFrame.bottom - mScreenLocation[1] - anchor.getHeight() - yoff) &lt;(mScreenLocation[1] - yoff - displayFrame.top);
  </code></pre>
  
  <p>so,i according to this point,to move item of the button by "setSelectionFromTop",let the judgment is no enougn to show on bottom of the button to achieve the effectiveness。</p>
  
  <p>In android 4.0.3,is Ok,the item move,and the popupwindow show the new position and aboved,
  But,
  in android 2.2,the popupwindow is still show the press Where,not the position after moving。</p>
  
  <pre><code>boolean onTop = (displayFrame.bottom - mScreenLocation[1] - v.getHeight() - 0) &lt; (mScreenLocation[1] - 0 - displayFrame.top);
  if(!onTop){
  mListMain.setSelectionFromTop(mListMain.getPositionForView(v),(displayFrame.bottom - v.getHeight() + displayFrame.top) / 2 );
  }
  </code></pre>
  
  <p>can help me,how to solve it?!..   T_T</p>