title: Android KeyBoard.Key disable iconPreview of special keys?
body: <p>I customize my own soft keyboard by implementing the KeyboardView.OnKeyboardActionListener interface.</p>
  
  <p>When the keys are pressed, it will show a preview popup.</p>
  
  <p><strong>My problem is how to disable the preview popup for special keys such as SHIFT and DELETE?</strong></p>
  
  <p>I have tried to set the android:iconPreview attribute to null but it didn't work.</p>
  
  <pre><code>&lt;Key
      android:codes="-1"
      android:keyIcon="@drawable/key_shift" 
      android:keyWidth="15%p"
      android:isModifier="true"
      android:isSticky="true"
      android:keyEdgeFlags="left" /&gt;
  </code></pre>
  
  <p>Have any idea?</p>
  
  <p>Thanks in advance!</p>