title: Android, View width change animation?
body: <p>I'm trying to make a timeout gauge bar animation effect:</p>
  
  <p>The width of a lengthy colorful bitmap image is decreasing, but not x-scaling.</p>
  
  <p>so the image looks not changing and the visible area shrinks.</p>
  
  <p>I couldn't find the sole ImageView clipping or masking support in android.</p>
  
  <p>And I managed to get the clipping effect by surrounding the ImageView in ViewGroup like:</p>
  
  <pre><code>&lt;FrameLayout android:id="@+id/shrink_box" ...&gt;
    &lt;ImageView android:src="@drawable/still_image" ...&gt;
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p>then changing the shrink_box's width will clip the portion of the still_image.</p>
  
  <p>But I failed to change the width of the view smoothly.
  I tried to change the LayoutParam.width in applyTransformation() but got an Exception, it seems not allowed.</p>
  
  <p>How can I make an Animation that changes the width of the view. OR is there a proper method to achieve the above effect?</p>