title: Android shrink and grow sequential animation
body: <p>I want to make a sequential animation in which two buttons shrink until they disappear and then they grow again to their original size.
  When I run it the buttons simply disappear without any animations</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;set xmlns:android="http://schemas.android.com/apk/res/android" 
      android:interpolator="@android:anim/accelerate_decelerate_interpolator"
      android:fillAfter="true"&gt;
  
      &lt;scale
          android:fromXScale="1"
          android:toXScale="0"
          android:fromYScale="1"
          android:toYScale="0"
          android:duration="400"
          android:pivotX="50%"
          android:pivotY="50%"
          /&gt; 
  
      &lt;scale
          android:startOffset="700"
          android:fromXScale="0"
          android:toXScale="1"
          android:fromYScale="0"
          android:toYScale="1"
          android:duration="400"
          android:pivotX="50%"
          android:pivotY="50%"
       /&gt; 
  
  &lt;/set&gt;  
  </code></pre>
  
  <p></p>
  
  <pre><code>Animation sgAnimation = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.shrink_grow);
  btPrimary.startAnimation(sgAnimation);
  btSecondary.startAnimation(sgAnimation);
  </code></pre>