title: What's the best implementation for transparent background with progressbar
body: <p>I have a <code>Button</code> on an <code>Activity</code>. If user press this <code>Button</code>, start some network operation. I want obscure content and show progress bar at center.</p>
  
  <p>My current implementation here:</p>
  
  <pre><code>&lt;FrameLayout
          android:clickable="true"
          android:id="@+id/progressContainer"
          android:background="@color/alphaDisabled"
          android:layout_width="match_parent"
          android:layout_height="match_parent"&gt;
  
     &lt;ProgressBar
          android:id="@+id/progress"
          android:layout_gravity="center"
          android:layout_centerInParent="true"
          style="?android:attr/progressBarStyle"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"/&gt;
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p>I'm use container because want to block clicking on any <code>Button</code> on the screen, while network work not finished.</p>
  
  <p>I try use only progress bar (without container). But in this case progress bar scaled to whole screen.</p>
  
  <p>Is the way with framelayout + progressbar is best way (implemetation + perfomance)?</p>