title: seekbar thumb / background scale (size) change
body: <p>I have a question about a <code>seekbar</code>.
  Everything works perfect, but I have a Problem with the background and the thumb.
  I can add a background with a special size of the thumb. If I change the size of the seekbar the background size will change identical to the seekbar size but
  the thumb keeps the original size. (I know that I can change the width and the height of the thumb with the attributes.)</p>
  
  <p>Now the question: Is there a way that the thumb changes automatically the size when I change the seekbar size inside the <code>activity_main</code> like the background.
  I need this for a special LED Bar.</p>