title: PagerTabStrip customization - moving tab background instead of standard indicator
body: <p>I am trying to use PagerTabStrip in my app but need a little customization. My problem is that I want the tab background to be moved instead of the standard indicator. The image should explain it better:</p>
  
  <p><img src="https://i.stack.imgur.com/BOPDym.png" alt=""></p>
  
  <p>Currently I don't show at all tab indicator, but use a tab background which is a selector (pressed &amp; selected). This tab background behaves like a tab indicator but is jumpy and I would like to move it smoothly when sliding left/right. </p>
  
  <p>I have have used the PagerTabStrip, got it to work and changed the height of the indicator to match the height of the tabbar but this didn't solve the problem because the indicator is drawn on top of the tabs and covers them. To solve the problem the indicator needs to be drawn behind the tabs. To do that I have modified PagerTabStrib and made a custom TabsContainer (by default LinearLayout is used in PagerTabStrip as a tabs container) an inner class which extends LinearLayout and overrides its onDraw() method where I want to draw the moving indicator. This way the indicator should be drawn behind the tabs, right? My problem with the code right now is that I don't get calls to onDraw() inside my custom  TabsContainer. What do You think about this solution and about this problem? Do You see any better solution?
  Thanks for any help.</p>