title: Smooth animation when tab switches
body: <p>I am using ActionBar.Tabs with ViewPager, and it looks like <img src="https://i.stack.imgur.com/XUvoS.jpg" alt="enter image description here"></p>
  
  <p>I implemented the <code>ActionBar.TabListener</code> and <code>ViewPager.OnPageChangeListener</code> to support that when user swipe pages in ViewPager, the tab indicator will change accordingly (the blue indicator will move to the corresponding tab).</p>
  
  <p>Now I realized that the blue indicator changes without any animation, and it doesn't look good. (when I swipe from tab1 to tab2, the blue indicator disappear under tab1 and appear under tab2). Is there a way to change it so that when I switch tabs, the blue tab indicator moves smoothly between tabs?</p>