title: Android SurfaceView thread
body: <p>I  created custom SurfaceView which contains circles. And I want to rotate this circle using touch events. But I do not understand when thread of SurfaceView must pause and resume. 
  If the thread must run all time when app is active or only when the circle rotates??? 
  I run LunarLander sample and in this app thread running all time when app is active. 
  whether it is right or not?</p>