title: Artifacts when hardware acceleration disabled on devices that support it
body: <p>I'm writing an app with rather complex UI and one of the parts of that UI is particular view that can be moved across the screen (or moved away from screen).
  For that purpose, I've implemented custom layout manager that positions that panel off screen initially and moves it to the screen when certain TouchEvents happen.
  So basically I'm moving a view with .layout call from touch handler.
  That particular view does have a background, underlying views don't, background for activity is set in the theme.</p>
  
  <p>This works flawlessly on old androids (like 2.1) and modern androids (like 4.3) with hardware acceleration, but shows unexpected results when run on modern androids with h/w acceleration disabled.</p>
  
  <p>In that case everything is fine as long as on-screen portion of the movable view remains the same.
  Once I start resizing that view or moving it off-screen, it's starting to leave artifacts. This basically looks like background is no longer erased for dirty regions, all the underlying views are drawn, but on dirty background with parts of the view that I just moved away.</p>
  
  <p>Dumping flags from underlying views just after .layout'ing the movable view shows, that I ad D flags are set, so they should be redrawn anyway, but calling .invalidate on that regions manually with appropriate rect fixes the problem (but this is a bad solution for a number of reasons).</p>
  
  <p>What am I doing wrong?</p>