code: protected void startAnimation (Animation anim, long tickStamp)
      {
          // account for any view scrolling that happened before this animation
          // was actually added to the view
          if (_vdx != 0 || _vdy != 0) {
              anim.viewLocationDidChange(_vdx, _vdy);
          }
  
          _animmgr.registerAnimation(anim);
      }
docs: Called when the time comes to start an animation. Derived classes may override this method
  and pass the animation on to their animation manager and do whatever else they need to do
  with operating animations. The default implementation simply adds them to the media panel
  supplied when we were constructed.
  
  @param anim the animation to be displayed.
  @param tickStamp the timestamp at which this animation was fired.