title: Animating a CALayer's mask size change
body: <p>I have a <code>UIView</code> subclass which uses a <code>CAShapeLayer</code> mask on its <code>CALayer</code>. The mask uses a distinct shape, with three rounded corners and a cut out rectangle in the remaining corner.</p>
  
  <p>When I resize my <code>UIView</code> using a standard animation block, the <code>UIView</code> itself and its <code>CALayer</code> resize just fine. The mask, however, is applied instantly, which leads to some drawing issues.</p>
  
  <p>I've tried animating the mask's resizing using a <code>CABasicAnimation</code> but didn't have any luck getting the resizing animated.</p>
  
  <p>Can I somehow achieve an animated resizing effect on the mask? Do I need to get rid of the mask, or will I have to change something about the way I currently draw the mask (using <code>- (void)drawInContext:(CGContextRef)ctx</code>).</p>
  
  <p>Cheers,
  Alex</p>