Shape overlay ("inverse path") on ImageView
<p>I have a problem: I would like to draw a grey overlay on an image. There is a path and I would  like to colour <em>outside</em> of the path. Clipping is not good, because the edges are not anti-aliased (and I have to make it work on 2.1).</p>

<p>I have made it work on camera (right side). There is a FrameLayout, holding a SurfaceView (camera preview) and a View over it. The view fills the overlay color on full canvas, then with xfermode deletes the paths (Mode.CLEAR).</p>

<p>Using the same method I get the picture on the right. 
First I made my View an ImageView descendant, but that was completely bad. Then, I added an ImageView with the image below my view (like the camera preview), but the same result. Then Used other imageview out of the framelayout, but same. Of course, I always tried to set the bgcolor to transparent, draw Color.TRANSPARENT, but it didn't work. I don't know what is the problem. Maybe Mode.CLEAR clears the whole screen on that area? Why it is working with camera surfaceview and not with and imageview (or even another surfaceview)?</p>

<p>I have been googling for 7 hours, and no real solutions. Can you please help me what I am doing bad, and share some "tricks"? As I said before, I need anti-aliased edges (severals shapes have many curves and diagonals), so I cannot clip (not even if drawing strokes, its awful).</p>

<p>Thank you in advance.</p>

<p>Figure: <a href="http://s16.postimage.org/72bcp5kad/img_overlay.jpg" rel="nofollow">http://s16.postimage.org/72bcp5kad/img_overlay.jpg</a></p>
