How do I antialias the clip boundary on Android's canvas?

As far as I know, you can't antialias clip regions.

I'd suggest using bitmap masking instead. Render the the pink, white, and light gray foreground to one bitmap, render the outer/inner circle mask (the grayscale alpha channel) to another bitmap, and then use Paint.setXfermode to render the foreground bitmap with the mask as its alpha channel.

An example can be found in the ApiDemos source code here.

I know this is not a general answer, but in this particular case, you could draw arcs with a thick stroke width, instead of the circles + mask.

I too had this same problem. I tried using Bitmap masking (xFermode) to fix the Aliasing, but it was heavy.

So for API < 19, I used the Bitmap masking way and for API >= 19, I used Path.Op. Instead of clipping the path and then drawing the shape. I did a REVERSE_DIFFERENCE of the path and the shape(which is of type Path). You can perform operations on Path from API 19 and above.

Works perfectly for me!