I'm using Android's android.graphics.Canvas class to draw a ring. My onDraw method clips the canvas to make a hole for the inner circle, and then draws the full outer circle over the hole:

    clip = new Path();
    clip.addRect(outerCircle, Path.Direction.CW);
    clip.addOval(innerCircle, Path.Direction.CCW);

    canvas.save();
    canvas.clipPath(clip);
    canvas.drawOval(outerCircle, lightGrey);
    canvas.restore();

The result is a ring with a pretty, anti-aliased outer edge and a jagged, ugly inner edge:

What can I do to antialias the inner edge?

I don't want to cheat by drawing a grey circle in the middle because the dialog is slightly transparent. (This transparency isn't as subtle on on other backgrounds.)