Android: How to blur the edge of a circle using onDraw method?

Question

I have the following method:

protected void onDraw(Canvas i_Canvas) {            
        int x = (int) m_X;
        int y = (int) m_Y;

        Path path = new Path();
        path.addCircle(
            m_Cx,
            m_Cy,
            m_Radius,
            Path.Direction.CCW);
        i_Canvas.clipPath(path);

        Rect rect = new Rect(x, y, x + 240, y + 240);

        i_Canvas.drawBitmap(m_FullImageBitmap, rect, rect, m_Paint);
    }

Using this I am trying to create a cropped area of some bitmap in a circle shape.

I also want to blur the edges of that circle area. For example: 5px from the edge towards the centre of the shape will be blurred. How can I implement this?

Answer 1

I think you would have to apply a BlurMaskFilter when drawing the image:

m_Paint = new Paint(0);
m_Paint.setColor(0xffffffff);
m_Paint.setMaskFilter(new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL));