Question

Say I’ve got a fully rectangle image:

Now when I show it in an ImageView, I want one corner to be cut off, like this:

How can I achieve this on runtime?

Answer 1

I’ve solved it using this code:

    public static Bitmap maskImage(Context context, Bitmap original) {
            if (original == null)
                    return null;

            Bitmap result = Bitmap.createBitmap(original.getWidth(), original.getHeight(), Config.ARGB_8888);
            Canvas c = new Canvas(result);
            Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
            paint.setColor(android.graphics.Color.WHITE);
            paint.setStyle(Paint.Style.FILL);
            paint.setAntiAlias(true);

            Path path = new Path();
            path.moveTo(result.getWidth(), result.getHeight());
            path.lineTo(result.getWidth() - dpToPx(context, CORNERWIDTHDP), result.getHeight());
            path.lineTo(result.getWidth(), result.getHeight() - dpToPx(context, CORNERHEIGHTDP));

            path.close();

            paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));

            c.drawBitmap(original, 0, 0, null);
            c.drawPath(path, paint);

            paint.setXfermode(null);
            return result;
    }