How to drawRoundRect() if Build.VERSION.SDK_INT < 21?

The method canvas.drawRoundRect()is only available on devices with Build.VERSION.SDK_INT >= 21.

The method canvas.drawArc() also requires SDK_INT >= 21.

Is it possible to drawRoundRect on older devices?

Yes. According the official docs: https://developer.android.com/reference/android/graphics/Canvas#drawRoundRect(android.graphics.RectF,%20float,%20float,%20android.graphics.Paint)

There are two versions of drawRoundRect. The for lower apis(<21) accepts Rect as param.

So you can do something like this:

@Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.RED);
        paint.setAntiAlias(true);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            canvas.drawRoundRect(0, 0, 0, 0, 2f, 3f, paint);
        } else {
            RectF rect = new RectF(10, 10, 20, 20);
            canvas.drawRoundRect(rect, 0, 0, paint);
        }
    }

Change the values according to your use-case.