@Override
  public void setAlpha(int alpha) {
    super.setAlpha(alpha);
    if (alpha != mPaint.getAlpha()) {
      mPaint.setAlpha(alpha);
      super.setAlpha(alpha);
      invalidateSelf();
    }
  }
If both the radii and border width are zero or bitmap is null, there is nothing to round.
drawee/src/main/java/com/facebook/drawee/drawable/RoundedBitmapDrawable.java