@Override
    protected void onDraw(Canvas canvas) {
        Drawable drawable = mBorderDrawable;
        if (drawable != null && mBorderSize > 0 && mBorderColor != 0)
            drawable.draw(canvas);
        super.onDraw(canvas);
    }
Get all border size

@return px value
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/TextView.java