public void setStartEndTrim(float startAngle, float endAngle) {
        mRing.setStartTrim(startAngle);
        mRing.setEndTrim(endAngle);
    }
Set the start and end trim for the progress spinner arc.

@param startAngle start angle
@param endAngle   end angle
ptr-lib/src/in/srain/cube/views/ptr/header/MaterialProgressDrawable.java