@Override
            public void onAnimationRepeat(Animation animation) {
                ring.storeOriginals();
                ring.goToNextColor();
                ring.setStartTrim(ring.getEndTrim());
                mRotationCount = (mRotationCount + 1) % (NUM_POINTS);
            }
Set the colors used in the progress animation from color resources.
The first color will also be the color of the bar that grows in response
to a user swipe gesture.

@param colors
library/src/main/java/com/baoyz/widget/MaterialDrawable.java