@Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        Drawable drawable = mTouchDrawable;
        if (drawable != null) {
            drawable.setBounds(mShadowRadius, mShadowRadius, getWidth() - mShadowRadius, getHeight() - mShadowRadius);
        }
    }
Update the background color of the circle image view.

@param colorRes Id of a color resource.
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/FloatActionButton.java