@Override
    public void flip() {
        super.flip();
        // Keep the checkmark animators in sync with the flip animator.
        if (mCheckmarkScaleAnimator.isStarted()) {
            mCheckmarkScaleAnimator.reverse();
            mCheckmarkAlphaAnimator.reverse();
        } else {
            if (!getSideFlippingTowards() /* front to back */) {
                mCheckmarkScaleAnimator.start();
                mCheckmarkAlphaAnimator.start();
            } else /* back to front */ {
                mCheckmarkScaleAnimator.reverse();
                mCheckmarkAlphaAnimator.reverse();
            }
        }
    }
Must be <= 1f since the animation value is used as a percentage.
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/checkable/CheckableFlipDrawable.java