public void setInnerDrawable(Drawable d) {
            mDrawable.setCallback(null);
            mDrawable = d;
            mDrawable.setCallback(this);
            assignDrawableBounds(getBounds());
            invalidateSelf();
        }
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