Callback for AppBarLayout state

SimpleCollapsingToolbarCallback.java

public abstract class SimpleCollapsingToolbarCallback implements AppBarLayout.OnOffsetChangedListener {


    public enum State {

        EXPANDED,
        COLLAPSED

    }

    public abstract void onCollapsingToolbar(State state);

    @Override
    public void onOffsetChanged(AppBarLayout appBarLayout, int i) {
        if (Math.abs(i) - appBarLayout.getTotalScrollRange() == 0) {
            onCollapsingToolbar(State.COLLAPSED);
            Log.d("STATE", "COLLAPSED");
        } else {
            onCollapsingToolbar(State.EXPANDED);
            Log.d("STATE", "EXPANDED");
        }
    }
}