How to properly hide&show the actionbar using the new design library API?

Question

Background

Suppose I have these elements in the activity:

• actionbar (actually a Toolbar)
• tabs (using TabLayout )
• ViewPager, with fr

Answer 1

Based on @android developer solution which sometimes expand the app bar when list is fully scrolled I made a small change expanding or collapsing the list depending on the scrolled amount (if it's bigger than the header height then expand).

mHeaderHeight = getResources().getDimensionPixelSize(R.dimen.appbar_height);

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        switch (newState) {
            case RecyclerView.SCROLL_STATE_IDLE:
                mAppBar.setExpanded(mScrolledAmount < mHeaderHeight , true);
                break;
        }
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        mScrolledAmount += dy;
    }
});

EDIT: What works even better for me is having different thresholds to expand and collapse

     switch (newState) {
            case RecyclerView.SCROLL_STATE_IDLE:
                if (mScrolledAmount < 50){
                    mAppBar.setExpanded(true , true);
                }
                if (mScrolledAmount > mHeaderHeight) {
                    mAppBar.setExpanded(false, true);
                }
                break;
        }