ViewPager in a NestedScrollView

Question

I need to create an interface like Google Newsstand which is a sort of ViewPager (horizontal scroll) over a collapsing header (vertical scroll). One of my requirements is to

Answer 1

Actually the NestedScrollView doesn't need to to be direct sibling of CollapsingToolbarLayout in CoordinatorLayout. I have achieved something realy bizzare. The appbar_scrolling_view_behavior works in 2 nested fragments.

My activity layout:

<android.support.design.widget.CoordinatorLayout>

    <android.support.design.widget.AppBarLayout>

            <android.support.design.widget.CollapsingToolbarLayout>

                <include
                    layout="@layout/toolbar"/>

            </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/container"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

</android.support.design.widget.CoordinatorLayout>

In the "container" frameLayout I have inflated this fragment:

<android.support.constraint.ConstraintLayout>

    ... some content ...

    <android.support.v4.view.ViewPager/>

    ...

</android.support.constraint.ConstraintLayout>

And fragments inside that ViewPager looks like this:

<RelativeLayout>

    <android.support.v7.widget.RecyclerView/>

    ....

</RelativeLayout>

Fact that NestedScrollView can be so deep in the CoordinatorLayout children hierarchy and scroll behaviors stil works did suprised me.