CoordinatorLayout doesn't work with NestedScrollView inside Fragment in ViewPager - android-layout

Question

I have an Activity with next layout
Activity layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.AppBarLayout
android:id="#+id/issue_browse_app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/app_default_color"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/issue_browse_toolbar"
app:layout_scrollFlags="scroll|enterAlways"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize" />
<android.support.design.widget.TabLayout
android:id="#+id/issue_browse_tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/issue_browse_view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
ViewPager after instantiating has 2 fragments
First visible fragment's layout
<?xml version="1.0" encoding="utf-8"?>
<ViewSwitcher xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/issue_browse_view_switcher"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white">
<FrameLayout
android:id="#+id/issue_browse_status_buttons_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="#dimen/issue_status_browse_buttons"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:id="#+id/issue_browse_fragment_view_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="start" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginTop="1000dp"
android:text="end" />
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</FrameLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:orientation="vertical">
<TextView
android:id="#+id/issue_browse_load_error_text"
style="#style/list_view_empty_view_style"
android:drawableTop="#drawable/error" />
<TextView
android:id="#+id/issue_browse_refresh_after_error"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="#dimen/content_offset_small"
android:textColor="#c0bebe" />
</LinearLayout>
</ViewSwitcher>
How you can see, there is NestedScrollView with app:layout_behavior="#string/appbar_scrolling_view_behavior"
And regardless of the fact, has NestedScrollView this tag or not, Coordinator doesn't hide Toolbar.
Where is error in this code?

Answer 1

You are not using "CollapsingToolbarLayout"
Doc says:
CollapsingToolbarLayout is a wrapper for Toolbar which implements a
collapsing app bar. It is designed to be used as a direct child of a
AppBarLayout.
For your understanding refer below example
<android.support.design.widget.CoordinatorLayout
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v4.view.ViewPager
android:id="#+id/issue_browse_view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
style="#style/ToolBarStyle"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>