Develop Reference

How to scroll and collapse a LinearLayout with Toolbar in Coordinator Layout

I'm trying to accomplish a scrolling behavior with coordinator layout in my application.
I've the following layout structure for the activity.
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.Dark.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/AppTheme.Dark.PopupOverlay"/>
</android.support.design.widget.AppBarLayout>
<!-- The layout to be collapse with toolbar -->
<LinearLayout
android:id="#+id/ll_collapse_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
When I scroll up the recycler view items the toolbar collapses and goes up out of the window and when I scroll down I get the toolbar back.
Is it possible to collapse the LinearLayout with toolbar when I scroll the Recycler View?

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="in.test.ProfileActivity">
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<LinearLayout
android:id="#+id/ll_collapse_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_collapseMode="parallax"
android:orientation="horizontal"></LinearLayout>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>

I don't understand why recyclerview in nestedscrollview load all data

I am worried about RecyclerView in NestedScrollView loading all data.
I just want RecyclerView to load a part of data as many as visible on screen, not all data.
The main view of my app consists of CollapsingToolbarLayout a TabLayout, and a ViewPager.
One fragment of ViewPager has a NestedScrollview for collapsing up CollapsingToolbarLayout.
Also, that fragment (of FrameLayout of second xml) has the real RecyclerView.
I don't understand why the RecyclerView in NestedScrollView is loading all the data. Once I remove the NestedScrollView, all works good.
But I think I might use NestedScrollView for collapsing up CollapsingToolbarLayout. How can I resolve it? Thank you in advance
activity_main.xml
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsingToolbarLayout"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
...
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:minHeight="?attr/actionBarSize"
android:gravity="center_vertical"
android:layout_marginTop="16dp"
android:layout_marginBottom="8dp"
android:fitsSystemWindows="true"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"/>
<android.support.design.widget.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_gravity="bottom"
android:fitsSystemWindows="true"
app:layout_collapseMode="pin"
app:tabIndicatorColor="?attr/colorAccent"
app:tabIndicatorHeight="3dp"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
<android.support.design.widget.NavigationView
android:id="#+id/navigation"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#fff"
app:headerLayout="#layout/nav_header"
app:menu="#menu/navigation_drawer_items"
app:itemIconTint="?attr/colorPrimary"
app:itemTextColor="#color/black">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
fragment_for_viewpager.xml
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.TabLayout
android:id="#+id/rankSortTabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_collapseMode="parallax"
app:tabIndicatorColor="#color/lightgrey"
app:tabIndicatorHeight="1dp"/>
<FrameLayout
android:id="#+id/rank_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
recyclerview_subfragment.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/rankSortRecyclerView"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>

Why my Tab Layout and Toolbar are showing like this?

As you can see in the image. These two are not aligned properly. I am not able to understand why this is happening.
My toolbar is in Coordinator Layout in app_bar_main.xml and my Tab Layout is in fragment_main. I didn't add the tab layout in coordinator layout because I don't want to show it in all my views, just in my fragment main file.
My code in app_bar_main.xml:
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</android.support.design.widget.CoordinatorLayout>
Code in fragment_main.xml:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
xmlns:app="http://schemas.android.com/apk/res-auto">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:id="#+id/tabs"
android:backgroundTint="#FFFFFF"
app:tabMode="fixed"
app:tabGravity="fill"
app:popupTheme="#style/AppTheme.PopupOverlay">
</android.support.design.widget.TabLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/view_pager_1">
</android.support.v4.view.ViewPager>
</FrameLayout>
Can you tell what I am doing wrong?
Image

For those who were not able to solve this.
I was able to solve it through an approach.
I added the above code in Main Activity and then set the visibility of tablayout and Toolbar in other fragments as GONE and in fragment which I want it to enable as VISIBLE.
To set visibility as gone you do:
TabLayout tabLayout = (TabLayout) getActivity().findViewById(R.id.tabs);
tabLayout.setVisibility(View.GONE);
ViewPager viewPager = (ViewPager) getActivity().findViewById(R.id.view_pager_1);
viewPager.setVisibility(View.GONE);
And to set it as visible just replace GONE with VISIBLE.

app_bar_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:elevation="0dp">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.AppBarLayout>
<!-- The main content view -->
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
</FrameLayout>
</android.support.design.widget.CoordinatorLayout>
fragment_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white">
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="50dp"
app:tabMode="fixed"
app:tabGravity="fill"
app:tabTextColor="#color/empty_area"
app:tabSelectedTextColor="#android:color/white"
app:tabIndicatorColor="#android:color/white"
android:background="#color/colorPrimary" />
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/tab_layout" />
<View
android:id="#+id/drop_shadow"
android:layout_width="match_parent"
android:layout_height="3dp"
android:layout_below="#+id/tab_layout"
android:background="#drawable/shadow_bottom" />
</RelativeLayout>
The other way, as you mentioned is to put the tab layout inside the AppBarLayout in app_bar_main.xml

Scrolling with Collapsing Toolbar and Tabs

I'm trying to make a layout with a CollapsingToolbarLayout which has scroll|exitUntilCollapsed flag, and a TabLayout which has scroll|enterAlways scrollFlag property. Basically I want my toolbar to be pinned and show and hide the tabs while scrolling. I've modified the cheesesquare app from https://github.com/chrisbanes/cheesesquare. Here is my layout xml;
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
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/appbar"
android:layout_width="match_parent"
android:layout_height="#dimen/detail_backdrop_height"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:fitsSystemWindows="true">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginStart="48dp"
app:expandedTitleMarginEnd="64dp">
<ImageView
android:id="#+id/backdrop"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:fitsSystemWindows="true"
app:layout_collapseMode="parallax" />
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:layout_collapseMode="pin" />
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.FloatingActionButton
android:layout_height="wrap_content"
android:layout_width="wrap_content"
app:layout_anchor="#id/appbar"
app:layout_anchorGravity="bottom|right|end"
android:src="#drawable/ic_discuss"
android:layout_margin="#dimen/fab_margin"
android:clickable="true"/>
</android.support.design.widget.CoordinatorLayout>
And here is the result;
The tabs are not positioned properly. And they don't care about the enterAlways property.

Hey this may solve your problem.
just add android:layout_gravity="bottom" to tablayout and android:gravity="top" to toolbar.

Remove attribute app:layout_behavior="#string/appbar_scrolling_view_behavior" & app:layout_scrollFlags="scroll|enterAlways" from android.support.design.widget.TabLayout and add attribute android:layout_gravity="bottom".
Also set android.support.v7.widget.Toolbar height as 104(Toolbar+TabLayout height) to show both Toolbar and TabLayout during collapsed state.
Here is an working example:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="256dp"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:titleEnabled="false">
<ImageView
android:id="#+id/image_header"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax" />
<android.support.v7.widget.Toolbar
android:id="#+id/anim_toolbar"
android:layout_width="match_parent"
android:layout_height="104dp"
android:minHeight="?attr/actionBarSize"
android:gravity="top"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:titleMarginTop="13dp" />
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:tabGravity="fill"
app:tabMode="scrollable"
style="#style/MyCustomTabLayout"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab_map"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
app:backgroundTint="#f44336"
android:src="#drawable/ic_maps_my_location" />
</android.support.design.widget.CoordinatorLayout>
Hope this will help~

I am a bit unclear on what is to be achieved here.
Do you not want the TAB to move up and down while scrolling? If so, you want to put the TabLayout outside the CollapsingToolbarLayout. Because anything that you put inside the CollapsingToolbarLayout, will move on scrolling.
From the comment you have put, I have modified your xml to imitate that of the YouTube screen. The toolbar is put outside the coordinator layout since it's pinned permanently and is not affected by the scrolling. Something that's worth mentioning is "One note: all views using the scroll flag must be declared before views that do not use the flag. This ensures that all views exit from the top, leaving the fixed elements behind." This is taken from the android blogpost http://android-developers.blogspot.in/2015/05/android-design-support-library.html. This is why I have moved the toolbar out of the AppBarLayout.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"/>
<android.support.design.widget.CoordinatorLayout
android:id="#+id/main_content"
android:layout_below="#id/toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
</RelativeLayout>
I have put the TabLayout static, but you can make it scrollable. If this is not what you are looking for, kindly explain pictorially what is to be achieved here. I will be glad to help.

I built two samples with parallax and one with RecyclerView on top of AppbarLayout
One with only parallax is
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/htab_maincontent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<!--
OUTLINE
<CoordinatorLayout>
<AppbarLayout>
<CollapsingToolbarLayout>
<ImageView/>
<Toolbar/>
<TabLayout/>
</CollapsingToolbarLayout>
</ AppbarLayout >
<NestedScrollView/>
</CoordinatorLayout>
-->
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appbarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.MaterialComponents.Dark.ActionBar">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapsingToolbar"
android:layout_width="match_parent"
android:layout_height="256dp"
android:fitsSystemWindows="true"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:contentScrim="?attr/colorPrimary">
<ImageView
android:id="#+id/ivHeader"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/header"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax" />
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
android:layout_gravity="top"
android:layout_marginBottom="?attr/actionBarSize" />
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="#android:color/transparent"
app:tabIconTint="#F57C00"
app:tabIndicatorColor="#F57C00"
app:tabIndicatorHeight="4dp"
app:tabMode="scrollable"
app:tabSelectedTextColor="#F5F5F5"
app:tabTextColor="#FFE0B2" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPager2"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And the one that RecyclerView above AppbarLayout is
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/htab_maincontent"
android:layout_width="match_parent"
android:background="#EEEEEE"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<!--
OUTLINE
<CoordinatorLayout>
<AppbarLayout>
<CollapsingToolbarLayout>
<ImageView/>
<Toolbar/>
<TabLayout/>
</CollapsingToolbarLayout>
</ AppbarLayout >
<NestedScrollView/>
</CoordinatorLayout>
-->
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.MaterialComponents.Dark.ActionBar">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapsingToolbar"
android:layout_width="match_parent"
android:layout_height="330dp"
android:fitsSystemWindows="true"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:contentScrim="?attr/colorPrimary">
<ImageView
android:id="#+id/ivHeader"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/header"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax" />
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
android:layout_gravity="top"
android:layout_marginBottom="?attr/actionBarSize" />
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="#android:color/transparent"
app:tabIconTint="#F57C00"
app:tabIndicatorColor="#F57C00"
android:translationY="-30dp"
app:tabIndicatorHeight="4dp"
app:tabMode="scrollable"
app:tabSelectedTextColor="#F5F5F5"
app:tabTextColor="#FFE0B2" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/constraintLayout"
app:behavior_overlapTop="30dp"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPager2"
android:layout_width="match_parent"
android:background="#fff"
android:layout_marginStart="10dp"
android:layout_marginEnd="10dp"
android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And setting TabLayout translationY on scroll with
// Check if scrolling up or down
var initTransitionY = tabLayout.translationY
tabLayout.post {
initTransitionY = tabLayout.translationY
}
appbar.addOnOffsetChangedListener(AppBarLayout.OnOffsetChangedListener { appBarLayout, verticalOffset ->
//Check if the view is collapsed
if (abs(verticalOffset) >= appbar.totalScrollRange) {
collapsingToolbar.title = "Collapsed"
} else {
collapsingToolbar.title = ""
}
tabLayout.translationY =
initTransitionY + initTransitionY * (verticalOffset / appBarLayout.totalScrollRange.toFloat())
})
For full samples and other samples you can check out this repo

add android:layout_gravity="bottom" to android.support.design.widget.TabLayout

AppBarLayout and RecyclerView not siblings

I have a toolbar which I would like to behaves as material design specifications. In this way, I wrapped it in a AppBarLayout. The problem is that the RecyclerView is a child of a ViewPager:
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".ui.home.HomeActivity">
<ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never"/>
<android.support.design.widget.AppBarLayout
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="#+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<com.rocket.android.views.SlidingTabLayout
android:id="#+id/pager_indicator"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/tab_and_nav_bar"/>
</android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>
How can I attach the AppBarLayout to react to an arbitrary RecyclerView which is not his sibling?

Here is how I solved it.
<android.support.design.widget.CoordinatorLayout
android:id="#+id/coordinatorLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.home.HomeActivity">
<ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="#dimen/d2"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"/>
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/tab_and_nav_bar"/>
</android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>
This brings a padding-related problem for the pages in the ViewPager. I solved this one adding a padding which size is the same height of the tab layout. It works. Not the best solution though.