Develop Reference

Bottom Sheet Above Bottom Navigation

My goal is to place a "bottom sheet" on top of a BottomNavigationView like this:
But it stays the following way. Both views collapse:
This is the xml of my main activity:
<?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:background="#drawable/tierrota"
tools:context="com.example.juanjose.myapplication.ViajesActivity">
<!-- include main content -->
<include layout="#layout/bottomsheet" />
<!-- include bottom sheet -->
<include layout="#layout/bottom_navigation" />
</android.support.design.widget.CoordinatorLayout>
Code of bottom_navigation:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<android.support.design.widget.BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:itemBackground="#color/colorClarito"
app:itemIconTint="#drawable/nav_item_color_state"
app:itemTextColor="#drawable/nav_item_color_state"
app:menu="#menu/bottom_navigation_main" />
</RelativeLayout>
And code of bottom sheet
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/bottom_sheet"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:behavior_hideable="false"
app:behavior_peekHeight="80dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior">
<TextView
android:layout_width="match_parent"
android:layout_height="80dp"
android:background="#color/colorBackgroundSemi"
android:gravity="center"
android:text="Bandeja de entrada"
android:fontFamily="#font/eraslght"
android:textColor="#color/colorLetra"
app:layout_anchor="#+id/bottom_navigation"
app:layout_anchorGravity="top"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="coisa2"
android:textColor="#android:color/white" />
</LinearLayout>
I am new with these two elements. Is there someone who knows any way to achieve what I'm looking for?
I want my "bottom sheet" to act as such and can expand. My ultimate goal is to add a RecyclerView inside the BottomSheet.

To use the BottomSheet, it should be a child of the CoordinatorLayout. Here I have used relative layout as a parent layout for bottom navigation to stay at the bottom and then CoordinatorLayout above bottom navigation.
Here's a article that will help you.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="#android:color/transparent">
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_above="#id/bottom_navigation_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="?attr/colorPrimary" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/bottom_sheet_parent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000000"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior">
<LinearLayout
android:id="#+id/bottom_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<View
android:layout_width="20dp"
android:layout_height="4dp"
android:layout_gravity="center"
android:layout_marginTop="10dp"
android:background="#drawable/view_bottom_sheet_top" />
<TextView
android:id="#+id/near_by"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="#font/normal"
android:gravity="center"
android:includeFontPadding="false"
android:padding="10dp"
android:text="Book Now"
android:textAllCaps="true"
android:textColor="?attr/colorPrimaryText"
android:textSize="12sp" />
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view_maps"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/bottom_view"
android:layoutAnimation="#anim/layout_animation">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
</android.support.design.widget.CoordinatorLayout>
<android.support.design.widget.AppBarLayout
android:id="#+id/bottom_navigation_parent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:fitsSystemWindows="true"
app:elevation="1dp">
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/colorContainerBackground"
/>
<!-- Start BottomNavigationView -->
<!-- End BottomNavigationView -->
</android.support.design.widget.AppBarLayout>
</RelativeLayout>
Don't forget to add this in your Activity/Fragment
private RelativeLayout bottomSheetParentLayout;
private BottomSheetBehavior mBottomSheetBehaviour;
mBottomSheetBehaviour = BottomSheetBehavior.from(bottomSheetParentLayout);
if (bottomNavigation != null) {
mBottomSheetBehaviour.setPeekHeight(bottomNavigation.getHeight() + 90);
}

Wrap the two elements inside a linear layout. Not sure how coordinator layout behaves but I think it will not allow you to "order" elements (similar to frame layout).

As far as I have understood your question, you want the RecyclerView to be shown in your bottom sheet. That is what makes the problem a lot easier. Let me tell you how.
You need to have a fixed height for your bottom navigation like this.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<android.support.design.widget.BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="80dp"
android:layout_alignParentBottom="true"
app:itemBackground="#color/colorClarito"
app:itemIconTint="#drawable/nav_item_color_state"
app:itemTextColor="#drawable/nav_item_color_state"
app:menu="#menu/bottom_navigation_main" />
</RelativeLayout>
Now in your bottom sheet, configure the RecyclerView with a clipToPadding attribute in it. Which will have some padding at the bottom of your RecyclerView. The idea is to have nothing in the covered area of the RecyclerView which is coming out with the bottom sheet.
Here's how you should declare your RecyclerView in your bottom sheet.
<android.support.v7.widget.RecyclerView
android:id="#+id/my_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:paddingBottom="80dp" />
Note that, I set the paddingBottom exactly to 80dp which is the height of the navigation view.
I hope this might help.

If you also have a CollapsingToolBar/Toolbar arrangement, this is the best solution for you:
<androidx.constraintlayout.widget.ConstraintLayout 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:clickable="true">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/cord_main_content"
android:layout_width="match_parent"
android:layout_height="0dp"
android:fitsSystemWindows="true"
app:layout_constraintBottom_toTopOf="#id/home_bottom_navigation_view"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/home_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.appcompat.widget.Toolbar
android:id="#+id/home_frag_toolbar"
style="#style/Widget.Toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:logo="#drawable/ic_infinet_logo_white"
app:navigationIcon="#drawable/ic_back_arrow" />
</com.google.android.material.appbar.AppBarLayout>
<FrameLayout
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/home_frag_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<FrameLayout
android:id="#+id/bottom_sheet_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/white"
android:clickable="true"
app:behavior_hideable="true"
app:behavior_peekHeight="#dimen/mini_player_height"
app:behavior_skipCollapsed="false"
app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">
<FrameLayout
android:id="#+id/player_frag_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<fragment
android:id="#+id/player_mini_frag_container"
android:name="com.kokonetworks.kokonet.player.PlayMusicMiniFragment"
android:layout_width="match_parent"
android:layout_height="#dimen/mini_player_height" />
</FrameLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/home_bottom_navigation_view"
android:layout_width="match_parent"
android:layout_height="56dp"
android:layout_alignParentBottom="true"
android:background="#color/colorPrimary"
app:itemBackground="#color/colorPrimary"
app:itemHorizontalTranslationEnabled="false"
app:itemIconTint="#drawable/nav_item_background"
app:itemTextColor="#drawable/nav_item_background"
app:labelVisibilityMode="auto"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/home_bottom_navigation_menu" />
</androidx.constraintlayout.widget.ConstraintLayout>
It ensures that:
BottomSheet is a child of the CoordinatorLayout
BottomNavigation is still rested at the bottom
CollapsingToolbar/AppBarLayout arrangement is still in place as expected

To use the BottomSheet, it should be a child of the CoordinatorLayout, as iamnaran said.
So simply:
Put everything in RelativeLayout
Put BottomSheet in CoordinatorLayout
Set the BottomNavigation property "alignParentBottom" to true
Make new xml file in /res/value and put
<resources>
<dimen name="bottomNavigationHeight">50dp</dimen>
</resources>
Set the MarginBottom of the CoordinatorLayout (parent of BottomSheet) to
android:layout_marginBottom="#dimen/bottomNavigationHeight"
You can skip steps 4 and 5 by setting the MarginBottom of the CoordinatorLayout to:
android:layout_marginBottom="50dp"
But this may lead to confusion in near future
The whole code should look something like this:
<RelativeLayout
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"
>
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/clBottomSheet"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="#dimen/bottomNavigationHeight">
<FrameLayout
android:id="#+id/standardBottomSheet"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:elevation="9dp"
style="?attr/bottomSheetStyle"
app:layout_behavior = "com.google.android.material.bottomsheet.BottomSheetBehavior"
app:behavior_peekHeight="80dp">
</FrameLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bttm_nav"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:menu="#menu/bottom_menu_nav"
>
</com.google.android.material.bottomnavigation.BottomNavigationView>
</RelativeLayout>

FAB not positioning inside CoordinatorLayout with RecyclerView

I am trying to display a list of items with a FAB to add a new item. The current screen is as below.
I have a CoordinatorLayout which has only a RecyclerView and the FAB. My problem is the FAB is not getting anchored to the bottom of the page, but to the bottom of the RecyclerView whose height seems to behave as if its wrap_content, but I've declared as match_parent. The RecylerView has a silver background for illustrative purposes.
<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"
tools:context="com.ae.apps.tripmeter.fragments.expenses.TripsListFragment">
<android.support.v7.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:background="#color/silver"
android:layout_margin="#dimen/activity_horizontal_margin"
app:layoutManager="LinearLayoutManager"
tools:listitem="#layout/fragment_trip"/>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:src="#android:drawable/ic_input_add"
app:elevation="8dp"/>
I can't figure out why I am not able to position the FAB at the bottom of the page.

Try putting the RecyclerView in a 'content' layout file and add it to the main layout via
<include layout="#layout/content_recyclerview" />
EDIT:
The FAB should not be placed in the Fragment if it is to reside at the bottom of the Activity. Remove the FAB from the fragment and add it to the main activity. Like this:
<?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="com.your_company.your_project">
<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="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay"/>
</android.support.design.widget.AppBarLayout>
<-- ref. your recycler here -->
<include layout="#layout/content_with_your_list"/>
<-- Put the FAB here -->
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:src="#android:drawable/ic_input_add"
/>
</android.support.design.widget.CoordinatorLayout>
Now in your fragment remove the FAB! It should reside in your main activity with the CoordinateLayout. Use a simple LinearLayout in your fragment.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_your_main_activity"
>
<android.support.v7.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/silver"
android:layout_margin="#dimen/activity_horizontal_margin"
app:layoutManager="LinearLayoutManager"/>
</LinearLayout>
You will need to make changes were appropriate in order to fit you your project.
Toggle FAB visibility
In order to toggle the visibility of the FAB add the following property to the FloatingActionButton in your Parent Activity.
android:visibility="gone"
and make it visible in code with:
mFab.setVisibility(View.VISIBLE);
or invisible, again with
mFab.setVisibility(View.GONE);
Whenever you need, eg. when a fragment is displayed or removed.

You probably want something like this?
Example
<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.support.v7.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_gravity="bottom|end"
android:src="#android:drawable/ic_input_add"
android:layout_margin="8dp"
app:elevation="8dp"/>
If you want to have some layout under fab, you should use relative layout as root layout. And put my code in this relative layout.

I use the following to anchor the fab at bottom of the recyclerView and it gives me my desired output. Try with this..
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
<android.support.design.widget.FloatingActionButton
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_margin="16sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>

Hiding View in Fragment on Scroll of Other View

I am using Navigation drawer activity in content_main there is one linear layout which will be inflate with fragment.
content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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:id="#+id/content_home"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="net.techdesire.khabargujarat.HomeActivity"
tools:showIn="#layout/app_bar_home">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragment_container"/>
</RelativeLayout>
fragment_home.xml
<android.support.percent.PercentRelativeLayout
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="fragment.HomeFragment">
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
app:layout_heightPercent="40%"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp"
app:layout_heightPercent="60%"
android:layout_below="#+id/viewpager">
<TextView
android:id="#+id/about"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:text="#string/about_khijadiya"
android:textAppearance="#style/TextAppearance.AppCompat.Large"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/about"
android:text="#string/dummy"
android:textAppearance="#style/TextAppearance.AppCompat.Medium"/>
</RelativeLayout>
</android.support.percent.PercentRelativeLayout>
I have large content in textview named about. I want to make it scrollable,like in image.First scroll relativelayout to full screen and if content of about is still overflow then make only about textview scrollable. When scroll reach to top and if user swipe down from there then re-display viewpager.

I think, your requirement is collapsing the view while scrolling.
So you can use
"android.support.design.widget.CollapsingToolbarLayout".
It is implemented in material design.
You can refer this link:
http://www.androidhive.info/2016/05/android-working-with-card-view-and-recycler-view/

RecyclerView and Toolbar, can't scroll bottom item into view

EDIT: See Using the Master/Detail template in ViewPager Fragments (download link) for full code
I have a toolbar and a recyclerView. When the layout is first inflated the last item of the recyclerView is out of the scroll-able region of the screen and is therefore not visible. After rotating the item appears. It is apparent that the toolbar is pushing the recyclerView outside the boundaries of the screen. If I add padding to the bottom of the recyclerView with the height of the toolbar the issue is resolved BUT only for the initial inflation of the layout. After rotation I am left with a gap on the bottom of the screen. I'm using sdk 23.
A possible workaround would be to programmatically remove the padding after the very first inflation of the layout. I assume I could use:
onCreateView(){ if (onSaveInstanceState != null) removePadding();}
However, I'd rather not have to do a dodgy work-around.
My app is basically exactly the same as the Master/Detail-flow template supplied in Android Studio, except that I use fragments and a single Activity. There is no such issue in the template.
Any ideas?
fragment_item_list.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"
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:id="#+id/app_bar"
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="?attr/actionBarSize"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="#+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<include layout="#layout/item_list" />
</FrameLayout>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:src="#android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
item_list.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"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/item_list"
android:name="com.idragonit.scrolltabs.ItemListFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
app:layoutManager="LinearLayoutManager"
tools:context="com.idragonit.scrolltabs.ItemListActivity"
tools:listitem="#layout/item_list_content" />
item_list_content.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="#+id/id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" />
<TextView
android:id="#+id/content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" />
</LinearLayout>
snippet of ItemListFragment.java
Toolbar toolbar = (Toolbar) root.findViewById(R.id.toolbar);
toolbar.setTitle("List");

I added:
android:layout_gravity="fill_vertical"
android:layout_marginBottom="?attr/actionBarSize"
to item_list.xml. The issue persists. The first time the layout is inflated it shows the bottom element as expected. After rotating to landscape and back to portrait it leaves a margin the size of the actionBar at the bottom of the screen.
This issue does not happen in the Master/Detail-flow template available in Android Studio and the code for item_list.xml, item_list_twopane.xml and activity_item_list are exactly the same as the code used in item_list.xml, land/item_list.xml and fragment_item_list.xml in my project. Yet, as the attached images show, the preview of the AppBar shows the flexible space in the Android template but not my code.
EDIT: When I click on the reference for "?attr/actionBarSize" in the template it navigates to a different line in android SDK's values.xml, which starts with <declare-styleable name="AppCompatTheme">. The same line of code in my app references a different line starting with<declare-styleable name="Theme">.
Screenshots:

<?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:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:orientation="vertical">
<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="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v7.widget.RecyclerView
android:id="#+id/item_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:scrollbars="vertical" />
</LinearLayout>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_gravity="bottom|right"
android:layout_marginBottom="#dimen/activity_vertical_margin"
android:layout_marginRight="#dimen/activity_horizontal_margin"
android:src="#drawable/ic_add"
app:backgroundTint="#color/colorPrimary" />
</android.support.design.widget.CoordinatorLayout>

You must add
android:layout_paddingBottom="?attr/actionBarSize
Instead of
android:layout_marginBottom="?attr/actionBarSize
This works for me

How to get Toolbar to overlay sibling layout (z-ordering)

For the life of me, I cannot get this Toolbar to layout on top (note: not above, but on top of) its sibling LinearLayout. The only way I can get the Toolbar to overlay its sibling is by specifying the Toolbar's elevation to be > 0, but this doesn't work for pre-5.0.
I am using a parent FrameLayout, and the child Toolbar is located after its sibling LinearLayout in the XML. What am I missing? Even the Android Studio preview pane shows the Toolbar on top of the LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
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">
<LinearLayout
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:id="#+id/fragment_main_container"
tools:context=".MainActivity"
tools:ignore="MergeRootFrame"
android:orientation="vertical"
>
<FrameLayout
android:layout_weight="4"
android:layout_width="match_parent"
android:layout_height="0dp">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/ic_launcher"
/>
</FrameLayout>
<ListView
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="5"
android:id="#+id/home_list_listview"
android:drawSelectorOnTop="true"
android:divider="#null"
android:dividerHeight="0dp"
tools:listitem="#layout/home_list_item"
>
</ListView>
<TextView
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:text="#string/slogan"
android:gravity="center"
android:textColor="#color/colorPrimaryDark"
/>
</LinearLayout>
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/actionBarSize"
android:background="#android:color/transparent"
/>
</FrameLayout>

Turns out I had a fragment committing the linear layout over the main activity, which already contained it. Oops!

That's because of FrameLayout.
If you want to use FrameLayout, the views will not relate each other.
So all you need to do is ...
set "height of toolbar" to MarginTop of LinearLayout.
Hope, it will help.