Develop Reference

Scrolling appbar leaving blank space on top of recyclerview

Hi, I have tried to implement the appbar scrolling behavior and it works fine, however, if I scroll when I'm right on the top it seems like there is extra space for one recyclerview row. How do I get rid of the extra space?
activity_main:
<androidx.coordinatorlayout.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=".MainActivity"
android:fitsSystemWindows="true">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_scrollFlags="scroll|snap|enterAlways" />
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/nav_host" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
fragment_recyclerview:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".fragments.recyclerviewFragment.RecyclerviewFragment"
>
<androidx.recyclerview.widget.RecyclerView
android:paddingTop="?attr/actionBarSize"
android:clipToPadding="false"
android:scrollbars="none"
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:layout_gravity="bottom|right"
app:layout_anchorGravity="bottom|end|right"
app:layout_anchor="#id/recyclerView"
android:id="#+id/floatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="24dp"
android:backgroundTint="#color/green_300_org"
android:contentDescription="#string/add_a_task"
android:src="#drawable/ic_baseline_add_24"
app:tint="#color/black" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>

Instead of adding this attribute to the RecyclerView of fragment_recyclerview.xml:
app:layout_behavior="#string/appbar_scrolling_view_behavior"
add it in your activity_main.xml file, and it will work fine.
It will be like:
<include
layout="#layout/nav_host"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
Then you can remove the top padding from your RecyclerView, and you don't need to use CoordinatorLayout in the fragment_recyclerview.xml file as well.

BottomNavigationView problem with scrollFlags

Need the BottomNavigationView to always show by default (without any user interaction).
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".presentation.MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppBarOverlay">
<androidx.appcompat.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/AppPopupOverlay" />
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/content_main" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
The content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/app_bar_main">
<androidx.fragment.app.FragmentContainerView
android:id="#+id/nav_host_fragment_content_main"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="#navigation/drawer_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
Home fragment
<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".presentation.ui.home.HomeFragment"
android:orientation="vertical">
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPagerContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"/>
<FrameLayout
android:id="#+id/ad_frame"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottomNav"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_anchorGravity="bottom"
android:background="#color/colorPrimary"
app:itemIconTint="#color/tab_selector"
app:itemTextColor="#color/tab_selector"
app:menu="#menu/bottom_navigation_menu"/>
</androidx.appcompat.widget.LinearLayoutCompat>
Unfortunately it seems that there is no answer yet on this anywhere. I tried to set layout_behavior, scrollFlags and layout_anchorGravity to bottom on BottomNavigationView but nothing works.
If I remove the scrollFlags on Toolbar only then the BottomNavigationView shows, but need the Toolbar having a scroll behavior but leaving the BottomNavigationView untouch.

The problem that the BottomNavigationView is affected by the scrolling flag set with app:layout_behavior in the activity container.
There is a couple of approaches you'd use to fix this:
First: add the BNV just below the CoordinatorLayout to be a part of the activity; so the layout would be:
<ConstraintLayout>
<CoordinatorLayout>
<AppBarLayout>
<content_main>
<frameLayout>
<BottomNavigationView>
Drawback: you could have other fragments transacted in the FragmentContainerView and the BNV won't be hidden in them. You can hide the BNV by setting its visibility.
Second: Transfer the ToolBar to the fragment; and set it when the fragment is created. The layout scheme would be:
Activity: just have the FragmentContainerView
Home Fragment
<ConstraintLayout>
<CoordinatorLayout>
<AppBarLayout>
<content_main>
<frameLayout>
<BottomNavigationView>
The drawback to this that you've to create and change the ToolBar for any fragment transaction in the FragmentContainerView.
Also you'd have a look at this similar question.

Static BottomNavigation inside CoordinatorLayout but not as direct child

I have top level container with CoordinatorLayout and Toolbar that hides when scolling, this container contain fragments.
<androidx.coordinatorlayout.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=".ui.screens.main.MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:elevation="0dp"
android:theme="#style/AppTheme.AppBarOverlay">
<androidx.appcompat.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.PopupOverlay" />
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/content_main" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
One of my fragments contain RecycleView and BottomNavigation
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:pp="http://schemas.android.com/tools"
android:id="#+id/cl_content"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.core.widget.NestedScrollView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.recyclerview.widget.RecyclerView/>
</androidx.core.widget.NestedScrollView>
<BottomNavigation />
</androidx.constraintlayout.widget.ConstraintLayout>
The problem that the BottomNavigation scrolls with the content, when the app start the BottomNavigation almost invisible, and when I scroll down the BottomNavigation became visible and vise versa, I need it to be static without scroll behavior, is there any configuration for that?
I guess the problem because BottomNavigation is not direct child of CoordinatorLayout but is there workaround?
Demo project(ignore slideshow and gallery):
https://github.com/pavelpoley/CoordinatorLayoutQuestion

Remove app:layout_behavior="#string/appbar_scrolling_view_behavior" from your content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:showIn="#layout/app_bar_main">
</androidx.constraintlayout.widget.ConstraintLayout>
UPDATE: After demo project has been updated with a more complex hierarchy provided solution above didn't work as expected.
I did a lot of research and couldn't find any clean solution to have BottomNavigationView inside CoordinatorLayout but not as a direct child.
The only solution was to move BottomNavigationView inside CoordinatorLayout as a child and then change its visibility based on androidx.navigation.NavController destination.
Source code: https://github.com/dautovicharis/CoordinatorLayoutQuestion/commits/master

You can make a couple of changes
Add exitUntilCollapsed flag to the Toolbar
app:layout_scrollFlags="scroll|enterAlways|exitUntilCollapsed"
Remove the app:layout_behavior from the NestedScrollView, and add it to root ConstraintLayout
By applying those, the layouts will be:
<androidx.coordinatorlayout.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=".ui.screens.main.MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:elevation="0dp"
android:theme="#style/AppTheme.AppBarOverlay">
<androidx.appcompat.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|exitUntilCollapsed"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/content_main" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And fragment:
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:pp="http://schemas.android.com/tools"
android:id="#+id/cl_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.core.widget.NestedScrollView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.recyclerview.widget.RecyclerView/>
</androidx.core.widget.NestedScrollView>
<BottomNavigation />
</androidx.constraintlayout.widget.ConstraintLayout>

Toolbar extends when keyboard opens

I have a toolbar that is beneath the status bar. If I click on a TextInputLayout, the keyboard opens but my toolbar will extend as shown here (if the keyboard is closed, the Toolbar has the usual size):
My xml-files:
The toolbar:
<androidx.appcompat.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/backgroundColor"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.SubAppBarOverlay"
app:popupTheme="#style/AppTheme.PopupOverlay"
app:title="Title"
android:elevation="4dp" />
Where it is included:
<androidx.constraintlayout.widget.ConstraintLayout 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="?attr/backgroundColor"
android:fitsSystemWindows="false"
tools:context=".EditDayActivity">
<include
android:id="#+id/sub_toolbar"
layout="#layout/sub_toolbar"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<RelativeLayout
android:id="#+id/scrollViewContainer"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/sub_toolbar"
android:fitsSystemWindows="false">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
android:fitsSystemWindows="true">
</ScrollView>
</RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Try removing the android:fitsSystemWindows="true" from your toolbar
Edit:
Maybe you should use a coordinatorlayout instead and put your toolbar in there.

I had the same problem and eventually got around it by using CoordinatorLayout as my activity root with app:statusBarColor="#color/some_color" and moving android:fitsSystemWindows="true" there. Probably not the best solution but the only one that worked with my layout.
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MyActivity"
app:statusBarBackground="#color/some_color">
...
</androidx.coordinatorlayout.widget.CoordinatorLayout>

I eventually managed to solve my problem by putting the ScrollView directly into the ConstraintLayout like this (and not using a RelativeLayout):
<androidx.constraintlayout.widget.ConstraintLayout
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="?attr/backgroundColor"
android:fitsSystemWindows="true"
tools:context=".MyActivity">
<include
... />
<ScrollView
... />
</androidx.constraintlayout.widget.ConstraintLayout>

Collapsing toolbar not pin the card view

I have created a XML with appbar layout, collapsing toolbar layout with imageview and nested scroll view in order to preform parallax scrolling.
However, I want to add a cardview inside the collapsing toolbar and pin it using the collapsing mode. It can't pin after scroll up. I have no idea what I made wrong. Anyone can help?
Here is my XML code:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#00FFFFFF">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapsingtoolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_collapseMode="pin">
//textview
</androidx.cardview.widget.CardView>
<ImageView
android:id="#+id/imageView7"
android:layout_width="360dp"
android:layout_height="360dp"
android:scaleType="centerCrop"
app:srcCompat="#drawable/logo"
tools:srcCompat="#drawable/logo" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
android:id="#+id/scrollview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="false"
android:overScrollMode="always"
app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
//my content
</LinearLayout>
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>

As far as I know, only Toolbar can be pinned inside of CollapsingToolbarLayout. Everything else collapses. So you either put your layout you want to pin inside of Toolbar Layout (not recommended, will change size of toolbar, and positions of nav buttons, etc.) or you move it outside of CollapsingToolbar.
Just remember that AppBarLayout acts like a vertical LinearLayout.
One possible idea, if you design allows it, is to remove CollapsingToolbarLayout and try to build your UI inside of AppBarLayout. You can control what goes away and what stays using layout_scrollFlags.

This is a very simple technique that you can apply
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/home_bg_color"
tools:context=".ui.match_detailds.MatchDetailsActivity">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/coordinatorLayout"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/app_barlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.AppBarOverlay">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collaps_toolabar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
app:expandedTitleTextAppearance="#style/CollapsingToolbarLayoutExpandedTextStyle"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">
<androidx.appcompat.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="#dimen/_150sdp"
app:layout_collapseMode="pin"/>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="#dimen/_150sdp"
app:layout_collapseMode="pin">
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/layout_currentMatch_item"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginTop="#dimen/_150sdp"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:layout_collapseMode="parallax"
app:layout_collapseParallaxMultiplier="1">
</androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:id="#+id/nestedviewhome"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>