I try to implement proper scroll behaviour with the following setup in my android application.
For navigation I use the jetpack navigation in combination with a Toolbar layout and a bottom navigation. I also use the principle of 'one activity, many fragments'. Each item of the bottom navigation launches a corresponding Fragment based on my navigation graph. This requires me to use a NavHostFragment in my layout.
My Toolbar layout is part of the activity layout and gets populated based on the current fragment. Some fragments require a collapsing Toolbar, which also gets added when needed. But when having a collapsing toolbar I face the following problem:
In the particular case I have a collapsing Toolbar, the NavHostFragment is populated with a RecyclerView. In other cases it appears I can add app:layout_behavior="#string/appbar_scrolling_view_behavior" to the RecyclerView and get the expected result, because the RecyclerView is a direct child of the CoordinatorLayout. In my case the RecyclerView is a child of a Fragment, which is basically a FrameLayout (according to the Layout Inspector). This leads to the problem, that the layout_behaviour on the RecyclerView has no effect as the RecyclerView is not a direct child of the CoordinatorLayout.
I couldn't come up with a working solution for this problem. Does anybody have an idea?
layout/activity_overview.xml
<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"
tools:context=".OverviewActivity">
<androidx.coordinatorlayout.widget.CoordinatorLayout android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/toolbarCoordiantor"
android:layout_marginTop="?attr/actionBarSize"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#id/overview_bottom_navigation"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent">
<fragment android:layout_width="match_parent" android:layout_height="wrap_content"
android:id="#+id/overview_fragmentholder"
android:name="androidx.navigation.fragment.NavHostFragment"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/toolbar"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
android:layout_marginBottom="?attr/actionBarSize"
android:layout_marginTop="?attr/actionBarSize"
app:navGraph="#navigation/nav_graph"
app:layout_constraintVertical_bias="1.0"/>
<include layout="#layout/toolbar"
android:id="#+id/toolbar"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/overview_bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:foregroundGravity="bottom"
app:menu="#menu/navigation"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:itemBackground="#color/white"
app:itemIconTint="#color/bottom_navigation_color_states"
app:itemTextColor="#color/bottom_navigation_color_states"/>
layout/toolbar.xml
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapsingToolbarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap|snapMargins"
android:minHeight="?attr/actionBarSize">
<androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/expandedToolbarContentContainer"
android:layout_marginTop="?attr/actionBarSize"
app:layout_collapseMode="parallax"/>
<androidx.appcompat.widget.Toolbar android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
style="#style/AppTheme.DarkToolbar"
android:id="#+id/toolbarView">
<androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/round_outline"
style="#style/AppTheme.DarkToolbar.Container"
android:id="#+id/toolbarContentContainer"/>
</androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.CollapsingToolbarLayout>
layout/list.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/dish_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layoutAnimation="#anim/layout_animation_fall_down"
/>
Try to wrap up host_fragment with NestedScrollView with needed behaviour, like this:
<androidx.core.widget.NestedScrollView
android:id="#+id/nestedScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:fitsSystemWindows="true"
android:transitionGroup="true"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<fragment
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/my_nav_host" />
</androidx.core.widget.NestedScrollView>
Jurij Pituljas approach will prevent scrollToPosition method of RecyclerView to work. Addidionally navigating back to fragments with RecyclerView will reset its scroll position to the top.
A better approach is described here. Even there is no need for the surrounding FrameLayouts in the referenced article. Instead of wrapping the fragment within a NestedScrollView, just wrap any non scrolling fragment layout views into a NestedScrollView.
Activity layout with NavHostFragment: No need to wrap the fragment into a scrolling view. Just set the layout_behavior.
...
<fragment
android:id="#+id/navigation_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:navGraph="#navigation/navigation_graph" />
...
Fragment layout with root RecyclerView: Nothing special to do at all as RecyclerView has scrolling capabilities.
<androidx.recyclerview.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
Fragment layout with e.g. TextView: Wrap within root NestedScrollView to add scrolling capabilities.
<androidx.core.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="non scrolling content wrapped" />
</LinearLayout>
</androidx.core.widget.NestedScrollView>
Related
I have a weird problem where the Snackbar is being attached to the scroll view, so when a user scrolls the snackbar moves with the scrolling instead of staying position on the bottom of the screen.
I know it's caused by how I've set up my layout but I don't know a solution to either better setup my layout, or stop this behavior.
<?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=".MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapse_toolbar"
style="?attr/collapsingToolbarLayoutMediumStyle"
android:layout_width="match_parent"
android:layout_height="?attr/collapsingToolbarLayoutMediumSize"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:title="">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:elevation="0dp"
app:layout_collapseMode="pin"
app:title="" />
</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:fitsSystemWindows="true"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<androidx.fragment.app.FragmentContainerView
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
app:defaultNavHost="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="#navigation/nav_graph" />
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
As you can see I'm wrapping the FragmentContainerView inside of a NestedScrollView which works and allows the CollapsingToolbarLayout to work as expected, as well as the child fragments content to scroll as I want.
Each child fragment just implements a basic layout a bit like:
<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"
android:fitsSystemWindows="true">
//... Lots of text views etc etc
</androidx.coordinatorlayout.widget.CoordinatorLayout>
I tried removing the top level NestedScrollView and implementing it at each fragment, but that caused lots of issues with the CollapsingToolbarLayout and the child fragment content overlapping etc.
Is there a more straightforward solution to this?
Thanks for any input
I have the following code
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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=".ui.main.MainActivity">
<fragment
android:id="#+id/navHostFragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/main_graph" />
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="8dp">
<include layout="#layout/bottom_sheet" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
And
<?xml version="1.0" encoding="utf-8"?><!--suppress AndroidUnknownAttribute -->
<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/bottomSheet"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/bottom_sheet_corners"
android:clickable="true"
android:focusable="true"
app:behavior_hideable="false"
app:behavior_peekHeight="0dp"
app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior"
tools:ignore="ContentDescription">
<com.mobilemedia.tanuki.ui.view.RoundedView
android:id="#+id/bottomSheetContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:topLeftCornerRadius="16dp"
app:topRightCornerRadius="16dp">
<fragment
android:id="#+id/bottomSheetNavHostFragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/bottom_sheet_graph" />
</com.mobilemedia.tanuki.ui.view.RoundedView>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/collapsedView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<View
android:layout_width="32dp"
android:layout_height="4dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:background="#drawable/bottom_sheet_indicator"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
I need to listen to the change in height bottom sheet layout for change the position of elements relative to this height
The item must always be at a height from bottom sheet despite the fact that he is on another fragment in navHostFragment
How listen change height from bottom sheet?
In common case, you can listen to the bottom sheet slide by using BottomSheetCallback. Override onSlide method and put your actions inside. This method called when the bottom sheet is being dragged. And you can get all the properties of bottomSheet, including height.
But the better way is to implement custom CoordinatorLayout.Behavior. This works only if your depending views and BottomSheet are the children of the same coordinatorlayout.
Just extend CoordinatorLayout.Behavior and override layoutDependsOn and onDependentViewChanged methods. CoordinatorLayout was made to solve issues like that.
There are many articles about this on the internet, for example.
There is also a standard floating action button behavior in the android library.
The third way is to use MotionLayout. But it is a more complex, and it can be difficult to start. So I should not suggest it, because it could be over powerful for this task.
I have this layout for my activity which uses multiple fragments that have RecyclerView in it. The FrameLayout here is the container for the fragments. The problem is that, although I set my FrameLayout's bottom to the top of BottomNavigationView, last element of RecyclerView gets hidden under BottomNavigationView.
My code for activity layout:
<androidx.constraintlayout.widget.ConstraintLayout
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">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ToolbarTheme"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:logo="#drawable/money_icon"
/>
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/toolbar"
app:layout_constraintBottom_toTopOf="#+id/bottomNavigationView"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottomNavigationView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/bottom_nav_menu" />
Code for fragment includes RecyclerView:
<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:background="#color/dark_gray"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/finishedSlipsRecycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</androidx.recyclerview.widget.RecyclerView>
Screenshot of the problem:
Obviously the issue is because of this line:
app:layout_behavior="#string/hide_bottom_view_on_scroll_behavior"
Just remove it and everything will be fine.
EDIT:
Replace your ConstraintLayout in
Code for fragment includes RecyclerView:
by FrameLayout since it only contains one element. I think there's a problem with putting the ConstraintLayout inside FrameLayout like this.
The problem actually raised due to RecyclerView flows over FrameLayout. The better definition and the answer of the problem can be found here
I'm using Horizontal ViewPager2 which has 4 fragments inside. Each fragment has SwipeRefreshLayout on a RecyclerView. The issue that I'm facing is that when RecyclerView is at top position then onClick on any item is list is not working. If I scroll the RecyclerView a bit down then onClick works fine. And when RecyclerView is at top position then if SwipeRefreshLayout is in refreshing state then onClick works fine. It seems SwipeRefreshLayout is conflicting with ViewPager2 in touch events. It works fine with simple ViewPager. What could be the actual problem and how can we handle it? Any ideas would be appreciable.
Thanks
xml:
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/fragment_home"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<include
android:id="#+id/headerPanel"
layout="#layout/home_header"
app:viewModel="#{viewModel}" />
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/swipe_refresh_layout"
android:layout_width="match_parent"
android:layout_height="0dp"
android:paddingStart="#dimen/home_post_side_spacing"
android:paddingEnd="#dimen/home_post_side_spacing"
app:colorScheme="#{#color/fayvo_color}"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#+id/headerPanel"
app:onRefreshListener="#{() -> viewModel.manualRefresh()}"
app:refreshing="#{viewModel.isRefreshing}"
android:background="#f0f0f0">
<RelativeLayout
android:id="#+id/rl_rv"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_homePosts"
adapter="#{viewModel.postObservableArrayList}"
addToTop="#{viewModel.addToTop}"
clearList="#{viewModel.clearList}"
showLoader="#{viewModel.isPagingEnabled && viewModel.isLoading}"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
<FrameLayout
android:id="#+id/emptyFrameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="#{viewModel.showEmptyLayout?View.VISIBLE:View.GONE}" />
<include
android:id="#+id/postUploadProgressLayout"
layout="#layout/item_post_upload_progress"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:viewModel="#{viewModel}" />
</RelativeLayout>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
<View
android:id="#+id/tooltipView"
android:layout_width="1dp"
android:layout_height=".1dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
I was also facing the same issue, it is due to nested scrolling. After a lot of searching i came to know that coordinator layout should be userd as parent layout. App bar also needs to be added and after that it should work perfectly.
It resolved the issue.
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/coordinateLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/fragmentAppBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#null"
app:elevation="0dp" />
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/swipeLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvMemberList"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
tools:listitem="#layout/holder_member_item" />
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
As i see you have also app bar so user constraint layout and include your app bar and coordinator layout inside that
so hierarchy should be like
ConstraintLayout
AppBar
CoordinatorLayout
A simpler solution is that Change Direct parent of ViewPager2 from CosntraintLayout to some other layout i.e. LinearLayout and it will work fine.
I have an app with the one Activity, many Fragments model, where several Fragments have a RecyclerView to show cards with content. I also have implemented the BottomAppBar from Material Design 2.0, and everything is fine except when the AppBar blocks the last CardView in the RecyclerView.
In terms of layout, I have a RecyclerView inside ConstraintLayout inside a Fragment, which sits in a FrameLayout in the main activity.
The documentation shows that for the BottomAppBar to be hidden on Scroll, we need to implement RecyclerView inside a NestedScrollView. There is one question here on SO where the answer has stated the same as well, but there seems to be no actual documentation or examples to demonstrate how this is to be done, except for this article on Medium, which uses the NestedScrollView in an Activity directly, holding a CoordinatorLayout which holds a ConstraintLayout.
Note: I think it also works on magic, because duplicating the layout in my fragment doesn't have any effect at all in my app.
How do I use NestedScrollView here?
PS : I need to have the TextView, as I set the RecyclerView to VISIBILITY.GONE and set the TextView to VISIBLE when I have no data to display.
Fragment Layout
<android.support.constraint.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/constraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="in.domain.APPNAME.Fragments.FragmentList">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerViewIncident"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingBottom="30dp"
android:visibility="visible"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
<TextView
android:id="#+id/emptyView"
android:layout_width="wrap_content"
android:layout_height="17dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="No Incidents to display"
android:visibility="visible"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.503"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Activity Layout
<?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:id="#+id/uberLayout"
tools:context=".APPNAME">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="#+id/containerFrameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</android.support.constraint.ConstraintLayout>
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.bottomappbar.BottomAppBar
android:id="#+id/bottom_app_bar"
style="#style/Widget.MaterialComponents.BottomAppBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:backgroundTint="#color/colorPrimary"
app:fabAlignmentMode="center"
app:navigationIcon="#drawable/baseline_menu_white_24dp"
app:hideOnScroll="true"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
</android.support.design.bottomappbar.BottomAppBar>
<android.support.design.widget.FloatingActionButton
android:id="#+id/floatingActionButton"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:clickable="true"
android:src="#drawable/baseline_add_white_24dp"
app:backgroundTint="#color/brightred"
app:fabSize="normal"
app:layout_anchor="#+id/bottom_app_bar"
tools:layout_editor_absoluteX="160dp"
tools:layout_editor_absoluteY="465dp" />
</android.support.design.widget.CoordinatorLayout>
</android.support.design.widget.CoordinatorLayout>
you shouldn't put the BottomAppBar and the FloatingActionButton in a separate CoordinatorLayout. Ditch the CoordinatorLayout they're in, the ConstraintLayout around your FrameLayout and that may already solve the problem.
<?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:id="#+id/uberLayout"
tools:context=".APPNAME">
<FrameLayout
android:id="#+id/containerFrameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
<android.support.design.bottomappbar.BottomAppBar
android:id="#+id/bottom_app_bar"
style="#style/Widget.MaterialComponents.BottomAppBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:backgroundTint="#color/colorPrimary"
app:fabAlignmentMode="center"
app:navigationIcon="#drawable/baseline_menu_white_24dp"
app:hideOnScroll="true"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<android.support.design.widget.FloatingActionButton
android:id="#+id/floatingActionButton"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:src="#drawable/baseline_add_white_24dp"
app:backgroundTint="#color/brightred"
app:fabSize="normal"
app:layout_anchor="#+id/bottom_app_bar" />
</android.support.design.widget.CoordinatorLayout>
I'm using a similar layout, the only difference being a <fragment> instead of a <FrameLayout>, and the BottomAppBar hides on scroll just fine. We don't need to use a NestedScrollView, if our scrolling content is a RecyclerView anyway, because RecyclerView implements NestedScrollingChild.
This interface should be implemented by View subclasses that wish to support dispatching nested scrolling operations to a cooperating parent ViewGroup.