Develop Reference

TextView inside fragment with layout_gravity set to center hides behind tabs in tabbed activity

I am trying to implement a scrolling fragment in the Tabbed activity. There's only a single TextView inside the fragment and it works fine as far as layout_gravity is not changed. But as soon as layout_gravity is set to center the content of the TextView hides behind the tabs.
Here's the code:
Fragment
<androidx.core.widget.NestedScrollView 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=".Fragment_1">
<TextView
android:id="#+id/frag1_tv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="#dimen/text_margin"
android:textSize="#dimen/text_medium"
android:textAlignment="center"
android:textColor="#color/black"
android:text="#string/buddha_vandana_mar" />
</androidx.core.widget.NestedScrollView>
And ViewPager:
<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=".PrayerActivity">
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:liftOnScroll="true"
android:theme="#style/Theme.BuddhaPoojapathMarathi.AppBarOverlay">
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"/>
</com.google.android.material.appbar.AppBarLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Without layout_gravity:center looks like following:
With layout_gravity:center set looks like following:

Add android:fitsSystemWindows="true" in your root layout.
<androidx.core.widget.NestedScrollView 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=".Fragment_1"
android:fitsSystemWindows="true"
>

Title in CollapsingToolbarLayout truncates on SearchView open

Whenever I open a SearchView within a CollapsingToolbarLayout, the page title gets squashed and truncated to 1 side for some reason rather than being positioned underneath the SearchView widget. Is there a way to prevent this from happening?
Main layout
<?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/myCoordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<include layout="#layout/collapsing_toolbar" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/myRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:scrollbarStyle="outsideInset"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/myFab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:src="#drawable/ic_search"
android:contentDescription="#string/string_search"
android:layout_margin="16dp" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Collapsing toolbar layout
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.appbar.AppBarLayout
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="wrap_content"
android:id="#+id/myAppBarLayout">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/myCollapsingToolbarLayout"
android:layout_width="match_parent"
android:layout_height="250dp"
android:fitsSystemWindows="true"
app:layout_scrollFlags="scroll|snap|exitUntilCollapsed"
app:maxLines="3">
<androidx.appcompat.widget.Toolbar
android:id="#+id/myToolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:contentInsetStartWithNavigation="0dp"
app:layout_collapseMode="pin" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>

Your CollapsingToolbarLayout was covered by your RecyclerView, try to change the Main layout

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>

RecyclerView does not scroll while searching

I have a recyclerview assoicated with a filtered search in a toolbar. When I start the search, the number of items displayed by the recyclerview is far larger than the screen size. But when I try to scroll up by swiping to look at the elements off the screen, there no response. I thought RecyclerViews like ListViews always support scrolling. Any ideas why my RecyclerView is not scrolling?
Here is the coordinator layout for the tool bar, search, and recycler view that gets included in my main layout (I apologize for the formatting but the insert code widget does not work correctly):
<?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.lampreynetworks.cpa.CPA_Activity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar_search_id"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/colorToolbarBackground"
android:theme="#style/AppThemeDark"
app:contentInsetEnd="0dp"
app:contentInsetStart="0dp">
</android.support.v7.widget.Toolbar>
<android.support.v7.widget.RecyclerView
android:id="#+id/card_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>
The main layout is as follows
<?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:id="#+id/base_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.lampreynetworks.cpa.CPA_Activity"
android:orientation="vertical">
<include
android:id="#+id/toolbar_search"
layout="#layout/toolbar_search_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<android.support.v4.widget.DrawerLayout
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/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout
android:id="#+id/borderLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="4dp"
android:background="#drawable/text_view_border"
android:orientation="vertical">
<TextView
android:id="#+id/text_connect_status"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="6dp"
android:text="some text"
android:textColor="#color/orange"
android:textStyle="bold"/>
</RelativeLayout>
<ListView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_below="#+id/borderLayout"
android:layout_marginLeft="4dp"
android:layout_marginStart="4dp"
android:choiceMode="none"
android:stackFromBottom="false">
</ListView>
</RelativeLayout>
<android.support.design.widget.NavigationView
android:id="#+id/navigation_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:menu="#menu/nav_drawer_menu"/>
</android.support.v4.widget.DrawerLayout>
</LinearLayout>
All other aspects appear to be okay. The list interactively responds to user input text and click actions on the recyclerview items are able to obtain the searched-for information. But this list never scrolls. I have tried numerous approaches taking hints from related issues (adding various types of scroll layouts, invoking scroll-related attributes in various places, etc. all within the coordinator layout) but the behavior remains unchanged. There must be something really stupid that I am doing to kill such a basic behavior.

Try moving the RecyclerView outside of the AppBarLayout as follows:
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.lampreynetworks.cpa.CPA_Activity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar_search_id"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/colorToolbarBackground"
android:theme="#style/AppThemeDark"
app:contentInsetEnd="0dp"
app:contentInsetStart="0dp">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/card_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>

change recyclerview height to wrap_content.
<android.support.v7.widget.RecyclerView
android:id="#+id/card_recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
put your recyclerview out of AppBarLayout.

My listview is above the appbar

I have a whatsapp like appbar menu option, but the list view is above this frame layout. and I have added scroll behavior also. It was working perfectly fine until I made changes and now i dont know how to fix it.
<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"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.example.feelingoodlivinbeta.socialdreams_a1.HostMainMenuActivity">
<include layout="#layout/toolbar" />
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize">
<io.codetail.widget.RevealFrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<include layout="#layout/settings_menu_host_layout" />
</io.codetail.widget.RevealFrameLayout>
</FrameLayout>
<include layout="#layout/content_host_main_menu" />
</android.support.design.widget.CoordinatorLayout>

Try to add app:layout_behavior="#string/appbar_scrolling_view_behavior" in your "content_host_main_menu.xml" parent layout