Develop Reference

Recyclerview crop last and first items shadow

Recyclerview crop first and last items shadows and i cant't fix it with any attributes.
I have a such xml screen:
<?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"
tools:context=".screens.view.CreateRequestFragment">
<ScrollView
android:id="#+id/createRequestScrollView"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/sendRequestButton"
app:layout_constraintEnd_toEndOf="parent"
android:background="#color/transparent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!-- ... some elements inside scrollview -->
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/usersRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/margin_m"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/selectUsersTitle" />
</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>
<Button
android:id="#+id/sendRequestButton"
style="#style/OnDutyButtonStart"
android:text="Send Request"
android:layout_margin="#dimen/margin_m"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
tools:text="Send Request" />
</androidx.constraintlayout.widget.ConstraintLayout>
In this case i get cropped last and first items shadows:
but i need it like this:
If i add margin or padding - i get the same with blank white space and always cropped shadows.

Accessibility implementation in nested RecyclerView

In my application i have nested recycler view. UI looks like this
XML layouts
Parent
<?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/relativeLayout"
android:layout_width="match_parent"
android:background="#0F171E"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/Parent_recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="4dp"
android:scrollbars="vertical"
android:importantForAccessibility="no"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
Child
<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="wrap_content"
android:background="#0F171E"
android:focusable="true"
android:focusableInTouchMode="true">
<TextView
android:id="#+id/category"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="24dp"
android:importantForAccessibility="no"
android:text="Category"
android:textColor="#C4DFEF"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/Child_RV"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:descendantFocusability="afterDescendants"
android:importantForAccessibility="yes"
android:contentDescription="Category"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.01"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/category" />
</androidx.constraintlayout.widget.ConstraintLayout>
During vertical navigation, I'm need to announce "Category" followed by whatever child recycler view item supposed to say. Also, during vertical navigation, focus should not go to "Category" header, instead it should go directly to child recycler view item.
I have tried couple of things but it did not work. Currently i'm hearing text in format
"child item" item 2 of 15 in list "Category".
Any suggestions.
Noticed that you tube app on android Tv does this , it speaks the row title before speaking child item details.

RecyclerView inside of NestedScrollView only showing 1 element at a time

I have a RecyclerView inside of a NestedScrollView, my problem is that the RecyclerView is very short, only large enough to show 1 element at a time. The dataset is small (3-5 elements) so my goal is to show all elements at once.
I've tried disabling nested scrolling, changing the layout_height to wrap_content/match_parent, etc. but to no avail.
Code:
<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView 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="#color/white"
android:paddingBottom="52dp">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp">
<!-- A bunch of other layouts -->
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/documents_rv"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:paddingBottom="8dp"
android:visibility="gone"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="#id/title"
app:layout_constraintTop_toBottomOf="#id/doc1"
tools:visibility="visible"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
Update, item xml (I know it could be replaced with just 1 TextView, but for now it will stay as is):
<?xml version="1.0" encoding="utf-8"?>
<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="wrap_content"
android:layout_marginTop="4dp"
android:orientation="horizontal">
<ImageView
android:id="#+id/doc_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/ic_doc"
tools:ignore="ContentDescription" />
<TextView
android:id="#+id/doc_name"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="4dp"
android:gravity="center_vertical" />
</LinearLayout>

Not an ideal solution since it uses nested layouts, but I was able to display all items by wrapping my RecyclerView in a RelativeLayout:
<RelativeLayout
android:id="#+id/list_container"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:paddingBottom="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="#id/title"
app:layout_constraintTop_toBottomOf="#id/title">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/documents_list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>

RecyclerView card items not centering, when RecyclerView parent is ConstraintLayout?

I have a list of card views which has the flag of the country and name of it. The CardView has a ConstraintLayout as a child for aligning the views inside, and has a LinearLayout as parent.
The RecyclerView in MainActivity has a ConstraintLayout as Parent(which is the parent view by default created by AndroidStudio when doing a new project)
<?xml version="1.0" encoding="utf-8"?> <!-- MAIN ACTIVITY XML-->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_marginTop="10dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:layout_width="#dimen/card_view_item_main_width"
android:layout_height="#dimen/card_view_item_main_height">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/countryCardImage"
android:layout_width="match_parent"
android:layout_height="128dp"
android:contentDescription="#string/imagen_pais"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"/>
<TextView
android:id="#+id/countryCardText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="visible"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintVertical_bias="1"
/>
</android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?> <!-- ITEMMAIN.XML -->
<android.support.constraint.ConstraintLayout
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"
tools:context=".main.ui.main.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/listMain"
android:layout_width="0dp"
android:layout_height="0dp"
android:scrollbars="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintHorizontal_weight="0"
/>
</android.support.constraint.ConstraintLayout>

In your item root view, the layout_gravity="center" is not going to work on LinearLayout with layout_width="wrap_content: on a RecyclerView, so you could try changing its width to match_parent, and either change the gravity to android:gravity="center" or move android:layout_gravity="center" to its child view:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_marginTop="10dp"
android:layout_width=“match_parent”
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:layout_width="#dimen/card_view_item_main_width"
android:layout_height="#dimen/card_view_item_main_height"
android:layout_gravity="center">

The problem is in layout item, you set the layout_width="wrap_content" in LinearLayout, and in main layout, layout_width in Recyclerview is 0dp (must be match_parent) so it's not center in main layout because the main layout depend on item layout => wrong with this case.
In your layout item, change like this:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_marginTop="10dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical">

Center items in RecyclerView grid

I have main layout which includes my View which have RecyclerView and have grid applied on it. Now items have default width because of drawable i apply, and now they are aligned to left instead to center what i want to achieve.
My main layout:
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="0dp"
android:layout_height="0dp"
android:id="#+id/main_view"
xmlns:app="http://schemas.android.com/apk/res-auto">
<include android:id="#+id/constraint_more"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
android:visibility="gone"
layout="#layout/list_more_view"/>
</android.support.constraint.ConstraintLayout>
More layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/list_more_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/list_more_bg">
<TextView
android:id="#+id/textview_title_more"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:gravity="center_vertical"
android:paddingLeft="20dp"
android:shadowRadius="2"
android:text="#string/title"
android:textColor="#color/list_text_color"
android:textSize="25dp"/>
<ImageView
android:id="#+id/button_closemore"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_marginEnd="10dp"
android:layout_marginRight="10dp"
android:contentDescription="#string/close_button"
android:src="#drawable/btn_close"
app:layout_constraintBottom_toBottomOf="#id/textview_title_more"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerview_morelist"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#id/textview_title_more" />
</android.support.constraint.ConstraintLayout>
And the item layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/constraintlayout_item_view"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:background="#drawable/plate_basic">
<TextView
android:id="#+id/textview_unit_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:maxLines="2"
app:autoSizeTextType="uniform"
android:textColor="#color/item_text_color"
android:paddingTop="#dimen/tile_title_padding"
app:layout_constraintTop_toTopOf="parent"/>
</android.support.constraint.ConstraintLayout>
So the thing is items in this more view are all aligned to left but i want the whole view of items centred, i tried with setting the width to wrap content and than centring with gravity but no success.

Change constraintlayout_item_view to have:
android:layout_width="match_parent"
Then set textview_unit_title to have:
android:layout_width="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
That should place the TextView centered inside its row.
In addition, your main layout's width and height are a little strange:
android:layout_width="0dp"
android:layout_height="0dp"
They should probably both be match_parent