Develop Reference

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>

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

Android Textview Scrolling Issue

Firstly, I am new to android so if I have missed something basic I do apologise.
I have created a GridView to store some information. The GridView consists of a 3x6 grid. In each cell, there is an image and text directly under the image. As the GridView is so large I have implemented a scrollbar.
This is how the page should look normally and is when first loaded/selected :
Everything looks wonderful, however, when I scroll down to the bottom and then back up, the text seems to wrap up and then push the image out of place. I am not sure why this is?
This is how the page looks after I have scrolled down and they scroll back up :
For the GridView, I have an XML file with the GridView itself along with a TextView at the very top called content_rewards.xml. I have also create an XML file for each picture/text in the grid itself called relics_gridlayout.xml. I believe I am probably missing a property of the TextViews in either one of these files, however, I am not sure which one or which property. I don't think it has anything to do with the grid or adapter itself hence I will not include that code.
content_rewards.xml
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:fitsSystemWindows="true"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="25dp">
<GridView
android:id="#+id/customgrid"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_below="#+id/os_texts"
android:columnWidth="100dp"
android:numColumns="auto_fit"
android:stretchMode="spacingWidthUniform"
android:verticalSpacing="35dp"
android:scrollbars="horizontal"
tools:layout_constraintTop_creator="1"
android:layout_marginTop="116dp"
tools:layout_constraintLeft_creator="1"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<TextView
android:id="#+id/textView4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="B = 0 S = 0 G = 0"
android:textSize="24sp"
tools:layout_constraintRight_creator="1"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toTopOf="#+id/customgrid"
app:layout_constraintRight_toRightOf="parent"
tools:layout_constraintLeft_creator="1"
android:layout_marginBottom="8dp"
app:layout_constraintLeft_toLeftOf="parent"/>
</android.support.constraint.ConstraintLayout>
relics_gridlayout.xml
<?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"
android:padding="3dp">
<ImageView
android:id="#+id/os_images"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="#mipmap/ic_launcher" />
<TextView
android:layout_below="#+id/os_images"
android:id="#+id/os_texts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="This is Just Dummy Text"
android:textAlignment="center"
android:textSize="18dp"
android:textStyle="bold"/>
</RelativeLayout>
Any help would be great. Thanks.

<?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="#ECEFF1"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="#layout/app_bar_main">
<GridView
android:id="#+id/grd1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:gravity="center"
android:horizontalSpacing="6dp"
android:numColumns="auto_fit"
android:stretchMode="columnWidth"
android:verticalSpacing="6dp">
</GridView>
</RelativeLayout>
This should solve your problem.
The scrolling view behavior will handle the scrolling irrespective of the size
Now add the Text view out of the Relative layout to view it always.
Or have a parent as Nested scrolling View and allow the nested scrolling enabled as false
setNestedScrollingEnabled(false)
A sample from my code that I already have used successfully to resolve such issue
Use your Grid view instead of Recycler View.
If you want the Item Text View to be always of 2 lines then set munLines="2" in the item Layout
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/swipe_container_reports"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.AppCompatTextView
android:id="#+id/tab_header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:text="#string/user_reports"
android:textAllCaps="true"
android:textColor="#color/colorPrimaryDark"
android:textSize="#dimen/tab_label"
app:textAllCaps="true" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/reports_recycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fadeScrollbars="false"
android:nestedScrollingEnabled="false"
android:padding="4dp" />
</RelativeLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</android.support.v4.widget.SwipeRefreshLayout>

This is a problem that i faced as well , the only solution that i could come up with was hardcoding the height of the grid item.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="100dp"
android:padding="3dp">
A better option would be to use recycler view with a grid layout manager.

you can use LinearLayout and assign weights so that every item in your grid view occupy same space
Update the relics_gridlayout.xml with below code ( you may need to adjust gravity and layout weights)Try this
<?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:id="#+id/linearLayout_root_single_home_option"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/os_images"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#mipmap/ic_launcher"
android:layout_weight="9" />
<TextView
android:id="#+id/os_texts"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is Just Dummy Text"
android:textSize="18dp"
android:textStyle="bold"
android:layout_weight="1" />
</LinearLayout>

How to center RecyclerView items horizontally with vertical GridLayoutManager

I have a vertical RecyclerView using a GridLayoutManager. I want each column to be centered, but the columns begin all the way on the left. In the following picture you can see what I'm talking about. I used the ugly color scheme to illustrate the columns and background. The green is the background for each item in the RecyclerView, the red is the background of the RecyclerView itself:
http://imgur.com/a/J3HtF
I'm setting it up with:
mRecyclerView.setLayoutManager(new GridLayoutManager(this, 2));
Here's the column_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="120dp"
android:layout_height="180dp"
android:orientation="vertical"
android:padding="4dp">
<ImageView
android:id="#+id/movie_column_photo"
android:layout_width="80dp"
android:layout_height="120dp"/>
<TextView
android:id="#+id/movie_column_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
Here's the recyclerview xml:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/company_details_recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical">
</android.support.v7.widget.RecyclerView>
</LinearLayout>

Try letting the column item fill the width of the column while centering everything inside:
<?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="180dp"
android:orientation="vertical"
android:padding="4dp">
<ImageView
android:id="#+id/movie_column_photo"
android:layout_width="80dp"
android:layout_height="120dp"
android:layout_gravity="center_horizontal"/>
<TextView
android:id="#+id/movie_column_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"/>
</LinearLayout>

To restate #kris larson's answer;
If you are using ConstraintLayout, adding android:layout_gravity="center" or android:layout_gravity="center_horizontal" to the parent layout in item's XML would be enough (the first parent in hierarchy).
In your case, the codes would be something similar to this:
<android.support.constraint.ConstraintLayout
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_width="match_parent"
android:layout_height="180dp"
android:orientation="vertical"
android:padding="4dp"
android:layout_gravity="center">
<ImageView
android:id="#+id/movie_column_photo"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_width="80dp"
android:layout_height="120dp"/>
<TextView
android:id="#+id/movie_column_title"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</android.support.constraint.ConstraintLayout>

Simply set the width of the root layout for your column_item.xml to match_parent will center RecyclerView items horizontally.

Wrap your recyclerview inside the constraintlayout, something like this:
<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" >
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/book_list"
android:layout_width="wrap_content"
android:layout_height="match_parent"
app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:spanCount="2" />
Hope it helps!!

2 Images On Top of Each Other - XML - Android

So I want to use 2 images. One should be on top of the other but smaller, so that the border of the image that's behind is only shown.
Take a look at these 2 photos.
Image that's behind (The border Image)
[IMG]http://i66.tinypic.com/25zgguh.jpg[/IMG]
Image that should be inside the border
[IMG]http://i67.tinypic.com/10mpgt4.jpg[/IMG]
XML CODE
<com.inthessaloniki.cityguide.view.SelectorRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_poi_list_item"
android:layout_width="match_parent"
android:layout_height="#dimen/fragment_poi_list_recycler_item_size"
android:minHeight="#dimen/fragment_poi_list_recycler_item_size"
android:listSelector="#drawable/selector_clickable_item_bg_inverse">
<ImageView
android:id="#+id/fragment_poi_list_item_image"
android:layout_width="match_parent"
android:layout_height="#dimen/fragment_poi_list_recycler_item_size"
android:adjustViewBounds="true"
android:scaleType="centerCrop" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="#dimen/fragment_poi_list_recycler_item_panel_height"
android:layout_alignParentBottom="true"
android:gravity="center_vertical"
android:orientation="vertical"
android:paddingLeft="#dimen/global_spacing_xs"
android:paddingRight="#dimen/global_spacing_xxs"
android:background="#color/fragment_poi_list_recycler_item_panel_bg">
<TextView
android:id="#+id/fragment_poi_list_item_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="#style/TextAppearance.CityGuide.Body1.Inverse"
android:fontFamily="sans-serif"
android:maxLines="2"
android:ellipsize="end" />
<TextView
android:id="#+id/fragment_poi_list_item_distance"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_grid_distance"
android:drawablePadding="#dimen/fragment_poi_list_recycler_item_icon_padding"
android:textAppearance="#style/TextAppearance.CityGuide.Body1.Inverse"
android:fontFamily="sans-serif"
android:maxLines="1"
android:ellipsize="end" />
</LinearLayout>
I was thinking if I could add an android:background="First Image" and make my Image view center but leaving some space on the edges for the background to be shown.
Would have posted 2 more images showing how the app is and how it should look, but the site won't let me post more than 2 links cause my reputation is lower than 10 -_-
Thanks in advance for the help!!!

Do it like this:
<com.inthessaloniki.cityguide.view.SelectorRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_poi_list_item"
android:layout_width="match_parent"
android:layout_height="#dimen/fragment_poi_list_recycler_item_size"
android:minHeight="#dimen/fragment_poi_list_recycler_item_size"
android:listSelector="#drawable/selector_clickable_item_bg_inverse">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/background_image"
tools:context=".MainActivity">
<ImageView
android:id="#+id/view"
android:layout_margin="5dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/foreground_image" />
</RelativeLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="#dimen/fragment_poi_list_recycler_item_panel_height"
android:layout_alignParentBottom="true"
android:gravity="center_vertical"
android:orientation="vertical"
android:paddingLeft="#dimen/global_spacing_xs"
android:paddingRight="#dimen/global_spacing_xxs"
android:background="#color/fragment_poi_list_recycler_item_panel_bg">
<TextView
android:id="#+id/fragment_poi_list_item_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="#style/TextAppearance.CityGuide.Body1.Inverse"
android:fontFamily="sans-serif"
android:maxLines="2"
android:ellipsize="end" />
<TextView
android:id="#+id/fragment_poi_list_item_distance"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_grid_distance"
android:drawablePadding="#dimen/fragment_poi_list_recycler_item_icon_padding"
android:textAppearance="#style/TextAppearance.CityGuide.Body1.Inverse"
android:fontFamily="sans-serif"
android:maxLines="1"
android:ellipsize="end" />
</LinearLayout>

hope I got it clear, you could simply use two layout and adjust margin for the small one.
put your images as RelativeLayout background or use ImageView in layouts
<?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">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="25dp"></RelativeLayout>
</RelativeLayout>