Develop Reference

How do I keep a part of my activity fixed and static

I'm making an app that allows a user to stream a video and then also comment / Ask questions below it, what happens is that when the keyboard is opened the video player is scrolled to make room on the screen for the keyboard.
Layout of the Activity :
<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/root_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimaryDark"
android:orientation="vertical"
android:weightSum="2"
tools:context=".LiveVideoBroadcasterActivity">
//player portion starts here
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:isScrollContainer="false"
android:layout_weight="0.7">
<android.opengl.GLSurfaceView
android:id="#+id/cameraPreview_surfaceView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:orientation="horizontal"
android:padding="2dp"
android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageButton
android:id="#+id/settings_button"
style="?borderlessButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:adjustViewBounds="true"
android:onClick="showSetResolutionDialog"
android:src="#drawable/ic_settings_white_24dp"
android:tint="#color/colorAccent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageButton
android:id="#+id/changeCameraButton"
style="?attr/borderlessButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:onClick="changeCamera"
android:src="#drawable/ic_switch_camera_white_24dp"
android:tint="#color/colorAccent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toEndOf="#+id/settings_button"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/stream_live_status"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|top"
android:layout_margin="8dp"
android:layout_marginEnd="4dp"
android:background="#drawable/rounded_live"
android:padding="5dp"
android:text="#string/live_indicator"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
//player portion ends here
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1.3"
android:orientation="vertical"
android:visibility="visible">
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_constraintBottom_toBottomOf="#+id/linearLayout3"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.core.widget.NestedScrollView
android:id="#+id/scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="50dp"
android:paddingTop="40dp">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/show_chat"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</androidx.core.widget.NestedScrollView>
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<EditText
android:id="#+id/stream_name_edit_text"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:hint="#string/stream_name"
android:textColor="#color/colorAccent"
android:textColorHint="#color/colorSelect" />
<Button
android:id="#+id/toggle_broadcasting"
style="#style/TextAppearance.AppCompat.Widget.Button"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
android:backgroundTint="#color/colorPrimaryDark"
android:onClick="toggleBroadcasting"
android:text="#string/start"
android:textColor="#color/colorAccent" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#drawable/chatbox"
android:weightSum="3"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent">
<EditText
android:id="#+id/textmassge"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_gravity="bottom"
android:layout_weight="2.5"
android:hint="Enter Message"
android:textColor="#color/colorPrimary"
android:textColorHint="#color/colorPrimary"
android:textSize="20sp"
tools:ignore="Autofill,HardcodedText" />
<androidx.appcompat.widget.AppCompatImageButton
android:id="#+id/send_button"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.5"
android:background="#android:color/transparent"
android:src="#drawable/ic_arrow_back_black_24dp"
android:tint="#color/colorAccent" />
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
I tried to keep the whole layout in a constraint layout and a give static height and width but, since I need the app to be responsive enough so as to work across multiple devices , I opted for this approach using linearlayout and weightsum.

android Seekbar width "match_parent" not working

I'm creating a seekbar in a dialog fragment, and for some reason, the seekbar width is not taking the whole available width. I guess it has something to do with the dialogfragment somehow.
here is my xml file:
<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">
<SeekBar
android:id="#+id/seekBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="12dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<ImageButton
android:id="#+id/play_pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="12dp"
android:background="#drawable/play_icon"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/seekBar" />
<TextView
android:id="#+id/player_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="12dp"
android:layout_marginEnd="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/play_pause"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/seekBar" />
</androidx.constraintlayout.widget.ConstraintLayout>
you can see that the seekbar width is set to "match parent" but it's not working.
Although it's look good in the preview.

Use RelativeLayout as root layout for dialog XML file like this...
<RelativeLayout 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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<SeekBar
android:id="#+id/seekBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="12dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageButton
android:id="#+id/play_pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="12dp"
android:background="#drawable/play_icon"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/seekBar" />
<TextView
android:id="#+id/player_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="12dp"
android:layout_marginEnd="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/play_pause"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/seekBar" />
</androidx.constraintlayout.widget.ConstraintLayout>
</RelativeLayout>

How to load RecyclerView items step by step in NestedScrollView?

I have gallery page in my project. There are RecyclerView, ScrollView and other basic views in gallery page. My RecyclerView loads all images when open the page. This causes the app to freeze. I want to use RecyclerView feature like load items part by part.
Actually my XML is too long so I didn't add some views in following 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:id="#+id/detail_fragment_scroll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/transparent"
android:clipChildren="false"
android:clipToPadding="false"
android:fillViewport="true"
android:fitsSystemWindows="false"
android:focusable="true"
tools:context=".DetailActivity">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/detail_fragment_constraint"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"
android:focusable="true"
android:scrollbars="none">
<TextView
android:id="#+id/feed_detail_category"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="12dp"
android:layout_marginTop="12dp"
android:paddingLeft="8dp"
android:paddingTop="2dp"
android:paddingRight="8dp"
android:paddingBottom="2dp"
android:textColor="#android:color/black"
android:textSize="12sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/feed_detail_image" />
<TextView
android:id="#+id/feed_detail_date"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
app:layout_constraintBottom_toBottomOf="#+id/feed_detail_category"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="#+id/feed_detail_category" />
<TextView
android:id="#+id/feed_detail_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:paddingLeft="8dp"
android:paddingTop="8dp"
android:paddingRight="8dp"
android:paddingBottom="8dp"
android:textColor="#android:color/black"
android:textSize="24sp"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/feed_detail_category" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/comment_recycler_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/no_comment_text" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>

Android Studio Linear Layout Design issue

I am having an issue with designing Android Studio Layout for App. In linear layout, I want to add first two layouts in the first column horizontally and then in the next column, I wish to add that three buttons in horizontally and finally in the last column want to add Listview. Any help would be highly appreciated. As currently, everything falls into one row.
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
tools:context=".MainActivity">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<james.view.VideoView
android:id="#+id/remoteVideoView"
android:layout_width="120dp"
android:layout_height="90dp"
/>
<james.view.VideoView
android:id="#+id/localVideoView"
android:layout_width="120dp"
android:layout_height="90dp"
/>
<Button
android:id="#+id/startVideoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start Call"
/>
<Button
android:id="#+id/stopVideoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="End Call"
/>
<Button
android:id="#+id/sendmessage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="msg"
/>
<ListView
android:id="#+id/errorList"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
</android.support.constraint.ConstraintLayou
This is how I want my layout to be

If you don't understand Constraints. You can use regular LinearLayout.
<?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="match_parent"
android:orientation="vertical"
android:padding="10dp"
tools:context=".MainActivity"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="90dp"
>
<james.view.VideoView
android:id="#+id/remoteVideoView"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
/>
<james.view.VideoView
android:id="#+id/localVideoView"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_marginLeft="10dp"
android:layout_weight="1"
/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
>
<Button
android:id="#+id/startVideoButton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Start Call"/>
<Button
android:id="#+id/stopVideoButton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="End Call"/>
<Button
android:id="#+id/sendmessage"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="msg"/>
</LinearLayout>
<ListView
android:id="#+id/errorList"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginTop="10dp"
android:layout_weight="1"
>
</ListView>
</LinearLayout>
Quite simple!

Solution:
This is exactly how you want, Just copy paste and your job is done:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
tools:context=".MainActivity">
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/linearLayout2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<james.view.VideoView
android:id="#+id/remoteVideoView"
android:layout_width="120dp"
android:layout_height="90dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/localVideoView"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<james.view.VideoView
android:id="#+id/localVideoView"
android:layout_width="120dp"
android:layout_height="90dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toEndOf="#+id/remoteVideoView"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
<LinearLayout
android:id="#+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/linearLayout2">
<Button
android:id="#+id/startVideoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Start Call" />
<Button
android:id="#+id/stopVideoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="End Call" />
<Button
android:id="#+id/sendmessage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="msg" />
</LinearLayout>
<ListView
android:id="#+id/errorList"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginEnd="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/linearLayout3">
</ListView>
</android.support.constraint.ConstraintLayout>
Try it. Hope it helps.

This is a sample xml, similar to your image. Since your code uses constraintLayout I have created the xml using constraintLayout instead of linear layout. I have created this from the design screen and not from the text screen. This is the 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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="49dp"
android:layout_marginStart="49dp"
android:layout_marginTop="32dp"
android:text="Button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="67dp"
android:layout_marginRight="67dp"
android:layout_marginTop="32dp"
android:text="Button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="193dp"
android:text="Button"
app:layout_constraintEnd_toEndOf="#+id/button"
app:layout_constraintStart_toStartOf="#+id/button"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="29dp"
android:layout_marginStart="29dp"
android:text="Button"
app:layout_constraintBaseline_toBaselineOf="#+id/button3"
app:layout_constraintStart_toEndOf="#+id/button3" />
<Button
android:id="#+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="35dp"
android:layout_marginEnd="17dp"
android:layout_marginRight="17dp"
android:layout_marginTop="193dp"
android:text="Button"
app:layout_constraintBottom_toTopOf="#+id/recyclerView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="19dp"
android:layout_marginEnd="22dp"
android:layout_marginLeft="22dp"
android:layout_marginRight="22dp"
android:layout_marginStart="22dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/button5" />
</android.support.constraint.ConstraintLayout>
`
Please see if this helps you. This is not exact screen as per your requirements.

Make buttons in GridLayout fill empty space

Need help at stretching my buttons in GridLayout so they would take all of the free space under the TextView
Here is my hierarchy
P.S. source code:
<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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="#+id/display"
android:layout_width="match_parent"
android:layout_height="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:columnCount="4"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/display">
<Button
android:id="#+id/buttonOne"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="1"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/display" />

check if you are assigning the height and width in px, and change them to % (percentage).. is there any way you can show the source ?
P.S. this is how i fixed it.. i've changed it to Linear
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/re``s-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="#+id/display"
android:layout_width="match_parent"
android:layout_height="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<GridLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnCount="4"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/display">
<Button
android:id="#+id/buttonOne"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="1"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/display" />
</GridLayout>