Develop Reference

ConstraintLayout - how to keep circle from pushing other views off the page? check minimum dimension?

I am trying to set up a layout for a counting app, which has a large circular button slightly above the centre of the screen and a counter display below it. I'm having trouble keeping the circle circular, entirely on the screen, and not overlying the other view in all situations.
The setup I'm currently using is a ConstraintLayout with two TextViews. The button TextView uses an xml oval as its background, and is set to be circular with the "layout_constraintDimensionRatio" attribute set to one. In portrait mode the width is set to 80% of the available space, and all is well when the screen is fairly standard in normal use.
The problem occurs if the available screen dimensions for the app are more square so that the vertical dimension is smaller than the horizontal dimension. In this case the width is still set first so my circle covers the other view or partially slips off screen.
Currently in the landscape layout I have the timer off to one side. Ideally in the landscape layout I would keep the button centred and the counter to the right, but to stop increasing the size of the button if there is not enough space for the timer.
I think that ideally I would set the layout up to check whether the horizontal or the vertical space is shorter initially, then set the smaller dimension first. Is this possible? Or perhaps is there a better approach to achieving my desired layout?
Any help would be really appreciated,
Thank you,
Katie
This is the default xml layout:
<?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"
android:background="#android:color/white"
tools:context=".ui.CounterFragment">
<ImageView
android:id="#+id/imageView"
android:layout_width="0dp"
android:layout_height="0dp"
android:contentDescription="#string/content_description_background_image"
android:scaleType="fitStart"
android:src="#drawable/dog_image_jpg_light"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintDimensionRatio="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1"
tools:visibility="visible" />
<TextView
android:id="#+id/timer_display"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/timer_display"
android:textSize="40sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/guidelineHorizontal" />
<TextView
android:id="#+id/counter_button"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#drawable/circle_selector"
android:contentDescription="#string/counter_button_content_description"
android:text="#string/counter_text"
app:layout_constraintBottom_toTopOf="#+id/timer_display"
app:layout_constraintDimensionRatio="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.375"
app:layout_constraintWidth_percent=".8" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineVertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.5" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineHorizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.75" />
</androidx.constraintlayout.widget.ConstraintLayout>
This is the landscape layout:
<?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"
android:background="#android:color/white"
tools:context=".ui.CounterFragment">
<ImageView
android:id="#+id/imageView"
android:layout_width="0dp"
android:layout_height="0dp"
android:contentDescription="#string/content_description_background_image"
android:scaleType="fitStart"
android:src="#drawable/dog_image_jpg_light"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintDimensionRatio="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1"
tools:visibility="visible" />
<TextView
android:id="#+id/timer_display"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/timer_display"
android:textSize="40sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/counter_button"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/counter_button"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#drawable/circle_selector"
android:contentDescription="#string/counter_button_content_description"
android:text="#string/counter_text"
app:layout_constraintBottom_toBottomOf="#id/guidelineHorizontal"
app:layout_constraintDimensionRatio="1"
app:layout_constraintEnd_toStartOf="#id/guidelineVertical87"
app:layout_constraintHeight_percent="0.8"
app:layout_constraintStart_toEndOf="#id/guidelineVertical12"
app:layout_constraintTop_toTopOf="#id/guidelineHorizontal" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineVertical75"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.75" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineHorizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.5" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineVertical12"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.125" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guidelineVertical87"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.875" />
</androidx.constraintlayout.widget.ConstraintLayout>

As you suggest, the primary issue with your layout is the percentage width/height set at 80% and driving the rest of the layout. You are losing control of the circle height and nothing keeps it from growing to cover other views.
Take a look at ConstraintLayout chains. They are a powerful tool and will let you tie your views together so they don't trounce one another. They will help you solve the overlay problem.
You will still want to set the width of the circle to 80% of the width or height depending on the orientation of the device. I assume that you want the side margins to be such that the circle can be 80% of the view but will allow the circle to be smaller if it needs to fit the screen and not overlap the other views. One way to do this is to define two Space widgets that are 10% of the layout width and 10% high. Place one in the upper left corner of the layout and the other in the lower right. Constrain the circle to these Space widgets on the left, top and right. Place the circle in a vertical chain with the TextView below.
Here is a mock up of what it would look like. You will have to work with your layout to get it right, but these are some concepts that should help. (Is seems to me that this can also be done without the Space widgets, but that solution is not occurring to me right now. I'll post back if it dawns on me.)
The XML follows the GIF.
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white">
<TextView
android:id="#+id/timer_display"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/timer_display"
android:textSize="40sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/counter_button" />
<TextView
android:id="#+id/counter_button"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#drawable/circle"
android:text="#string/counter_text"
app:layout_constraintBottom_toTopOf="#+id/timer_display"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintEnd_toStartOf="#+id/spaceBottomRight"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toEndOf="#+id/spaceStart"
app:layout_constraintTop_toBottomOf="#+id/spaceStart"
app:layout_constraintVertical_bias="0.375"
app:layout_constraintVertical_chainStyle="packed" />
<Space
android:id="#+id/spaceBottomRight"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHeight_percent="0.10"
app:layout_constraintWidth_percent="0.10" />
<Space
android:id="#+id/spaceStart"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintHeight_percent="0.10"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintWidth_percent="0.10" />
</androidx.constraintlayout.widget.ConstraintLayout>

Android UI: Fill the remaining screen with a max_height limit

I wonder how to implement the following design in Android xml. The contents will have height wrap-contents with the most priority, and it could even fill the whole screen if there are enough contents. The image above it should fill up the remaining height - however it also has a limited max-height of 160dp. It seems if I use layout-weight or match-parent, the max-height param does not work anymore. Is there a way to do this in the xml? Or do I have to do it in the Java file programmatically? Thanks.

try something like this:
I'm using two textView just for test
<?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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#42A5F5">
<TextView
android:id="#+id/imageView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#EC407A"
android:maxHeight="160dp"
android:text="Image"
android:textSize="48sp"
app:layout_constrainedHeight="true"
app:layout_constraintBottom_toTopOf="#+id/textView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="#+id/textView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#FFEE58"
android:text="Content"
android:textSize="48sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
</androidx.constraintlayout.widget.ConstraintLayout>
those are the important lines
android:maxHeight="160dp"
app:layout_constrainedHeight="true"

ConstraintLayout - Fixing uneven dp on different device

My current constraint layout gives me even spacing in the layout preview and also on my api 28 + 29 emulators, it displays even spacing. However when I use my real api 19 device to test the spacing, it gives me uneven spacing (check picture below). What's the cause for the uneven spacing and how can I fix it so that it's even for all devices?
I ended up using guidelines and margins and that fixed the issue:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="200dp"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ImageView
android:id="#+id/fragevent_threephotolayout_image1"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="16dp"
android:layout_marginBottom="16dp"
android:layout_marginStart="16dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toLeftOf="#id/guideline"
android:layout_marginEnd="4dp"/>
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guideline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.65"/>
<androidx.constraintlayout.widget.Guideline
android:id="#+id/guideline2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.5"/>
<ImageView
android:id="#+id/fragevent_threephotolayout_image2"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#id/guideline2"
android:layout_marginEnd="16dp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toRightOf="#+id/guideline"
app:layout_constraintTop_toTopOf="#id/fragevent_threephotolayout_image1"
android:layout_marginBottom="4dp"
android:layout_marginStart="4dp"/>
<ImageView
android:id="#+id/fragevent_threephotolayout_image3"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginEnd="16dp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toRightOf="#id/guideline"
app:layout_constraintBottom_toBottomOf="#id/fragevent_threephotolayout_image1"
app:layout_constraintTop_toBottomOf="#id/guideline2"
android:layout_marginLeft="4dp"
android:layout_marginTop="4dp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

you must check some ways for it:
Don't use percents for width and height
Use margin left and right instead of start and end
Use padding instead of margin
As you see in your images, margin top or bot between 2 images of right side don't have an issue, so you can do what happen between them on others.

different devices have a different screen size that's why uneven space occurs, with
help of SDP master we can rectify this issues, below i gave sdp master link kindly add
this to yous "res" folder
kindly go to the link copy dimen value file inside the res folder and paste to
you res folder, and use this dimen values instead of manually given size(like 10 dp
12 dp)

You can use with Linear Layout as Below
<?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="200dp"
xmlns:app="http://schemas.android.com/apk/res-auto">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp"
android:orientation="horizontal"
android:weightSum="1">
<ImageView
android:id="#+id/fragevent_threephotolayout_image1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="#mipmap/ic_launcher"
android:layout_marginRight="6dp"
android:layout_weight="0.4"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="2"
android:layout_marginLeft="5dp"
android:layout_weight="0.6">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:layout_marginBottom="5dp"
android:src="#mipmap/ic_launcher"
android:layout_weight="1"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:layout_marginTop="5dp"
android:src="#mipmap/ic_launcher"
android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

Constraint layout cut out some of my views

I'm using my android phone with 5'5 screen size and still cut out my
my imgView_icon and my btnConnectFacebook. I can't see them on my screen.
what's wrong then in my XML?
<?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"
android:layout_gravity="center"
android:background="#fff"
tools:context="com.clearmindai.member.module.login.LoginActivity">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/medium"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent">
<ImageView
android:id="#+id/imgView_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toTopOf="#+id/tvHeaderText"
android:layout_marginLeft="#dimen/medium"
android:src="#drawable/ic_login_logo"/>
<TextView
android:id="#+id/tvHeaderText"
app:layout_constraintTop_toBottomOf="#+id/imgView_icon"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toTopOf="#id/tvBodyText"
android:layout_marginTop="#dimen/small"
android:layout_marginLeft="#dimen/medium"
android:textColor="#color/black"
android:fontFamily="#font/gtwalsheimprolight"
android:layout_width="wrap_content"
android:textSize="#dimen/large"
android:text="I AM THE HEADER"
android:layout_height="wrap_content"/>
<TextView
android:id="#+id/tvBodyText"
app:layout_constraintTop_toBottomOf="#+id/tvHeaderText"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toTopOf="#id/imgViewLogo"
android:layout_marginTop="#dimen/very_small"
android:layout_marginLeft="#dimen/medium"
android:text="Lorem ipmsum magic sit amendium"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<ImageView
android:id="#+id/imgViewLogo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/img_login"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/tvBodyText"
app:layout_constraintBottom_toTopOf="#+id/btnConnectFacebook"/>
<com.facebook.login.widget.LoginButton
android:id="#+id/btnConnectFacebook"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="#dimen/small"
android:paddingTop="#dimen/small"
android:layout_gravity="center_horizontal"
app:layout_constraintTop_toBottomOf="#+id/imgViewLogo"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginStart="#dimen/medium"
android:layout_marginEnd="#dimen/medium"
app:layout_constraintStart_toStartOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
please let me know if I need to upload the images for a better perspective of my problem.
maybe because my images are big?
if my images are big how can I proportionally set a width and height for my photos
where it can dynamically adjust to its parent size or screen size?

This may happen because you are using android:layout_height="wrap_content"
on your imageView.
If your image is too large your layout won't be responsive anymore (because 900dp image, for example, will take all the screen size while using wrap_content).
how can i proportionally set a width and height
You can tell your image or any other view what size to be in precents like this:
<Button
android:id="#+id/button"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintWidth_percent="0.5" //50% of the screen Width
app:layout_constraintHeight_percent="0.5" //50% of the screen Height
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

I think below solution might work for you.
Remove app:layout_constraintBottom_toTopOf="#+id/tvHeaderText" from ImageView Icon
and Remove app:layout_constraintTop_toBottomOf property from all other views.
Hope it will solve your issue. :)

ConstraintLayout layout_constraintDimensionRatio not working

I used constraintLayout and layout_constraintDimensionRatio="1:1"
(width is wrap_content, height is 0dp (match_constraint))
As a result, I expected width and height to be 1:1, but it's not working.
What is wrong?
I attached code and screenshot.
<?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">
<TextView
android:id="#+id/t1"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:background="#android:color/holo_blue_bright"
android:gravity="center"
android:text="Hello World!11"
app:layout_constraintDimensionRatio="1:1" />
</android.support.constraint.ConstraintLayout>
screenshot
I quote android developer site about Constraintlayout.
https://developer.android.com/reference/android/support/constraint/ConstraintLayout.html#DimensionConstraints
Ratio :: You can also define one dimension of a widget as a ratio of
the other one. In order to do that, you need to have at least one
constrained dimension be set to 0dp (i.e., MATCH_CONSTRAINT), and set
the attribute layout_constraintDimentionRatio to a given ratio. For
example:
<Button android:layout_width="wrap_content"
android:layout_height="0dp"
app:layout_constraintDimensionRatio="1:1" />
will set the height of the button to be the same as its width.
but it was not working.

You forget to add your constraints
<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">
<TextView
android:id="#+id/t1"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:background="#android:color/holo_blue_bright"
android:gravity="center"
android:text="Hello World!11"
app:layout_constraintDimensionRatio="1" />
</android.support.constraint.ConstraintLayout>
0dp is only applied to the child views of ConstraintLayout.
Any view should apply the attribute rules of its parent.

As off version 1.1.0 this has changed.
You can now define:
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintDimensionRatio="W,1:1"
app:layout_constraintDimensionRatio="H,1:1"
Check the link below to find all the documentation regarding DimensionConstraints:
Link to the docs

In my case I have a problem like i have to fill my layout inside container with A4 size paper ratio.
Problem
I am getting A4 size resume pages as images from backend so i have to append those images in Viewpager in which i am using ImageView to display those images.
Solution
I went through Constraint layout document in which Ratio section is there. So i can use layout_constraintDimensionRatio for solving my problem.
So my xml that is used to Display the whole Layout is following, in my case i have used app:layout_constraintDimensionRatio="1:1.27" as with:height ratio but the actual ratio is app:layout_constraintDimensionRatio="1:1.41"
<?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:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/orange">
<!-- divider line which i used as restricting my A4 size container height-->
<View
android:id="#+id/divider"
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/headline_title_color"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias=".85"/>
<!-- A4 size Image View-->
<ImageView
android:id="#+id/resumeContainer"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginLeft="12dp"
android:layout_marginTop="16dp"
android:layout_marginRight="12dp"
android:layout_marginBottom="16dp"
android:background="#color/green"
android:text="#string/change"
android:src="#drawable/banner"
app:layout_constraintBottom_toTopOf="#id/divider"
app:layout_constraintDimensionRatio="1:1.27"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<!-- for Bottom two buttons -->
<com.bold.job.utils.CustomButton
android:id="#+id/preview"
style="#style/tertiaryButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:onClick="preview"
android:text="#string/preview_resume"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toLeftOf="#id/guideline"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#id/divider"
/>
<android.support.constraint.Guideline
android:id="#+id/guideline"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.5" />
<com.bold.job.utils.CustomButton
android:id="#+id/preview2"
style="#style/tertiaryButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:onClick="preview"
app:layout_constraintLeft_toRightOf="#id/guideline"
app:layout_constraintRight_toRightOf="parent"
android:text="#string/preview_resume"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#id/divider"
/>
</android.support.constraint.ConstraintLayout>

Please notice the last line, adding constraints around the edges makes the constraint work.
You can also use the design view in Studio, and drag and drop the constraints between objects.
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Available chats" />
<ListView
android:id="#+id/listChats"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#+id/textView"/>