How to achieve the following layout with dynamic width in Constraint Layout?

Question

I have a constraint layout with a simple card view with a text inside, and a text at the bottom. I want the card's width to be at least the width of the bottom text. So something like setting a minimum width.

I drew a picture illustrating what I want but wasn't able to implement it in Constraint Layout.

Answer 1

Barriers will do the magic for you!
With this feature you automatically get the width of the widest object in a certain scope.

From Android Documentaion:

A Barrier references multiple widgets as input, and creates a virtual guideline based on the most extreme widget on the specified side. For example, a left barrier will align to the left of all the referenced views.

The following xml will check the widest width of the views content_text and bottom_text

    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/barrier"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:barrierDirection="end"
        app:constraint_referenced_ids="content_text,bottom_text" />

Now you can use this barrier as a constrain in any other view (inside the same ConstraintLayout)

    <View
        android:id="@+id/card_background"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/colorPrimary"
        app:layout_constraintBottom_toBottomOf="@id/content_text"

        app:layout_constraintEnd_toEndOf="@id/barrier"

        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/content_text" />

That's what my result looks like:

Sample 1

Sample 2

My complete 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_margin="16dp"
    tools:context=".MainActivity">

    <View
        android:id="@+id/card_background"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/colorPrimary"
        app:layout_constraintBottom_toBottomOf="@id/content_text"

        app:layout_constraintEnd_toEndOf="@id/barrier"

        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/content_text" />

    <TextView
        android:id="@+id/content_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@color/colorPrimaryDark"
        android:paddingTop="16dp"
        android:paddingBottom="16dp"

        android:text="This is a very large content text. It is so long that it needs a second line"
        android:textColor="@android:color/black"
        android:textSize="22sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/bottom_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="This is a bottom text with a particular length"
        android:textColor="@android:color/black"
        android:textSize="14sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/card_background" />


    <!-- Magic happens here -->
    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/barrier"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:barrierDirection="end"
        app:constraint_referenced_ids="content_text,bottom_text" />

</androidx.constraintlayout.widget.ConstraintLayout>

Hope this helps.
Here could you read more about barriers