androidandroid-constraintlayoutconstraint-layout-chains

Spread-chain group of elements with ConstraintLayout

I'm having an issue to spread-chain 2 groups of elements with Constraint Layout. I understand the goal of this new layout is to use a flat hierarchy so I'd like to avoid putting my elements inside a child layouts.

I looked at some awesome resources like constraintlayout.com but couldn't figure out how to make it work for my specific case - which I think can be common..

Here is an image of what I'd like to achieve. In red, spaces 1, 2 and 3 need to have the same height (just like spread chain).

a representation of what I want

Thank you for your attention :)

Solution

  • You can achieve this using:

    <?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:orientation="vertical"
                                                   android:layout_width="match_parent"
                                                   android:layout_height="match_parent">

    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toTopOf="@+id/button2"
            app:layout_constraintVertical_chainStyle="packed"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>
    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button2"
            app:layout_constraintTop_toBottomOf="@+id/button"
            app:layout_constraintBottom_toTopOf="@+id/button3" 
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>
    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button3"
            app:layout_constraintTop_toBottomOf="@+id/button2"
            app:layout_constraintBottom_toTopOf="@+id/space"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>
    <Space
            android:id="@+id/space" 
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintBottom_toTopOf="@+id/button4"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"/>
    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button4"
            app:layout_constraintTop_toBottomOf="@+id/button3"
            app:layout_constraintBottom_toTopOf="@+id/button5"
            app:layout_constraintVertical_chainStyle="packed" 
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>
    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button5"
            app:layout_constraintTop_toBottomOf="@+id/button4"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>

    Output