ConstraintLayout Flow helper example

Question

I have read in a blog entry that in ConstraintLayout 2.0.0, a way was introduced to create a flow of views. What I exactly want to achieve: I have several TextViews with a fixed size next to each other. Depending on screen size, some TextViews should be pushed into the next line.

Example on big screen with six TextViews:

[AAA] [BBB] [CCC] [DDD]

[EEE] [FFF]

Example on small screen with six TextViews:

[AAA] [BBB]

[CCC] [DDD]

[EEE] [FFF]

I already saw this Stackoverflow question proposing to use a FlexboxLayout, but there is a comment saying that the same thing now can be achieved using ConstraintLayout.

Anybody can give me an example on how to achieve the desired behavior using ConstraintLayout? I was not able to find any instructions about this. Thanks in advance.

Answer 1

You can achieve this by adding a androidx.constraintlayout.helper.widget.Flow virtual view inside the androidx.constraintlayout.widget.ConstraintLayout and by referencing all your textviews with app:constraint_referenced_ids attribute.

Example below shows how I've achieved it.

<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:orientation="vertical">      <TextView         android:id="@+id/text1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[AAAAAAAA]"         tools:ignore="MissingConstraints" />      <TextView         android:id="@+id/text2"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[BBBBBBBB]"         tools:ignore="MissingConstraints" />      <TextView         android:id="@+id/text3"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[CCCCCCCC]"         tools:ignore="MissingConstraints" />      <TextView         android:id="@+id/text4"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[DDDDDDDD]"         tools:ignore="MissingConstraints" />      <TextView         android:id="@+id/text5"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[EEEEEEEE]"         tools:ignore="MissingConstraints" />      <TextView         android:id="@+id/text6"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="[FFFFFFFF]"         tools:ignore="MissingConstraints" />      <androidx.constraintlayout.helper.widget.Flow         android:id="@+id/flow1"         android:layout_width="0dp"         android:layout_height="wrap_content"         android:padding="10dp"         app:constraint_referenced_ids="text1,text2,text3,text4,text5,text6"         app:flow_horizontalBias="0"         app:flow_horizontalGap="10dp"         app:flow_horizontalStyle="packed"         app:flow_verticalBias="0"         app:flow_wrapMode="chain"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout> 

Play around with app:flow_ attributes to change the arrangement of the textviews such as alignment, margin, etc. https://developer.android.com/reference/androidx/constraintlayout/helper/widget/Flow

Final result should look like below depending on your screen size.