How to set constraint to two views?

Question

So I have a constraintLayout like this

<ConstraintLayout>
    <TextView
    android:id="@+id/text_view"
    app:layout_constraintEnd_toStartOf="@+id/view1" />

    <View
    android:id="@+id/view1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"/>

    <View
    android:id="@+id/view2"
    aapp:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />
</ConstraintLayout>

Currently the textview's end is at the start of view1, however, when view1's visibility is gone, I want the end of textview to the start of view2, otherwise the long string may cover view2. Is there any way to set the constraint to two views or is there any better solution for this?

Answer 1

You can use a Barrier to constraint to multiple views.

<ConstraintLayout>

    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/barrier"
        app:barrierDirection="left"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:constraint_referenced_ids="view1,view2"/>    

    <TextView
        android:id="@+id/text_view"
        app:layout_constraintEnd_toStartOf="@id/barrier" />

    <View
        android:id="@+id/view1"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <View
        android:id="@+id/view2"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</ConstraintLayout>

The textview will be constraint to the view that is more to the left