android - Set value of property to value of another views property in XML?

Question

In Android's XML layout system, I'd like to be able to set the value of one views property to the value of another views property.

For example, something like this:

android:layout_marginRight="@id/rightBarButton:width"

Would set the marginRight value of this view to the width value of the rightBarButton view.

I already know I can do this programmatically, but is there a way to do this in XML?

question from:https://stackoverflow.com/questions/65875624/set-value-of-property-to-value-of-another-views-property-in-xml

Answer 1

Use constraint layout you don't need to specify margin just give right constraint of button1 to left constraint of buttonRight like this

<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="@color/white">

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="button1"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Button2"
    app:layout_constraintEnd_toStartOf="@+id/btn1"
    app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

this result image

another example

its code

<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="@color/white">

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="button1"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Button2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toStartOf="@+id/btn1"
    app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Barrier example

<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="@color/white">

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="button1"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<androidx.appcompat.widget.AppCompatButton
    android:id="@+id/btn2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Button2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toStartOf="@+id/btn1"
    app:layout_constraintTop_toTopOf="parent" />

<androidx.constraintlayout.widget.Barrier
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:barrierDirection="left"
    app:constraint_referenced_ids="btn1" />

</androidx.constraintlayout.widget.ConstraintLayout>

result image: