linphone-android/app/src/main/res/layout/voip_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>
        <import type="android.view.View"/>
        <variable
            name="viewModel"
            type="org.linphone.activities.main.viewmodels.DialogViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clickable="true"
        android:focusable="true">

        <View
            android:id="@+id/background"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_marginStart="10dp"
            android:layout_marginEnd="10dp"
            android:background="@drawable/shape_dialog_background"
            app:layout_constraintTop_toTopOf="@id/dialog_message"
            app:layout_constraintBottom_toBottomOf="@id/bottom_barrier"/>

        <TextView
            android:id="@+id/cancel_button"
            style="@style/big_orange_button_font"
            android:layout_width="0dp"
            app:layout_constraintWidth_max="@dimen/voip_dialog_button_max_width"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:background="@drawable/shape_rect_gray_button"
            android:gravity="center"
            android:onClick="@{() -> viewModel.onCancelClicked()}"
            android:padding="10dp"
            android:text="@{viewModel.cancelLabel, default=Cancel}"
            android:visibility="@{viewModel.showCancel ? View.VISIBLE : View.GONE}"
            app:layout_constraintEnd_toStartOf="@id/delete_button"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="@id/background"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintHorizontal_chainStyle="spread"/>

        <TextView
            android:id="@+id/delete_button"
            style="@style/big_orange_button_font"
            android:layout_width="0dp"
            app:layout_constraintWidth_max="@dimen/voip_dialog_button_max_width"
            android:layout_height="wrap_content"
            android:background="@drawable/shape_rect_orange_button"
            android:gravity="center"
            android:onClick="@{() -> viewModel.onDeleteClicked()}"
            android:padding="10dp"
            android:text="@{viewModel.deleteLabel, default=Delete}"
            android:visibility="@{viewModel.showDelete ? View.VISIBLE : View.GONE}"
            app:layout_constraintEnd_toStartOf="@id/ok_button"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@id/cancel_button" />

        <TextView
            android:id="@+id/ok_button"
            style="@style/big_orange_button_font"
            android:layout_width="0dp"
            app:layout_constraintWidth_max="@dimen/voip_dialog_button_max_width"
            android:layout_height="wrap_content"
            android:layout_marginEnd="10dp"
            android:background="@drawable/shape_rect_green_button"
            android:gravity="center"
            android:onClick="@{() -> viewModel.onOkClicked()}"
            android:padding="10dp"
            android:text="@{viewModel.okLabel, default=OK}"
            android:visibility="@{viewModel.showOk ? View.VISIBLE : View.GONE}"
            app:layout_constraintEnd_toEndOf="@id/background"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@id/delete_button" />

        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/top_barrier"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="top"
            app:barrierMargin="-10dp"
            app:constraint_referenced_ids="ok_button,delete_button,cancel_button"/>

        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/bottom_barrier"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="bottom"
            app:barrierMargin="20dp"
            app:constraint_referenced_ids="ok_button,delete_button,cancel_button"/>

        <TextView
            android:id="@+id/dialog_message"
            style="@style/dialog_message_font"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:layout_marginStart="20dp"
            android:layout_marginEnd="20dp"
            android:gravity="center"
            android:text="@{viewModel.message, default=Message}"
            app:layout_constraintBottom_toTopOf="@id/top_barrier"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</layout>