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

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

    <data>
        <import type="android.view.View"/>
        <variable
            name="visibility"
            type="Boolean" />
    </data>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="@{visibility ? View.VISIBLE : View.GONE}"
        android:background="#99c4c4c4"
        android:focusable="true"
        android:clickable="true">

        <ProgressBar
            android:id="@+id/progress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:indeterminate="true"
            android:indeterminateTint="?attr/accentColor"/>

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_below="@id/progress"
            android:layout_marginTop="10dp"
            android:textColor="@color/primary_color"
            android:textStyle="bold"
            android:text="@string/operation_in_progress_wait" />

    </RelativeLayout>

</layout>