Quelle  activity_recipientlist.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:visibility="invisible">

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.google.android.material.search.SearchBar
                android:id="@+id/toolbar"
                style="@style/Threema.SearchBar.Style"
                android:layout_height="wrap_content"
                android:layout_width="match_parent"
                android:hint="@string/title_choose_recipient"
                android:outlineProvider="none"
                app:navigationIcon="?attr/homeAsUpIndicator" />

            <include layout="@layout/connection_indicator" />

        </FrameLayout>

        <com.google.android.material.tabs.TabLayout
            android:id="@+id/sliding_tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </com.google.android.material.appbar.AppBarLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <androidx.viewpager.widget.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <com.google.android.material.progressindicator.CircularProgressIndicator
            android:id="@+id/progress_sending"
            android:layout_width="48dp"
            android:layout_height="48dp"
            android:layout_gravity="center"
            android:indeterminate="true"
            android:visibility="gone" />

    </FrameLayout>

</LinearLayout>