Signal-Android/res/layout/camera_contact_selection_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="?android:windowBackground">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/camera_contacts_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/conversation_list_toolbar_background"
        android:theme="?actionBarStyle"
        app:title="@string/CameraContacts_select_signal_recipients"
        app:layout_constraintTop_toTopOf="parent" />

    <View
        android:id="@+id/camera_contacts_top_shadow"
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:background="@drawable/search_toolbar_shadow"
        app:layout_constraintTop_toBottomOf="@id/camera_contacts_toolbar" />

    <LinearLayout
        android:id="@+id/camera_contacts_empty"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="60dp"
        android:layout_marginStart="50dp"
        android:layout_marginEnd="50dp"
        android:orientation="vertical"
        android:gravity="center_horizontal"
        android:visibility="gone"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/camera_contacts_toolbar">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/no_contacts"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            style="@style/Signal.Text.Body"
            android:text="@string/CameraContacts_no_signal_contacts"
            android:fontFamily="sans-serif-medium"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:gravity="center_horizontal"
            style="@style/Signal.Text.Body"
            android:text="@string/CameraContacts_you_can_only_use_the_camera_button"/>

        <Button
            android:id="@+id/camera_contacts_invite_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_gravity="center"
            style="@style/Button.Borderless"
            android:text="@string/CameraContacts_invite_a_contact_to_join_signal" />

    </LinearLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/camera_contacts_list"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="@id/camera_contacts_footer_barrier"
        app:layout_constraintTop_toBottomOf="@id/camera_contacts_toolbar" />

    <View
        android:id="@+id/camera_contacts_bottom_shadow"
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:background="@drawable/compose_divider_background"
        app:layout_constraintBottom_toTopOf="@id/camera_contacts_footer_barrier" />

    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/camera_contacts_footer_barrier"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:barrierDirection="top"
        app:constraint_referenced_ids="camera_contacts_selected_list,camera_contacts_send_button" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/camera_contacts_selected_list"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:paddingTop="22dp"
        android:paddingBottom="22dp"
        android:paddingStart="16dp"
        android:clipToPadding="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@id/camera_contacts_send_button"
        app:layout_constraintStart_toStartOf="parent"/>

    <ImageView
        android:id="@+id/camera_contacts_send_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="6dp"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="6dp"
        android:tint="@color/white"
        app:srcCompat="@drawable/ic_send_lock_24"
        android:background="@drawable/camera_send_button_background"
        android:padding="8dp"
        app:layout_constraintBottom_toBottomOf="@id/camera_contacts_selected_list"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="@id/camera_contacts_selected_list" />

    <androidx.constraintlayout.widget.Group
        android:id="@+id/camera_contacts_footer_group"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"
        app:constraint_referenced_ids="camera_contacts_send_button,camera_contacts_selected_list,camera_contacts_bottom_shadow" />

</androidx.constraintlayout.widget.ConstraintLayout>