ring-android/app/src/main/res/layout/frag_conversation.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="@color/grey_25">

    <ProgressBar
        android:id="@+id/pb_loading"
        android:layout_width="64dp"
        android:layout_height="64dp"
        android:layout_centerInParent="true"
        android:indeterminate="true" />

    <LinearLayout
        android:id="@+id/trustRequestMessageLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:orientation="vertical"
        android:visibility="gone">

        <TextView
            android:id="@+id/tvTrustRequestMessage"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/white"
            android:gravity="center"
            android:padding="30dp"
            tools:text="Jean is not in your contacts yet" />

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="@color/lighter_gray" />

    </LinearLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/hist_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/trustRequestMessageLayout"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentBottom="true"
        android:clipToPadding="false"
        android:divider="@null"
        android:listSelector="@color/transparent"
        android:paddingTop="8dp"
        android:paddingBottom="60dp"
        android:transcriptMode="normal"
        app:layoutManager="LinearLayoutManager"
        app:stackFromEnd="true"
        tools:listitem="@layout/item_conv_msg_peer" />

    <LinearLayout
        android:id="@+id/ongoingcall_pane"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:layout_below="@id/main_toolbar"
        android:background="#e3c1c1"
        android:gravity="center"
        android:visibility="gone">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="@string/conversation_action_go_to_call"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textColor="@color/text_color_primary" />
    </LinearLayout>

    <androidx.cardview.widget.CardView
        android:id="@+id/unknownContactPrompt"
        style="?android:attr/buttonBarStyle"
        android:layout_width="match_parent"
        android:layout_height="42dp"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="12dp"
        android:padding="0dp"
        android:visibility="gone"
        app:cardBackgroundColor="#4CAF50"
        app:cardCornerRadius="@dimen/radius_message_input">

        <Button
            android:id="@+id/btnAddContact"
            style="@style/Widget.MaterialComponents.Button.TextButton"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="0dp"
            android:background="?attr/selectableItemBackground"
            android:gravity="center"
            android:padding="0dp"
            android:text="@string/ab_action_contact_add"
            android:textColor="@color/white" />
    </androidx.cardview.widget.CardView>

    <androidx.cardview.widget.CardView
        android:id="@+id/trustRequestPrompt"
        style="?android:attr/buttonBarStyle"
        android:layout_width="match_parent"
        android:layout_height="42dp"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="12dp"
        android:padding="0dp"
        android:visibility="gone"
        app:cardCornerRadius="@dimen/radius_message_input">

        <LinearLayout
            style="?android:attr/buttonBarStyle"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="0dp"
            android:orientation="horizontal"
            android:padding="0dp"
            android:weightSum="3">

            <Button
                android:id="@+id/btnBlock"
                style="@style/Widget.MaterialComponents.Button.TextButton"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="?attr/selectableItemBackground"
                android:gravity="center"
                android:text="@string/block"
                android:textColor="@color/color_primary_dark" />

            <Button
                android:id="@+id/btnRefuse"
                style="@style/Widget.MaterialComponents.Button.TextButton"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="?attr/selectableItemBackground"
                android:gravity="center"
                android:text="@string/refuse"
                android:textColor="@color/color_primary_dark" />

            <Button
                android:id="@+id/btnAccept"
                style="@style/Widget.MaterialComponents.Button.TextButton"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="?attr/selectableItemBackground"
                android:gravity="center"
                android:text="@string/accept"
                android:textColor="#4CAF50" />
        </LinearLayout>
    </androidx.cardview.widget.CardView>

    <androidx.cardview.widget.CardView
        android:id="@+id/cvMessageInput"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:visibility="gone"
        app:cardCornerRadius="@dimen/radius_message_input"
        app:cardElevation="6dp"
        tools:visibility="visible">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:orientation="horizontal">

            <Spinner
                android:id="@+id/number_selector"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:visibility="visible"
                tools:listitem="@layout/item_number_selected"
                tools:visibility="gone" />

            <ImageButton
                android:id="@+id/send_data"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:background="?selectableItemBackgroundBorderless"
                android:contentDescription="@string/send_file"
                android:padding="8dp"
                android:tint="@android:color/darker_gray"
                app:srcCompat="@drawable/ic_upload_black" />

            <ImageButton
                android:id="@+id/btn_take_picture"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_marginEnd="4dp"
                android:background="?selectableItemBackgroundBorderless"
                android:contentDescription="@string/take_a_photo"
                android:padding="8dp"
                android:tint="@android:color/darker_gray"
                app:srcCompat="@drawable/ic_photo_camera" />

            <cx.ring.views.MessageEditText
                android:id="@+id/msg_input_txt"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:background="@null"
                android:hint="@string/write_a_message"
                android:imeOptions="actionSend|flagNoExtractUi"
                android:importantForAutofill="no"
                android:inputType="textShortMessage|textImeMultiLine|text|textMultiLine|textCapSentences"
                android:maxLines="5"
                android:padding="8dp" />

            <ProgressBar
                android:id="@+id/pb_data_transfer"
                android:layout_width="30dp"
                android:layout_height="30dp"
                android:indeterminate="true"
                android:visibility="gone" />

            <TextView
                android:id="@+id/emoji_send"
                style="?attr/borderlessButtonStyle"
                android:background="?selectableItemBackgroundBorderless"
                android:layout_width="50dp"
                android:layout_height="match_parent"
                android:padding="0dp"
                android:text="👍"
                android:textSize="18sp" />

            <ImageButton
                android:id="@+id/msg_send"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:background="?selectableItemBackgroundBorderless"
                android:contentDescription="@string/send_message"
                android:padding="8dp"
                android:tint="@android:color/darker_gray"
                app:srcCompat="@drawable/ic_send_black"
                android:visibility="gone"/>
        </LinearLayout>
    </androidx.cardview.widget.CardView>
</RelativeLayout>