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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".client.CallActivity">

    <RelativeLayout
        android:id="@+id/main_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true">

        <!--
        <Button
            android:id="@+id/call_accept_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_toLeftOf="@+id/call_refuse_btn"
            android:layout_toStartOf="@+id/call_refuse_btn"
            android:backgroundTint="#447542"
            android:text="Accept" />

        <Button
            android:id="@+id/call_refuse_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_alignTop="@+id/call_accept_btn"
            android:layout_marginEnd="58dp"
            android:layout_marginRight="58dp"
            android:backgroundTint="#ff6e6e"
            android:text="Refuse" />
-->
        <RelativeLayout
            android:id="@+id/contact_bubble_layout"
            android:layout_width="fill_parent"
            android:layout_height="200dp"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:layout_marginBottom="16dp">

            <ImageView
                android:id="@+id/contact_bubble"
                android:layout_width="200dp"
                android:layout_height="fill_parent"
                android:layout_above="@+id/contact_bubble_txt"
                android:layout_centerHorizontal="true" />

            <TextView
                android:id="@+id/contact_bubble_txt"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_centerHorizontal="true"
                android:gravity="center_horizontal"
                android:text="Adrien Béraud"
                android:textAlignment="gravity"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:textIsSelectable="true"
                android:textColor="@color/text_color_primary" />

        </RelativeLayout>

        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="false"
            android:layout_centerHorizontal="true"
            android:layout_below="@+id/contact_bubble_layout">

            <android.support.design.widget.FloatingActionButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/call_refuse_btn"
                android:src="@drawable/ic_call_end_white_24dp"
                app:backgroundTint="@color/error_red"
                app:rippleColor="@android:color/white"
                app:elevation="6dp"
                app:pressedTranslationZ="12dp"
                android:layout_below="@+id/contact_bubble_layout"
                android:layout_centerHorizontal="true"
                android:layout_margin="8dp" />

            <android.support.design.widget.FloatingActionButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/call_accept_btn"
                android:src="@drawable/ic_call_white_24dp"
                app:backgroundTint="#4caf50"
                app:rippleColor="@android:color/white"
                app:elevation="6dp"
                app:pressedTranslationZ="12dp"
                android:layout_below="@+id/contact_bubble_layout"
                android:layout_toLeftOf="@+id/call_refuse_btn"
                android:layout_toStartOf="@+id/call_refuse_btn"
                android:layout_margin="8dp" />
        </LinearLayout>

        <android.support.design.widget.FloatingActionButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/call_hangup_btn"
            android:src="@drawable/ic_call_end_white_24dp"
            app:backgroundTint="@color/error_red"
            app:rippleColor="@android:color/white"
            app:elevation="6dp"
            app:pressedTranslationZ="12dp"
            android:layout_below="@+id/contact_bubble_layout"
            android:layout_centerHorizontal="true"
            android:layout_margin="8dp"
            android:visibility="gone" />

    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/call_status_bar"
        android:layout_width="match_parent"
        android:layout_height="?android:attr/actionBarSize"
        android:layout_alignParentTop="true"
        android:visibility="visible">

        <ImageView
            android:id="@+id/image_call"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_gravity="left"
            android:layout_marginLeft="15dp"
            android:layout_marginRight="10dp"
            android:src="@drawable/ic_call_white_24dp" />

        <TextView
            android:id="@+id/call_status_txt"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@+id/image_call"
            android:textColor="@color/text_color_primary"
            android:textSize="12sp" />

        <ViewSwitcher
            android:id="@+id/security_switcher"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:visibility="gone">

            <Button
                android:id="@+id/confirm_sas"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:textColor="@color/white"
                android:textSize="12sp" />

            <ImageView
                android:id="@+id/lock_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="end|center_vertical" />
        </ViewSwitcher>


        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/security_indicator"
            android:src="@drawable/ic_lock_white_24dp"
            android:tint="#4caf50"
            android:layout_centerVertical="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true"
            android:layout_margin="16dp"
            android:visibility="gone" />

    </RelativeLayout>

    <ToggleButton
        android:id="@+id/speaker_toggle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@drawable/toggle_speaker_selector"
        android:textOff=""
        android:textOn=""
        android:visibility="gone" />

</RelativeLayout>