<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:background="#2f3d4c"
    android:paddingBottom="40dp"
    android:paddingTop="20dp">

    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:background="@drawable/bt_mensagens"
        android:id="@+id/bt_mensagens"
        android:contentDescription="@string/content_bt_mensagens" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="#000000"
        android:visibility="gone"
        android:id="@+id/box_buttons_msg"
        android:orientation="vertical"></LinearLayout>

</LinearLayout>