Signal-Android/app/src/main/res/layout/audio_view.xml

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="org.thoughtcrime.securesms.components.AudioView">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        tools:background="#ff00ff">

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

        <org.thoughtcrime.securesms.components.WaveFormSeekBarView
            android:id="@+id/seek"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:paddingStart="12dp"
            android:paddingTop="8dp"
            android:paddingEnd="8dp"
            android:paddingBottom="8dp"
            android:thumb="@drawable/audio_wave_thumb"
            tools:progress="50" />

        <TextView
            android:id="@+id/duration"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:fontFamily="sans-serif-light"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textColor="?conversation_item_sent_text_secondary_color"
            android:textSize="@dimen/conversation_item_date_text_size"
            android:visibility="gone"
            tools:text="00:30"
            tools:visibility="visible" />

    </LinearLayout>

</merge>