Signal-Android/app/src/main/res/layout/revealable_message_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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:parentTag="android.widget.LinearLayout">

    <FrameLayout
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_marginEnd="8dp"
        android:layout_marginTop="2dp"
        android:layout_marginBottom="2dp"
        android:layout_gravity="center"
        tools:background="#1D8663">

        <androidx.appcompat.widget.AppCompatImageView
            android:id="@+id/revealable_icon"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:scaleType="center"
            tools:background="@color/transparent_white_20"
            tools:src="@drawable/ic_viewed_once_24"/>

        <com.pnikosis.materialishprogress.ProgressWheel
            android:id="@+id/revealable_progress"
            android:layout_width="24dp"
            android:layout_height="24dp"
            android:visibility="gone"
            android:layout_gravity="center"
            app:matProg_barColor="@color/core_white"
            app:matProg_rimColor="@color/transparent"
            app:matProg_linearProgress="true"
            app:matProg_spinSpeed="0.2"
            app:matProg_barWidth="2dp"
            app:matProg_rimWidth="2dp"
            app:matProg_circleRadius="24dp"
            tools:visibility="visible"/>

    </FrameLayout>

    <TextView
        android:id="@+id/revealable_text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:layout_gravity="center_vertical"
        style="@style/Signal.Text.Preview"
        android:fontFamily="sans-serif-medium"
        android:maxLines="2"
        android:ellipsize="end"
        tools:text="@string/RevealableMessageView_view_photo" />

</merge>