FossifyGallery/app/src/main/res/layout/pager_photo_item.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:id="@+id/photo_holder"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/gif_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
        android:id="@+id/subsampling_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone"/>

    <com.simplemobiletools.commons.views.MyTextView
        android:id="@+id/photo_details"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="@dimen/small_margin"
        android:layout_marginRight="@dimen/small_margin"
        android:background="@color/gradient_grey_start"
        android:padding="@dimen/small_margin"
        android:textSize="@dimen/smaller_text_size"
        android:visibility="gone"
        tools:text="My image\nAnother line"/>

</RelativeLayout>