fedilab-Android-App/app/src/main/res/layout/activity_media.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
    Copyright 2017 Thomas Schneider

    This file is a part of Mastalab

    This program is free software; you can redistribute it and/or modify it under the terms of the
    GNU General Public License as published by the Free Software Foundation; either version 3 of the
    License, or (at your option) any later version.

    Mastalab is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
    the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
    Public License for more details.

    You should have received a copy of the GNU General Public License along with Mastalab; if not,
    see <http://www.gnu.org/licenses>.
-->
<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"
    android:id="@+id/main_container_media"
    >
    <com.github.chrisbanes.photoview.PhotoView
        android:visibility="gone"
        android:layout_centerInParent="true"
        android:id="@+id/media_picture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:ignore="ContentDescription" />
    <VideoView
        android:layout_centerInParent="true"
        android:visibility="gone"
        android:id="@+id/media_video"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ImageView
        android:visibility="gone"
        android:layout_margin="5dp"
        android:src="@drawable/ic_first_page"
        android:id="@+id/media_prev"
        android:layout_centerVertical="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:layout_width="20dp"
        android:layout_height="20dp"
        tools:ignore="ContentDescription" />
    <ImageView
        android:visibility="gone"
        android:layout_margin="5dp"
        android:id="@+id/media_next"
        android:src="@drawable/ic_last_page"
        android:layout_centerVertical="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_width="20dp"
        android:layout_height="20dp"
        tools:ignore="ContentDescription" />
    <!-- Main Loader -->
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/loader"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        >
        <ProgressBar
            android:id="@+id/pbar_inf"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:indeterminate="true" />
        <TextView
            android:id="@+id/loader_progress"
            android:textSize="12sp"
            android:visibility="gone"
            android:layout_marginTop="10dp"
            android:textColor="?attr/colorAccent"
            android:layout_below="@+id/pbar_inf"
            android:layout_width="50dp"
            android:gravity="center"
            android:layout_height="wrap_content" />
    </RelativeLayout>
</RelativeLayout>