<chapter id="screensavers-0">
  <title>Setting Screensavers</title>
  <highlights>
    <para>This chapter describes how to set preferences for the screensaver.
This chapter also provides information on how to modify the displays that
are available for the screensaver.</para>
  </highlights>
  <sect1 id="screensavers-1">
    <title>Introduction to Screensavers</title>
    <indexterm>
      <primary>screensavers</primary>
      <secondary>introduction</secondary>
    </indexterm>
    <indexterm>
      <primary>gnome-screensaver</primary>
      <see>screensavers</see>
    </indexterm>
    <para>A <firstterm>screensaver</firstterm> is an application that
replaces the image on a screen when the screen is not in use. The screensaver
application for the GNOME Desktop is <application>gnome-screensaver</application>.
The following sections describe how to set preferences for the <application>gnome-screensaver</application> application, and how to change the themes that
are available for the screensaver.</para>
  </sect1>
  <sect1 id="screensavers-2">
    <title>Setting Screensaver Preferences</title>
    <indexterm>
      <primary>screensavers</primary>
      <secondary>setting preferences</secondary>
    </indexterm>
    <para>All screensaver preferences and settings are stored in <application>GConf</application>.</para>
    <para>To modify screensaver application preferences, users can use the <application>Screensaver</application> preference tool.  For information on screensaver preferences, see <citetitle>GNOME Desktop User's Guide</citetitle>.</para>
    <para>Users can also run the command <command>/usr/bin/gnome-screensaver-preferences</command> to open
the <guilabel>Screensaver Preferences</guilabel> dialog.</para>
    <para>To set default screensaver settings and policy for all users, modify the screensaver settings in the Default GConf Configuration Source.</para>
    <para>To set mandatory screensaver settings and policy for all users, modify the screensaver settings in the Mandatory GConf Configuration Source.</para>
  </sect1>
  <sect1 id="screensavers-3">
    <title>Modifying Screensaver Themes</title>
    <indexterm>
      <primary>screensavers</primary>
      <secondary>modifying screensaver themes</secondary>
    </indexterm>
    <para>The screensaver application allows users
to choose one or more <firstterm>screensaver themes</firstterm>. A screensaver
theme is an application that displays images on the screen of the user when
the screen is not in use. The available screensaver themes are listed in the <application>Screensaver</application> preference tool.</para>
    <para>To add a new screensaver theme, copy the executable file for the <firstterm>screensaver theme engine</firstterm> to somewhere in your PATH or into the
screensaver theme engine executable directory.  The screensaver theme engine executable directory for your system can be determined using the following command:
<screen><userinput>pkg-config --variable=privlibexecdir gnome-screensaver</userinput></screen>

Next, add a <filename>.desktop</filename> file for the theme into the screensaver themes directory.  The screensaver themes directory for your system
can be determined using the following command:
<screen><userinput>pkg-config --variable=themesdir gnome-screensaver</userinput></screen>

In the Exec field of the <filename>.desktop</filename> file include any arguments that are required to run the screensaver
theme on the whole screen, rather than in a window.  For example, some legacy screensaver theme engines may require you 
to include the <literal>-root</literal> option to display the screensaver
display on the whole screen.</para>
    <para>The <application>Screensaver</application> infrastructure implements themes according to the <ulink
    url="http://www.freedesktop.org/wiki/Standards/menu-spec">XDG menu
    specification</ulink>. By supporting this specification, GNOME allows you
    to:</para>

    <itemizedlist>
      <listitem>
        <para>Customize the themes easily. You can edit a small number
        of files to customize the available themes. You do not need to modify
        your applications or move files.</para>
      </listitem>

      <listitem>
        <para>Install themes easily. You do not need to provide
        information about the system when you install
        the themes.</para>
      </listitem>

      <listitem>
        <para>Configure the system so that users cannot modify the themes.</para>
      </listitem>
    </itemizedlist>

  <para>For more information, see <xref linkend="menustructure-0"/>.</para>

  </sect1>
</chapter>
