NAME
    Screensaver::Any - Common interface to screensaver/screenlocker
    functions

VERSION
    This document describes version 0.007 of Screensaver::Any (from Perl
    distribution Screensaver-Any), released on 2019-09-04.

DESCRIPTION
    This module provides common functions related to screensaver.

    Supported screensavers: KDE Plasma's kscreenlocker ("kde"), GNOME
    screensaver ("gnome"), Cinnamon screensaver ("cinnamon"), and
    "xscreensaver". Support for more screensavers, e.g. Windows is more than
    welcome.

NOTES
    In GNOME 3.8 and later, "gnome-screensaver" command has been removed
    (one of the reasons is consideration of the eventual move to Wayland).
    Locking/unlocking screen can be done if you install "gnome-screensaver"
    separately, or use other screensaver like "xscreensaver", or use "gdm"
    (in which case you can use a command like "dbus-send --type=method_call
    --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver
    org.gnome.ScreenSaver.Lock").

FUNCTIONS
  activate_screensaver
    Usage:

     activate_screensaver(%args) -> [status, msg, payload, meta]

    Activate screensaver immediately and lock screen.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  deactivate_screensaver
    Usage:

     deactivate_screensaver(%args) -> [status, msg, payload, meta]

    Deactivate screensaver and unblank the screen.

    If screen is not being blank (screensaver is not activated) then nothing
    happens. If screen is being blanked (screensaver is activated) then
    unblank the screen.

    Often the screen is also locked when being blanked. On some
    screensavers, like xscreensaver, deactivating won't unlock the screen
    and user will need to unlock the screen herself first. Some other
    screensavers, like GNOME/cinnamon, will happily unlock the screen
    automatically.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  detect_screensaver
    Usage:

     detect_screensaver() -> str

    Detect which screensaver program is currently running.

    Will return a string containing name of screensaver program, e.g. "kde",
    "gnome", "cinnamon", "xscreensaver". Will return undef if no known
    screensaver is detected.

    This function is not exported by default, but exportable.

    No arguments.

    Return value: (str)

  disable_screensaver
    Usage:

     disable_screensaver(%args) -> [status, msg, payload, meta]

    Disable screensaver so screen will not go blank or lock after being
    idle.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  enable_screensaver
    Usage:

     enable_screensaver(%args) -> [status, msg, payload, meta]

    Enable screensaver that has been previously disabled.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  get_screensaver_timeout
    Usage:

     get_screensaver_timeout(%args) -> [status, msg, payload, meta]

    Get screensaver idle timeout, in number of seconds.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: Timeout value, in seconds (float)

  prevent_screensaver_activated
    Usage:

     prevent_screensaver_activated() -> [status, msg, payload, meta]

    Prevent screensaver from being activated by resetting idle timer.

    You can use this function to prevent screensaver from being activated,
    if it is not yet being activated. This is usually done by resetting the
    idle counter. With KDE, this is called "simulating user activity". With
    xscreensaver, one can use the -deactivate on the CLI.

    This function will need to be run periodically and often enough (more
    often than the idle timeout period) to actually keep the screensaver
    from ever being activated.

    If screensaver is already activated, then nothing happens.

    This function is not exported by default, but exportable.

    No arguments.

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  screensaver_is_active
    Usage:

     screensaver_is_active(%args) -> [status, msg, payload, meta]

    Check if screensaver is being activated.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  screensaver_is_enabled
    Usage:

     screensaver_is_enabled(%args) -> [status, msg, payload, meta]

    Check whether screensaver is enabled.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: (any)

  set_screensaver_timeout
    Usage:

     set_screensaver_timeout(%args) -> [status, msg, payload, meta]

    Set screensaver idle timeout.

    Examples:

    *   Set timeout to 5 minutes:

         set_screensaver_timeout( timeout => 300);

    *   xscreensaver

        To set timeout for xscreensaver, the program finds this line in
        "~/.xscreensaver":

          timeout:    0:05:00

        modifies the line, save the file, and HUP the xscreensaver process.

    *   gnome

        To set timeout for gnome screensaver, the program executes this
        command:

          gsettings set org.gnome.desktop.session idle-delay 300

    *   cinnamon

        Not yet supported.

    *   KDE

        To set timeout for the KDE screen locker, the program looks for this
        line in "~/.kde/share/config/kscreensaverrc":

          Timeout=300

        modifies the line, save the file.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   screensaver => *str*

        Explicitly set screensaver program to use.

        The default, when left undef, is to detect what screensaver is
        running,

    *   timeout => *duration*

        Value.

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (payload) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: Timeout value, in seconds (float)

HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/Screensaver-Any>.

SOURCE
    Source repository is at
    <https://github.com/perlancar/perl-Screensaver-Any>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=Screensaver-Any>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2019, 2018, 2017 by perlancar@cpan.org.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.