path: root/driver/xscreensaver-demo.man

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.TH XScreenSaver 1 "09-Nov-2013 (5.23)" "X Version 11"
.SH NAME
xscreensaver-demo - interactively control the background xscreensaver daemon
.SH SYNOPSIS
.B xscreensaver\-demo
[\-display \fIhost:display.screen\fP]
[\-prefs]
[--debug]
.SH DESCRIPTION
The \fIxscreensaver\-demo\fP program is a graphical front-end for 
setting the parameters used by the background
.BR xscreensaver (1)
daemon.
It is essentially two things: a tool for editing the \fI~/.xscreensaver\fP
file; and a tool for demoing the various graphics hacks that 
the \fIxscreensaver\fP daemon will launch.

The main window consists of a menu bar and two tabbed pages.  The first page
is for editing the list of demos, and the second is for editing various other
parameters of the screensaver.
.SH MENU COMMANDS
All of these commands are on either the \fBFile\fP or \fBHelp\fP menus:
.TP 4
.B Blank Screen Now
Activates the background \fIxscreensaver\fP daemon, which will then run
a demo at random.  This is the same as running
.BR xscreensaver-command (1)
with the \fI\-activate\fP option.
.TP 4
.B Lock Screen Now
Just like \fBBlank Screen Now\fP, except the screen will be locked as 
well (even if it is not configured to lock all the time.)  This is the
same as running
.BR xscreensaver-command (1)
with the \fI\-lock\fP option.
.TP 4
.B Kill Daemon
If the xscreensaver daemon is running on this screen, kill it.
This is the same as running
.BR xscreensaver-command (1)
with the \fI\-exit\fP option.
.TP 4
.B Restart Daemon
If the xscreensaver daemon is running on this screen, kill it.
Then launch it again.  This is the same as doing
``\fIxscreensaver-command -exit\fP'' followed by ``\fIxscreensaver\fP''.

Note that it is \fInot\fP the same as doing
``\fIxscreensaver-command -restart\fP''.
.TP 4
.B Exit
Exits the \fIxscreensaver-demo\fP program (this program) without
affecting the background \fIxscreensaver\fP daemon, if any.
.TP 4
.B About...
Displays the version number of this program, \fIxscreensaver-demo\fP.
.TP 4
.B Documentation...
Opens up a web browser looking at the XScreenSaver web page, where you
can find online copies of the
.BR xscreensaver (1),
.BR xscreensaver\-demo (1),
and
.BR xscreensaver\-command (1)
manuals.
.SH DISPLAY MODES TAB
This page contains a list of the names of the various display modes, a
preview area, and some fields that let you configure screen saver behavior.
.TP 4
.B Mode
This option menu controls the activation behavior of the screen saver.
The options are:
.RS 4
.TP 4
.B Disable Screen Saver
Don't ever blank the screen, and don't ever allow the monitor to power down.
.TP 4
.B Blank Screen Only
When blanking the screen, just go black: don't run any graphics.
.TP 4
.B Only One Screen Saver
When blanking the screen, only ever use one particular display mode (the
one selected in the list.)
.TP 4
.B Random Screen Saver
When blanking the screen, select a random display mode from among those
that are enabled and applicable.  If there are multiple monitors
connected, run a different display mode on each one.  This is the default.
.TP 4
.B Random Same Saver
This is just like \fBRandom Screen Saver\fP, except that the \fIsame\fP
randomly-chosen display mode will be run on all monitors, instead of
different ones on each.
.RE
.TP 4
.B Demo List
Double-clicking in the list on the left will let you try out the indicated
demo.  The screen will go black, and the program will run in full-screen
mode, just as it would if the \fIxscreensaver\fP daemon had launched it.
Clicking the mouse again will stop the demo and un-blank the screen.

Single-clicking in the list will run it in the small preview pane on the
right.  (But beware: many of the display modes behave somewhat differently
when running in full-screen mode, so the scaled-down view might not give
an accurate impression.)

When \fBMode\fP is set to \fBRandom Screen Saver\fP, each name in the list
has a checkbox next to it: this controls whether this display mode is
enabled.  If it is unchecked, then that mode will not be chosen.  (Though
you can still run it explicitly by double-clicking on its name.)
.TP 4
.B Arrow Buttons
Beneath the list are a pair of up and down arrows. Clicking on the down 
arrow will select the next item in the list, and then run it in full-screen
mode, just as if you had double-clicked on it.  The up arrow goes the other
way.  This is just a shortcut for trying out all of the display modes in turn.
.TP 4
.B Blank After
After the user has been idle this long, the \fIxscreensaver\fP daemon
will blank the screen.
.TP 4
.B Cycle After
After the screensaver has been running for this long, the currently
running graphics demo will be killed, and a new one started.  
If this is 0, then the graphics demo will never be changed:
only one demo will run until the screensaver is deactivated by user 
activity.

The running saver will be restarted every this-many minutes even in
\fIOnly One Screen Saver\fP mode, since some savers tend to converge
on a steady state.
.TP 4
.B Lock Screen
When this is checked, the screen will be locked when it activates.
.TP 4
.B Lock Screen After
This controls the length of the ``grace period'' between when the
screensaver activates, and when the screen becomes locked.  For
example, if this is 5 minutes, and \fIBlank After\fP is 10 minutes,
then after 10 minutes, the screen would blank.  If there was user
activity at 12 minutes, no password would be required to un-blank the
screen.  But, if there was user activity at 15 minutes or later (that
is, \fILock Screen After\fP minutes after activation) then a password
would be required.  The default is 0, meaning that if locking is
enabled, then a password will be required as soon as the screen blanks.
.TP 4
.B Preview
This button, below the small preview window, runs the demo in full-screen
mode so that you can try it out.  This is the same thing that happens when
you double-click an element in the list.  Click the mouse to dismiss the
full-screen preview.
.TP 4
.B Settings
This button will pop up a dialog where you can configure settings specific
to the display mode selected in the list.
.SH SETTINGS DIALOG
When you click on the \fISettings\fP button on the \fIDisplay Modes\fP
tab, a configuration dialog will pop up that lets you customize settings
of the selected display mode.  Each display mode has its own custom
configuration controls on the left side.

On the right side is a paragraph or two describing the display mode.
Below that is a \fBDocumentation\fP button that will display the display
mode's manual page, if it has one, in a new window (since each of the
display modes is actually a separate program, they each have their
own manual.)

The \fBAdvanced\fP button reconfigures the dialog box so that you can
edit the display mode's command line directly, instead of using the 
graphical controls.
.SH ADVANCED TAB
This tab lets you change various settings used by the xscreensaver daemon
itself, as well as some global options shared by all of the display modes.

.B Image Manipulation

Some of the graphics hacks manipulate images.  These settings control
where those source images come from.
(All of these options work by invoking the
.BR xscreensaver\-getimage (1)
program, which is what actually does the work.)
.RS 4
.TP 4
.B Grab Desktop Images
If this option is selected, then they are allowed to manipulate the
desktop image, that is, a display mode might draw a picture of your
desktop melting, or being distorted in some way.  The
security-paranoid might want to disable this option, because if it is
set, it means that the windows on your desktop will occasionally be
visible while your screen is locked.  Others will not be able to
\fIdo\fP anything, but they may be able to \fIsee\fP whatever you left
on your screen.
.TP 4
.B Grab Video Frames
If your system has a video capture card, selecting this option will allow
the image-manipulating modes to capture a frame of video to operate on.
.TP 4
.B Choose Random Image
If this option is set, then the image-manipulating modes will select a
random image file to operate on, from the specified source.  That
source may be a local directory, which will be recursively searched
for images.  Or, it may be the URL of an RSS or Atom feed (e.g., a
Flickr gallery), in which case a random image from that feed will be
selected instead.  The contents of the feed will be cached locally and
refreshed periodically as needed.
.PP
If more than one of the above image-related options are selected, then
one will be chosen at random.  If none of them are selected, then an
image of video colorbars will be used instead.
.RE
.PP
.B Text Manipulation

Some of the display modes display and manipulate text.  The following
options control how that text is generated.  (These parameters control
the behavior of the
.BR xscreensaver\-text (1)
program, which is what actually does the work.)
.RS 4
.TP 4
.B Host Name and Time
If this checkbox is selected, then the text used by the screen savers
will be the local host name, OS version, date, time, and system load.
.TP 4
.B Text
If this checkbox is selected, then the literal text typed in the 
field to its right will be used.  If it contains % escape sequences,
they will be expanded as per
.BR strftime (2).
.TP 4
.B Text File
If this checkbox is selected, then the contents of the corresponding
file will be displayed.
.TP 4
.B Program
If this checkbox is selected, then the given program will be run,
repeatedly, and its output will be displayed.
.TP 4
.B URL
If this checkbox is selected, then the given HTTP URL will be downloaded
and displayed repeatedly.  If the document contains HTML, RSS, or Atom,
it will be converted to plain-text first.

Note: this re-downloads the document every time the screen saver
runs out of text, so it will probably be hitting that web server multiple
times a minute.  Be careful that the owner of that server doesn't
consider that to be abusive.
.RE
.PP
.B Power Management Settings

These settings control whether, and when, your monitor powers down.
.RS 4
.TP 4
.B Power Management Enabled
Whether the monitor should be powered down after a period of inactivity.

If this option is grayed out, it means your X server does not support
the XDPMS extension, and so control over the monitor's power state is
not available.

If you're using a laptop, don't be surprised if this has no effect:
many laptops have monitor power-saving behavior built in at a very low
level that is invisible to Unix and X.  On such systems, you can 
typically only adjust the power-saving delays by changing settings 
in the BIOS in some hardware-specific way.
.TP 4
.B Standby After
If \fIPower Management Enabled\fP is selected, the monitor will go black
after this much idle time.  (Graphics demos will stop running, also.)
.TP 4
.B Suspend After
If \fIPower Management Enabled\fP is selected, the monitor will go
into power-saving mode after this much idle time.  This duration should
be greater than or equal to \fIStandby\fP.
.TP 4
.B Off After
If \fIPower Management Enabled\fP is selected, the monitor will fully
power down after this much idle time.  This duration should be greater
than or equal to \fISuspend\fP.
.TP 4
.B Quick Power-off in "Blank Only" Mode
If the display mode is set to \fIBlank Screen Only\fP and this is
checked, then the monitor will be powered off immediately upon
blanking, regardless of the other power-management settings.  In this
way, the power management idle-timers can be completely disabled, but
the screen will be powered off when black.  (This might be preferable
on laptops.)
.RE
.PP
.B Fading and Colormaps

These options control how the screen fades to or from black when
a screen saver begins or ends.
.RS 4
.TP 4
.B Fade To Black When Blanking
If selected, then when the screensaver activates, the current contents
of the screen will fade to black instead of simply winking out.  (Note:
this doesn't work with all X servers.)  A fade will also be done when
switching graphics hacks (when the \fICycle After\fP expires.)
.TP 4
.B Unfade From Black When Unblanking
The complement to \fIFade Colormap\fP: if selected, then when the screensaver
deactivates, the original contents of the screen will fade in from black
instead of appearing immediately.  This is only done if \fIFade Colormap\fP
is also selected.
.TP 4
.B Fade Duration
When fading or unfading are selected, this controls how long the fade will
take.
.TP 4
.B Install Colormap
On 8-bit screens, whether to install a private colormap while the
screensaver is active, so that the graphics hacks can get as many
colors as possible.  This does nothing if you are running in 16-bit
or better.
.PP
.RE
There are more settings than these available, but these are the most 
commonly used ones; see the manual for
.BR xscreensaver (1)
for other parameters that can be set by editing the \fI~/.xscreensaver\fP
file, or the X resource database.
.SH COMMAND-LINE OPTIONS
.I xscreensaver\-demo
accepts the following command line options.
.TP 8
.B \-display \fIhost:display.screen\fP
The X display to use.  The \fIxscreensaver\-demo\fP program will open its
window on that display, and also control the \fIxscreensaver\fP daemon that
is managing that same display.
.TP 8
.B \-prefs
Start up with the \fBAdvanced\fP tab selected by default
instead of the \fBDisplay Modes\fP tab.
.TP 8
.B \-debug
Causes lots of diagnostics to be printed on stderr.
.P
It is important that the \fIxscreensaver\fP and \fIxscreensaver\-demo\fP
processes be running on the same machine, or at least, on two machines
that share a file system.  When \fIxscreensaver\-demo\fP writes a new version
of the \fI~/.xscreensaver\fP file, it's important that the \fIxscreensaver\fP
see that same file.  If the two processes are seeing 
different \fI~/.xscreensaver\fP files, things will malfunction.
.SH ENVIRONMENT
.PP
.TP 8
.B DISPLAY
to get the default host and display number.
.TP 8
.B PATH
to find the sub-programs to run.  However, note that the sub-programs 
are actually launched by the \fIxscreensaver\fP daemon, not 
by \fIxscreensaver-demo\fP itself.  So, what matters is what \fB$PATH\fP
that the \fIxscreensaver\fP program sees.
.TP 8
.B HOME
for the directory in which to read and write the \fI.xscreensaver\fP file.
.TP 8
.B XENVIRONMENT
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.
.TP 8
.B HTTP_PROXY\fR or \fPhttp_proxy
to get the default HTTP proxy host and port.
.SH UPGRADES
The latest version of xscreensaver, an online version of this manual,
and a FAQ can always be found at https://www.jwz.org/xscreensaver/
.SH SEE ALSO
.BR X (1),
.BR xscreensaver (1),
.BR xscreensaver\-command (1),
.BR xscreensaver\-getimage (1),
.BR xscreensaver\-text (1)
.SH COPYRIGHT
Copyright \(co 1992-2015 by Jamie Zawinski.
Permission to use, copy, modify, distribute, and sell this software
and its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation.  No representations are made about the
suitability of this software for any purpose.  It is provided "as is"
without express or implied warranty.
.SH AUTHOR
Jamie Zawinski <jwz@jwz.org>, 13-aug-92.

Please let me know if you find any bugs or make any improvements.