The xscreensaver-demo program is a graphical front-end for
setting the parameters used by the background
It is essentially two things: a tool for editing the ~/.xscreensaver
file; and a tool for demoing the various graphics hacks that
the xscreensaver 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.
All of these commands are on either the File or Help menus:
Blank Screen Now
Activates the background xscreensaver daemon, which will then run
a demo at random. This is the same as running
with the -activate option.
Lock Screen Now
Just like Blank Screen Now, 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
with the -lock option.
If the xscreensaver daemon is running on this screen, kill it.
This is the same as running
with the -exit option.
If the xscreensaver daemon is running on this screen, kill it.
Then launch it again. This is the same as doing
``xscreensaver-command -exit'' followed by ``xscreensaver''.
Note that it is not the same as doing
Exits the xscreensaver-demo program (this program) without
affecting the background xscreensaver daemon, if any.
Displays the version number of this program, xscreensaver-demo.
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.
This option menu controls the behavior of the screen saver. The options are:
Random Screen Saver
When blanking the screen, select a random display mode from among those
that are enabled and applicable. This is the default.
Only One Screen Saver
When blanking the screen, only ever use one particular display mode (the
one selected in the list.)
Blank Screen Only
When blanking the screen, just go black: don't run any graphics hacks.
Disable Screen Saver
Don't ever blank the screen, and don't ever allow the monitor to power down.
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 xscreensaver daemon had launched it.
Clicking the mouse again will stop the demo and un-blank the screen, making
the dialog box visible again.
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 Mode is set to Random Screen Saver, 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.)
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.
After the user has been idle this long, the xscreensaver daemon
will blank the screen.
jAfter 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
When this is checked, the screen will be locked when it activates.
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 Blank After 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, Lock Screen After 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.
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
This button will pop up a dialog where you can configure settings specific
to the display mode selected in the list.
This tab lets you change various settings used by the xscreensaver daemon
itself, rather than its sub-programs.
Grab Desktop Images
Some of the graphics hacks manipulate 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 do anything, but they may be able to see whatever you
left on your screen.
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.
Choose Random Image
If this option is set, then the image-manipulating modes will select a
random image file from disk, from the directory you specify in the text
entry field. That directory will be recursively searched for files,
and it is assumed that all the files under that directory are images.
If more than one of these 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.
(All three of these options work by invoking the
program, which is what actually does the work.)
Whether to print lots of debugging information.
Display Subprocess Errors
If this is set, then if one of the graphics demos prints something to
stdout or stderr, it will show up on the screen immediately (instead of
being lost in a hidden terminal or file that you can't see.)
If you change this option, it will only take effect the next time the
xscreensaver daemon is restarted. (All other settings take effect
Display Splash Screen at Startup
Normally when xscreensaver starts up, it briefly displays a splash dialog
showing the version number, a Help button, etc. If this option is
turned off, the splash screen will not be shown at all.
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
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.
If Power Management Enabled is selected, the monitor will go black
after this much idle time. (Graphics demos will stop running, also.)
If Power Management Enabled is selected, the monitor will go
into power-saving mode after this much idle time. This duration should
be greater than or equal to Standby.
If Power Management Enabled is selected, the monitor will fully
power down after this much idle time. This duration should be greater
than or equal to Suspend.
Whether to install a private colormap while the screensaver is active, so
that the graphics hacks can get as many colors as possible. (This only
applies when the screen's default visual is being used, since non-default
visuals get their own colormaps automatically.) This can also be overridden
on a per-demo basis.
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 Cycle After expires.)
Unfade From Black When Unblanking
The complement to Fade Colormap: 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 Fade Colormap
is also selected.
When fading or unfading are selected, this controls how long the fade will
There are more settings than these available, but these are the most
commonly used ones; see the manual for
for other parameters that can be set by editing the ~/.xscreensaver
file, or the X resource database.
When you click on the Settings button on the Display Modes
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 Documentation 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 may have their
The Advanced button reconfigures the dialog box so that you can
edit the display mode's command line directly, instead of using the
graphical controls. It also lets you configure the X visual type that
this mode will require. If you specify one (other than Any) then
the program will only be run on that kind of visual. For example, you
can specify that a particular program should only be run if color is
available, and another should only be run in monochrome. See the
discussion of the programs parameter in the Configuration
section of the
accepts the following command line options.
The X display to use. The xscreensaver-demo program will open its
window on that display, and also control the xscreensaver daemon that
is managing that same display.
Start up with the Advanced tab selected by default
instead of the Display Modes tab.
For use by the Gnome Control Center code: this causes this program to
be embedded inside the Control Center window.
Causes lots of diagnostics to be printed on stderr.
It is important that the xscreensaver and xscreensaver-demo
processes be running on the same machine, or at least, on two machines
that share a file system. When xscreensaver-demo writes a new version
of the ~/.xscreensaver file, it's important that the xscreensaver
see that same file. If the two processes are seeing
different ~/.xscreensaver files, things will malfunction.
to get the default host and display number.
to find the sub-programs to run. However, note that the sub-programs
are actually launched by the xscreensaver daemon, not
by xscreensaver-demo itself. So, what matters is what $PATH
the xscreensaver program sees.
for the directory in which to read and write the .xscreensaver file.
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.