The xscreensaver-demo program is a graphical front-end for
setting the parameters used by the background
xscreensaver(1)
daemon.
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.
MENU COMMANDS
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
xscreensaver-command(1)
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
xscreensaver-command(1)
with the -lock option.
Kill Daemon
If the xscreensaver daemon is running on this screen, kill it.
This is the same as running
xscreensaver-command(1)
with the -exit option.
Restart Daemon
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
``xscreensaver-command -restart''.
Exit
Exits the xscreensaver-demo program (this program) without
affecting the background xscreensaver daemon, if any.
About...
Displays the version number of this program, xscreensaver-demo.
On the left is a list of the names of the various display modes, and
on the right are some fields that let you edit their behavior.
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 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 populate the fields on the right side of
the window.
Each name in the list has a checkbox next to it: this is a duplicate of
the Enabled checkbox, and indicates (and controls) whether
xscreensaver will use this display mode at all. If the box is not
checked, then this demo will not be run automatically (though you can
run it explicitly by double-clicking on its name.)
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.
Program Description
At the top will be a brief description of the program. Below that is a
text field where you can edit the arguments to the program as xscreensaver
will invoke it. (Note that most of these programs have their own man pages
that describe the command-line options they take.)
Enabled
The Enabled checkbox controls whether xscreensaver will use this
display mode at all. This way, all the modes can remain available, but
you can choose which ones will be automatically run.
Visual
The Visual field is where you can select the X visual type that this
demo 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
xscreensaver(1)
manual.
This is a combo-box, so you can either select an item from the popup menu,
or type in a specific visual's hexadecimal ID.
Demo
This button runs the demo in full-screen mode so that you can try it out.
Click the mouse to dismiss it.
Documentation
Since each of the display modes is actually a separate program, they each
may have their own manual. This opens a window viewing the man page of
this program, if it has one.
SCREENSAVER OPTIONS TAB
This tab lets you change various settings used by the xscreensaver daemon
itself, rather than its sub-programs.
Blank After
After the user has been idle this long, the xscreensaver daemon
will blank the screen.
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.
Require Password
Whether the screen saver should lock the screen when it activates.
Lock After
If Require Password is selected, this controls the length of
the ``grace period'' between when the screensaver activates, and when the
screen becomes locked. For example, if this is 0:05:00,
and Blank After is 0:10:00, 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 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.
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
xscreensaver-getimage(1)
program, which is what actually does the work.)
Verbose Diagnostics
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
immediately.)
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
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.
Standby After
If Power Management Enabled is selected, the monitor will go black
after this much idle time. (Graphics demos will stop running, also.)
Suspend After
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.
Off After
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.
Install Colormap
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.
Fade Duration
When fading or unfading are selected, this controls how long the fade will
take.
There are more settings than these available, but these are the most
commonly used ones; see the manual for
xscreensaver(1)
for other parameters that can be set by editing the ~/.xscreensaver
file, or the X resource database.
COMMAND-LINE OPTIONS
xscreensaver-demo
accepts the following command line options.
-display host:display.screen
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.
-prefs
Start up with the Screensaver Options tab selected by default
instead of the Graphics Demos tab.
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.
ENVIRONMENT
DISPLAY
to get the default host and display number.
PATH
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.
HOME
for the directory in which to read and write the .xscreensaver file.
XENVIRONMENT
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.