FvwmBacker - the fvwm background changer module
can only be invoked by fvwm. Command line invocation of the
module will not work.
The FvwmBacker module provides functionality to change the background when
changing desktops. Any command can be executed to change the backgrounds.
Actually, any arbitrary command can be sent to fvwm to execute, so you could
also do things such as changing window border colors, etc.
The FvwmBacker module is the original work of Mike Finger.
Copyright 1994, Mike Finger. The author makes no guarantees or warranties of any
kind about the use of this module. Use this module at your own risk. You may
freely use this module or any portion of it for any purpose as long as the
copyright is kept intact.
During initialization, FvwmBacker
gets config info from fvwm
module configuration database (see fvwm
(1), section MODULE
). Available options are discussed in a later section.
FvwmBacker can be invoked by fvwm during initialization by inserting the line
AddToFunc StartFunction I Module FvwmBacker
in the .fvwm2rc file.
FvwmBacker can be started using a 'Module FvwmBacker' command or stopped using a
'KillModule FvwmBacker' command at any time when fvwm is running.
FvwmBacker must reside in a directory that is listed in the ModulePath option of
fvwm for it to be executed by fvwm.
The following options can be placed in the .fvwm2rc file
- *FvwmBacker: Command (Desk d, Page x y) command
- Specifies the command to execute when the viewport
matches the arguments for the desk d, page x coordinate and y coordinate.
Any or all of these three numeric arguments can be replaced with an
asterisk (*) to indicate that any value matches, in this case Desk or Page
parts can be skipped.
If either the Desk or the Page parts are omitted, the command
is not executed if only the desk or the page is switched. If neither is
given, the command is executed only once when the module is started. This
is not the same as using asterisks for the numeric arguments: if asterisks
are used, the command is always executed when only the desk or page
changes, if the corresponding part is omitted, the command is never
executed when only the desk or page changes.
If the command is -solid FvwmBacker uses the next argument as
a color in the X database and sets the background to that color without
generating a system call to xsetroot (only single word color names may be
If the command is colorset FvwmBacker uses the background
specified in colorset n for the given desk. Please refer to the
fvwm man page for details about colorsets.
Otherwise the command is sent to fvwm to execute.
- *FvwmBacker: RetainPixmap
- Causes FvwmBacker to retain and publish the Pixmap with
which the background has been set. This works only for the -solid
or colorset commands. This is useful for applications which want to
use the root Pixmap on the background to simulate transparency (for
example, Eterm and Aterm use this method). This option should also be used
for the RootTransparent colorset option. Note: with a colorset background
this command may add a lot of memory to the X server. For example, this
adds the pixmap width times height bytes with a TiledPixmap image,
screen_width times screen_height bytes with a Pixmap image or a C,B,D,R,S
or Y Gradient and screen_width bytes with a VGradient or screen height
bytes with an HGradient.
- *FvwmBacker: DoNotRetainPixmap
- Cancels the effect of the previous option. This is the
It it possible to replace FvwmBacker's configuration at run-time, although it is
not yet possible to remove existing configuration lines. This is done by
simply removing the old configuration from within fvwm and then read a new
one. This can be done in many ways, for example by using an fvwm function or
one of the modules FvwmCommand
*FvwmBacker: Command (Desk 0) -solid black
*FvwmBacker: Command (Desk 1) -solid blue
There is continued support for the now deprecated option:
- *FvwmBacker: Desk d command
It is functionally equivalent to omitting the page coordinates with
*FvwmBacker: Command (Desk Id) command
The following are excerpts from an .fvwm2rc file which describe FvwmBacker
# Set Up Backgrounds for different desktop pages (2 desks, 3x2 pages).
*FvwmBacker: Command (Page 2 *) -solid steelblue
*FvwmBacker: Command (Desk 0, Page 0 0) Exec fvwm-root $[HOME]/bg2.xpm
*FvwmBacker: Command (Desk 0, Page 0 1) -solid midnightblue
*FvwmBacker: Command (Desk 0, Page 1 *) -solid yellow
*FvwmBacker: Command (Desk 1, Page * 0) -solid navy
*FvwmBacker: Command (Desk 1, Page * 1) Colorset 5
Mike Finger (email@example.com)
(doodman on IRC, check the #linux channel)
Andrew Davison (firstname.lastname@example.org)
Michael Han (email@example.com)
Mikhael Goikhman (firstname.lastname@example.org)