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       FvwmBacker - the fvwm background changer module


       Module FvwmBacker

       FvwmBacker can only be invoked by fvwm.  Command line invocation of the
       FvwmBacker 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’s module
       configuration  database  (see  fvwm(1),   section   MODULE   COMMANDS).
       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 used).

              If  the  command  is  colorset  FvwmBacker  uses  the background
              specified in colorset n for the given desk.  Please refer to the
              man page of the FvwmTheme module 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 (see
              the  FvwmTheme man page).  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  default.


       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 withing 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  or


       DestroyModuleConfig FvwmBacker*
       *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:

              *FvwmBacker: Command (Desk Id) command


       The  following  are  excerpts  from  an  .fvwm2rc  file  which describe
       FvwmBacker initialization commands:

       # 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 (
                   (doodman on IRC, check the #linux channel)

Modified by

       Andrew Davison (

       Michael Han (

       Mikhael Goikhman (