WallBrowser

config

##  Lines from my main config

## Border color for the thumbs in the WallBrowser Menu
InfoStoreAdd wallthumbs_color "SteelBlue4"

##  Path to the wallpapers folder
InfoStoreAdd wallpapers_folder "$[FVWM_USERDIR]/wallpapers"

##  The WallBrowser module also expects folder ~/.fvwm/.wallthumbs to exist

DestroyMenu MenuRoot
AddToMenu MenuRoot
+ DynamicPopupAction MakeMenuRoot

DestroyFunc MakeMenuRoot
AddToFunc MakeMenuRoot 
+ I SetScrotFilepath
+ I DestroyMenu recreate MenuRoot
+ I AddToMenu MenuRoot MissingSubmenuFunction WallBrowser
+ I AddToMenu MenuRoot MenuRoot Title
+ I AddToMenu MenuRoot "%mm_urxvt.png%&Console" StartFvwmConsole 64x35
+ I AddToMenu MenuRoot "%mm_identify.png%&Identify" Pick Module FvwmIdent
#+ I AddToMenu MenuRoot "Fvwm&Talk" Module FvwmForm FvwmForm-Talk
+ I AddToMenu MenuRoot "%mm_xerrors.png%&Xerrors" \
      RunInUrxvt 49x27 Xerrors tail -f $[HOME]/.xsession-errors
+ I AddToMenu MenuRoot "" Nop
+ I AddToMenu MenuRoot "%mm_scrot.png%&Scrot	>" \
      Popup ScrotMenu
+ I AddToMenu MenuRoot "%mm_images.png%&Walls	>" \
      Popup "$[infostore.wallpapers_folder]"
+ I AddToMenu MenuRoot "%system_menu.png%&Modules	>" Nop
+ I AddToMenu MenuRoot "" Nop
+ I AddToMenu MenuRoot "%mm_application-exit.png%&Destroy" Pick Destroy
#+ I AddToMenu MenuRoot "%mm_config.png%&Config	>" \
#      Popup ConfigMenu

##  Using the WallBrowser module to make the thumbnail menu 
DestroyFunc WallBrowser
AddToFunc WallBrowser I ModuleSynchronous \
    WallBrowser "$[infostore.wallthumbs_color]" "$[0]"

#---------------------------#
#    WALLPAPER MENUSTYLES   #
#---------------------------#

CopyMenuStyle * WallpaperMenuStyle
MenuStyle WallpaperMenuStyle VerticalMargins 7 7
MenuStyle WallpaperMenuStyle VerticalItemSpacing 30 30

WallBrowser

#!/usr/bin/perl

##  I tried to rewrite this using ->event_loop and ->terminate, to query
##  FVWM's configuration database to obtain its settings and vars. But
##  it confounded me. It seems that commands were sent to FVWM, but only
##  processed by FVWM after the initial wallpaper menu was exited. If
##  this module was not part of a MissingSubmenuFunction menu, I doubt
##  this problem would occur. So I have now resolved to not obtain this  
##  module'ssettings from the configuration database. 

use utf8 ;
use strict ;
use warnings ;
use v5.20 ;

use lib `fvwm-perllib dir`;
use FVWM::Module;
use Image::Magick ;             
#use Data::Dump qw( dump ) ;

my $module = new FVWM::Module(
    Name => 'WallBrowser',
    Debug => 0,
);

##  Read in the current folder for this dynamic menu
my $dir = pop ;
##  Color for border around thumbnail.
#my $wallthumb_border_color = "SteelBlue4" ;
#$module->showMessage("wall_bdr_color: $wallthumb_border_color") ;
my $wallthumb_border_color = pop ;

##  Folder in which to store wallpaper thumbnails.
my $thumbdir = "$ENV{FVWM_USERDIR}/.wallthumbs" ;
##  Menu icon for folder entries in the menu.
my $icon_dir = "$ENV{HOME}/.icons/AwOken/clear/24x24/places/awoken/awokenclear/folder-photos.png" ;
##  Long menu labels get truncated. Maximum length for labels in chars. 
my $charmax = 25 ;
##  Fvwm menustyle name for this menu.
my $menustyle = "WallpaperMenuStyle" ;
##  Cmnd string used to generate the folder menu.
my $menucmd = 'fvwm-menu-directory --icon-file __PIXMAP__ ' ;
$menucmd .= "--icon-dir \"$icon_dir\" --links --dir \"$dir\" " ;
$menucmd .= '--command-file="Module FvwmWallpaper \"%f\"" ' ;
$menucmd .= '--func-name WallBrowser ' ;

##  Magick properties to create a nice thumbnail.
my $wallthumb_geom = "80x40!" ;
my $wallthumb_border_width = 4 ;
##  my $wallthumb_pad_color = "grey9" ;
##  my $wallthumb_pad_geom = "x4" ;
my $quality = 99 ;

##  Create thumbs for all images in the current folder.
foreach my $wall (glob("$dir/*.{png,jpg}")) { 

    ##  generate a filename for the thumbnail.
    my $thumb = $wall ;
    $thumb =~ s/^.*\/// ;
    $thumb =~ s/[.]\w\w\w$/.png/ ;
    $thumb = "$thumbdir/$thumb" ;

    ##  Goto next wally if a good thumb already exists.
    if (-e $thumb)  {
        my @wallstat = stat($wall) ;
        my @thumbstat = stat($thumb) ;
        next if $wallstat[9] <= $thumbstat[9] ;
        unlink $thumb ;
    }

    ##  Create a new thumb.
    thumbificate($wall, $thumb) ;
    say STDERR "WallThumb : $thumb" ;
}

foreach my $line (`$menucmd`)  {

    chomp $line ;

    ##  Discarding unwanted menu entries 
    if ($line =~ /Nop$/ or $line =~ /Exec cd/) {
        next 

    ##  Add a title to the menu.
    } elsif ($line =~ /^AddToMenu\s+(\S+)/)  {

        #my $menuname = $1 ;
        #$module->showMessage("debugX: $1") ;

        ##  my $title = $line ;
        ##  $title =~ s/^.*\/// ;
        ##  $title =~ s/\"//g ;
        ##  my $out = "$line \"Walls\" Title " ;

        #sendcmd($out) ;
        sendcmd($line) ;
        sendcmd("ChangeMenuStyle $menustyle $1") ;

    ##  For each wallpaper entry, substitite in a thumbicon. 
    } elsif ($line =~ /^.*__PIXMAP__%([^"]*)([.]\w\w\w)["](.*)$/) {

        ##  Shorten the menu label if too long.
        my $name = "" ;
        my $num = $charmax - 5 ;
        if (length($1) > $num) {
            $name = substr $1, 0, $num ;
            $name .= "-$2" ;
        } else {
            $name = "$1$2" ;
        }
        
        ##  Make menu entry with thumbicon, and send to fvwm.
        #my $out = '+ "%' . "$thumbdir/$1.png%$name\"$3" ;
        my $out = '+ "%' . "$thumbdir/$1.png%\"$3" ;
        sendcmd($out) ;

    ##  Add a ">" to all folder entries.
    } elsif ($line =~ /^(.*\"%\/[^"]+)(\"\sPopup.*)$/)  {
        sendcmd("$1\t>$2") ;

    } else {
        sendcmd($line) ;
    }
}

exit ;


####  SUBROUTINES

sub thumbificate {

    my $wall = shift ;
    my $thumb = shift ;

    ##  Abort thumb if magick cannot read the wallpaper.
    my $err = 1  ;
    return 0 if not open(WALL, $wall) ;
    my $image = Image::Magick->New(quality => $quality) ;
    $err = $image->Read(file=>\*WALL) ;
    close(WALL) ;
    return 0 if $err ;

    ##  Create thumbnail
    return 0 if $image->Thumbnail(
        geometry => $wallthumb_geom,
    ) ;

    ##  Add a colored border to the thumb
    return 0 if $image->Border(
        width => $wallthumb_border_width,
        height => $wallthumb_border_width,
        bordercolor => $wallthumb_border_color,
    ) ;

##    ##  Add another border to top and bottoms sides, 
##    ##  but using the menus background color.
##    return 0 if $image->Border(
##        bordercolor => $wallthumb_pad_color,
##        geometry => $wallthumb_pad_geom,
##    ) ;

    ##  Save the thumb into its storage folder.
    $err = 1 ;
    open(THUMB, ">$thumb") ;
    $err = $image->Write(
        file => \*THUMB, 
        filename => $thumb, 
        quality => $quality,
        ) ;

    close THUMB ;

    if ($err) { return 0 } else { return 1 } ;
}

sub sendcmd {
    foreach (@_) {
        $module->send($_) ;
        #$module->showMessage("debug: $_") ;
    } 
}

WallBrowser.nfo

####  WallBrowser

How I did the Graphs at the top right of this screenshot : http://i.imgur.com/RKC2K1O.png?1

Other fvwm configs have similar wallpaper menus like this, although mine might be prettier. 
I started by looking in the fvwm-nightshade config, specifically his WallpaperBrowser
function, which he credits to someone called taviso. But looking at that functions huge piperead
command, I decided to reimplement it a an fvwmperl module, and use imagemagick to improve the
wallpaper thumbnails.

Wallpaper menus like this use the fvwm-menu-directory command which has its own manpage, and 
the MissingSubmenuFunction menu option. There are basic examples for MissingSubmenuFunction in 
the fvwm manpage and the fvwm-menu-directory manpage. It dynamically creates fvwm menus 
based on some directory structure, with the assistance of a helper function.

Files below
1] Lines from my main config.
2] WallBrowser, fvwmperl module


##  On Debian, tells you which perl lib to install to provide a certain perl module
http://deb.perl.it/debian/cpan-deb/

####  MORE INFO ABOUT FVWMPERL MODULES

##  Read the hidden fvwmperl manpages 
    $ fvwm-perllib man index

##  A folder full of simple fvwmperl examples
ftp://ftp.fvwm.org/pub/fvwm/devel/sources/tests/perl/

##  An excellent fvwmperl module example
http://www.fvwmforums.org/phpBB3/viewtopic.php?f=38&t=3069&hilit=fvwmsleep