I’ve spent the last few years trying to find the holy grail of FOSS toolchains for producing and displaying my presentations.
I started with OpenOffice.org Impress (which I have sworn never to use again after it ate several presentations), dallied with Clutter’s opt, seriously used KeyJNote, before moving to Mac OS X last year and settling on Apple’s Keynote.
While travelling this year without a Mac, i’ve resumed my search for the perfect toolchain, and I think i’ve found a setup that works pretty well.
It’s uses Inkscape to build the slides, a text file to order slides, KeyJNote to display them, and Rake to tie it all together. Oh, and it’s versioned with Bazaar.
Each slide goes on a new line in order.txt:
/home/auxesis/Desktop/devopsdays/slides/blank.png
# http://www.flickr.com/photos/tim_norris/2600844073/
/home/auxesis/Desktop/devopsdays/slides/scalable.png
# http://www.flickr.com/photos/barbour/404053639/
/home/auxesis/Desktop/devopsdays/slides/distributed.png
# http://www.flickr.com/photos/numstead/535460927/
/home/auxesis/Desktop/devopsdays/slides/nagios-plugin-format.pngYou can easily add comments between slides to keep track of image sources or write down ideas.
Then there’s a Rake task for building the KeyJNote command line and setting up displays:
desc "setup external displays"
task :displays do
system("xrandr --output VGA --mode 1024x768")
system("xrandr --output VGA --same-as LVDS")
end
desc "perform presentation"
task :perform => :displays do
options = "--transition Crossfade --transtime 250 -c persistent"
command = "keyjnote #{options} @#{File.dirname(__FILE__)}/order.txt"
system(command)
endFinally, there’s a Rake task for building the PNGs from the SVGs created through Inkscape:
desc "build pngs from svgs"
task :build do
Dir.glob("sources/*.svg").each do |file|
if modified?(file)
basename = File.basename(file, '.svg')
slide = "slides/#{basename}.png"
system("inkscape -e #{slide} -f #{file}")
end
end
end
def modified?(filename)
index_filename = File.join(File.dirname(__FILE__), "cache", "index")
# read or initialise index
if File.exists?(index_filename)
@index = File.open(index_filename, 'r') { |f| Marshal.load(f) }
else
@index = {}
end
# check if modified
if @index[filename]
modified = File.mtime(filename) > @index[filename][:mtime]
else
modified = true
end
# update index
@index[filename] = {:mtime => File.mtime(filename)}
File.open(index_filename, 'w') { |f| Marshal.dump(@index, f) }
return modified
endThis keeps an index of SVG mtimes, and only rebuilds a slides if you modify the SVG.
Then to view the presentation, it’s a simple:
$ rake build ; rake performNow that you’re just dealing with a bunch of files, you can version control the whole presentation with something like bzr (which handles binary content really well). It’s worth setting up an ignore list so all the generated slides don’t get versioned:
slides/*
*.cache
cache/*