[solved] two pdf-presentations - switching slides simultaneously

Question

[note: I changed the subject to better suit the solution we found. (orig: dual head: two WMs, one keyboard -> I want simultaneous input!)]
Apart from my Xinerama setup I configured Xorg to run separte WMs on both screens. By default only one of them has the mouse and/or keyboard focus.
But I would like to have simultaneous input, especially for the keyboard!
It's for a talk at a conference for which I have created a (pdf) presentation. What I'm trying to do is running two versions of my presentation, each on one of the heads. The beamer VGA-ouput shall show the plain presentation, while my laptop ought to give me additional notes. However, both heads should change slides simultaneously with one single click.
Any ideas on how to get simultaneous input on both screens? Or might there be another goal to achive this. All I want is two instances of xpdf that both change slides on hitting space-key. I don't really care how it is done, two heads sharing the same input was just my first idea.
Last edited by saciel (2008-03-17 03:57:41)

Answer 1

So here is what I call SI(E)Mple PREsentation -- siempre -- for now. A very rudimental shell script solution. Siempre can open two pdf-files and manages the creation and deletion of the required keybindings. The two instances have to be arranged on the screen(s) manually after. Maybe I'll add some more options later.
#!/bin/bash
#SI(E)Mple PREsentation - start two instances of xpdf with simultaneous page
# turning enabled;
if test \( -z $2 \); then echo "Usage: siempre <file.for.audience> <file.with.notes>"; exit; fi
# commandline-parameters are kept simple for now; you can just pass the name
# of two pdf-files; spaces in file names are NOT SUPPORTED;
BEAMER=$1;
NOTES=$2;
# path to your standard xpdfrc file:
CONFIG="~/.xpdfrc"; #/etc/xpdfrc
# create a temporary xpdfrc (based on existing configuration), adding
# keybindings for simultaneous page-turning; any previous bindings for 'space'
# and 'backspace' are overwritten;
mkdir /tmp/siempre;
if test \( -n "$CONFIG" \); then cp $CONFIG /tmp/siempre/xpdfrc; fi
echo "bind space any nextPage run(/tmp/siempre/xpdf_next)" | cat - >> /tmp/siempre/xpdfrc;
echo "bind backspace any prevPage run(/tmp/siempre/xpdf_prev)" | cat - >> /tmp/siempre/xpdfrc;
# create temporary scripts for page-turning in the remote session; this is
# necessary as the "run" command in the keybindings cannot handle spaces;
echo -e "#!/bin/bash\nxpdf -remote 2ndInstance -exec nextPage" > /tmp/siempre/xpdf_next;
echo -e "#!/bin/bash\nxpdf -remote 2ndInstance -exec prevPage" > /tmp/siempre/xpdf_prev;
chmod 744 /tmp/siempre/xpdf_{next,prev};
# invoke both instances of xpdf; first one is the beamer presentation, second
# one is for additonal notes; kill the note-instance when the main presentation
# is closed;
xpdf -remote 2ndInstance $NOTES & xpdf -cfg /tmp/siempre/xpdfrc $BEAMER;
xpdf -remote 2ndInstance -quit;
# delete temporary files;
rm -r /tmp/siempre/;
Last edited by saciel (2008-03-17 13:38:05)