Guidance sought on collaboration techniques

James Simmons jim.simmons at
Wed Feb 11 15:49:42 EST 2009

When I wrote collaboration into the View Slides activity I just copied 
the code from the base Read activity so I could copy an entire slideshow 
from one machine to another.  That didn't work all that well, so now I'm 
considering something that I think is both more practical and a better 
use of collaboration.  The idea is to have buddies that join a slideshow 
passively view a show being navigated by the master user, sort of like 
looking over someone's shoulder when he reads.

What I have in mind is this:

1). The View Slides user (who I will call the master user) offers to 
share his slideshow.
2).  One or more buddies choose to join the slideshow.
3).  At the time of joining the buddies are given a version of View 
Slides which has several things disabled.  For instance, they cannot 
share the slideshow themselves, and they cannot navigate through the 
slideshow either.  They will only see the current image being viewed by 
the master user, plus they will know what the current page number is and 
how many total pages there are in the show.
4).  When the master user changes pages, he will send a message to all 
the buddies telling them the new page number, etc. and that will cause 
them to request a download of the current image from the master user.  
When this image is fully downloaded their program will display it and 
update the page number shown in the toolbar.  The buddies always get the 
image from the master user, never from each other.
5).  When a buddy resumes a shared session from his Journal he will 
rejoin the shared show in progress if it is still being shared.  If it 
isn't he will see the last image he viewed, and the toolbar will show 
the total page count and the page number of that image.

It occurred to me that the Chat activity must be doing something kind of 
like this, but I haven't been able to figure out the code in that 
Activity.  It looks like pieces are missing and are perhaps inherited 
from the base Activity class.

I'm hoping someone here can guide me to some tutorial, code samples, and 
the like to help me figure out how to write the collaboration code for 
my Activity.  I've been looking for tutorials on Telepathy on the 
internet and haven't found anything that looks like what I need.


James Simmons

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