Collaborative Text Editor

[Ed Suominen]

I'm thinking of implementing a real-time collaborative text editor in Python
using Twisted. An initial plan is to use a Twisted PB server daemon that
accepts user:password:f ile connections from text editor clients to make
changes to a specified file on the server, and have the text editor clients
update their local copies of the file based on local user input or input
entered from other users, relayed via the server.

Jabber compatibility would be nice, as would color-coding of different
users' text, etc. But I really want to keep this as simple as possible for
a specific purpose. (I've written with twisted PB recently and am very
pleased with its power and ease of use.)

I'd appreciate pointers to any existing, simple Python-based text editors
suitable for being adapted to this purpose. "Suitable" means under an
OSI-approved license and written cleanly and modularly to facilitate
incorporation into another project.

Offers to collaborate would be gratefully accepted. The result, if any, will
be GPL'd and released. If anyone wants to take these ideas and run with a
project of their own, be my guest.

Thanks,
Ed Suominen

[Ville Vainio]

>>>>> "Ed" == Ed Suominen <ed***@spam-eepatents.com> writes:

Ed> I'm thinking of implementing a real-time collaborative text
Ed> editor in Python using Twisted. An initial plan is to use a
Ed> Twisted PB server daemon that

...

Ed> Jabber compatibility would be nice, as would color-coding of
Ed> different users' text, etc. But I really want to keep this as
Ed> simple as possible for

Do check out Leo:

http://webpages.charter.net/edreamleo/front.html

Not so much because of the potential for code looting (many seem to
use scintilla for that, http://www.scintilla.org/), but because it
would just be a neat idea and would further augment Leo's mind blowing
qualities :-).

--
Ville Vainio http://tinyurl.com/2prnb

[John J. Lee]

Ed Suominen <ed***@spam-eepatents.com> writes:

I'm thinking of implementing a real-time collaborative text editor in Python
using Twisted.
Cool! I've wondered about this in the past. Not sure how useful it
would turn out to be, but would be fun to find out.

An initial plan is to use a Twisted PB server daemon that
accepts user:password:f ile connections from text editor clients to make
changes to a specified file on the server, and have the text editor clients
update their local copies of the file based on local user input or input
entered from other users, relayed via the server.
I wonder if client-server is the way to go here. On the surface, P2P
seems more natural fit.

The way I've always imagined it working is as follows. I'm sure
experimentation is the way to find out what works, though, so Twisted
certainly sounds like a great idea.

- At any time, exactly one person has control.

- The only person able to move the cursor and edit text is the one
with control.

- Anybody may flag up that they want control. Everybody is notified
when this happens.

- Control passes from one person to another by means of the person
with control yielding it to a specified person.
If I were doing this (which I'm not, of course), I would go out of my
way to meet the following goals:

- Critical: the way should be left open to implementing the protocol
on any decent editor.

- Important: the protocol should be efficient, so that latency is
minimised. I imagine this requires pushing changes out rather than
polling to check for changes, and having reasonably high-level
primitive operations -- maybe insert, cut, paste, move, maybe
rectangle-wise cut/paste operations too, maybe indent / dedent, plus
operations on a circular clipboard stack (strange image ;-).

Jabber compatibility would be nice, as would color-coding of different
users' text, etc.
Jabber certainly seems an entirely secondary thing: if it helps meet
your goals, great. If not, who cares?

I don't see how colour coding would work, other than to have text that
has been entered since the last switch of control coloured
differently.

[...] I'd appreciate pointers to any existing, simple Python-based text editors
suitable for being adapted to this purpose. "Suitable" means under an
OSI-approved license and written cleanly and modularly to facilitate
incorporation into another project.

[...]

I know vim is Python-scriptable, and has a fairly wide user base
(especially if you count).

For a number of reasons I've been meaning to learn vi properly for
ages, but find it very hard to kick my emacs habit...

have-the-appropriate-amount-of-fun-ly y'rs
John

[Bengt Richter]

On 14 Jul 2004 23:21:38 +0100, jj*@pobox.com (John J. Lee) wrote:

Ed Suominen <ed***@spam-eepatents.com> writes:

I'm thinking of implementing a real-time collaborative text editor in Python
using Twisted.
Cool! I've wondered about this in the past. Not sure how useful it
would turn out to be, but would be fun to find out.

An initial plan is to use a Twisted PB server daemon that
accepts user:password:f ile connections from text editor clients to make
changes to a specified file on the server, and have the text editor clients
update their local copies of the file based on local user input or input
entered from other users, relayed via the server.

I wonder if client-server is the way to go here. On the surface, P2P
seems more natural fit.

The way I've always imagined it working is as follows. I'm sure
experimentatio n is the way to find out what works, though, so Twisted
certainly sounds like a great idea.

- At any time, exactly one person has control.

Why not like a multiplayer game, where everyone sees the same world
(document with signs of other player's activity) and all are able
to play (select text for editing) at the same time (just not on overlapping text).
- The only person able to move the cursor and edit text is the one
with control. Why? Why not have two windows, one with the common world view, where
anyone can select thus-far unselected text -- which on selection changes
appearance and may have hint-info floating to say whose selection is is, etc --
and the other window to edit the selected text, which would only change in
the common view when an editing person did a save. A save-and-release would
make the text selectable by others again.

- Anybody may flag up that they want control. Everybody is notified
when this happens. See above. They just do a selection, and either succeed or not, according
to first come first served.
- Control passes from one person to another by means of the person
with control yielding it to a specified person. Too bothersome. Also, if someone goes off and forgets to close his session,
there should be a timeout. Perhaps a selection should have a for-how-long entry,
and it should show counting down in the hint.


If I were doing this (which I'm not, of course), I would go out of my
way to meet the following goals:

- Critical: the way should be left open to implementing the protocol
on any decent editor.

- Important: the protocol should be efficient, so that latency is
minimised. I imagine this requires pushing changes out rather than
polling to check for changes, and having reasonably high-level
primitive operations -- maybe insert, cut, paste, move, maybe
rectangle-wise cut/paste operations too, maybe indent / dedent, plus
operations on a circular clipboard stack (strange image ;-).
I'd ask game people how they manage and cache common state.

Jabber compatibility would be nice, as would color-coding of different
users' text, etc.

Not excluded from game-like approach.
Jabber certainly seems an entirely secondary thing: if it helps meet
your goals, great. If not, who cares? Being able to communicate separately with the current editor of any of all the
active areas would seem useful.
I don't see how colour coding would work, other than to have text that
has been entered since the last switch of control coloured
differently. I'd use one slight background color change or such to indicate a text area under edit,
and use hints or right-click popups or such for additional details and comm access.
Selection in structured text such as xml etc might operate with useful constraints,
or optionally as with raw text.
[...]

I'd appreciate pointers to any existing, simple Python-based text editors
suitable for being adapted to this purpose. "Suitable" means under an
OSI-approved license and written cleanly and modularly to facilitate
incorporation into another project.[...]

Since selection and common-state viewing would be in a separate window,
the result of a selection could be getting a temp file locally for editing,
and any editor should be able to handle that.

The save and save-and-release functions might require some specialized macros,
but I'd guess any decent editor could be made to do it. Or maybe wrap editor
execution in a shell that notices file updates and the final editor exit...
I know vim is Python-scriptable, and has a fairly wide user base
(especially if you count).

For a number of reasons I've been meaning to learn vi properly for
ages, but find it very hard to kick my emacs habit...

have-the-appropriate-amount-of-fun-ly y'rs
John

Just OTTOMH...

Regards,
Bengt Richter

[Peter Hansen]

John J. Lee wrote:

The way I've always imagined it working is as follows. I'm sure
experimentation is the way to find out what works, though, so Twisted
certainly sounds like a great idea.

- At any time, exactly one person has control.

- The only person able to move the cursor and edit text is the one
with control.

[snip other ideas]

There are already editors that support such things, so imagining
how it works, while interesting, might not be the best approach
to get started... vim, for example, already can do this sort
of thing. I'm certain there are others out there.

-Peter

[Paramjit Oberoi]

> I'm thinking of implementing a real-time collaborative text editor in Python

using Twisted. An initial plan is to use a Twisted PB server daemon that
accepts user:password:f ile connections from text editor clients to make
changes to a specified file on the server, and have the text editor clients
update their local copies of the file based on local user input or input
entered from other users, relayed via the server.

Also take a look at SubEthaEdit:

http://www.codingmonkeys.de/subethaedit/index.html

[Nick Vargish]

jj*@pobox.com (John J. Lee) writes:

Cool! I've wondered about this in the past. Not sure how useful it
would turn out to be, but would be fun to find out.
See SubEthaEdit (Mac OS X only, unfortunately) for a very nice
implementation of this idea.
I wonder if client-server is the way to go here. On the surface, P2P
seems more natural fit.
I think client-server is the way to go, it reduces complexity when you
have more than two people collaborating at once. The person who
initiates the edit session has the cannonical version of the file.
- At any time, exactly one person has control.

SubEthaEdit allows all participants to write at the same time. Text
from each participant is marked with a highlight color specific to
that contributor.

Token-passing is an interesting idea, but it could be frustrating for
people who do not get the token (which could happen for any number of
reasons, deserved or undeserved).

Nick

--
# sigmask || 0.2 || 20030107 || public domain || feed this to a python
print reduce(lambda x,y:x+chr(ord(y )-1),' Ojdl!Wbshjti!=o bwAcboefstobudi/psh?')

[Ed Suominen]

Nicola Larosa on the twisted-python mailing list pointed me to a very
helpful link:

Are you aware of LeoN?
http://ryalias.freezope.org/souvenirs/leon

Leo (without 'N') is an outlining editor written in Python, old and
powerful, and LeoN is an extension for collaborative editing based on
Twisted, new and alpha, but probably worth a look.
Ed Suominen wrote:
I'm thinking of implementing a real-time collaborative text editor in
Python using Twisted. An initial plan is to use a Twisted PB server daemon
that accepts user:password:f ile connections from text editor clients to
make changes to a specified file on the server, and have the text editor
clients update their local copies of the file based on local user input or
input entered from other users, relayed via the server.

Jabber compatibility would be nice, as would color-coding of different
users' text, etc. But I really want to keep this as simple as possible for
a specific purpose. (I've written with twisted PB recently and am very
pleased with its power and ease of use.)

I'd appreciate pointers to any existing, simple Python-based text editors
suitable for being adapted to this purpose. "Suitable" means under an
OSI-approved license and written cleanly and modularly to facilitate
incorporation into another project.

Offers to collaborate would be gratefully accepted. The result, if any,
will be GPL'd and released. If anyone wants to take these ideas and run
with a project of their own, be my guest.

Thanks,
Ed Suominen

[Jacek Generowicz]

Nick Vargish <na*******@band ersnatch.org> writes:

jj*@pobox.com (John J. Lee) writes:

Cool! I've wondered about this in the past. Not sure how useful it
would turn out to be, but would be fun to find out.

See SubEthaEdit (Mac OS X only, unfortunately) for a very nice
implementation of this idea.

There is also something called Hydra.

(And make-frame-on-display in Emacs, can be used for the same sort of
thing.)

[John J. Lee]

Peter Hansen <pe***@engcorp. com> writes:

John J. Lee wrote:

The way I've always imagined it working is as follows. I'm sure
experimentation is the way to find out what works, though, so Twisted
certainly sounds like a great idea.
- At any time, exactly one person has control.
- The only person able to move the cursor and edit text is the one
with control.

[snip other ideas]

There are already editors that support such things, so imagining
how it works, while interesting, might not be the best approach
to get started... vim, for example, already can do this sort
of thing. I'm certain there are others out there.

Could you provide a link to any info on how to do this in vim?
John