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Re: [ecf-dev] Google Summer Of Code ideas

Hi Marek,

[Moritz and Roland...please see below for questions about SIP/codecs/Java media]

[Mik please see below for questions about Mylyn integration with ECF as a SOC project]

Marek Zawirski wrote:
1) Mylyn integration
I'm asking really nicely Remy, is it possible at all? :) If not I'm just leaving you list of some ideas (possibly stupid as I'm not experienced user of Mylyn).

Major function implemented by Remy is sending tasks between users. I've thought what could be added and my output is:

a) Chat/call with some user from issue-tracking system, such as bug reporter, possibly software client, or commenting developer. This is probably one of most obvious feature, but result in problem of mapping Issue-Tracking System (let me name it ITS if you don't mind) users database to IM users list. First, I thought about heuristic basing on usernames: cliking on username results in Menu "Chat with..." and possible guesses in your buddy list, or manual user selection. Such selection could be stored in some mapping, possibly locally or on ITS. However, I don't now is ITS a good place for such sensitive data? When looking for solution, I've found which address this problem and is related to Higgins framework(?). Do somebody know what's the current status of these issue? I guess it would require changes in Mylyn itself possibly?

Some generalization of a) would be creating mutliuser chat/conference for a task. Similar problems I guess + additional issue: multiuser chat support in ECF providers.

b) Also related to a). Make contacts/communication part of an issue context. ITS allows to define contacts of a task by providing: reporter, assigned user (or users, depending on ITS), commenting users. Is it enough?

This would require Monitoring API implementation or some manual adding to context(?). As it may be hard to distinct whether such chat is related to this issue or is it "just" chat with friends during work, coding same time ;) However, when somebody is initiating shared editor session, it's quite sure that this contact is related to this task. Some contacts may be also extracted from @author tags of javadocs possibly. That's however, more language and company recommendations specific, I'm afraid. It's just another way of creating communication-context which might be seen as general problem.

Anyway, there are still some problems with contacts mapping, as IMHO it would be better to store them in ITS-usernames form in context (more general form), and define mappings in other part (as users may use different IM for example).

Another problem is that creating communication/contacts context in form of Mylyn context will make it unusable for non-Mylyn ITS users.

c) When having some task-oriented chat with somebody, it mabye useful to add log from part of conversation to ITS, don't you think? This may include extended problem recognition after interview with reporter or implementation status details after chat with developer. However, it would be nice to do it easily, without too much manual reformatting, so just selecting some fragment. That's mainly copy-paste transformation support possibly. That's small feature possibly.

d) Some fun and maybe not possible;) Real-time task synchronization. When >= 2 developers work on some task(s) simultaneously and want online synchronization of their contexts without manual sync. I don't know Mylyn details yet, especially context model and synchronization model. So I'm not sure is it possible to create such synchronization session. This may be a complex one.

I also wonder how much part of implementation of a) - d) or others require intervention in Mylyn code. Is it in fact ECF project, or Mylyn project using ECF (is it a problem?)? Possibly not everything could be done as Mylyn Bridge as my first my guess.

I also wonder how much part of implementation of a) - d) or others require intervention in Mylyn code. Is it in fact ECF project, or Mylyn project using ECF (is it a problem?)?

It's not inherently a problem, but would require coordination with Mylyn team (if it in fact does require changes to Mylyn code as opposed to additions via further plugins). I've copied Mik Kersten on this email to get his input on some of the questions you raise.

Possibly not everything could be done as Mylyn Bridge as my first my guess.

2) VNC

Yes...this would be a terrific project IMHO. The reason we haven't worked on this so far is captured in a single word: 'resources'. We just haven't had enough time/interested people to do it.

(possibly) resourcesNumber++ ;>

Sounds great.

What about realization?
I've read about proposed idea to create some interface for application
sharing with VNC as one of implementation, or some existing interfaces
may be used (e.g. ISharedObject?). This could be used for session
sharing possibly. VNC protocol need to be implemented or some external
library used.

Yes. There are different approaches would be to make a localhost socket connection to a running VNC server/host, and basically have the ECF host get screen sharing data from localhost, send it over the wire, and then display on remote clients.

I wonder what is a purpose of making ECF a proxy for real VNC server. Is it really needed? Do you mean better control or some tunneling (with encryption?).

Compression, encryption, and/or tunneling certainly can/could be done. Also, using ECF can distribute the VNC server output to several/group of receivers.

In simple model VNC server could just listen/bind on * interface, not only localhost, being more standalone. All what is shared then is some URL and possibly some settings? This may have some drawbacks maybe... (?)

This would be OK, but it would limit what you can/could do with ECF (on servers or clients). For example...if you are sending the VNC server screen output and mouse/keyboard input over ECF provider, then you can/could have some ways to do a) recording; b) have bots that respond to certain kinds of mouse/keyboard input...for example.

Some months ago I tried to contact the VNClipse folks to ask them if they would be interested in working together...and didn't hear anything back. They may have been busy, or things may have changed, so it would probably be worthwhile to try to contact them again. I can't immediately remember what the license was, but at that time they were not making the source available.

I'll just write to them.

OK, great.

One other licensing issue is that the VNC source itself (including the java clients) are GPL, so if we want to use/modify any of that code the resulting code cannot be under the EPL (Eclipse license). ECF has both EPL-based components (i.e. those hosted/distributed at, and those *not* under EPL (the 'ECF Extras' hosted at, so we can work around these issues for a SOC project in any case.

Did you mean TightVNC GPL implementation?


I've done some zoom in at its vncviewer code - VNC client. It appears to be not very very complicated, ~20classes / ~20KLOC. However, implementation is sticked to AWT/SWING, so would require embedding AWT Canvas component or forking project and porting it to SWT. In the latter case, things looks rather straight-forward.
BTW: interesting TightVNC feature is recording of session from client.


I personally do not, as I'm not an SWT expert. In other java-based impls of VNC, we've used the native code impls of VNC and talked to them via a localhost socket connection as you suggest below (booo) :). There may very well be ways to write a VNC server in java using SWT...and given SWT's native implementation it could be sufficiently performant on some/all platforms. I don't know. But there are several people on the ECF committer list that are very good WRT SWT and UI: Boris Bokowski, Remy Suen, Chris Anisczyck and others. Hopefully we can pull them into the conversation

I'd appreciate your comments:) Things that I'm especially wondering are they possible: - is it possible to make SWT "secondary" output to some user-provided framebuffer class, register some redrawing listener for a whole desktop, even when non-SWT window is focused? - is it possible to grab mouse/keyboard input from other windows, even when non-SWT window is focused?

I doubt it (for both questions), but this is indeed something that should be asked of SWT experts. Perhaps it would be a good idea to pose these questions in the SWT newsgroup(s)?

Still, some external native code could be started like with Skype, but AFAIK VNC servers are provided in different ways and under different licenses. Eventually it could be configured by user, but what are Eclipse-embedding benefits then...

BTW What java-based impl did you mean, Scott? Some closed-source?

No, I meant the java client provided with realvnc (I think that's the name).

3) SIP

4) SIP implementation, not yet made for ECF(?). I don't have much
experience (except user-side) with that protocol, just wondering how
laborious this task may be...

This is a great question for our two VOIP committers: Moritz Post (did the Jingle VOIP SOC project last year), and Roland Fru (has worked quite a lot with SIP and Asterisk).

In either case I think a SIP provider (implementer of the ECF call API) would be great.

Ok, again, I'm asking kindly for some comments:)
I've found JAIN SIP API and reference implementation of SIP and SDP, made as part of Java Specification Request. However, I've read it is bit outdated, on JSDP page - don't know how/why. JSDP is unofficial (out of JSR) implementation od SDP. Basic signaling part of this project may be not very hard. I'm expecting more problems with interoperability and mainly - transport/RTP and codecs/audio implementations.
Or do you have other experiences?

I'm forwarding this onto Moritz Post, who did the 2007 VOIP project (Jingle). He ended up using Java Media codecs/audio implementations to do this, as I expect that's what the JAIN sip implementation does. I've noticed that the JAIN SIP implementation doesn't seem to be getting a lot of new work recently, so I'm not sure of it's status. Moritz and Roland please comment about existing SIP implementations that you know about.

The codecs, audio, RTP part may be already implemented as part of Moritz Post GSoC work possibly(?). AFAIK jingle is just another signaling protocol with similar role as SIP with SDP, so maybe audio, compression and streaming code may be shared?

That is very possible. I'll let Moritz and Roland answer your questions more directly.



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