8/30/06 FSG Accessibility meeting notes	.

Attending:

Gunnar Schmidt

Olaf Schmidt

Bill Hanaman

Janina Sajka

John Goldthwaite

Aaron Leventhal

Will Walker

Peter Farrenti

Cathy Laws

George Kraft

Larry Weiss

Doug Beatty

We have minutes posted today from last week. Do we need a week to review those? Lets defer approval of those until next week.

Aaron- Mozilla accessibility hackfest October 10-12. There are twelve participants, Mozilla foundation is sending about half. They are sending people from IBM and Sun and paying expenses. If you know other people who should be there, let us know.

George- what is the Official day for the Gnome part?

Will- we are trying for Gnome meeting on Sunday October 8th.

George- and a summary for the rest of the group on the 9th?

Will- yes, if they will allow it in the larger group plus a call to action for the larger group.

Janina- we are looking for someone to head the Keyboard workgroup. Earl will stay with us until we present our 1.0 version to the FSG board. I believe Bill posted his responses to Gunnar’s questions so we are moving forward on that and discuss it next week. If someone is interested in the team leader position, we are accepting self nominations as will as other nominations. Anything else on keyboard? Could someone give a summary of the AT-SPI meeting from the last hour?

Bill- I can make a very high level summary. KDE is continuing to investigate and prototype to implement something very like AT-SPI using D-Bus as the protocol. Harold Fernengel has been writing code which uses the Q accessible classes to fulfill the AT-SPI methods in a couple of selected interfaces for instance base accessible class, accessible text and accessible values.

Gary Cramblett is working on an IDL compiler which generates Python bindings for the D-Bus back end. Harrold’s work is largely hand coded or he is relying on hand coded D-Bus XML’s while Gary’s is more automated to create stubs. It is a proof of concept and is not yet an automated system based on the IDL’s. Gary is continuing to look at automation techniques. My main question had to do with the degree of automation in generation of the stubs and the degree of correspondence between D-Bus API and the AT-SPI IDL.

Janina - Anyone want to add to that? Questions? (None) Could this group be helpful in our action item from that meeting of finding an example of main loop integration? Do you think Michael is the best person to ask?

Bill- mozilla has used the main loop for a long time But not sure who is the best person to take that action item. I would write Michael or Oliver who did the work on open office or might be familiar with how Michael did that.

Aaron- Jin Shen knows a lot more about how Mozilla integrates with gtk than I do

Bill- Mozilla doesn’t have its own internal event loop does it?

Aaron - yes, it has several layers of it, probably three.

Janina- is that something to point Harold to?

Aaron-. Let’s get the question in an email as was suggested, then we can really discuss it.

Bill- Aaron, when we do get the email, if you would be willing to pose the question to Jin and I’ll pose the similar question to Michael and see if either yields a code example.

Janina- I don’t have any specific agenda beyond this

Bill- could I ask people on the keyboard group to look at the html source code I sent out to make sure it is acceptable? If so, I’ll go ahead and update the test assertions. I do have a question about that keyboard issue, we had some late comments from Gregg Vanderheiden. And we incorporated some of them. Does anyone feel we need to take more action on Gregg’s comments before we push forward?

Aaron- did you put change bars in the document?

Bill- no, I didn’t, if you want to do it, I can.

Aaron- no problem, it has been months since I read it would it would be good to review it all.

Bill- Does anyone have any comments about the D-Bus work or comments? I was looking at the source code today and although I can’t say I understand all of it, I have a better understanding than I did.

Aaron- if it happens will everyone will move to it, we eventually will get rid of the CORBA in favor of D-Bus?

Bill- I think there are a couple of questions about that and there may be some misunderstandings. While I think there is support in theory to do that, there are some tough questions. How much performance degradation would Gnome people be willing to sacrifice for interoperability with KDE4. We want to have a shared space but we are comparing a mature infrastructure with a not yet written one and those are hard kinds of choices. There are a number of things that need to be resolved. One is performance, another is preserving things like the ability to communicate across different users. That means the bus used in D-Bus aught not be the user application bus, it probably should be the system bus. Don’t know if anyone has looked at that. Right now, in the current Gnome implementation, everything is bound to a particular user but in Gnome 2.17 we are planning to remove that restriction. There are technologies that make it very attractive to use CORBA’s abilities to do things across a network. If you are doing a remote displayed desktop, how do you make that accessible? The CORBA infrastructure gives you a way to do it that is fairly straight forward.but D-Bus doesn’t currently have the capability to do remote communication. I’m not saying that would be a stopper but there a number of possible RSEs and the question is how many would have to be sorted out. The other issues are what are migration paths for other applications? What about Open office; it will have a bridge to atk. For all this to work, someone would have to write an atk to D-Bus bridge.

Aaron- yes

Bill- I’m not sure that KDE has someone to do that. Gnome would like to make the move but it has to be motivated and resourced to do the work. We’d like to make the move but it has to be a move that everyone is ready to make. I’m not trying to be obstructionist, just trying to say that in reality there are some barriers to putting momentum behind it..

Larry- I don’t think you are being obstructionist, you are just trying to be realistic. We don’t want to regress and you are just pointing out all the things that would have to happen to take on something like this.

Bill- In theory the desire is there. If it was just up to Gnome, although nobody is that fond of CORBA, I don’t think there is enough motivation to kick Bonobo and Orbit out of the desktop just yet even if we didn’t have ABI restrictions. There are more interesting things to work on. I suspect that it wouldn’t happen anytime soon. If we can work closely together, maybe it will happen a bit sooner than it would otherwise.

George- Bill, I would like to see the group come up a prioritized list of pro’s and con’s. I didn’t know that D-Bus wouldn’t allow applications to come over the network.

Bill- I could be wrong. My information could be out of date. People were talking about having a network proxy for D-Bus but it was local to a machine.

George- it would be good to get a wiki list of the things that need to be done. We could add and delete things as they are taken care of. I don’t know how big that list is. Is it one man year or fifteen man years?

Janina- I like that idea a lot. Some of the things that Bill noted, even if only half of them are true, they are serious concerns. If you can’t deliver accessibility to remote desktops, that is particularly important in a lot of business deployments. I am sure that is something D-Bus intends to address at some point. This is not just accessibility problem so other people will be working on it - need to communicate. We adopted the many worlds proposal some time ago, it was the right decision and continues to be the right decision.

Olaf- I like the idea of a wiki collection of points. Maybe it makes sense to collect points for the current framework and obstacles we have for using that for KDE and D-Bus. We tend to repeat discussions on the current framework. There are some points, just as Gnome can’t commit to D-Bus right now, the current AT-SPI architecture doesn’t meet the needs of KDE. We need to have some changes there and we need to have all those issues listed, how much work would be necessary and if it can be done in an ABI compatible way.

Bill- Gary has a nice wiki about his work so might be able to have the discussion there. I like the wiki idea because it is in between the endless repeating of email and gives you a place to comment or revise opinions, fix mistakes.

Janina- do we have that at accessibility.org?

George- yes we do, if you go to our home page on the left side, there is a link for to the wiki. We can start creating sub-pages there.

Bill- Olaf, I was composing a list of pro’s and con’s for KDE, should I post that on the wiki or would you want to see it first?

Olaf- either way.

Janina- let’s start the wiki, it sounds like a useful tool.

Bill- one of the thing that I think Gary was intending in his orca work was to create Python bindings that were the same as the pi-orbit bindings so that a client like orca could talk to both flavors of application without caring which it was talking to or rather it would be able to use the same methods on Python objects.. Is that your understanding, Will?

Will- I think that’s right, we just wanted to get something working on D-Bus, some version of AT-SPI and see how it works, see what its performance is like and then take it from there. Orca should not have to worry about where it is getting its information. We may need another layer so that it can talk to both CORBA and D-Bus based solutions.

Bill- It looked like Python being an object orient language, that you would get an object.Message and that message might be objects.text.GetTextAtOfset there might be two different back ends loaded, depending on the object class. The exact object class be one way if from a Gnome app, other if from a KDE applet but the method signatures would be the same and orca wouldn’t care.

Will- pretty much, the method signatures would be the same, the interface that applied would be the IDL that we cared about. If we center on the IDL as the solution, it should be pretty workable, it wouldn’t be a walk in the park to do it but at least in Orca we have isolated all the access to the AT-SPI to one module.

Bill- could we answer a question Olaf raised about KDE assistive technologies?	If Orca can do it, then in theory any KDE assistive technology could do a similar thing if written in Python. It could use the same mechanism to talk to CORBA based accessible applications as well as KDE D-Bus applications.

Olaf- there were two things. I may have had a misunderstanding with Gary. I though we could have the D-Bus IDL compiler generate the exact same API or ABI as Orbi2 does. He said the bindings generated by ORBIT2 are CORBA specific. Maybe there was a misunderstanding but we would need some changes to the way CORBA bindings are generated to have this independency.

Bill- I think that is true of the CORBA bindings but P Y orbit that is used by Orca is a layer on top of that. The notion is that the Python binds would look the same. There are Python bindings that are specified by the OMG’s but They are at a high level, generic looking. With Python you could write binds that look very much the same but not be CORBA. You can’t do that with C.

Will- with the Python bindings you have a hard time finding the CORBA in them, they just look like the IDL. There are a few spots where you will see CORBA, that is mostly in the importing of modules and getting them set up. Once you start looking at the registry and AT-SPI you’ll be hard pressed to find them. The one thing you will see is that if there are exceptions that are raised if there is a failure, it will be CORBA comm error. They aren’t even documented, they just appear.

Olaf- Well, maybe Gary’s reply was based on these exceptional things. I asked if you could generate the same bindings, he said that it was not but they may be 95% is working and 5% is not, I didn’t ask him for the specifics.

Bill- If I understand correctly, ABI is kind of different with Python, because Python loads things at runtime. Python does some runtime resolving of things. Doesn’t it?

Will- yes it does.

Bill- I think its actual ABI is sort of adaptive. You wouldn’t have to change the source code and you wouldn’t have to recompile. If it loaded the D-Bus ABI, It wouldn’t technically be the same ABI but it would be compatible.

Olaf- the second thing is that even if we had compatible bindings based on Orbit2 and based on glib bindings, it would not be possible to use them as they are for KDE applications because of the event loop.

Bill-right

Olaf- I don’t think you could do that in Python itself. We would like to have a generic KDE interface that would be used in all languages supported by KDE but especially C++. So we would have to check if other Orbs like omni orbit have their own event loops. According to the documentation omni Orbit doesn’t run on platforms where KDE is running.

Bill- I think I said that Orbit didn’t have C++ bindings but that’s not the case. That’s not to say you’d want to use those but they do exist but I’m not sure what condition they are in.

Janina- anything else?

George- FSG is migrating servers off CVS servers to Bazaar NG. Has anyone had experience using Bazaar NG and thought that was an okay move?

Bill- it’s a minority revision control system isn’t it?

George- yes

Janina- I’m not aware of anyone else using it.

George- They want to migrate soon.

Janina- we like to keep CVS for a month so we can finish the Keyboard spec with familiar technology. I will send an email to FSG. I’m not sure about accessibility for Bazaar NG. Apparently you can do some command line things.

George- I’d also like to get some feedback on the accessability of the wiki. Please check it.

Janina- some of the things coming out of the w3c might give us a better way to handle this. There are quite a few blind folks using wikis who have had some problems. I’ll check to see what work arounds they have found.

John Goldthwaite

2006-10-25T13:16:08