Last week I attended a week-long meeting at the Sun offices in Dublin. The purpose of the trip was to hammer out issues with the D-Bus AT-SPI port, so that everyone can feel more confident about its readiness for Gnome 3.0.
What a great week we ended up having. I should first say thanks to all that attended, Willie Walker, Mike Gorse, Li Yuan, Ke Wang, Brad Taylor, and Rob Taylor. Sun, Novell & Codethink also need thanking. They paid for everyone to be there, some flying from China, with no foundation money involved. The Gnome community is extremely lucky to have Willie devoting his time to accessibility. I dread to think what Gnome a11y would be like without his organization and direction
Willie organized the event, I imagine more out of fear at what he found in the D-Bus AT-SPI code-base than anything else. All told I think everyone was pleasantly surprised. The project will take a-lot of work to get to the level of maturity required, but loads has already been done. What is required of us for Gnome 3.0 isn’t our of our reach.
We started the week with a very brief overview of the design for AT-SPI D-Bus. Only Mike and I had much experience with the project and we wanted to get everyone up to speed. This very quickly turned into a Q&A session and we figured out what the main issues were on Monday afternoon. Tuesday was spent on the important task of checking the D-Bus protocol specification against both the code and the IDL spec. This bought up a number of bugs, issues and improvements. It was well worthwhile. Amazingly Wednesday & Thursday were spent hacking by everyone, which is a great feat considering that four of us had only peeked at the code previously. So much got done. Orca is now running with a fair degree of success and we can move on to performance issues and application-specific bugs. For a full run-down of the still-to-dos and what-got-dones take a look at the weeks wiki.
Dublin
Outside of work was great fun also. Dublin really is a beautiful city. Lots of green spaces nice buildings and extremely friendly people. The business park is pretty swanky also, and luckily the Oracle buildings are across the road from Sun. We went out to eat and drink in Temple bar, which apparently isn’t a bar. Wednesday involved a trip to the very very small Novell offices in Dublin. They are a way out of town, Brad and I were lucky to get there at all given the distinct lack of signs and road-names that have changed since Google scraped them. We met up with Alan McGovern, a Moonlight hacker, and along with a meal and a few drinks geeked the night away. Alberto Ruiz took us all out for a nice meal on Thursday night. I forget where it was. You’ll have to ask him for the recommendation. Later we attended the Sun Pub Quiz. Luckily for me, our arrival was just as the Quiz part was ending. I’m not so good with the questions.
Me for 3.0
What am I doing for 3.0 I hear you ask? I’m sure you didn’t but I’m going to blurt it out anyway. I’ll be finding time any-where I can to work on D-Bus accessibility. Codethink has already dedicated lots of my time to the project, and there may be a little more in the future. The accessibility plan looks a little sketchy in the road-map, but I believe that with some hard work it can become a big success for the big release.
After ranting about my work I’d love to hear what everyone else us up-to. There must me more than a few semi-secret 3.0 charges taking place.
Many thanks to racarr for posting about this earlier today. I had seen posts on the ‘Do-ifying’ of GTK but they had passed me by. ‘Do-ifying’ applications is a fantastic idea. We shouldn’t limit ourselves to GTK apps though.
The bit that caught my interest was that racarr was thinking of exposing a UI heirarchy over D-Bus to allow Gnome Do to find key-bindings and make them available. I suggested that AT-SPI would be a better way to do this, as all key-bindings are already exposed. I come to no conclusions over whether A11y is the best way. I’m biased. 
It did get me thinking about how A11y technologies could be used to provide general application assistance with Gnome Do.
Context sensitive ‘Do’ commands
Orca, the gnome screen reader, uses a11y mainly by responding to ‘focus’ events which are emitted when input focus moves to a new widget. Gnome Do could use ‘focus’ events to provide context-sensitive commands. By knowing which application, and which part of an application the user is currently focused on it might be possible to provide a more tailored selection of commands.
Perhaps the choice of ‘Do’ commands for each application would depend on finding out what D-Bus interfaces it supports.
Application generated ‘Do’ commands
Obviously for application generated commands we need methods of exposing these to Gnome Do. My preference would be to do this via D-Bus, which again a11y could help with. All ATs (Assistive technologies) need to know when new accessible applications appear on the desktop. Towards this end, D-Bus AT-SPI has a daemon that acts as an application registry and informs ATs when new applications are added. This registry could be made more generic so that Gnome Do would listen for new applications and register their ‘Do’ commands when they are started.
I can’t describe the registration interface here. I don’t know Gnome Do. I’m imagining a list of actions with a command name and descriptions, but it could well be much much more complicated.
Key Bindings
As racarr suggests, it should be possible to inspect the applications UI hierarchy to find all the key bindings and present them and their descriptions to Gnome Do. GOK, the gnome on screen keyboard, already does something VERY similar to this by inspecting an application and presenting all the actions of the currently focused window in a simple manner. There may be other things we can infer from the UI hierarchy, but I wouldn’t want to get too ambitious here.
I’ve often thought that a11y technology was under utilized. As applications on our desktop are already merging together a little by providing and accessing more D-Bus services, a11y seems like it could be well placed to enable some really innovate interfaces for the general user. If this happens it could really help experiences for accessibility users too. More bugs fixed, more descriptions added to widgets with key-bindings.
Congrats Mono A11y
Many congratulations to Mono Accessibility, team for getting their first release out into the open. The Mono A11y team must be one of the largest open-source A11y groups out there and I’m really excited about the work they are doing. WinForms and Moonlight are not yet my thing, but if Silverlight takes off the UIA provider they have created will undoubtedly form an essential part of Linux accessibility.
I don’t believe that it will be in the first release, but I’m really keen to see work start on the UIA client library for Mono. C# and Mono sound like a great place for developing new ATs.
AT-SPI D-Bus on freedesktop.org
For people who don’t know about Gnome accessibility or AT-SPI D-Bus:
AT-SPI D-Bus is a project which aims to use D-Bus instead of ORBit/CORBA as the IPC mechanism for Linux accessibility. For anyone interested in finding out about the Gnome accessibility architecture the developers page has some good information. Oddly enough KDE has a very good Gnome A11y overview, and Sun has a good diagram. Long story short the AT-SPI D-Bus aims to write a new, D-Bus based adapter for ATK, a registry daemon, and client libraries that are API compatible with the existing cspi and pyatspi.
The project has a new home on the freedesktop.org servers.
The code-base exists at: git://anongit.freedesktop.org/git/at-spi2/at-spi2-core.git.
We are keeping a page on the linux-foundation wiki updated with all our progress. Unfortunately I’d say that the code is not yet ready for a first release. For reasons soon evident the code isn’t currently getting the love it deserves. (Help MUCH appreciated)
The reason we chose freedesktop.org and the Linux Foundation instead of Gnome hosting is that we wanted to emphasize the cross-desktop possibilities of a D-Bus based accessibility architecture.
Gnome, KDE & Mono: How it all fits together
The Mono A11y architecture diagram is missing something important that the AT-SPI D-Bus project can add - QT accessibility.
The drive to D-Bus accessibility came from ORBit deprecation, the embedded community and an ideal of cross-desktop accessibility. Its the last motive that has me most excited right now. QT currently has a D-Bus framework based heavily off AT-SPI, but unfortunately it has never been taken far enough to be compatible with existing AT-SPI ATs. The reason that the ATK, cspi and pyatspi libraries are not getting my attention right now is that I really want to get started on bringing QT into the mix.
A QT adapter for AT-SPI D-Bus will certainly round-out the Accessibility infrastructure on Linux. Not being involved in the KDE community I don’t have much say on how they do A11y, but I hope to make it as easy as possible for them to choose AT-SPI D-Bus. Along with the Mono work this could mean that QT, GTK, ATK, Winforms & Swing apps are accessible, using the same ATs, in both KDE and Gnome. I think that would be a fantastic achievement. If we work hard enough accessibility could be one of the big success stories of a joint Akademy/Guadec next year.
I like this meme, its a fantastic window into how depressingly geeky we all are.
- Grab the nearest book.
- Open it to page 56.
- Find the fifth sentence.
- Post the text of the sentence in your journal along with these instructions.
- Don’t dig for your favorite book, the cool book, or the intellectual one: pick the CLOSEST.
“Some learned people are intelligent.”
From “Mathematics for the Nonmathematician” by Morris Kline. This is actually an excellent book supposedly for non-science majors to learn about mathematics. In reality its a very nice read on the history of mathematics, with some problems thrown in.
The choice of this book was a grey area according to the rules. The closest was a copy of Nature Genetics, but this is published in volumes and so started at page 700. The next closest was a stack of books, the top one being the latest Buffy comic. I’m not sure comics count. Can anyone make a firm decision about that?
