WebKitGTK+ Hackfest 2013: The Return of the Thing

The WebKitGTK+ Hackfest 2013As many other WebKitGTK+ hackers (30 in total), I flew last Saturday to A Coruña to attend the 5th edition of the WebKitGTK+ Hackfest, hosted once again by Igalia at their premises and where people from several different affiliations gathered together to try to give our beloved port a boost.

As for me, I flew there to work mainly on accessibility related issues, making the most of the fact that both Joanie (Orca maintainer) and Piñeiro (ATK maintainer) would be there too, so it should be possible to make things happen faster, specially discussion-wise.

And turns out that, even if I feel like I could have achieved more than what I actually did (as usual), I believe we did quite well in the end: we discussed and clarified things that were blocking the mapping of new WAI-ARIA roles in WebKitGTK+, we got rid of a bunch of WebKit1-specific unit tests (Joanie converted them into nice layout tests that will be run by WebKit2GTK+ too), we got a few new roles in ATK to be able to better map things from the web world and and we fixed a couple of issues in the way too.

Of course, not everything has been rainbows and unicorns, as it seems that one of the patches I landed broke the inspector for WebKit2GTK+ (sorry Gustavo!). Fortunately, that one has been rolled out already and I hope I will be able to get back to it soon (next week?) to provide a better patch for that without causing any problem. Fingers crossed.

In the other hand, my mate Brian Holt joined us for three days too and, despite of being his first time in the hackfest, he got integrated pretty quickly with other hackers, teaming up to collaborate in the big boost that the network process & multiple web processes items have went through during the event. And not only that, he also managed to give a boost to his last patch to provide automatic memory leak detection in WebKitGTK+, which I’m sure it will be a great tool once it’s finished and integrated upstream.

Anyway, if you want more details on those topics, or anything else, please check out the blog posts that other hackers have been posting these days, specially Carlos’s blog post, which is quite extensive and detailed.

Samsung LogoOf course, I would like to thank the main sponsors Igalia and the GNOME Foundation for making this thing happen again, and to my employer Samsung  for helping as well by paying our trips and accommodation, as well as the snacks and the coffee that helped us stay alive and get fatter during the hackfest.

Last, I would like to mention (in case anyone reading this wondered) that it has indeed felt a bit strange to go the city where I used to live in and stay in a hotel, not to mention going to the office where I used to work in and hang around it as a visitor. However, both my former city and my former colleagues somehow ensured that I felt as “at home” once again, and so I can’t do anything about it but feeling enormously grateful for that.

Thank you all, and see you next year!

GUADEC, WebKit and bikes

I'm going to GUADECIt seems this year GUADEC is going to be pretty close to my place and so I will surely attend, but this time I won’t go by plane but by bike, which since some months ago has become my main vehicle for moving around the beautiful city where I live in: A Coruña.

Also, besides hanging around the venue and trying to help as much as possible as the local I am, I’ll be talking about WebKitGTK+ in the afternoon on Thursday 26th, so feel free to come round the room if you feel curious about the current status of the whole thing and the current plans for the short and medium term, which are mostly focused around WebKit2 and the roadmap we’re already following.

You probably already read some news related to this coming from my mates in the Igalia WebKit team, (like the improvements in Accelerated Compositing or the migration of our handsome browser Epiphany to using WebKit2), yet I will try to deliver an interesting talk to y’all. I just hope I’ll be able to do it (but please forgive me if I don’t).

So that’s it. As usual, just feel free to talk me if you see me around if you want. I’ll basically be around the venue most of the time during GUADEC, and will attend a11y and WebKitGTK+ BoFs on the 30th and 31st, so I’d say it will be pretty easy to find me.

Accessibility support in WebKit2GTK+

As Piñeiro already mentioned in some posts, last week a bunch of hackers attended the ATK/AT-SPI Hackfest 2012 here at the Igalia offices, in the lovely city of Coruña.

As the guy working on accessibility support for WebKitGTK+, I attended the hackfest to join some other great people representing different projects, such as Mozilla, Orca, AT-SPI, ATK, GTK+ and Qt. So, apart from helping with some “local” organizational details of the hackfest and taking some pictures, I spent some time hacking in WebKitGTK+‘s accessibility code and participating in some discussions.

And from that dedication I managed to achieve some interesting things too, being my favorite ones a big refactoring of the a11y code in WebCore (so it’s now better organized and hence more readable and easy to hack on) and pushing my patch for enabling accessibility support in WebKit2GTK+, after going through a meticulous process of review (see the related WK bug), which started with the patch I wrote and attached back when attending to the WebKitGTK+ hackfest, as I mentioned in my previous entry in this blog.

Yeah, I know that some weeks have already passed since then and so perhaps you’re thinking this could have been done faster… but I’ve spent some weeks on holidays in Barcelona in December (pictures here!) and so I wouldn’t have much time before January to devote to this task. However, the patch got integrated faster than what I would expect when I proposed the first version of it, so I’m quite satisfied and happy anyway just by being able to announce this at this moment. Hope you share my joy :-)

So, what does this mean from the point of view of accessibility in GNOME? Well, that’s an easy question to answer: from now on, every browser that uses WebKit2GTK+ will be as much accessible as those using the previous version of WebKitGTK+, and this is definitely a good thing. Of course, I’m certain there will be bugs in this specific part that will need fixing (as it always happens), but for the time being this achievement means “yet another thing less” preventing us from pushing for upgrading some applications to switch to WebKit2GTK+, such as devhelp (some ongoing work already done, as my mate Carlos announced yesterday), yelpliferea… and the mighty Epiphany browser, which is rocking more and more ech day that goes by.

Last, I’d like to share with you an screenshot showing this new stuff, but as I am a little bit tired of always using Minibrowser (that small browser we use for testing WebKit2), so I decided to try instead that new branch Carlos recently pushed for devhelp, so you could check that what I mentioned before is actually true.

So here you have it (along with a couple of additions done with Gimp):

As you can see, devhelp is running and Accerciser is showing the full hierarchy of accessible objects associated to the application, starting in the UI process (GTK+ world) and continuing in the Web process, where all the accessible objects from the WebKitGTK+ world are being exposed. As I explained in a previous post, the magic making possible the connection between the two process is done by means of the AtkSocket and the AtkPlug classes, also represented in the screenshot attached above.

So, that’s it.

WebKitGTK+ Hackfest: WK2, a11y and Ephiphany’s ad blocker extension

Some posts have been already published about this during the last days, but just in case you missed them I will mention it here again: Last week, a bunch of hackers gathered together in the Igalia office in Coruña for the third edition of the WebKitGTK+ hackfest , and a lot of work has been done, as Juanjo has already summarized in his “WebKitGTK+ hackfest wrap up” post.

WebKitGTK+ 2011 Hackfest

So, as everything has been already said from a more general perspective, I’d like to write my very personal wrap up here, focused on the tasks that I’ve been working on, which can be summarized in three:

  • Enabling accessibility support in WebKit2GTK+.
  • Rewrite of the Ad Blocker extension for Epiphany.
  • Bug fixing in WebKitGTK+‘s accessibility related code.

Enabling accessibility support in WebKit2GTK+

This has been, by far, the task I devoted most of the time to during the hackfest, mainly focused on writing a ‘feature complete’ patch that could be applied upstream, and thus that could be reviewed in first place. But, what do I mean by “a ‘feature complete’ patch”? Well, perhaps you are already aware of the initial results already got in the WebKit2GTK+ a11y realm, but those results were obtained with a patch still in a very early state and, among other things, lacking a very important requirement for getting it accepted upstream: tests.

Fortunately, I can now proudly say that I managed to find a good way to write those tests (specially tricky due to the multiprocess architecture of WebKit2) and that there shouldn’t be any problem either with getting them work properly in the buildbots, which was something I was quite concerned about by the begining of the week, to be honest.

Besides the tests, the other obvious problem was that such a patch was not widely tested yet with the Orca screen reader (I use Accerciser for development purposes most of the time), and that would for sure unveil issues that would need fixing before being really able to propose a patch for reviewing, and so that was the other aspect where I put the spotlight during this week.

And regarding to this, I have to say that Joanmarie Diggs was working tirelessly by testing Orca with my WebKit2GTK+ a11y patch, reporting bugs, and helping me a lot to prioritize the tasks that would need to be done. From all those, I mainly worked this week in the following ones:

  • Emitting the AtkDocument’s signals (‘load-complete’, ‘load-stopped’ and ‘reload’), which was working only in WebKitGTK+ but not in WebKit2GTK+. See the bug report and the patch (still pending on review) for this issue in bug 73750. Also, I reported and worked for a while in another bug related to this, which is now already fixed upstream (see bug 73746). Yay!
  • Ensure that the accessibility hierarchy doesn’t break when (re)loading, which was causing that Orca stopped speaking unless it “manually” drilled down the full a11y hierarchy after the (re)load. I finally fixed that issue yesterday and integrated it in the patch for enabling a11y support in WebKit2GTK+, now already attached and pending on review along with bug 72589.

So, the conclusion of this part would be that we have now a patch in WebKit’s bugzilla (see bug 72589) that, once it’s approved, would enable accessibility in WebKit2GTK+ once and for all. Of course, this will probably take some time before it gets accepted upstream, but it’s yet another nice milestone in my opinion, and I personally hope it would happen on time for GNOME 3.4. Time will tell, though.

Rewrite of the Ad Blocker extension for Epiphany

This was another thing I’ve been randomly working on since some time ago (whenever “spare” time permitted), and that I was able to advance quite a lot right after coming back from the parental leave I enjoyed on September (did I say my second child was born on August the 30th?). However, the patch was not finished by any means, and some issues kindly pointed by Xan in bugzilla needed fixing before being able to say aloud something like “hey, the new ad blocker is now in town!”.

Thus, we thought it would be good to devote some time during the hackfest to try to close this task too, so we did: Xan reviewed the new version of the patch (addressing the issues he previously pointed out), I made some last changes based on that new feedback from him and we finally pushed it to the repository, replacing the old ad blocker extension with this new one, which is based in Midori‘s ad blocker and so is compatible with Adblock Plus filters, which work very well IMHO.

So, this basically means that the new ad blocker extension will be present from Epiphany 3.4 on. Check out the related bug in GNOME‘s bugzilla: bug 660154

Bug fixing in WebKitGTK+’s accessibility related code

Besides working in the WebKit2GTK+ a11y realm and on finishing the new ad blocker extension, I’ve also spent some time (although not as much as I would have wanted) fixing regressions in WebKitGTK+‘s a11y code as reported by Joanie (basically bug 72804 and bug 72830).

Compared to the other two points, this has been of course a pretty small contribution, but worth doing anyway since they were very important for Orca to work properly with WebKitGTK+ based browsers (special mention to bug 72830 here).

Conclusion

From the work-related point of view, I’d say this hackfest has been highly productive in general, as we achieved many goals which, as Juanjo pointed out in his wrap up post, “were not mainly about fixing critical and blocker bugs and implementing basic missing features, but about more ambitious and challenging” ones. As for me, I’m pretty happy with the results I got, specially with the WK2 a11y patch, which has now a much better shape, and so I hope we can integrate it soon upstream.

And from a more personal point of view, I’d like to say I had a great time (again!) this year in the hackfest, and not only because of the achiements got, but also because I had quite a lot of fun as well, because I met new people and because I felt, more than ever, part of a community and a project which I love.

To finish, I’d just like to mention that I’ve been taking some pictures during the hackfest, which you can check out in this photo set in flickr (pictures uploaded with Frogr, of course!). Nayan has also taken some pictures as well, check them out here.

WebKitGTK+ 2011 Hackfest (The End)

Of course, thanks a lot to the sponsors that made this possible: Collabora, Motorola, Igalia and the always awesome GNOME Foundation. I hope we’ll be able to repeat it next year, since this hackfest it’s only getting more and more awesome every time it happens.

WebKit Contributors Meeting, sockets & plugs

Last week some of the members of the Igalia WebKit team,  attended to the second edition of the WebKit Contributors Meeting in Cupertino, California, in order to gather round with other WebKit contributors to discuss and work around our favorite web engine, away from IRC and with a more personal and “human” touch.

WebKit Contributors Meeting '11 - group photo

As for me, it was the first time I attended this unconference and I have to say it was a great experience overall, even if accessibility (the field I usually work on through the GTK port of WebKit) was not precisely a hot topic there. But in the other hand, I managed to put some faces to people I just knew from IRC, attended to several interesting discussions and sessions, did some actual work ™ and met Chris Fleizach, the guy from Apple involved in accessibility for the Mac port, who attended the meeting on Tuesday morning and discussed with me some interesting topics, mainly about the implementation of the accessibility support in the Mac port of WebKit2.

For those of you that are not up to date with what WebKit2 means and what’s the current state of the whole thing, I’d recommend you to take a look to the WebKit2 wiki, although I can already advance you that one of the main features (if not the main one) of WebKit2 is the new multi-process architecture, which will go bundled right along with the engine, instead of doing the split in the final application, like Google Chrome does now with WebKit1 (see the wiki for more details, and some nice diagrams too, like the following one).

WebKit2 multi-process architecture

The problem however, from the accessibility point of view, is how to expose such a new architecture to Assistive Technologies (ATs) while, at the same time, having those ATs seeing just one process (the UI process), regardless of the different processes that would be running on each of the tabs (the Web proceses). In other words, how to “hide” to the ATs that they are extracting accessibility related information from a multi-process based browser, so they still keep the illusion of having only one application exposing accessibility objects, as it used to be so far.

Talking to Chris about how they implemented this in the Mac port, he told me they basically needed to make up a way to transparently connect the UI process and the Web Process, so navigation between the root accessibility object in the Web Process and the “leaf” accessibility object in the UI process were done in a seamless way, through a mechanism that would basically allow bidirectional communication in the same way it used to be when there was just one process running. This makes a lot of sense, if you ask me, since you “just” (saying it as if it were not a complex task, even though it actually is) add this mechanism to WebKit2 accessibility code and you’ll automagically get your ATs working as they used to work, without any other changes needed from their side.

However, when it comes to ATK/AT-SPI, which is what we currently use in GNOME to expose accessible objects from applications to ATs, it looks like such a mechanism (or something pretty similar) is already available by means of the AtkSocket and the AtkPlug classes, both subclasses of AtkObject, which basically act as a bridge that allows to connect two AtkObject‘s so the children of one of those (the Plug) are exposed as children of the other one (the Socket), no matter they’re in the same process or in different ones. And this, unless I’m missing something, is exactly what we’d need in WebKit2, probably along with some other things and tweaks that I just can’t think of at this moment. But at least is definitely a very good start point, IMHO.

But… how to communicate those sockets and plugs if they are in different processes? You might be wondering… Well, if you are using the D-Bus implementation of AT-SPI, also known as AT-SPI2, the needed bits for that (the implementation for the atk_socket_embed() and atk_plug_get_id() functions) are already implemented by the ATK bridge (at-spi2-atk), so the only thing you’ll need to do is to provide the remaining implementation of the AtkSocket and AtkPlug classes, register those new AtkObject‘s as the right accessible objects for your widgets (or whatever your “normal” objects are) and to use the ID that at-spi2-atk provides for the AtkPlug object to connect from the AtkSocket object… and you’re done.

However, I have to say that the documentation I’ve found so far about AtkSocket and AtkPlug is not precisely very detailed, so I basically ended up looking directly at the code and trying to write myself a small example to better understand things. And at this point, I asked in the #a11y channel in GIMPNet and it was Mike Gorse who kindly handed me out a nice tarball with an example they had written in C#, which was exactly what I was looking for. Yay! Thanks, Mike!

However, I’d be more interested in a plain C, GObject based, implementation of that example which would serve me both to better understand how it works and to use it as the base for further tests in WebKitGTK, so I went ahead and wrote it, and this is how the results look now, as seen through Accerciser‘s eyes:

AtkSocket / AtkPlug example in action

As you can see, there are two processes running, ta-socket and ta-plug, and in ta-socket we have an AtkObject named “The Socket” which is exposing, as his only child, the whole subtree present in the other process ta-plug, starting in another AtkObject named “The Plug”… which is exactly, although of course at a much smaller dimension, what I think we would like to see happening in the accessibility tree of any WebKitGTK based application in the future, once that WebKit2 is mature enough to replace WebKit1.

Obviously, this shouldn’t be taken as a “we’re done with WebKitGTK/WebKit2 when it comes to a11y” comment or the like. Actually this is just the beginning of the whole thing… But I think, or at least I would like to think, that is at least a good start point :-) .

And before you shoot… “yes”, I’m already planning to help improve the ATK documentation in this regard with the knowledge I acquired while working on this examples, even perhaps next week during the ATK/AT-SPI hackfest (it’s actually one of the proposed tasks) I’ll be attending here in Coruña, at the Igalia offices.

By the way, feel free to grab the source for this example from its git respository at gitorious:

git clone http://git.gitorious.org/atksocket-atkplug-example/mainline.git

WebKitGTK+ hackfest 2010

After the daily reports written by Diego in his blog, few more things can be told about the WebKitGTK+ hackfest hosted at the Igalia offices last week, but I’d like to comment anyway some impressions from my personal point of view, if you don’t mind reading them.

First of all, this was the second time I attended to this hackfest (I “kind of” attended last year hackfest as well) but now things were pretty different for me, basically because one year ago I was not part of the Igalia WebKit team yet, hence my contributions in the hackfest were pretty small (see my post back then for more details). However, this time I attended full-time to the event and I must say I’m really proud of the work I’ve been doing right there, which I hope will eventually lead to the resolution of this WebKit metabug, which was about fixing bugs blocking ORCA support from WebKitGTK based applications.

But fortunately, the work I’ve been doing during the last week was just a pretty small and humble contribution compared to all the work that has been done by the rest of the people attending to the hackfest, like fixing GTK3 and GObject Introspection issues, fully integrating in libsoup all the new cache stuff written for WebKitGTK (which eventually lead to removing the equivalent code from WebKitGTK, as my mate Sergio told some weeks ago, as soon as some bots upgrade to the latest version of libsoup), adding support for profiling in JavascriptCore, implementing some missing and advanced features into the DumRenderTree (aka DRT, the so beloved tool for writing functional tests), fixing spell-checking support… and bugfixing in general (as well as, most likely, lots of other things I’m failing to recall right now). You can read Diego’s blog for more details on those.

Other than that, there was also time for working in Epiphany were some notorious fixes and improvements also happened. Those I can remember right now are the new error pages for epiphany, the implementation of a certificates viewer and new font preferences, getting rid of GConf in epiphany-extensions and general bugfixing tasks. As you can easily understand, as the devoted and committed Epiphany user that I am, I’m pretty excited with these improvements as well. Not needed to say anything about this patch committed at the beginning of the hackfest, I guess, in my opinion this is one of those cases where a picture is clearly worth a thousand words:-)

hackfest mooded epiphany

So, as you can see it was a quite productive week after all here in Coruña!

Last but not least, I’d like to specially thank The GNOME Foundation for sponsoring the event, as well as Igalia and Collabora for helping make this possible once again. Hope we can repeat it next year, and that more people will join the event to help making WebKitGTK an even better web engine for the GNOME platform.

See pictures of the hackfest here: