Author Archives: robster

GUADEC: Wayland talks today

The order of the Wayland talks are going to be flipped compared to the printed schedule. This means my introductory talk to Wayland will be before the panel discussion which should give valuable background for the subsequent discussions. Hopefully see you there!

The Waylanders are coming

This GUADEC there will be a couple of sessions on Friday afternoon from 2pm about Wayland. I’ll be giving a presentation with a brief introduction to what Wayland is, what new features we’ve worked on in the last cycle as well as what’s planned for the next one. As this is GUADEC i’ll of course be covering how we’re doing with getting Wayland integrated into GNOME. There will also be a Wayland panel discussion where you can ask your tricky questions of myself, Owen Taylor, Robert Bragg and Kristian Høgsberg – to get things started i’ve got some already prepared!

And if that’s not enough Wayland for you, on Monday we’ll be BoF’ing between 10am and 2pm in room A218. It would be great to see you there.

Wayland & Weston 1.2.0 is out

The latest release of the Wayland protocol and support library along with the Weston compositor is now out. For the GNOME community this release is particularly interesting:

  • It is the first one to advertise a stable API for the implementation of compositors (libwayland-server) – which will prove useful with the porting of gnome-shell & mutter to Wayland
  • Two new protocol enhancements have been staged for inclusion: subsurfaces from Pekka Paalanen which will be the basis for implementing Clutter-GTK on Wayland and support for input methods from Jan Arne Petersen. These are not yet in the core of the Wayland protocol but will be moved there when the API has been proven.
  • HiDPI support – Alexander Larsson implemented this for Wayland and GTK+ too

At GUADEC i’ll be speaking about the current state of the Wayland project and plans going forward. If you have a particular topic or question you’d like me to cover please let me know in the comments.

Clutter & Cogl Wayland update

Lots of us over at Intel towers are working hard to bring you a great new Wayland powered experience.

Cogl and Clutter have now been updated to work with the latest Wayland master. You need to compile master Cogl with:

./configure --enable-wayland-egl-platform=yes --enable-gl

And then to run any applications using Cogl on Wayland you need to setup the environment variable COGL_RENDERER=egl_wayland then you can run cogl-crate!

For Clutter you need to compile Clutter master with:

./configure --enable-wayland-backend

You also need to set an environment variable to choose the Clutter backend too – in this case it’s CLUTTER_BACKEND=wayland (and you need to set COGL_RENDERER too) then you can run test-actors!

Or just look at the video below 🙂

Direct Vimeo link!

A big kudos needs to go to Robert Bragg, Neil Roberts and Emmanuele Bassi for helping make this happen.

The Clutter client side support is basically complete so i’ve now moved onto working on GTK and MX – watch this space for updates!

Nicely formatting number types

I came across the following compiler warning today:

||   CC     libplurk_la-plurk-item-view.lo
|| plurk-item-view.c: In function ‘construct_image_url’:
plurk-item-view.c|233| warning: format ‘%lld’ expects type ‘long long int’,
but argument 3 has type ‘gint64’

Tut tut tut .. a compiler warning! How could the commiter had let this happen? Lets look at the code …

url = g_strdup_printf ("", ...);

Ahaha .. they’re probably using a 32-bit system, the nice thing to do here is:

url = g_strdup_printf ("" G_GINT64_FORMAT ".gif", ...);

To handle the case that on a 64-bit system you can represent a gint64 as a long rather than needing to go for a long long. I’ve seen this quite a bit with debugging output for size_t for which G_GSIZE_FORMAT is definitely your friend.


Spent some of my morning fixing a build issue that came down to the use of AC_ARG_ENABLE. I thought it was worth recording some notes for its use:

Something enabled by default:

                              [Enable badgers @<:@default=yes@:>@])],

Something disabled by default:

                              [Enable badgers @<:@default=no@:>@])],

Observe that in this case the only thing that changes is the default value in the third parameter to AC_ARG_ENABLE (and also the documentation :-))

Something enabled by default but with a –disable syntax:

                              [Disable badgers],

Notice that this case is just the same as the first except with the help changed. Of course you actually need to use the value from the flag. I think this is more readable if presented outside the AC_ARG_ENABLE parameters this is possible because AC_ARG_ENABLE always sets a variable called enable_<thing>. Awesome, huh?

For conditional pkg-config:

AS_IF([test "x$enable_badgers" = "xyes"],
      [PKG_CHECK_MODULES(BADGERS, [badgers-1.0])],

For conditional building:

AM_CONDITIONAL(ENABLE_BADGERS, test "x$badgers" = xyes)

Work with us!

Are you graduating this year? Or recently graduated? Do you want to work in Open Source? Do you have the right to work in the UK? Do you want to work with some of the best minds in the field: Chris Lord, of Happy Wombats fame; Damien Lespiau, the Clutter GST mastermind; Emmanuele Bassi, our Clutter super-hero; Jussi Kukkonen, who puts the clue in Geoclue; Ross Burton, our EDS magician; Srini Ragavan, Evolution shiny-thing maker; Thomas Wood, of the MX and control-center massive; Tomas Frydrych, our Antarctic naming scheme generator and of course pippin.

Interested? Take a look at our job entry. I should be around as FOSDEM so feel free to corner me to talk.


GUADEC is going really well this year, great to catch up with folks. A big thank you to everyone who came along to my tips and tricks talk yesterday. I hope that everyone discovered something new; I certainly did whilst preparing it. As suggested i’ll try and get this content all collated up into a wiki page. Watch this space.

Awesome photo CC gonzalemario –

GNOME in Moblin: People panel

Previously i’d talked about how we use GNOME technologies in the Moblin Myzone. Now i’m going to talk about another component that i’m responsible for, the People Panel.

An important aspect of the Moblin user experience is about communicating with others and this panel provides quick access to do this. The core of the content is provided by an abstraction, simplification and aggregation library called Anerley. This provides a “feed” of “items” (an addressbook of people) that aggregates across the system addressbook, powered by EDS, and your IM roster, powered by Telepathy. You have small set of actions you can do on these people such as start an IM conversation / email / edit them with Contacts. The core of our IM experience is supplied by the awesome Empathy. We’ve been working with the upstream maintainers to accomodate some of the needs of Moblin into the upstream source. This included the improvements to the accounts dialog and wizard that landed for GNOME 2.28.

One of the biggest problems with the IM experience in Moblin 2.0 was that it was easy to miss when somebody was talking to you. If you were looking away when the notification popped up, whoops, it’s gone. With our switch to Mission Control 5 I was able to integrate a Telepathy Observer into Anerley and the People Panel. An Observer will be informed of channels that are requested on the system. This allows us to show ongoing conversations in the panel and by exploiting channel requests and window presentation allow the user to switch between ongoing conversations. This wouldn’t have been possible without the assistance of the nice folks in #telepathy and at Collabora: Sjoerd, Will, Jonny and countless others.