QEdje Is Working! :D

There are quite a few Free Software libraries out there for making GUIs (graphical user interfaces). The most famous are probably GTK+ (started by the GIMP and used by Gnome, XFCE and LXDE) and QT (started by Trolltech and used by KDE), however there are quite a few more such as GNUStep, Motif (used by CDE), FLTK (used by EDE) and EFL (used by Enlightenment).

EFL, the Enlightenment Foundation Libraries, are particularly interesting. They are incredibly lightweight, running quite happily on a mobile phone, yet allow all sorts of animation (as in, proper 2D animation rather than just moving/spinning/stretching things) and are completely themable. The way this works (from what I can find out) is that every EFL program uses the Evas canvas ("canvas" is the name given to a widget which allows arbitrary drawing on top, rather than imposing some kind of structure), then Etk and EWL draw on top (the canvas is created implicitly by Etk and EWL, even if you don't make one explicitly). This is opposite to most toolkits, like GTK+ for example, where the widgets are drawn in the window (which is usually divided up into a rigid structure) and canvases are implemented as widgets.

A nice feature of the EFL is called Edje. Edje allows an application to be written without worrying about the GUI, instead just requiring that an external file be called. These external files describe the interface, and are entirely declarative (that is, they say "I want a button" rather than "This is how to draw a button"), think of it like the HTML of a web page, with Edje being the web browser which draws it (actually, this would be a more appropriate description of XUL, but I can't get my head around XUL's seemingly overcomplicated use of CSS, JavaScript and XML :( ).

Edje files are compiled into compressed archives (using EET) which act like incredibly far-reaching themes. This means that a theme doesn't just contain pretty pictures to use as buttons, or the programming to draw the right lines at the right locations, it actually contains the entire user interface. To continue the web page analogy, if Gmail or Facebook used an analogous system then instead of merely being able to change the theming via CSS (which may have to be specifically forced from the browser preferences, because web-app people suck balls), you could actually use a completely different webpage to interact with the underlying application (no more "New look!" announcements, since anybody could use any look they wanted all of the time).

Now to address the title of this post ;) As I've described, Edje is a declarative system. An awesome feature of this is that Edje can be completely replaced without the user even noticing, since the point is to say "I want a button" and not care about how it gets done. Well, the developers of Canola looked at moving to QT, since it offers more features than EFL, is more widely developed, developed for and installed. However, they found that Edje was too awesome to leave behind, so they ported it to QT and called it QEdje! What's particularly nice about QEdje is that a) the canvas used instead of Evas, called QZion, is rather abstract in itself, so that different QT systems can be used to do the work (eg. direct drawing to the screen with the QPainter backend, more abstract layout with the QGraphicsView backend or 3D accelerated with the KGameCanvas backend, depending on the environment it is being used in) and b) the huge wealth of QT widgets can be used in the program (this is pretty powerful considering that as well as buttons, labels and tickboxes, QT also has a whole web browser, Open Document Format compatible rich text areas and an abstracted audio/video multimedia engine (which, so far, uses Gstreamer (Rhythmbox, Totem, etc.), Xine (GXine, xine-ui), VLC, Mplayer, QuickTime (QuickTime Player, etc.) on Mac and DirectShow (Windows Media Player, Media Player Classic, etc.) on Windows).

After a little wrangling I've got it to compile and the examples are working. This means I can have a play about, so I'll report on my findings :)

Some phrases should be culled

Although 'screen real estate' is up there, the top dog must be 'bling bling'. With that in mind I've been pimping my laptop in anticipation of the influx of potential new Free Software users in the form of the next academic year's worth of firstyears. I am now running Ubuntu Gutsy, which overall seems to be following the less-dramatic-upgrade tendancy I've seen in Ubuntu (Breezy>Dapper was very pervasive, Dapper>Edgy seemed nice, Edgy>Feisty didn't really seem worth it, Feisty>Gutsy? Dunno yet), but it means that along with working out how to get ATI's crapware to 'work' I can run Compiz Fusion (using XGL, eww) which seems nice, although I really don't like the 'CompizConfig' tool, it is in serious need of some UI lovin' (who in their right mind would provide users an integer system for animations without telling them what animation each number corresponds to? Plus, the amount of conflicting stuff is annoying, like 'minimise effect' not being disabled when minimise/maximise animations are enabled).

I've installed E17 as well, which has changed a bit since I last played around with it. Although it has gained features on the whole the process of configuring the thing is a real mess. The 'shelves' idea is OK I guess, but as far as I can tell I can no longer use the modules as desktop widgets (strange, considering how other desktop systems are moving in the opposite direction) which would be a shame. Still, I have set up a new non-admin user called fss-test and set up a nice enlightenment configuration to use (although Amarok, Rhythmbox, MPD and Exaile all crash for that user :( Banshee seems to be OK so far (Banshee has become very nice recently too I have noticed!), but that's what you get for using pre-release software). I wanted to have KDE4 running too, but the packages are pretty bare at the moment (Plasma is the main area I'm interested in but they only have 2 plasmoids in the vanilla setup, the rest of them living in the 'playground' directory in subversion, which I have tried unsuccessfully to compile).

Now that I know my own laptop will stand up well in the first-impression-critical world of the Freshers' Fair I want to get other machines on board. I have asked my friend Heminder if I can borrow his laptop to demo stuff on and I think he agreed, I'm not sure. I'll try and hunt down some more (perhaps James could pop along, since he is supposed to be a member and has Fedora installed on his laptop, making no live CD needed).

Oh well, time to get back to the real world and make sure my monetary hurdles are overcome.

PS: Must test Wii controller with my laptop, since demoing that would be awesome :)