Recently Aaron wrote a blog series for the introduction of Spark, I want to cite a central saying of one post:

I want the things which I help make to become opportunities for others in their turn to participate with their own voice, their own movement and their own passion.

If I reflect my own motivation for my work on KWin and especially the areas of work I decided to work on in the 4.9 cycle I see quite some parallels to the paragraph cited above. But personally I would phrase it slightly different:

I want to help others to do awesome.

This describes perfectly what I am currently working on. I no longer want to write fancy effects – in fact I stopped adding effects quite some time ago. I don’t want to extend KWin to be the window manager which incorporates all other window manager concepts no matter how useful they are – we stopped doing that as well.

But still I want that our users get the window manager they want. Whether it is fancy effects or a tiling window manager or new concepts for virtual desktops, KWin should be the base for it.

At the heart of all these efforts we have the scripting bindings. While we already had bindings since 4.6 they never really got used – this will change 🙂 But JavaScript bindings is just one part of the game, the other part is declarative, that is QML, bindings.

In 4.8 we already experimented with QML for the window switcher layouts to test whether QML fits our needs and I am very happy so far with it. But 4.8 does not yet include the possibility to really write own layouts. While it is possible to do so, there is no way to configure a custom one or even distribute this.

For 4.9 the installation of the window switcher has been adjusted to use the Plasma Package structure which makes it possible to install window switcher through the plasmapkg tool. But this is only part of it: plasmapkg has been extended to support any kind of scriptable KWin content, be it window switchers, KWin scripts or KWin effects written in JavaScript (decoration to be added soon).

For this KWin scripts follow also the Plasma Package structure which is quite awesome as it finally allows to dynamically enable/disable scripts through our KCM:

This dialog wants to tell me: “I want Get Hot New Stuff integration” to directly download new scripts from the Internet. And sure it does need that and this will be added for the 4.9 release.

The screenshot shows two scripts I’m currently working on – both will be shipped with KWin in 4.9. Videowall is a script which scales fullscreen video players over all attached screens to generate a video wall. This is the first script which actually replaces functionality from KWin core. KWin had the functionality to disable multiscreen support for fullscreen windows and that really cluttered both code and UI. And it just did not make any sense. There are just no valid usecases to have in general fullscreen windows span all screens, except for video walls. And that’s what we have here: a small KWin script to make an obsoleted functionality sane. We improved KWin for everyone by removing an difficult and confusing control module without taking away the functionality for expert users.

But even more interesting than the video wall is the other script. This is not a JavaScript based KWin script, but a declarative QML script. It will replace the existing C++ based implementation of the desktop change OSD without any functionality loss. Which means less code and much more readable code 🙂

And what’s really awesome: JavaScript and QML have the same bindings, the API is exactly the same. So going from QML to JavaScript and vice versa is extremely simple. But that’s not all with QML based KWin scripts you can include live window thumbnails. So this is a technology to allow you to do awesome new switchers like Present Windows or Desktop Grid.

As you notice I’m currently dogfooding the bindings to myself. This helps me to see what is needed, what can be improved and to ensure that the bindings will work for any given usecase we can imagine. My wish is to see for example the complete window tiling support in KWin to be rewritten as a KWin script. This should be possible and would proof that you can use scripting to get a completely different window management.

So if you want to make awesome things with your window manager, now is the time to get started. Don’t hesitate to contact me and demand further bindings if anything is missing.

Disclaimer: QML support has not yet been merged into master.