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Category: PlasmaPhone

My 2020 with KWin Wayland

Over the last few years and especially since the Wayland goal vote, the Plasma team, we have been focusing on having our Plasma Wayland experience work at least as good as our traditional Plasma X11 experience does. Today I’d like to wrap up my experience on this front for 2020.

Despite having been working on KDE and even Plasma projects for a long while, I’d never gotten much deep into working on KWin internally. I dipped my toes in it in 2019 when working on the key states feature (that plasmoid that says if caps lock is pressed or not, which we needed because the KDE Slimbook didn’t have an LED for the Caps Lock). Here I’ll discuss a bit how it evolved over time.


Tablet support

It’s probably been my first big feature contribution to KWin. From 5.19 you’ve been able to use your tablets to draw things, all features should work fine and life should work. In the beginning, I was mostly interested in getting the 2-in-1 tablet with a pen work, hence implementing this one first.
The rest of the spec implementation is pending review here and hopefully should make it into 5.21:

Screen casting support

This is something I’ve worked on mostly with my Blue Systems hat on, but still is something very important for our daily usage of Wayland, especially nowadays where working remotely is more important than ever and sharing our screens and windows is something that we need to do on a daily basis.

KWin used to support already sharing screens, or rather xdg-desktop-portal-kde could, now we centralised the implementation in KWin and made sure it’s as performant as possible. It was admittedly rather complex to put together, but allowed me to understand how the system works and helped me have a better insight of the architecture.

Input Methods

Plasma Mobile is becoming a palpable reality and input is very important on any touch device. In Plasma Mobile we’d been relying on having Qt’s embedded virtual keyboard since the beginning and while it worked reasonably well, we needed to make it possible for us to offer more and better solutions. This time, we implemented the unstable input-method protocol which allowed us to use keyboards implemented in a separate process, hence making it possible to integrate the Maliit keyboard transparent, as well as the weston keyboard if minimalism is your thing.

Maliit keyboard

This, of course, opens the possibility of much more development on top in terms of other better virtual keyboards, improving the current ones or the integration of more esoteric kinds of input methods (e.g. ibus, fcitx, emoji keyboard or even spell checkers and the likes).

Developing comfortably

Something that was clear to me as soon as the Wayland Goal was shaping up was that we had to find ways to free ourselves a bit from the ABI limitations. From the beginning, Wayland interfaces started to be developed in KWayland under KDE Frameworks 5. This meant that server-side implementations had to stay backwards compatible to certain versions of KF5 and that we couldn’t do certain things. We moved KWayland Server components into a separate component here, that is released with Plasma and we can develop as we see fit: Note that KWayland Client classes stay there where they always were.

This has allowed us in turn to adopt the usage of qtwaylandscanner, which is a tool that generates certain boilerplate C++ code for us from the xml spec, allowing us to focus on the parts we care about in the implementation. This makes Wayland protocol implementation a bit more straightforward while removing some code. You can see the MRs Adrien and Vlad made doing this if you’re curious about the changes it conveys. Our first protocol implementation to use qtwaylandscanner was the keystate protocol I mentioned earlier.


As it’s important to explain what we do so people are aware of it, I decided to take some time this year to explain the different aspects of our Wayland initiative and overall why Wayland makes sense. You can see it explained here, I wouldn’t recommend you to look at them all, but it could be useful for you to look at the one that fits your perspective better.

KWin and Wayland

Wayland for Product creators

Wayland for App Developers

Plasma Wayland: donde estamos y como ayudar (in Spanish)


I know there’s a lot of really exciting stuff coming up from the team. If you’re interested, stay tuned. We will be having a sprint early January to discuss different topics from major roadblocks to a light and comfortable experience.

Consider joining us either at the sprint or at the Wayland goal forums and work with us towards a better experience using Free Software and Plasma.

KDevelop runtimes: Docker and Flatpak integration

On my last blog post I discussed about how some assumptions such as the platform developed on can affect our development. We need to minimize it by empowering the developers with good tools so that they can develop properly. To that end, I introduced runtimes in our IDE to abstract platforms (much like on Gnome’s Builder or Qt Creator).

There are different platforms that we’ll be developing for and they need to be easily reachable when coding and testing. Both switching and interacting transparently with the different platforms.

To that end I implemented 4 approaches that integrate different runtimes:

  • Docker, allows you to develop directly against virtually any system. This is especially interesting because it enables to reproduce the environment our users are having: behavior on execution and project information (i.e. the imports are the ones from the target rather the ones on our local system). Docker is a wide-spread technology in the cloud, I hope many developers will see the value in integrating the deployed environment into the IDE while they are coding.
  • Flatpak, is a solution that targets specifically desktop Linux applications. We are talking about distributing bundled applications to users, there we have the opportunity to integrate the tooling specifically to that end: from fetching dependencies to testing on other devices (see videos below).
  • Android, as you know it’s something I’ve been pushing for years. Finally we are getting to a space where the IDE can help get some set up troubles out of the way.
  • The local host, i.e. what we have now.

And remember KDevelop is extensible. Do you want snapcraft?, vagrant?, mock? Contributions are very welcome!

If there’s something better than a list of technologies and buzzwords, that’s videos. Let’s see why this could change how you develop your software.

One development, any platform

We get to develop an application and switch back and forth the target platform we are developing for.

Here I put together a short video that tests Blinken on different platforms:

One development, any device

Using the right SDK is not enough proof that the application will work as expected on every device, especially those our users will be using. Being able to easily send our application to another device to test and play around with is something I had needed for longtime. Especially important when we need to test different form factors or input devices.

In this video we can see how we can easily test an application locally and when it works just switch to Android and send to the device for proper test on the smaller touch screen.

Here we can see how we can just test an application by executing it remotely on another device. This is done by creating a bundle of the application, sending it to the device where we want to test it and executing it there.

Hassle-free contributions

You can’t deny it. You’ve wanted to fix things in the past, but you couldn’t be bothered with setting up the development environment. Both Flatpak and Docker offer the possibility to maintainers to distribute recipes to set up development platforms that can and should be integrated so that we can dedicate this 1 hour in the week-end to fixing that bug that’s been annoying us rather than reading a couple of wikis and – oh, well, never mind, gotta make dinner.

We can do this either by providing the flatpak-builder json manifest (disclaimer: the video is quite slow).

Or a Dockerfile.

You can try this today by building kdevelop git master branch, feedback is welcome. Or wait for KDevelop 5.2 later this year. 🙂

Happy hacking!

Sprinting KDE Connect

What will happen?

KDE Connect is nowadays on a sweet moment where many things can happen. This is an interesting moment to sprint, because it will allow all of us to work together on interesting features that can then be merged at once with greater impact.

The things that are the most important to me are:

  • The Plasma Phone port. See more below.
  • Improvements on the Plasma Desktop integration. Currently it’s a bit weird. It mostly works, but then it’s currently lacking any interaction with the remote devices. We should review what it does and what can we do to offer what the user actually needs.
  • Using the phone (or any other device) to transparently provide data to the desktop system. We have many interesting listed ideas. Use the phone to provide location, the phone’s microphone and camera, etc.
  • File system synchronization

What will I do?

One of the things I’ve been working on lately is a new KDE Connect client. Initially with the Plasma Phone in mind, this new application opens a new window of opportunity also on other platforms. First of all, it should be right away usable on Jolla (when they adopt a saner set of dependencies) and the Ubuntu Phone.

From our point of view, one of the biggest problems of KDE Connect is that we have a hard time to pivot over to other deskop-based platforms, mostly because our desktop approach so far is a plasmoid, which isn’t very portable. Having a standalone application will help as well to reach such platforms as well.

Another thing I’d like to work on further is KDE software integration on Android. Things should be set by now, but we need work to shape the path further. Things like setting up the KDE Frameworks 5 CI for Android for example will be a huge step forward. Also building some other application for Android, will help us get a better overview of the current state.

Support us!

All of this will happen in the next KDE Connect sprint within the Randa Meetings. If you like KDE Connect and wish it to bloom into the tool we’re all looking forward to, consider donating!

Support KDE Sprints 2015!

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