I published an article about the recent Akademy conference on KDE’s news site, dot.kde.org. This article discusses the presentation Marco and I gave (Plasma: State of the Union), Wayland, Kirigami, Plasma Mobile and our award-winning colleague Kai. Enjoy the read!
As every year, also this year, I will be going to KDE’s yearly world summit, Akademy. This year, it will take place in Almería, Spain. In our presentation “Plasma: State of the Union“, Marco and I will talk about what’s going on in your favorite workspace, what we’ve been working on and what cool features are coming to you, and what our plans for the future are. Topics we will cover range Wayland, web browser integration, UI design, mobile and release and support planning. Our presentation will take place on Saturday at 11:05, right after the key note held by Robert Kaye. If you can’t make it to Spain next week, there will likely be video recordings, which I will post here as soon as they’re widely available.
This year’s Plasma Sprint is kindly being hosted by von Affenfels, a software company in Stuttgart, Germany, focusing on mobile apps. Let me try to give you an idea of what we’re working on this week.
One problem we’re facing in KDE is that for Linux, our most important target platform, we depend on Linux distributors to ship our apps and updates for it. This is problematic on the distro side, since the work on packaging has to be duplicated by many different people, but it’s also a problem for application developers, since it may take weeks, months or until forever until an update becomes available for users. This is a serious problem and puts us far, far behind for example deployment cycles for webapps.
Bundled app technologies such as flatpak, appimage and snap solve this problem by allowing us to create one of these packages and deploy them across a wide range of distributions. That means that we could go as far as shipping apps ourselves and cutting out the distros as middle men. This has a bunch of advantages:
- Releases and fixes can reach the user much quicker as we don’t have to wait for distros with their own cycles, policies and resources to pick up our updates
- Users can easily get the lastest version of the software they need, without being bound to what the distro ships
- Packaging and testing effort is vastly reduced as it has to only be done once, and not for every distro out there
- Distros with less man-power, who may not be able to package and offer a lot of software can make available many more appliations,…
- …and at the same time concentrate their efforts on the core of their OS
From a Plasma point of view, we want to concentrate on a single technology, and not three of them. My personal favorite is flatpak, as it is technologically the most advanced, it doesn’t rely on a proprietary and centralized server component. Unless Canonical changes the way they control snaps, flatpak should be the technology KDE concentrates on. This hasn’t been formally decided however, and the jury is still out. I think it’s important to realize that KDE isn’t served by adopting a technology for a process as important as software distribution that could be switched off by a single company. This would pose an unacceptable risk, and it would send the wrong signal to the rest of the Free software community.
How would this look like to the user? I can imagine KDE to ship applications directly. We already build our code on pretty much every commit, we are actually the best candidate to know how to build it properly. We’d integrate this seamlessly in Discover through the KDE store, and users should be able to install our applications very easily, perhaps similarly to openSUSE’s one click install, but based on appstream metadata.
We started off the meeting by going over and categorizing topics and then dove straight into the first topic: Communication and Design. There’s a new website for Plasma (and the whole of KDE) coming, thanks to the tireless work of Ken Vermette. We went over most of his recent work to review and suggest fixes, but also to get a bit excited about this new public face of Plasma. The website is part of a bigger problem: In KDE, we’re doing lots of excellent work, but we fail to communicate it properly, regularly and in ways and media that reach our target audience. In fact, we haven’t even clearly defined the target audience. This is something we want to tackle in the near future as well, so stay tuned.
But also webbrowsers….
Kai Uwe demo’ed his work on better integration of browsers: Native notifications instead of the out-of-place notifications created by the browser, controls for media player integration between Plasma and the browser (so your album artwork gets shown in the panel’s media controller), acccess to tabs, closing all incognito tabs from Plasma, including individual browser and a few more cool features. Plasma already has most of this functionality, so the bigger part of this has to be in the browser. Kai has implemented the browser side of things as an extension for Chromium (that’s what he uses, Firefox support is also planned), and we’re discussing how we can bring this extension to the attention of the users, possibly preinstalling it so you get the improvements in browser integration without having to spend a thought on it.
On and on…
We only just started our sprint, and there are many more things we’re working on and discussing. The above is my account of some things we discussed so far, but I’m planning to keep you posted.
On Monday, KDE’s Plasma team held its traditional kickoff meeting for the new development cycle. We took this opportunity to also look and plan ahead a bit further into the future. In what areas are we lacking, where do we want or need to improve? Where do we want to take Plasma in the next two years?
Our general direction points towards professional use-cases. We want Plasma to be a solid tool, a reliable work-horse that gets out of the way, allowing to get the job done quickly and elegantly. We want it to be faster and of better quality than the competition.
With these big words out there, let’s have a look at some specifics we talked about.
Release schedule until 2018
Our plan is to move from 4 to 3 yearly releases in 2017 and 2018, which we think strikes a nice balance between our pace of development, and stabilization periods around that. Our discussion of the release schedule resulted in the following plan:
- Plasma 5.9: 31 January 2017
- Plasma 5.10: May 2017
- Plasma 5.11: September 2017
- Plasma 5.12: December 2017
- Plasma 5.13: April 2018
- Plasma 5.14 LTS: August 2018
A cautionary note, we can’t know if everything exactly plays out like this, as this schedule, to a degree depends on external factors, such as Qt’s release schedule. Here’s what we intend to do, it is really our “best guess”. Still, this aligns with Qt’s plans, who are also looking at an LTS release in summer 2018. So, what will these upcoming releases bring?
UI and Theming
The Breeze icon theme will see further completion work and refinements in its existing icons details. Icon usage over the whole UI will see more streamlining work as well. We also plan to tweak the Breeze-themed scrollbars a bit, so watch out for changes in that area. A Breeze-themed Firefox theme is planned, as well as more refinement in the widget themes for Qt, GTK, etc.. We do not plan any radical changes in the overall look and feel of our Breeze theme, but will further improve and evolve it, both in its light and dark flavors.
One thing that many of our users are missing is support for a global menu similar to how MacOS displays application menus outside of the app’s window (for example at the top of the screen). We’re currently working on bringing this feature, which was well-supported in Plasma 4 back in Plasma 5, modernized and updated to current standards. This may land as soon as the upcoming 5.9 release, at least for X11.
Better support for customizing the locale (the system which shows things like time, currencies, numbers in the way the user expects them) is on our radar as well. In this area, we lost some features due to the transition to Frameworks 5, or rather QLocale, away from kdelibs’ custom, but sometimes incompatible locale handling classes.
The next releases overall will bring further improvements to our Wayland session. Currently, Plasma’s KWin brings an almost feature-complete Wayland display server, which already works for many use-cases. It hasn’t seen the real-world testing it needs, and it is lacking certain features that our users expect from their X11 session, or new features which we want to offer to support modern hardware better.
We plan to improve multi-screen rendering on Wayland and the input stack in areas such as relative pointers, pointer confinement, touchpad gestures, wacom tablet support, clipboard management (for example, Klipper). X11 dependencies in KWin will be further reduced with the goal to make it possible to start up KWin entirely without hard X11 dependencies.
One new feature which we want to offer in our Wayland session is support for scaling the contents of each output individually, which allows users to use multiple displays with vastly varying pixel densities more seamlessly.
There are also improvements planned around virtual desktops under Wayland, as well as their relation to Plasma’s Activities features. Output configuration as of now is also not complete, and needs more work in the coming months. Some features we plan will also need changes in QtWayland, so there’s some upstream bug-fixing needed, as well.
One thing we’d like to see to improve our users’ experience under Wayland is to have application developers test their apps under Wayland. It happens still a bit too often that an application ends up running into a code-path that makes assumptions that X11 is used as display server protocol. While we can run applications in backwards-compatible XWayland mode, applications can benefit from the better rendering quality under Wayland only when actually using the Wayland protocol. (This is mostly handled transparantly by Qt, but applications do their thing, so unless it’s tested, it will contain bugs.)
Plasma’s Mobile flavor will be further stabilized, and its stack cleaned up, we are further reducing the stack’s footprint without losing important functionality. The recently-released Kirigami framework, which allows developers to create convergent applications that work on both mobile and desktop form-factors, will be adjusted to use the new, more light-weight QtQuick Controls 2. This makes Kirigami a more attractive technology to create powerful, yet lean applications that work across a number of mobile and desktop operating systems, such as Plasma Mobile, Android, iOS, and others.
Planned improvements in our integration of online services are dependency handling for assets installed from the store. This will allow us to support installation of meta-themes directly from the KDE Store. We want to also improve our support for online data storage, prioritizing Free services, but also offer support for proprietary services, such as the GDrive support we recently added to Plasma’s feature-set.
We want to further increase our contributor base. We plan to work towards an easier on-boarding experience, through better documentation, mentoring and communication in general. KDE is recruiting, so if you are looking for a challenging and worthwhile way to work as part of a team, or on your individual project, join our ranks of developers, artists, sysadmins, translators, documentation writers, evangelists, media experts and free culture activists and let us help each other.
Our upcoming release, Plasma 5.8 will be the first long-term supported (LTS) release of the Plasma 5 series. One great thing of this release is that it aligns support time-frames across the whole stack from the desktop through Qt and underlying operating systems. This makes Plasma 5.8 very attractive for users need to that rely on the stability of their computers.
Qt, Frameworks & Plasma
In the middle layer of the software stack, i.e. Qt, KDE Frameworks and Plasma, the support time-frames and conditions roughly look like this:
Qt 5.6 has been released in March as the first LTS release in the Qt 5 series. It comes with a 3-year long-term support guarantee, meaning it will receive patch releases providing bug fixes and security updates.
In tune with Plasma, during the recent Akademy we have decided to make KDE Frameworks, the libraries that underlie Plasma and many KDE applications 18 months of security support and fixes for major bugs, for example crashes. These updates will be shipped as needed for single frameworks and also appear as tags in the git repositories.
The core of our long-term support promise is that Plasma 5.8 will receive at least 18 months of bugfix and security support from upstream KDE. Patch releases with bugfix, security and translation updates will be shipped in fibonacci rhythm.
To make this LTS extra reliable, we’ve concentrated the (still ongoing) development cycle for Plasma 5.8 on stability, bugfixes, performance improvements and overall polish. We want this to shine.
There’s one caveat, however: Wayland support excluded from long-term-support promises, as it is too experimental. X11 as display server is fully supported, of course.
Neon and Distros
You can enjoy these LTS releases from the source through a Neon flavor that ships an updated LTS stack based on Ubuntu’s 16.04 LTS version. openSuse Leap, which focuses on stability and continuity also ships Plasma 5.8, making it a perfect match.
The Plasma team encourages other distros to do the same.
After the 5.8 release, and during its support cycle, KDE will continue to release feature updates for Plasma which are supported through the next development cycle as usual.
Lars Knoll’s Qt roadmap talk (skip to 29:25 if you’re impatient and want to miss an otherwise exciting talk) proposes another Qt LTS release around 2018, which may serve as a base for future planning in the same direction.
It definitely makes a lot of sense to align support time-frames for releases vertically across the stack. This makes support for distributions considerably easier, creates a clearer base for planning for users (both private and institutional) and effectively leads to less headaches in daily life.
QtCon 2016 is a special event: it co-hosts KDE’s Akademy, the Qt Contributor summit, the FSFE summit, the VideoLan dev days and KDAB’s training day into one big conference. As such, the conference is buzzing with developers and Free software people (often both traits combined in one person).
Naturally, the Plasma team is there with agenda’s filled to the brim: We want to tell more people about what Plasma has to offer, answer their questions, listen to their feedback and rope them in to work with us on Plasma. We have also planned a bunch of sessions to discuss important topics, let me give some examples:
- Release Schedule — Our current schedule was based on the needs of a freshly released “dot oh” version (Plasma 5.0), Plasma 5 is now way more mature. Do we want to adjust our release schedule of 4 major versions a year to that?
- Convergence — How can we improve integration of touch-friendly UIs in our workflows?
- What are our biggest quality problems right now, and what are we going to do about it?
- How do we make Plasma Mobile available on more devices, what are our next milestones?
- How can we improve the Plasma session start?
- What’s left to make Plasma on Wayland ready for prime-time?
- How can we improve performance further?
You see, we’re going to be really busy here. You won’t see results of this next week, but this kind of meeting is important to flesh out our development for the next months and years.
Plasma 5.8 will be our first long-term supported release in the Plasma 5 series. We want to make this a release as polished and stable as possible. One area we weren’t quite happy with was our multi-screen user experience. While it works quite well for most of our users, there were a number of problems which made our multi-screen support sub-par.
Let’s take a step back to define what we’re talking about.
Multi-screen support means that connecting more than one screen to your computer. The following use cases give good examples of the scope:
- Static workstation A desktop computer with more than one display connected, the desktop typically spans both screens to give more screen real estate.
- Docking station A laptop computer that is hooked up to a docking station with additional displays connected. This is a more interesting case, since different configurations may be picked depending on whether the laptop’s lid is closed or not, and how the user switches between displays.
- Projector The computer is connected to a projector or TV.
The idea is that the user plugs in or starts up with that configuration, if the user has already configured this hardware combination, this setup is restored. Otherwise, a reasonable guess is done to put the user to a good starting point to fine-tune the setup.
This is the job of KScreen. At a technical level, kscreen consists of three parts:
- system settings module This can be reached through system settings
- kscreen daemon Run in a background process, this component saves, restores and creates initial screen configurations.
- libkscreen This is the library providing the screen setup reading and writing API. It has backends for X11, Wayland, and others that allow to talk to the exact same programming interface, independent of the display server in use.
At an architectural level, this is a sound design: the roles are clearly separated, the low-level bits are suitably abstracted to allow re-use of code, the API presents what matters to the user, implementation details are hidden. Most importantly, aside from a few bugs, it works as expected, and in principle, there’s no reason why it shouldn’t.
So much for the theory. In reality, we’re dealing with a huge amount of complexity. There are hardware events such as suspending, waking up with different configurations, the laptop’s lid may be closed or opened (and when that’s done, we don’t even get an event that it closed, displays come and go, depending on their connection, the same piece of hardware might support completely different resolutions, hardware comes with broken EDID information, display connectors come and go, so do display controllers (crtcs); and on top of all that: the only way we get to know what actually works in reality for the user is the “throw stuff against the wall and observe what sticks” tactic.
This is the fabric of nightmares. Since I prefer to not sleep, but hack at night, I seemed to be the right person to send into this battle. (Coincidentally, I was also “crowned” kscreen maintainer a few months ago, but let’s stick to drama here.)
So, anyway, as I already mentioned in an earlier blog entry, we had some problems restoring configurations. In certain situations, displays weren’t enabled or positioned unreliably, or kscreen failed to restore configurations altogether, making it “forget” settings.
Debugging these issues is not entirely trivial. We need to figure out at which level they happen (for example in our xrandr implementation, in other parts of the library, or in the daemon. We also need to figure out what happens exactly, and when it does. A complex architecture like this brings a number of synchronization problems with it, and these are hard to debug when you have to figure out what exactly goes on across log files. In Plasma 5.8, kscreen will log its activity into one consolidated, categorized and time-stamped log. This rather simple change has already been a huge help in getting to know what’s really going on, and it has helped us identify a number of problems.
A tool which I’ve been working on is kscreen-doctor. On the one hand, I needed a debugging helper tool that can give system information useful for debugging. Perhaps more importantly I know I’d be missing a command-line tool to futz around with screen configurations from the command-line or from scripts as Wayland arrives. kscreen-doctor allows to change the screen configuration at runtime, like this:
Disable the hdmi output, enable the laptop panel and set it to a specific mode
$ kscreen-doctor output.HDMI-2.disable output.eDP-1.mode.1 output.eDP-1.enable
Position the hdmi monitor on the right of the laptop panel
$ kscreen-doctor output.HDMI-2.position.0,1280 output.eDP-1.position.0,0
Please note that kscreen-doctor is quite experimental. It’s a tool that allows to shoot yourself in the foot, so user discretion is advised. If you break things, you get to keep the pieces. I’d like to develop this into a more stable tool in kscreen, but for now: don’t complain if it doesn’t work or eat your hamster.
Another neat testing tool is Wayland. The video wall configuration you see in the screenshot is unfortunately not real hardware I have around here. What I’ve done instead is run a Wayland server with these “virtual displays” connected, which in turn allowed me to reproduce a configuration issue. I’ll spare you the details of what exactly went wrong, but this kind of tricks allows us to reproduce problems with much more hardware than I ever want or need in my office. It doesn’t stop there, I’ve added this hardware configuration to our unit-testing suite, so we can make sure that this case is covered and working in the future.
Here’s a quick status update about where we currently stand with respect to multiscreen support in Plasma Desktop.
While for many people, multiscreen support in Plasma works nicely, for some of our users, it doesn’t. There are problems with restoring previously set up configurations, and around the primary display mechanism. We’re really unhappy about that, and we’re working on fixing it for all of our users. These kinds of bugs are the stuff nightmares are made of, so there’s not a silver bullet to fix everything of it, once and for all right away. Multiscreen support requires many different components to play in tune with each other, and they’re usually divided into separate processes communicating via different channels with each other. There’s X11 involved, XCB, Qt, libkscreen and of course the Plasma shell. I can easily at least three different protocols in this game, Wayland being a fourth (but likely not used at the same time as X11). There’s quite some complexity involved, and the individual components involved are actually doing their jobs quite well and have their specific purposes. Let me give an overview.
Plasma Shell renders the desktop, places panels, etc., When a new screen is connected, it checks whether it has an existing configuration (wallpaper, widgets, panels etc.) and extends the desktop. Plasma shell gets its information from QScreen now (more on that later on!)
KWin is the compositor and window manager. KWin/X11 interacts with X11 and is responsible for window management, movement, etc.. Under Wayland, it will also take the job of the graphical and display server work that X11 currently does, though mostly through Wayland and *GL APIs.
KScreen kded is a little daemon (actually a plugin) that keeps track of connected monitors and applies existing configs when they change
KScreen is a module in systemsettings that allows to set up the display hardware, positioning, resolution, etc.
Libkscreen is the library that backs the KScreen configuration. It offers an API abstraction over XRandR and Wayland. libkscreen sits pretty much at the heart of proper multiscreen support when it comes to configuring manually and loading the configuration.
The primary display mechanism is a bit of API (rooted in X11) to mark a display as primary. This is used to place the Panel in Plasma, and for example to show the login manager window on the correct monitor.
Libkscreen and Qt’s native QScreen are two different mechanism to reflect screen information. QScreen is mainly used for querying info (and is of course used throughout QtGui to place windows, get information about resolution and DPI, etc.). Libkscreen has all this information as well, but also some more, such as write support. Libkscreen’s backends get this information directly from Xorg, not going through Qt’s QScreen API. For plasmashell, we ended up needing both, since it was not possible to find the primary display using Qt’s API. This causes quite some problems since X11 is async by its nature, so essentially we ended up having “unfixable” race conditions, also in plasmashell. These are likely the root cause of the bug you’re seeing here.
This API has been added in Qt 5.6 (among a few other fixes) by Aleix Pol, one of our devs in the screen management team. We have removed libkscreen from plasmashell today and replaced it with “pure QScreen” code, since all the API we need for plasmashell is now available in the Qt we depend on.
These changes should fix much of the panel placement grief that bug 356225 causes. It does need some good testing, now it’s merged. Therefore, we’d like to see as many people, especially those reporting problem with multiscreen, to test against latest Plasma git master (or the upcoming Plasma 5.7 Beta, which is slated for release on June, 16th).
Remember the config
Another rough area that is under observation right now is remembering and picking the right configuration from a previous setup, for example when you return to your docking station which has another display connected. Bug 358011 is an example for that. Here, we get “spurious” events about hardware changes from X11, and I’m unsure where they come from. The problem is that it’s not easy to reproduce, it only happens for certain setups. This bug was likely introduced with the move to Qt 5 and Frameworks, it’s a regression compared to Plasma 4.
I’ve re-reviewed the existing code, added more autotests and made the code more robust in some places that seemed relevant, but I can’t say that we’ve found a sure solution to these problems. The code is now also better instrumented for debugging the areas at play here. Now we need some more testing of the upcoming beta. This is certainly not unfixable, but needs feedback from testing so we can apply further fixes if needed.
Code quality musings
From a software engineering point of view, we’re facing some annoying problems. It took us a long time to get upstream QScreen code to be robust and featureful enough to draw the lines between the components involved, especially QScreen and libkscreen more clearly, which certainly helps to reduce hard-to-debug race conditions involving hardware events. The fact that it’s almost impossible to properly unit test large parts of the stack (X11 and hardware events are especially difficult in that regard) means that it’s hard to control the quality. On the other hand, we’re lacking testers, especially those that face said problems and are able to test the latest versions of Qt and Plasma.
QA processes is something we spent some serious work on, on the one hand, our review processes for new code and changes to current code are a lot stricter, so we catch more problems and potential side-effects before code gets merged. For new code, especially the Wayland support, our QA story also looks a lot better. We’re aiming for near-100% autotest coverage, and in many cases, the autotests are a lot more demanding than the real world use cases. Still, it’s a lot of new code that needs some real world exposure, which we hope to get more of when users test Plasma 5.7 using Wayland.
I’ve just finished my travel preparations for this year’s Plasma sprint, which will start tomorrow with the arrival of my fellow hackers in Geneva, CH. Together with a few other groups in KDE and organized by our WikiToLearn friends, we’re honored to be guests at CERN, the European Organization for Nuclear Research where physicists and engineers are probing the fundamental structure of the universe. Of course, these scientists and engineers couldn’t do their work without Plasma, so we’re obliged to hold our meeting there. :-)
Topics range from our Wayland support to Plasma Mobile, documentation, how we can improve our desktop experience, and general planning for the next months. I’m also looking forward to some face-time with my fellow hackers, and discussions with the artists and usability experts who are holding a meeting of the visual design group in KDE. Only good stuff can come out of this.
Many thanks go to all the people who support KDE. This support makes meetings like next week’s possible. Please consider supporting us.