Ever since Qt Virtual Keyboard was introduced a couple of years ago I desired to integrate it with Hawaii, especially considering the effort to make the whole workspace adapt to different devices started a while ago.
However Qt Virtual Keyboard was a value-add component for Qt Enterprise customers, until things changed recently.
As part of the recent licensing change announcement, Qt Virtual Keyboard is now available also with GPLv3 license for Open Source users in addition to commercial Qt licensees.
This move allowed me to finally integrate Qt Virtual Keyboard with Hawaii, which soon will also be available on SDDM.
Qt Virtual Keyboard will be included with Qt 5.7 but it's possible to build the sources from the git repository now, against Qt 5.6.
The virtual keyboard is an input method so activating it is as easy as setting an environment variable, as outlined in the deployment guide:
export QT_IM_MODULE=qtvirtualkeyboard
To make it easier and less error prone a setting for Hawaii has been added that you can enable from the keyboard settings.
On desktop systems the keyboard is resized so that it won't cover search and password text fields.
Several months ago I was redesigning the Hawaii launcher.
Now Green Island offers a class called ApplicationManager that emits signals when an application is registered or unregister (that is when a window of a certain class first appears or when the last one is closed). This class is also exposed by a Wayland protocol for shells that are running in another process.
Soon I noticed that for some applications the launcher panel didn't show an icon and I realized there was something wrong with the app_id (also known as the class in wl_shell_surface).
The class name identifies the general class of applications and can be used by a task manager to know which desktop entry contains application information.
Unfortunately this is not as easy as it sounds because there is no way to tell that automatically.
So back in the day I had to set the class name to the executable name as you can see here.
This approach worked almost always because desktop entries were usually named after the executable.
However things changed recently, as a matter of fact desktop file names now follow the reverse DNS convention while executables keep being called like before.
This is now achieved by QtWayland with this commit reversing the QCoreApplication::organizationDomain property and appending the executable name. If the property is not set, QtWayland falls back to the old behavior.
The patch is available on Qt 5.4.2 and 5.5.0.
TL;DR: Rename your desktop files using the reverse DNS convention and set the organizationDomain properly.
In the previous installment I forgot to post a screenshot of multiple output windows.
Here it is:
The first big chunk of code for multiple output support was recently merged into the qtwayland dev branch, but there is one more patch that is under review now.
Now I'm gonna talk about the recent development on Green Island.
Refactoring
Green Island now has:
a library that people can use to make their compositors reusing Green Island bits;
an executable named "greenisland" that links to the library and loads a separate QML based home screen;
an executable named "greenisland-launcher" that helps you run the compositor in several different environments;
a QML plugin that provides additional components such as the SurfaceRenderer for QML based home screens;
Launcher
Green Island can run on a number of different setups: X11, Wayland, Raspberry Pi, KMS, you name it.
There is now a launcher that detects where it is running, sets environment variables and runs the actual compositor accordingly.
Plugins
It's now possible to write custom home screens with QML.
The format is very simple but it might change slightly until the next iteration is released:
the home screen is a directory containing QML files and it's placed under $XDG_DATA_DIRS/greenisland (for example /usr/share/greenisland/org.vendor.coolhomescreen/)
the directory has a file called Compositor.qml and this is where you connect to the compositor and get events such as when a window is mapped or unmapped and create a QML window representation
xdg-shell
Green Island supports the old wl-shell protocol as well as the new xdg-shell protocol that is now required for weston and Gtk+ clients.
Qt clients can also use xdg-shell but it's not the default, users need to set an environment variable to enable it.
For both protocols Green Island has its implementation which is independent from the one that comes from QtCompositor.
This allows me more freedom and frees me from the qtwayland release cycle.
I want to share with you some of the progress I recently made.
This is not all, more will come in another post.
Multi output support: part 1
Green Island now supports multiple outputs.
QtCompositor only support one output so in order to do this I did a little abstraction to enumarate outputs and played with QML to show them in the compositor window.
How does it work?
It's pretty simple: it has a ScreenModel that provides data such as name, primary boolean flag and geometry. The main QML file has a repeater using this model to create an OutputView for each output.
Every OutputView has layers to stack different kind of windows (panels, lock screen, workspaces), one of the layers is HotCorners which contains 8 hot corners.
During test and development one often need to fake outputs to test several different configurations without having real monitors, but this requires a dedicated backend and a configuration format.
So ScreenModel has its own backend code, one of the backends is based on QScreen and the other is for fake outputs.
Studying the problem and doing some prototype made me realize that QScreen has a very limited API (for example it doesn't detect when the primary output changes) and that this matter was already implemented with libkscreen.
It happens to be a framework that doesn't pull in undesired dependencies, so now Green Island is using it and I have to say it saved me a lot of work.
In the video below you can see a Green Island window with two 1024x768 outputs side by side, at some point the first one (which is also primary) is removed and all the windows are migrated to the other output that is now the new primary output.
Multi output support: part 2
A single big fat window for all the outputs is not such a great idea, it was good enough to continue the development keeping multiple outputs in mind but it's not the solution in the long run.
Such a solution may hit hardware limits pretty, plus outputs can have a different refresh rate so they really should not be done this way.
QtCompositor handles only one window so I patched it to be aware of multiple outputs with one window for each of them.
The patch targets the dev branch and at the time of this writing is in the review queue.
All the QML code was reused except for the Repeater and the logic to move windows when an output goes away was moved to C++.
This means that almost none of the code previously wrote was removed.
The hard part came when I needed to figure out how to show the same surface on multiple output windows.
Considering that QQuickItems cannot be shared between multiple windows I had to create a view for each output.
When a shell surface is created for a surface, the compositor creates a view that inherits from QQuickItem, the output is assigned based on the mouse pointer coordinates. No other view is created at this time because the position is calculated to be within output bounds considering the surface size.
More views are created on demand when the surface is mapped.
As windows are moved all views are moved accordingly, global coordinates are mapped to the output coordinates so that windows are shown only where they are meant to be.
Unresponsive applications
Wayland offers a ping/pong API that compositors use to know whether a surface is responsive or not, even with CSD (in the past there was some concern about this).
When a window is clicked, Green Island ping the surface and if it doesn't reply with a pong within 200ms it marks it as unresponsive and apply a colorize effect, draw some explanatory text, and intercepts mouse input. It also adds a couple of push buttons, one to wait for the application to become available again and the other to brutally murder the application.
QtDay and FOSDEM are over and I finally took some time to update the plans for the next Hawaii version.
First things first. Next Hawaii iteration will be the 0.3.0 release.
At first I thought to do minor improvements in a 0.2.1 version and release shortly after 0.2.0 but then I decided to do more work.
Most of the stuff is already implemented at this point, but it needs further improvements.
So what should you expect for Hawaii 0.3.0?
Weston 1.4 is here now so the plugin was ported to the new version, some code refactoring is needed though to make the code more manageable.
The plugin will also support drop-down windows and a whitelist for trusted clients that need to access some Wayland interfaces (a possible usage is a screenshot application).
Shell is going to be improved with better multiple screen management, multiple panels (you can have one panel for each edge), configuration directly accessible from the panel, elements in panels can be reordered.
There was also a major refactoring, components such as dialogs, popups and overlays were moved to a plugin that can be used by external QML applications.
This was necessary in order to separate the PolicyKit agent and notifications daemon from the shell.
Other desktops (I'm thinking about LXQt here) can use these components more easily now if they wish.
Both are not launched by the shell automatically and currently there's no switch to turn them on and off but there are units for the systemd user session so you can manage them from the command line or with a graphical frontend. I can't exclude a service manager integrated in Hawaii in the future but there are no plans yet.
Compositor and deamons now notify systemd upon startup and as I mentioned above there is support for systemd user session however I'm having some problems running weston.
Screensavers. Yes it's a bit anachronistic but some people might enjoy it.
It's disabled by default and currently there is no switch to turn it on and off, later a preferences applet will be available.
As I showed during FOSDEM, now Hawaii can switch between different layouts on the fly.
This is one of the main goals of this project and goes by the name of convergence these days.
I will talk more about it in another post but the idea is to have a dedicated user interface for different devices and even react to things like input devices or screen resolution changing.
This work also make it easier to implement animated wallpapers because the shell is now much modular and can load different components.
Currently the background is implemented by a QML component that according to the settings draws a picture, a solid color or a gradient.
Animated wallpapers are just loadable QML components that does nice stuff such as animations, react to mouse click and tap to change the background and so on.
At this point it becomes clear that Hawaii needs a generic way to deal with this things, hence the standard background is going to be split in a wallpaper plugin, a solid color plugin and a gradient plugin and will be no more different than animated wallpapers.
This was written after FOSDEM but never had the time to finish it and do the video so with too many months of delay I've got some time in my hands to post about the Hawaii desktop environment responsive user interface.
Hawaii is currently focused on desktops and laptops but it's always been a goal to get ready for other devices as well supporting screens with different DPIs.
Why bother, can't we just do the same user interface and let the controls scale according to DPIs and expand contents to fit the screen size? No, we can't because there are differences between devices.
Desktops and laptops have a keyboard and most of the time a mouse and to complicate things even further they can also have a touchpad, for example I own an Apple Magic Trackpad. Mobile devices, on the other hand, have touch input, no keyboard and higher DPIs.
The same user interface cannot be used for different devices, the user expects it to suit the device.
On a tablet the user expects to see an application at a time and use several gestures, there is also less screen space so you have to design interfaces with fewer things on screen.
The opposite is true on desktop where you can show multiple windows and some tiling feature is more than welcome and since the mouse is more precise you can put more controls on the screen.
Today there are some devices like the Yoga that can alternatively be turned into either a tablet or a laptop. The only problem is that it's not cheap, I will have to save money before buying one :)
That's why I prefer calling this responsive user interface rather than convergence.
Hawaii should react on events such as screen resolution change, mouse plugged in or touch input device plugged in and load the user interface that is willing to step in and show a user interface for the current setup.
To make development easier the switch happens reading settings with the QtConfiguration library that supports changes notifications. That's enough to simulate an event. In the future I plan to use Solid to determine what's the current setup like, but maybe QScreen and QTouchDevice will be sufficient.
Most things that a desktop environment need can be shared between shells, for example lock screen management, idle state management, notifications, power management and sounds are all features that need to be done once.
With Green Island, the QML compositor, one can also plug in different ways to manage windows and panels all with their Wayland protocol interface.
This is not all. Applications need to switch the user interface too, so I've been experimenting with QFileSelector and QQmlUrlInterceptor.
In the application demo I have used QQmlUrlInterceptor.
The application has a content directory with the QML code for the desktop with the following subdirectories that override files for specific profiles: +phone, +tablet, +touch
The +touch subdirectory contains code for all touch user interface, one example is the list view delegate, +phone and +tablet override the main view (the tablet version has a menu that can be pulled from the left with a gesture while the phone version has it always visible).
For demo purpose, the user has to pass all the relevant profiles to the application so for example if I want the tablet version both touch and tablet are passed as arguments.
Here's a little video showing the switch from a tablet UI to a desktop UI and different layouts for the same application.
As you can see the tablet user interface has two panels (launcher at the bottom edge and a smaller panel with indicators on top), it also have a desktop view with a search bar and application icons. Stacked below there's the background view. The desktop user interface is the classic Hawaii shell that has a bottom panel with more elements.
Since Hawaii 0.2.0 is closer I wanted to collect some stats about its memory usage.
Measuring resources usage reliably is a bit hard, but it seems that KSysGuard provides detailed results and keep shared libraries into account.
While I'm here I will compare Hawaii with XFCE, although there's no much value in it due to the difference between the two stacks except for being aware of what another low footprint desktop is doing in its current form.
So, let's see how much memory does it take Hawaii, measuring a session with some applications open (System Preferences, Terminal, Eyesight, Swordfish and QupZilla and Communi) after using it for a while.
Currently Hawaii is using Weston although in the future it will use Green Island, a QtQuick compositor using the QtCompositor API.
As you can see from the screenshot below, there are two Weston processes running.
Weston processes
Details below:
weston process memory usage
weston-keyboard process memory usage
Total memory usage: 23.4 MB
Now let's see the desktop environment...
Hawaii Shell memory usage
dconf-service memory usage
dconf-service is included to match XFCE which has xfconfd.
Total memory usage: 64.47 MB
Compare now with a low footprint X11 desktop environment: XFCE.
In the X11 world we need two programs to cover the Weston features: the Xorg server and a window manager/compositor, XFCE uses xfwm4.
Total memory usage: 122.9 MB
From the features point of view we should compare Xorg + xfwm4 with weston (122.9 MB vs 9 MB) but I think this is due to the different architecture.
To be fair I'm measuring only XFCE components that has a Hawaii counterpart, so xfce4-power-manager is not included and judging by the package description xfconfd can be compared to dconf.
The panel-6-systray process is not included either, if it does what the name suggests then Hawaii can't match it because it doesn't support the System Tray Protocol.
xfsettingsd might be left out (although I'm not sure) because Hawaii doesn't have a daemon to propagate settings. However Hawaii doesn't need it for settings such as icon theme, widgets style, fonts etc... they are managed by a platform theme plugin but other settings such as mouse cursor theme and size would need something to propagate those settings to Qt applications as well as non-Qt applications.
XFCE doesn't have a PolicyKit agent like Hawaii, or at least I couldn't find any.
xfce4-panel memory usage
xfdesktop memory usage
xfce4-session
panel-2-actions memory usage
xfconfd memory usage
xfsettingsd
xfce4-notifyd memory usage
Total memory usage: 31.22 MB
Desktop
Usage
Weston
9 MB
Hawaii (weston-keyboard + hawaii-desktop-shell + dconf)
EDIT: As requested in the comments I capture the output of free and memuse on my Archlinux system before running Hawaii from KMS (fullscreen 2560x1440) and from the Hawaii session.
