Wayland
Wayland is a protocol for a compositor to talk to its clients, as well as a library implementing this protocol. All major Linux desktop systems like Gnome, KDE do support Wayland, and there is also a reference implementation for a compositor called "Weston". XWayland implements a compatibility layer to seamlessly run legacy X11 applications on Wayland.
Contents
- 1 Requirements
- 2 Weston
- 3 GUI libraries
- 4 Window managers and desktop shells
-
5 Troubleshooting
- 5.1 Running graphical applications as root
- 5.2 LLVM assertion failure
- 5.3 Slow motion, graphical glitches, and crashes
- 5.4 nemo
- 5.5 X11 on tty1, wayland on tty2
- 5.6 gnome wayland on tty1, weston on tty2
- 5.7 weston-terminal
- 5.8 liteide
- 5.9 screen recording
- 5.10 remote display
- 5.11 Remote desktop and VM window input grabbing
- 6 See also
Requirements
Wayland only works on systems using KMS. As Wayland is only a library, it is useless on its own: to replace the X Server you need a compositor such as #Weston.
Buffer API support
For the GPU driver and Wayland composer to be compatible they must support the same buffer API. There are two main APIs: GBM and EGLStreams.
Buffer API | GPU driver support | Wayland compositor support |
---|---|---|
GBM | All except NVIDIA | All |
EGLStreams | NVIDIA | GNOME, Sway (from 0.13) |
Weston
Weston is the reference implementation of a Wayland compositor.
Installation
Install the weston package.
Usage
Cmd | Action |
---|---|
Ctrl+Alt+Backspace
|
Quit Weston |
Super+Scroll (or PageUp /PageDown )
|
Zoom in/out of desktop |
Super+Tab
|
Switch windows |
Super+LMB
|
Move Window |
Super+MMB
|
Rotate Window ! |
Super+RMB
|
Resize Window |
Super+Alt+Scroll
|
Change window opacity |
Super+K
|
Force Kill Active Window |
Super+KeyUp/KeyDown
|
Switch Prev/Next Workspace |
Super+Shift+KeyUp/KeyDown
|
Grab Current Window and Switch Workspace |
Super+Fn
|
Switch to Workspace n |
Super+S
|
Take a screenshot |
Super+R
|
Record a screencast. |
Now that Wayland and its requirements are installed you should be ready to test it out.
It is possible to run Weston inside a running X session:
$ weston
Alternatively, to try to launch Weston natively, switch to a terminal and run:
$ weston-launch
Then at a TTY within Weston, you can run the demos. To launch a terminal emulator:
$ weston-terminal
To move flowers around the screen:
$ weston-flower
To display images:
$ weston-image image1.jpg image2.jpg...
Configuration
Example configuration file for keyboard layout, module selection and UI modifications. See weston.ini(5) for full details. The Weston outputs differ slightly from xorg.conf
's Monitors:
$ ls /sys/class/drm card0 card0-VGA-1 card1 card1-DVI-I-1 card1-HDMI-A-1 card1-VGA-2
card0
is the unused built-in video adapter. The add-on adapter card1
is cabled to one HDMI and one DVI monitor, so the output names are HDMI-A-1
and DVI-I-1
.
~/.config/weston.ini
[core] # xwayland support modules=xwayland.so [libinput] enable_tap=true [shell] background-image=/usr/share/backgrounds/gnome/Aqua.jpg background-color=0xff002244 panel-color=0x90ff0000 locking=true animation=zoom close-animation=fade focus-animation=dim-layer #binding-modifier=ctrl #num-workspaces=6 ### for cursor themes install xcursor-themes pkg from Extra. ### #cursor-theme=whiteglass #cursor-size=24 ### tablet options ### #lockscreen-icon=/usr/share/icons/gnome/256x256/actions/lock.png #lockscreen=/usr/share/backgrounds/gnome/Garden.jpg #homescreen=/usr/share/backgrounds/gnome/Blinds.jpg #animation=fade ### for Laptop displays ### #[output] #name=LVDS1 #mode=1680x1050 #transform=90 #[output] #name=VGA1 # The following sets the mode with a modeline, you can get modelines for your preffered resolutions using the cvt utility #mode=173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync #transform=flipped #[output] #name=X1 #mode=1024x768 #transform=flipped-270 [input-method] #path=/usr/lib/weston/weston-keyboard [keyboard] keymap_rules=evdev #keymap_layout=gb,de #keymap_options=caps:ctrl_modifier,shift:both_capslock_cancel ### keymap_options from /usr/share/X11/xkb/rules/base.lst ### numlock-on=true [terminal] #font=DroidSansMono #font-size=14 [launcher] icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png path=/usr/bin/weston-terminal [launcher] icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png path=/usr/bin/gnome-terminal [launcher] icon=/usr/share/icons/hicolor/24x24/apps/firefox.png path=/usr/bin/firefox [launcher] icon=/usr/share/weston/icon_flower.png path=/usr/bin/weston-flower [screensaver] # Uncomment path to disable screensaver path=/usr/libexec/weston-screensaver duration=600
Minimal weston.ini
:
~/.config/weston.ini
[core] modules=xwayland.so [keyboard] keymap_layout=gb [output] name=LVDS1 mode=1680x1050 transform=90 [launcher] icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png path=/usr/bin/weston-terminal [launcher] icon=/usr/share/icons/hicolor/24x24/apps/firefox.png path=/usr/bin/firefox
XWayland
Install the xorg-server-xwayland package.
When you want to run an X application from within Weston, it spins up Xwayland to service the request. The following configuration is shown above:
~/.config/weston.ini
[core] modules=xwayland.so
Screencast recording
Weston has build-in screencast recording which can be started and stopped by pressing the Super+r
key combination. Screencasts are saved to the file capture.wcap
in the current working directory of Weston.
The WCAP format is a lossless video format specific to Weston, which only records the difference in frames. To be able to play the recorded screencast, the WCAP file will need to be converted to a format which a media player can understand. First, convert the capture to the YUV pixel format:
$ wcap-decode capture.wcap --yuv4mpeg2 > capture.y4m
The YUV file can then be transcoded to other formats using FFmpeg.
High DPI displays
For Retina or HiDPI displays, use:
~/.config/weston.ini
[output] name=... scale=2
Shell font
Weston uses the default sans-serif font for window title bars, clocks, etc. See Font configuration#Replace or set default fonts for instructions on how to change this font.
GUI libraries
See details on the official website.
GTK+ 3
The gtk3 package has the Wayland backend enabled. GTK+ will default to the X11 backend, but this can be overridden by modifying an environment variable: GDK_BACKEND=wayland
.
Qt 5
The qt5 package from the repositories has the Wayland support if qt5-wayland is installed.
To run a Qt 5 app with the Wayland plugin, set the QT_QPA_PLATFORM=wayland-egl
environment variable. For Arch, most QT applications do not work because of QTBUG-58423, will be fixed with qt-5.9: https://codereview.qt-project.org/#/c/184278/ .
Clutter
The Clutter toolkit has a Wayland backend that allows it to run as a Wayland client. The backend is enabled in the official package in extra.
To run a Clutter app on Wayland, set CLUTTER_BACKEND=wayland
.
SDL
Experimental wayland support is now in SDL 2.0.2 and enabled by default on Arch Linux.
To run a SDL application on Wayland, set SDL_VIDEODRIVER=wayland
.
GLFW
Experimental wayland support is now in GLFW 3.1 and can be enabled with the -DGLFW_USE_WAYLAND=ON
CMake option at compile time. You can also install the package glfw-wayland-gitAUR from the AUR.
EFL
EFL has complete Wayland support. To run a EFL application on Wayland, see Wayland project page.
Window managers and desktop shells
Name | Type | Description |
---|---|---|
GNOME | Stacking | See GNOME#Starting GNOME. |
sway | Tiling | Sway is an i3-compatible window manager for Wayland. Github |
Enlightenment | Stacking | More Info |
KDE Plasma | Stacking | See KDE#Starting Plasma |
Orbment | Tiling | orbment (previously loliwm) is a tiling WM for Wayland. |
Velox | Tiling | Velox is a simple window manager based on swc. It is inspired by dwm and xmonad. |
Orbital | Stacking | Orbital is a Wayland compositor and shell, using Qt5 and Weston. The goal of the project is to build a simple yet flexible and good looking Wayland desktop. It is not a full fledged DE but rather the analogue of a WM in the X11 world, such as Awesome or Fluxbox. |
Liri Shell | Stacking | Liri Shell is the desktop shell for Liri, built using QtQuick and QtCompositor as a compositor for Wayland. |
Maynard | (Unclear) | Maynard is a desktop shell client for Weston based on GTK. It was based on weston-gtk-shell, a project by Tiago Vignatti. |
Motorcar | (Unclear) | Motorcar is a wayland compositor to explore 3D windowing using Virtual Reality. |
Way Cooler | Tiling | way-coolerAUR is a customizeable (lua config files) Wayland compositor written in Rust. Inspired by i3 and awesome. |
Maze Compositor | Floating 3D | Maze Compositor is a 3D Qt based wayland compositor |
Grefsen | Floating | Grefsen is a Qt/Wayland compositor providing a minimal desktop environment. |
Some of installed wayland desktop clients might store information in /usr/share/wayland-sessions/*.desktop
files about how to start them in wayland.
Troubleshooting
Running graphical applications as root
Trying to run a graphical application as root via su, sudo or pkexec in a Wayland session (e.g. GParted or Gedit), be it in a terminal emulator or from a graphical component, will fail with an error similar to this:
$ sudo gedit No protocol specified Unable to init server: Could not connect: Connection refused (gedit:2349): Gtk-WARNING **: cannot open display: :0
Before Wayland, running GUI applications with elevated privileges could be properly implemented by creating a Polkit policy, or more dangerously done by running the command in a terminal by prepending the command with sudo
; but under (X)Wayland this does not work anymore as the default has been made to only allow the user who started the X server to connect clients to it (see the bug report and the upstream commits it refers to).
The most straightforward workaround is to use xhost to temporarily allow the root user to access the local user's X session. To do so, execute the following command as the current (unprivileged) user[1]:
xhost si:localuser:root
To remove this access after the application has been closed:
xhost -si:localuser:root
LLVM assertion failure
If you get an LLVM assertion failure, you need to rebuild mesa without Gallium LLVM until this problem is fixed.
This may imply disabling some drivers which require LLVM. You may also try exporting the following, if having problems with hardware drivers:
$ export EGL_DRIVER=/usr/lib/egl/egl_gallium.so
Slow motion, graphical glitches, and crashes
Gnome-shell users may experience display issues when they switch to Wayland from X. One of the root cause might be the CLUTTER_PAINT=disable-clipped-redraws:disable-culling
set by yourself for Xorg-based gnome-shell. Just try to remove it from /etc/environment
or other rc files to see if everything goes back to normal.
nemo
(20161229) prevent that the desktop is created <ref>nemo issue 1343</ref>
gsettings set org.nemo.desktop show-desktop-icons false
X11 on tty1, wayland on tty2
(20161209) windows of gnome applications end up on tty2 no matter where started (gnome issue 774775)
gnome wayland on tty1, weston on tty2
(20170106) apps started on gnome with WAYLAND_DISPLAY set to westen make it not respond any more (wayland issue 99489)
weston-terminal
(20161229) core dump when started on gnome
liteide
(20161229) core dump] on gnome and weston.
screen recording
(20161229) As of November 2016 there is an ongoing discussion how to implement screen recording. Currently the compositors implement at least basic functionality.
remote display
(20161229) there was a merge of FreeRDP into weston in 2013, enabled via compile time switch. The arch linux weston package currently has it not enabled.
Remote desktop and VM window input grabbing
Wayland does not allow exclusive input device grabbing (e.g. keyboard, mouse) by an application and to constrict the region of the input device to the application's window (freedesktop bug, Redhat, also related [2] and [3]).
This feature is needed in order to send hotkey combinations and modifiers to remote desktop and virtual machine windows. Also, the mouse pointer will not be restricted to the application's window which might cause a parallax effect where the location of the mouse pointer inside the window (VM or remote desktop) is displaced from the host's mouse pointer.
This limitation exists for both native Wayland and XWayland windows and keyboard handling extensions were proposed for both: XWayland and native Wayland clients.
There are Wayland protocol extensions for handling of the mouse pointer (and other pointing devices) in Wayland but compositors need to implement them so support in compositors might differ from one another, see relative pointer motion events and constraining pointer motions. Similar support already been added to XWayland, but again, compositors need implement this.