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Revision as of 14:28, 16 December 2015 by Ofourdan (talk | contribs) (Remove X11 requirement in mutter)

Wayland Desktop features progress

This purpose of this page is to list the current missing or incomplete features in GNOME on Wayland to achieve a user experience on par with what is found on X11.

This page is not meant to list known bugs or issues with existing features, nor how to debug Wayland issues, see How to debug Wayland problems for this.

It focuses primarily on GNOME because GNOME is the default desktop on Fedora Workstation, but features may need to be implemented at different levels not necessarily part of GNOME:

* kernel: drm, evdev, etc.
* libraries: underlying libraries, e.g. libinput, libwayland, etc.
* protocol: requires a new Wayland protocol or amending an existing protocol
* Xwayland: X11 compatibility
* mutter: Wayland compositor
* gtk+: toolkit, handles client side decorations in Wayland
* apps: requires new applications

remote display

  • protocol, mutter
  • Completion: 20%

Jonas is working on this. He is getting a 'pinos stream' out of gnome-shell.

screencast

  • mutter, apps
  • Completion: 100%

Not sure whats missing here, unless you want to define a Wayland protocol for this. Recording screencasts using gnome-shell's D-Bus api works just fine today in a Wayland session.

primary selection

Lyude has a protocol suggestion and a working weston implementation. See http://lists.freedesktop.org/archives/wayland-devel/2015-December/026084.html for the protocol.

dnd actions

  • protocol, gtk+, mutter, xwayland
  • Completion: 80%

Carlos has a protocol proposal, and working implementations. See https://bugzilla.gnome.org/show_bug.cgi?id=755625

Other dnd features

  • gtk+, protocol, mutter
  • Completion: 80%

Need to complete support for

  • Drag icons (DONE)
  • Hotspots (Jonas has patches in bugzilla)
  • Reliable drag end determination (needs an event in the protocol)
  • Cancel animation (needs an event)

kinetic scrolling

  • protocol, gtk+, mutter
  • Completion: 80%

Peter has a protocol proposal and a working implementation. See https://bugzilla.gnome.org/show_bug.cgi?id=756729

input methods

  • protocol, gtk+, mutter
  • Completion: 0% (TBD)

The default input method setup in GTK+ is entirely client-side (display server send key events, the ibus module sends them over D-Bus to IBus...). I was going to say that this basically works under Wayland as well, but then my system was locking up hard while I was interacting with the Kanji character chooser popup in the shell...

Rui is supposed to work on this.

on-screen keyboard

  • protocol, mutter
  • Completion: 0% (TBD)

The on-screen keyboard in gnome-shell currently does not work under Wayland. That needs to be fixed as a starting point. Doing a better job on OSK requires moving away from a key event based protocol to something more like a text protocol, which is where this task overlaps with input methods.

Rui is supposed to work on this.

relative/locking pointer confinement

Jonas has a protocol and implementations. Will land in Wayland 1.10. See https://bugzilla.gnome.org/show_bug.cgi?id=744104

hi-dpi support

  • protocol, gtk+, mutter
  • Completion: 100%

This should be complete, modulo bugs.

attached modal dialogs

I believe this was fixed in https://bugzilla.gnome.org/show_bug.cgi?id=745720 - No, I (ofourdan) think this is for simple dialogs/parent relationship whereas many apps in gtk+ simply use the dialog type without any specfific transient and mutter on X11 treats them as "transient for the group", placing them above all other toplevels of the same group, Wayland doesn't allow for this afaik.

graphics tablet support

  • protocol, libraries, gtk+
  • Completion: 0% (TBD)

Peter and Carlos have branches for this. At least the first part of it is supposed to land in Wayland 1.10.

A bigger missing piece here is the control-center configuration support.

startup notification

  • protocol, libraries, gtk+, mutter
  • Completion: 0% (TBD)

clipboard proxy for xwayland

  • Xwayland
  • Completion: 50%

Copy/paste does work, kinda. There seem to be some cases where things don't manage to get from one side to the other; I (ajax) have hit cases where copying a URL from Firefox (an X11 app) into Evolution (wayland-native) doesn't do anything. I suspect that's due to getting selection type negotiation wrong. Pasting URLs from Firefox to gnome-terminal seems to work just fine, and I doubt g-t is doing any content type negotiation.

touch proxy for xwayland

  • protocol, gtk+, mutter, Xwayland
  • Completion: 100%

This should be complete, modulo bugs.

accessibility features

  • protocol, gtk+, mutter
  • Completion: 0% (TBD)

Screen reading (orca) works more or less the same as under X: all the accessibility traffic goes over D-Bus (the a11y bus, to be precise).

Features that need to be reimplemented in the compositor (or gtk+) include:

  • keyboard accessibility features (sticky keys, slow keys, bounce keys, sound keys, etc)
  • visual bell - titlebar flashing won't work for csd. We should just flash the entire window in that case
  • mouse accessibility features such as hover-to-click

output rotation

XRandR control of Wayland outputs

  • protocol, Xwayland
  • Completion: 0% (TBD)
  • Note: There is a "read-only" XRandR support in Xwayland, but it cannot send request back to the Wayland compositor so X11 applications have no control over the output configurations.
  • See also: https://bugzilla.redhat.com/show_bug.cgi?id=1289714

[otaylor] We SHOULD NOT implement this. It's a vehicle for a game to mess up the user's system. The conceptual equivalent in Wayland is for an app to ask for it's buffer to be scaled or modeset fullscreen - and that needs to be implemented in Mutter - but I don't see providing to Xwayland apps; anything running under X11 I think just has to live with the screen's current configuration.

Device and Driver information

  • mutter, gnome-control-center
  • Completion: 0% (TBD)

We want to show the same kind of GPU information in the Details pane of gnome-control-center that we get from GL_RENDERER under X11; currently, it just says "Wayland" there. I'm not entirely sure why this isn't done, glGetString(GL_RENDERER) works just fine under EGL.

One thing we may want to do is show that result for both EGL and GLX contexts, since they may differ.

See https://bugzilla.gnome.org/show_bug.cgi?id=756914 for the discussion, and for why GL_RENDERER is not sufficient.

screensaver control

Not sure that anything is needed here. GNOME has been doing screensaver control entirely over D-Bus for many years.

Xfree86-VidModeExtension in Xwayland

XVideo extension in Xwayland

  • Xwayland
  • Completion: 0%

Technically the extension is present, but no adaptors are exposed. This should be wired up to the subsurface protocol if possible.

Optional surface IDs

  • protocol, gtk+, mutter
  • Completion: 50%

This will be useful for xdg-app portals, so the portal can place dialogs relative to application surfaces. Jonas has a protocol proposal and an implementation.

Hotplug USB devices

  • mutter
  • Completion: 0%

The DisplayLink USB2 devices work under X now when hotplugged as an extra screen. These should remain working under wayland.

Outputs on secondary GPUs

  • mutter
  • Completion: 0%

Laptops where the external outputs are only connected to a secondary GPU needs to be supported in some form. These work under X currently using reverse prime.

Window size hints

  • protocol
  • Completion: 0%

The wayland shell protocols lack the equivalent of ICCCM's WM_NORMAL_HINTS. The resize increment is particularly useful for terminal emulators, which have to resize with character cell granularity. Mutter will display this information when resizing an X window, so this works for xterm, but not for gnome-terminal.

We've just removed resize increments from GTK+, I don't think this should be added to Wayland.

Remove X11 requirement in mutter

  • mutter
  • Completion: 0%

Quoting Owen in upstream bug 759538: Currently, mutter will start Xwayland at startup unconditionally because it still depends on "X11 backend to GTK+ for various things within Mutter and GNOME Shell, such as theme drawing and input methods. I think we'd need to eliminate the use of GTK+ for input methods, then have some no-backend mode to use GTK+ for theme drawing without actually opening a connection to a display server".