UBports Is Making Progress With Unity 8 On The Desktop

[GizmoChicken]

I hope that canonical considers switching back to Unity 8 if this project gets mature enough. The Ubuntu Gnome interface is a sloppy hack.

Canonical continues to invest in Mir development for desktop use, and I rather doubt that Canonical is doing so merely as an academic exercise.

Rather, my guess is that, once Mir is feature complete (including having full Wayland compliance), if GNOME isn’t working out for Canonical, Canonical will revive Unity 8 (which is already nearly complete), or perhaps move to some other DE that could use Mir, such as MATE or Budgie 11, for example.

Again, just my guess.

[labyrinth153]

Why??? Why would you do this?

[GizmoChicken]

The Mir compositor running in Unity 8 could now support the Wayland protocol. That just means a Wayland client (eg. GTK+ apps) could run natively on Unity 8, it doesn't mean Unity 8 would be running as a Wayland client (since it's a Mir server). It's an "in addition to" not an "instead of".

bregma has considerable knowledge of Mir and Unity 8, so I feel awkward chiming in...

But just to clarify, the UBports has stated that their goal is for Unity 8 to be running as a Wayland client, eventually. And that’s a good thing, because Alan Griffiths stated that "Once Mir’s support for Wayland clients is on a par with the support for ‘native’ Mir clients we will likely phase out support for the latter."

Of course, phasing out support for “native” Mir clients is probably a long way off, which is good, because UBports isn't yet ready for Unity 8 to run as a Wayland client, and probably won't be for a long time. (And who knows, maybe the Mir team will decide to continue maintaining support for "native" Mir clients, even after support for Wayland clients is feature complete, in which case, there may be no need for Unity 8 to run as a Wayland client.)

As for the current reliance on XMir, that makes sense as a stopgap, until Mir provides better XWayland support.

Of course, if I've gotten any of the above wrong, I hope bregma will clarify my clarification.

[DanL]

Why??? Why would you do this?

Do what? Are you responding to the post before yours or the topic in general?

[GizmoChicken]

Why??? Why would you do this?

Why what? Why would who do what?

As for why UBports is working toward improving Unity 8 desktop performance, keep in mind that the devs at UBports still hope to achieve convergence: they want their phones be able to have a proper desktop mode when plugged into an external monitor.

If your question relates to why UBports continues to rely on XMir (rather than immediately moving exclusively to XWayland), XMir is being used as stopgap, until Mir provides better Wayland (and XWayland) support.

[Delgarde]

Of course, phasing out support for “native” Mir clients is probably a long way off, which is good, because UBports isn't yet ready for Unity 8 to run as a Wayland client, and probably won't be for a long time. (And who knows, maybe the Mir team will decide to continue maintaining support for "native" Mir clients, even after support for Wayland clients is feature complete, in which case, there may be no need for Unity 8 to run as a Wayland client.)

Of course, given that they never shipped a desktop running natively on Mir... are there actually many native Mir clients needing to be supported?

[GizmoChicken]

Of course, given that they never shipped a desktop running natively on Mir... are there actually many native Mir clients needing to be supported?

Aside from Unity 8 itself (and many of the apps that ship with it), probably not too many native Mir clients exist. But if Unity 8 is to run on a version of Mir that no longer supports native Mir clients, then Unity 8 (and many of the apps that ship with it) will need to be rewritten. Whether such a rewrite will require much work, or will be trivial, I don't know.

[lectrode]

Aside from Unity 8 itself (and many of the apps that ship with it), probably not too many native Mir clients exist. But if Unity 8 is to run on a version of Mir that no longer supports native Mir clients, then Unity 8 (and many of the apps that ship with it) will need to be rewritten. Whether such a rewrite will require much work, or will be trivial, I don't know.

Please excuse my ignorance, but if Mir drops support for native Mir applications, what is the point of having Mir at all instead of just using Wayland?

[GizmoChicken]

Please excuse my ignorance, but if Mir drops support for native Mir applications, what is the point of having Mir at all instead of just using Wayland?

Wayland is a protocol. To use Wayland requires a Wayland compliant compositor, such as Mutter or Kwin. The Mir dev team is, in effect, repurposing Mir to act as a Wayland compliant compositor.

A repurposed Mir (that could act as a Wayland compliant compositor on various distributions) may be helpful to smaller DE development groups that may lack the resources to develop their own Wayland complaint compositors. For example, as reported on Phoronix, Martin Wimpress (from MATE) has stated:

The rumors of Mir's death are greatly exaggerated. MATE is a very small team, with extremely constrained time. Implementing Wayland directly is, at our current development velocity, several years away IMO. If Mir could provide us a fast path to supporting Wayland we (and possibly other desktops without Wayland support) should explore it....Using Mir as the Wayland compositor, while still a chunk of work, is considerably less work.

So, you may ask, why not just use Mutter or KWin?

Given MATE's use of GTK, some think that MATE could use Mutter as a drop-in Wayland compositor. But according to Ikey Doherty ( ikey_solus) lead developer of Solus and Budgie) in this thread:

At the most fundamental level Mutter does not expose support for panel positioning or strut reservation on Wayland, nor arbitrary window placement for blessed windows, which is everything that mate-panel would actually *need* to be useful.

Of course, KWin may be more flexible than Mutter.

And actually, Budgie 11 (the future release of Budgie that will have Wayland support) is being developed with KWin. But whether Budgie 11 ultimately relies on KWin (or something else) for Wayland support remains to be seen.

Also, and not to knock KWin, but KWin was originally written for X11 and has been heavily modified to allow it to act as a Wayland-compliant compositor. In comparison, although Mir wasn't initially written to comply with the Wayland protocol, Mir was written from the ground up to achieve goals that are consistent with the goals of the Wayland protocol. So adapting the Mir display server to be Wayland compliant may be more straightforward than what's been required, thus far, to adapt KWin and Mutter to be Wayland-compliant compositors.

Hopefully, when finished, Mir will offer a generalized solution that will be easier for DE devs to apply.

[lectrode]

@GizmoChicken
Wow, that's a lot of great info (and sources to back it up to boot!). That fully answered not only my question, but follow up questions I didn't even know to ask. Thank you!