SDDM 0.21 Display Manager Released With Better Wayland Support, Qt6 Fixes

[Daktyl198]

Perhaps I was not clear enough. Why does a DM need to implement a Wayland-anything in order to work? Why can't it handle painting stuff on its own? You know, the good, old, put a picture in the background, two input fields and some buttons on top and be done with it.

Because unless you want what basically amounts to a TUI, or X11's ugly as sin CDE, you need a fair bit of complex rendering code. And why would you re-implement all of that yourself, on every single DM, when it already exists for you in the form of Wayland compositors? The same reason they all used X previously. It just so happens that it's even simpler using the Wayland system than it was with X.org.

Also, if you want a really simple DM, TUI display managers exist and are awesome. I use one myself. They only struggle a bit with mixed-resolution multi-monitor setups, but that's fine by me.

[Daktyl198]

that's what i asked, and what you said is what i expected but was not sure. Because i thought maybe it would matter if you load something in diwsplay manager stage compared to DE stage. But yes, that was dumb thing to be unsure of. Because obviously the kernel does not care.

Plus, the DM never exits. It just detaches itself from the screen so that the DE's compositor can take over. The libraries that the DM uses are never unloaded afaik.

[Noitatsidem]

Perhaps I was not clear enough. Why does a DM need to implement a Wayland-anything in order to work? Why can't it handle painting stuff on its own? You know, the good, old, put a picture in the background, two input fields and some buttons on top and be done with it.

I'm no expert, but I think you're missing the part where it needs to talk to your hardware.

[varikonniemi]

Plus, the DM never exits. It just detaches itself from the screen so that the DE's compositor can take over. The libraries that the DM uses are never unloaded afaik.

And even if they were, woulkdn't they still exist as cached in kernel?

[bug77]

I'm no expert, but I think you're missing the part where it needs to talk to your hardware.

Drivers is all you need for that. But no, you really don't need to talk to the hardware for a simple UI.

[Nocifer]

You wouldn't believe it but in order for the display (actually "graphical login") manager to support Wayland it needs to implement ... a Wayland server. That sounds almost comical in its brutal complexity and senselessness. Please ignore this comment. I'm rending the air. No one cares.

1) SDDM doesn't need to implement a Wayland server in Wayland mode any more than it needs to implement an X server in X mode. Or do you actually believe that SDDM implements an X server? Oh, do forgive me, I keep forgetting that you're not actually a developer who can actually read code.

2) Is this grey, barely legible text your new passive-aggressive way of protesting the imaginary harassment you are forced to endure in these here forums? Great job as always, birdie.

Perhaps I was not clear enough. Why does a DM need to implement a Wayland-anything in order to work? Why can't it handle painting stuff on its own? You know, the good, old, put a picture in the background, two input fields and some buttons on top and be done with it.

If I had to venture a guess, I'd say it's for the same reason(s) that a DE or any other program can't (or shouldn't) handle painting stuff on its own.

[Steffo]

You wouldn't believe it but in order for the display (actually "graphical login") manager to support Wayland it needs to implement ... a Wayland server. That sounds almost comical in its brutal complexity and senselessness. Please ignore this comment. I'm rending the air. No one cares.

Qt provides a Wayland server. No need to reimplemend it.

[tildearrow]

You wouldn't believe it but in order for the display (actually "graphical login") manager to support Wayland it needs to implement ... a Wayland server. That sounds almost comical in its brutal complexity and senselessness. Please ignore this comment. I'm rending the air. No one cares.

Fact: the color makes your message more attractive.

Well, at least it's better than running an entire X server just to launch a Wayland session, huh?
Or does SDDM still require an X server?

[blacknova]

Perhaps I was not clear enough. Why does a DM need to implement a Wayland-anything in order to work? Why can't it handle painting stuff on its own? You know, the good, old, put a picture in the background, two input fields and some buttons on top and be done with it.

It probably doesn't need too. I'm pretty sure if it was strictly necessary it is possible to implement DM on top of framebuffer, but you'd need graphics toolkit supporting working with framebuffer as well as implementing event processing pipeline.

[mrg666]

That was an unfortunate start of the thread. SDDM uses kwin here on my computer(s) for Wayland compositor.

See here
Add the following as a parameter to CompositorCommand into the SDDM config file created above (e.g. /etc/sddm.conf.d/10-wayland.conf):
/etc/sddm.conf.d/10-wayland.conf[Wayland]
CompositorCommand=kwin_wayland --drm --no-lockscreen --no-global-shortcuts --locale1