liquidshell in kdereview

Martin Flöser mgraesslin at
Tue Nov 7 15:42:40 GMT 2017

Am 2017-11-03 21:30, schrieb Martin Koller:
> Hi all,
> I'd like to announce an application I've implemented over the last few
> weeks - liquidshell
> liquidshell is a replacement for plasmashell
> It does not use QtQuick but instead relies on QtWidgets,
> therefore no hardware graphics acceleration is needed.


> The main motivation was to have a reliable desktop shell which does
> not hog the CPU or RAM.
> (CPU usage and stability were the things driving me mad with 
> plasmashell)
> It should be slick and have just the features I need in my daily
> work. No need having all the bells and whistles anyone can think of.
> Just have a plain, solid, fast workhorse.

I'm now playing devils advocate: which window manager are you using? If 
I understand correctly this is supposed to be a replacement for 
plasmashell in Plasma, which would mean that you use KWin.

Are you aware that KWin uses QtQuick for all its UI elements, such as 
Alt+TAB? Isn't that also a memory and resource hog? Shouldn't you come 
up with a replacement for KWin as well?

Also concerning no hardware graphics acceleration needed: who is going 
to render your UI? Do you really think the QPainter API is the best and 
most efficent to render a UI? Especially considering that in the end the 
whole thing needs to be transferred to the GPU. Are you aware that the 
compositor uses hardware acceleration to render the UI? If you don't use 
a compositor: are you aware that XServer itself uses hardware 
acceleration to render its UI (check glamor). Are you aware that if you 
don't have hardware acceleration everything is going to be rendered 
through llvmpipe? Do you really think QPainter is better than llvmpipe? 
Because I - having worked with that stuff for years in a low level area 
- doubt so.

I don't mind what you develop in your spare time. Not at all. What I 
mind is if a product is added to KDE as a competitor/replacement to a 
product I work on because of misunderstood things. What I see here is 
that you completely misunderstood what hardware acceleration means and 
gives to the system. I know, I know more than 90 % and all the 
"lightweight" people get this wrong. But you know what I observed more 
and more over the last years: people praise Plasma for the fast speed, 
responsiveness and low memory consumption. Why is that so, why do people 
no longer consider our software as bloated? Because we use QML and we 
use it well!

So if that gets added I want to have it made clear that this is not a 
"lightweight" product and I don't want it to be advertised as not using 
hardware acceleration. I don't want to see what you list in the main 
motivation. Because that will just result in people going all "KDE dev 
develops new desktop shell, because Plasma is unreliable". If that 
happens it pisses me off! And that's what's going to happen the way you 
phrased it. And what would piss me even more of is if that is due to you 
misunderstanding hardware acceleration.

KWin maintainer

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