Review Request: Support for transparent panel without composition

[David Nolden]

> On 2009-03-30 01:29:17, Aaron Seigo wrote:
> > an early decision was not to hack things into plasma. if someone wants translucent panels and other windows, use composition. it's the only way to do it properly. i have no interest in seeing plasma become a pile of hacks held together with chewing gum and baling wire. i left kicker's code base behind because of that "hey, look what we can do!" mentality that went into that code over the years.
> > 
> > now, this doesn't actually work in all cases (e.g. themes with solid panels), doesn't provide real translucency (e.g. see windows between the panels and the desktop), i can only imagine how this does (or doesn't) work with hiding panels and it pollutes the libplasma API with incomprehensible and very this-hack-specific methods.
> > 
> > i appreciate what you are trying to accomplish, but it's simply not in line with plasma's design principles.
> 
> Aaron Seigo wrote:
>     i also should address this comment:
>     
>     "All other major linux Desktop-Environments support transparent panels without composition"
>     
>     what other software does wrong is completely inconsequential.
>     
>     these other systems took this route at the time because at the time there was no compositing support in X11. and even when compositing did arrive, those code bases were so old and ossified and the compositing support was so crappy that nearly nobody bothered to even try taking advantage of compositing.
>     
>     but we're not writing the desktop of 5 years ago, and we're not trying to mimic the mistakes of 5 years ago, either.
>     
>     that's why, despite everyone else having a stupid xembed based system tray, we're doing something new and smarter.
>     that's why, despite everyone else shipping plain run command dialogs while people make bad clones of Quicksilver as third party add-ons, we work on krunner as a default component.
>     
>     so the "but others did it" reason is no reason at all. one needs to look at what a given thing is with fresh eyes and in the context of modern systems. and i'm not about to wait until we're the last ones doing it wrong to make the right decisions. being the first to make those decisions is not easy, and sure, being the Nth person afterwards to follow along and makes those decisions is easy. but it's a lot more rewarding to be the first ones to do something better than to only chase after other people's taillights once it is safe to do so.
> 
> David Nolden wrote:
>     The problem is that you're pushing technology  at the cost of the user. For perfectionists like me, who want a perfectly snappy desktop, or for people with badly supported video cards, composition still isn't an option. As developer of a core component of a major desktop environment, you should also have an eye at the present, not _only_ ot the future!
>     
>     About pollution of hack-specific methods: The "bool blendInterface()" function seemed the cleanes solution. But this could also be solved kdebase/plasma internally.
>     
>     Apart from that, this patch adds probably about 40 LOC, of which nothing seems to be an awful hack, while bringing a great advantage to really many _present_ users, so please think that position over again.. I fail to see how this can bring you into a maintenance nightmare.

About your technical comments:
Why should this not work with solid panels? Solid panels work just fine!
It does not provide _real_ translucency in the sense that you see windows between the panel and the desktop, but that feature is anyway nothing more than a "look what I can do" feature. I do see a problem with auto-hiding panels, since in that case it might happen more often that a panel is over a window, maybe the fake transparency should better be disabled for such a case.


- David


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On 2009-03-30 00:54:44, David Nolden wrote:
> 
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> 
> (Updated 2009-03-30 00:54:44)
> 
> 
> Review request for Plasma.
> 
> 
> Summary
> -------
> 
> Many people can not, or do not want to use composition. A semi-transparent panel highly increases the appeal of a Desktop, and there currently is only very few plasma themes available that have a nice-looking panel without transparency enabled.
> 
> All other major linux Desktop-Environments support transparent panels without composition(KDE 3.x, GNOME, and others), and since usually the only thing that needs to be visible through the panel is the Desktop itself, using a composition-less approach does not have much disadvantage here.
> 
> Here's I'm proposing a patch to achieve  this in a relatively clean way: The panel is painted and updated as if it was a plasmoid on the Desktop itself, grabbing the painted area plasma-internally directly from the  underlying desktop-view. The corresponding area of the panel is updated whenever the desktop is repainted, which means that animated plasmoids partially hidden under the panel, animations like the desktop-fading, moving plasmoids partially under the panel, etc. "just work".
> 
> Result: A nice looking panel for everyone, less work for theme designers. Please don't leave those behind who don't want or can not use desktop composition!
> 
> (Note: If you try this out, it doesn't work with all themes, since some themes seem to have no alpha-information in the non-composition case).
> 
> 
> Diffs
> -----
> 
>   trink/KDE/kdebase/workspace/plasma/containments/mid-panel/panel.cpp 940781 
>   trink/KDE/kdebase/workspace/plasma/containments/panel/panel.cpp 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/CMakeLists.txt 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/desktopview.h 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/desktopview.cpp 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/panelview.h 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/panelview.cpp 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/plasmaapp.h 940781 
>   trink/KDE/kdebase/workspace/plasma/shells/desktop/plasmaapp.cpp 940781 
> 
> Diff: http://reviewboard.kde.org/r/472/diff
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> David
> 
>