[RFC] store.kde.org: splitting off pre-Plasma5 Plasma themes?

[Friedrich W. H. Kossebau]

Hi,

when one goes to try some Plasme themes with Plasma5 from store.kde.org, one 
also gets a long list of KDE4 times themes. Often those due to their age even 
have high ratings & big download numbers because their were great at their 
time. so being listed first in the respective categories in the GHNS dialog 
even with Plasma5.

At the same time Plasma5 has seen some non-backward-compatible changes across 
theming, which are only visible on a closer look, but flaw the whole 
experience (especially given the old themes having high rating & download 
numbers, so "they must be good" for a user just seeing that).

Worse, the old unmaintained themes with their high rankings hide/shadow all 
those new themes created now by people, impeding the needed feedback cycle 
between users and theme creators.

What incompatible changes, you might ask? I am trying to distill a complete 
list, to write a tutorial for updating KDE4 times themes to Plasma5 times 
ones, here a short list of what I saw so far:
* "mini-*" panel-background variants got dropped, making non-full-width 
panels missing their sides
* clock hands rotation offset got changed from (0,width/2 to (width/2,width/
2)
* notes background changed to color variants
* panel/dialog/window shadows now must be provided by theme, no longer added 
by windowmanager


While there was some initial code to provide backward-compatibility using the 
"X-Plasma-API" entry in the metadata.desktop file, I have only seen one place 
trying to use that, but the list above is not handled by that (and also might 
be hard to).

At the same time all the new Plasma5-compatible themes added to store.kde.org 
do not work on any still existing KDE4 Plasma installations.

So the single category "Plasma Theme" as currently present screws both 
Plasma5, as well as those still left on KDE4 (for whatever reason, and 
officially now also unsupported by KDE).


So, what could be done to sort out all the ancient KDE4 Plasma themes?

I am no expert about GHNS. I have also no idea about the ontology used to 
organize stuff on opendesktop.org/store.kde.org, the items seem a bit random 
to me (there is "Plasma 5 Widgets", "Various Plasma 5 improvements", but 
other things are without versioning, despite being version specific like 
Wallpaper plugins)

When not knowning about technical details, I would have proposed to introduce 
a new category "Plasma 5 Themes", so the name clearly points out what target 
those themes are for (only).
And then shift either automatically any themes uploaded to opendesktop.org 
over to that new category, if their upload/update timestamp is more recent, 
or, if possible, the metadata.desktop file could be inspected and has a "X-
Plasma-API=5.0" entry. Or rely on the active theme maintainers to shift their 
product to that new category, at that time also showing a sign of "maintained 
theme".
This would allow a clean restart of the category, giving active theme 
creators all the proper attention and users only working themes (to what 
creators managed :) ), with any old cruft left in the old place, but still 
available there for manual download in case someone wants to pick content and 
e.g. port it to new Plasma5.

Though when looking at the technical details, I see plasma-themes.knsrc from 
plasma-desktop has "Categories=Plasma Theme" hardcoded, So existing 
installations will in the GHNS get feeded any content only for that category. 
And if the Plasma5-compatible themes get removed, the GHNS dialog will only 
show partially-broken ones.
Question: how grave would that be, how many people rely on that? And how 
quick could an updated plasma-themes.knsrc be pushed out to users, so the 
main transfer phase might be kept to a few weeks? Would distribution 
packagers be willing to do out-of-schedule patching of any supported Plasma 
packages to point to any new category?

Who would be the person on opendesktop.org side to assist with any changes?

Your thoughts? What alternative approaches would you prefer?

Cheers
Friedrich

PS: I am currently looking into porting Ivan's original Plasma themes Spoons, 
Glaze & Ascii to Plasma5, in cooperation with him, for some more sane visual 
alternatives, other than Fluffy Bunny & Unicorn ;) 
PPS: Also updated tutorials listed at https://techbase.kde.org/Development/
Tutorials/Plasma5#Themes a bit to Plasma5 where I could. Plan to also put 
there the Port-to-Plasma5 tutorial I assemble while doing those theme 
porting.