Plasma Next - Translations KCM - What Languages?

[John Layt]

Hi,

I'm doing some more work on the new KCM for Translations, i.e. the KCM in 
Plasma Next to configure the LANGUAGE env var that startkde will export for 
all apps running under Plasma Next to use, including Gtk as well as Qt apps.  
Because this is now the workspace/desktop wide setting, and not the setting 
for just KDE apps under all workspaces, the way the current KCM works may no 
longer be valid.

The current Languages KCM has two columns, "Available Languages" and 
"Preferred Languages".  The Available Languages is populated with the list of 
all KDE translations installed by calling KLocale::installedLanguages(), i.e. 
all the QStandardPaths::GenericDataLocation/locale/*/entry.desktop files 
installed.

Now, that seems a fine idea, until you think about non-KDE apps that may have 
other translation languages installed which won't get listed.  Are we 
concerned about those?  Is there a common cross-distro way to find out all 
languages that are installed?  Do we just scan all the locale/*/LC_MESSAGES/* 
or locale-bundle/*/LC_MESSAGES/* entries installed to get all the possible 
languages (and what is the difference between locale and locale-bundle)?  Or 
do we list all languages regardless of whether they are installed or not 
(probably way too many)?

If we stick with just KDE translations installed, do we copy the 
KLocale::installedLanguages() code (will we still be installing the 
entry.desktop files?), or use the new 
KLocalizedString::availableApplicationTranslations() method which requires 
setting an Application Domain to define which LC_MESSAGES file to look for (if 
so, which one)?

Cheers!

John.