Re: How to support application specific theming?

["Michael Dominic K." <mdk mdk am>]

On 6/6/07, Tommi Komulainen <tommi komulainen nokia com> wrote:
> Hi,
>
> We're trying to make our theme maintenance more modular by splitting
> application specific details out of the main gtkrc, and then load the
> additional gtkrc file only by the said application. This would allow
> developing applications with specific theming needs more independently
> without having centralized gtkrc maintenance becoming a bottleneck. It
> would also improve application startup time and memory consumption when
> your Aisleriot doesn't need to load the theming also for the browser,
> the media player, the calculator, ... and so on.
>
> However there doesn't seem to be any clean way to do it with gtk
> currently.
>
> gtk_rc_parse() and gtk_rc_add_default_file() don't use the normal search
> paths for themes, but worse handling theme switching would be quite
> awful (rereading gtkrc files, replacing an absolute file in a list of
> files with another, and rereading gtkrc files again) if even possible.
>
> GnomeProgram supports loading ~/.gnome2/<application>rc if it exists,
> but that scheme doesn't allow taking the current overall theme into
> account (bluish or reddish, light or dark, etc.) and load a themed
> bitmap from the right location.
>
> Supporting plugin specific theming adds its own problems as plugins can
> be installed after the application has been started.
>
>
>
> PROPOSAL:
>
> For application specific gtkrc file loading I'm proposing to add the
> capability of loading <application>rc in addition to gtkrc,
> gtkrc@<locale> to gtk. It should seamlessly handle search paths and
> theme switching.
>
> For plugins I'm thinking of providing an API for the plugin to call when
> they're loaded (or unloaded) and the filename given as parameter would
> be added to (or removed from) the list of files to be searched for
> similar to gtkrc.
>
> Main point here is that gtk+ is already handling the 'gtkrc' file nice
> and automatic, there just seems to be missing an API for applications to
> add their own files to be handled the same way.
>
>
> Comments?

I'll only add that gtkrc separation is especially important for
bitmap-based theming. Our current hildon global gtkrc is around 168K
in size.

--
Michael.