Re: [GUI] Integrating a GTK application into OS X

[John Ralls <jralls ceridwen us>]

On May 19, 2014, at 10:12 PM, scl <scl gplus gmail com> wrote:

> Hi,
>
> I'm developing in the GIMP project and am currently
> improving its integration into the OS X look and
> feel. As we are using GTK 2 I don't think we can use
> GTK's built-in OS X integration (in GTK+ 3.4).
> With respect to
> https://wiki.gnome.org/Projects/GTK+/OSX/Integration
> I'm improving an existing GTK+ 2 theme.
>
> While the natural goal is the tight integration into
> the OS X look and feel I'm on the other hand hesitating
> how close to the original such a theme can be to not
> infringe Apple's interests (see the Apple-vs.-Microsoft
> lawsuit years ago and the related PearOS story lately).
> From my point of view using the GTK-Quartz-Engine
> could solve it if it used the Cocoa framework instead
> of the outdated Carbon framework.
> Are there any experiences, best practices or guidelines
> to solve this integration problem?
> John, have you planned to update the GTK Quartz Engine
> soon?

No, because I don't think it's feasible. If there's any theming API exposed other than the HIToolbox that 
Richard used to write gtk-quartz-engine I haven't been able to find it. On the other hand, 5 major OS 
versions after Apple said Carbon is going away, HIToolbox is still there and still seems to be used by some 
Cocoa code.

I don't think we need to worry too much about Apple suing, or even sending lawyer letters to, Gnome over 
"look and feel". The Apple v. Microsoft case was over a whole OS (Windows 3.1), not an application running on 
Macs. They never went after M$ because Word and Excel on Macs had the Mac look and feel. Besides, Apple is 
now pretty thoroughly integrated into the Open Source Community and I think they probably understand and 
support our desire to get a better mac look and feel.

All that said, I'm not at all sure that gtk-quartz-engine is the right way to go. The API that HIToolbox 
exposes is quite limited and not really designed for theming. There are several clearlooks themes that look 
quite macish and the clearlooks engine works a whole lot better than gtk-quartz-engine ever did.

Regards,
John Ralls