Re: Alt and Command keys in the quartz backend

[Michael Natterer <mitch gimp org>]

On Tue, 2011-09-06 at 12:58 -0400, Paul Davis wrote:
> On Tue, Sep 6, 2011 at 12:49 PM, Michael Natterer <mitch gimp org> wrote:
> > On Tue, 2011-09-06 at 08:27 -0700, John Ralls wrote:
> 
>  [ ... imminent turf war ... ]
> 
> this seems to be about two different things, neither of which are in
> conflict (and i think john actually agrees with this).
> 
> 1) whether or not the Alt key should generate MOD1 as a modifier
> 2) whether or not code that wants to be cross-platform can assume that
> they can use MOD1 with its own chosen semantics
> 
> the problem is that (2) includes GTK, not just applications, and GTK
> already makes this assumption. as a result, john changed the modifier
> that alt/option generates on OS X, because (2) is not true for OS X.
> 
> if (2) was fixed so that GTK was not an example of code that assumes
> that MOD1 is free for any interpretation on any platform, then (1) is
> moot, and it really doesn't matter what the Alt key generates on OS X
> (hence, it could be MOD1).
> 
> but as long as (2) remains an issue within GTK itself, its hard to
> argue that a key that has clearly different purposes for a large body
> of platform users of OS X should be handled by GTK as if it had some
> different meaning based on another platform.

That's not what I'm asking for. The only special meaning of "Alt"
in GTK is to invoke mnemonics. Other than that, it's simply a modifier.
Same on the Mac, it's just a modifier. Let's just disable the mnemonics
on the Mac then.

The fact that the OS uses it to generate special characters is
not really relevant here. One X11 window manager "steals" key
combo A from the app, the other one key combo B, there is nothing
I can do about this.

Turning "Alt" into "Alt" fixes more than it breaks. It fixes e.g.
configuring GTK keybindings (you can easily make Alt-cursor do
word navigation then, the config file says alt, it's all correctly
mapped, the modifier says alt, and it just works).

And it's not just key bindings. Alt-click should be alt-click,
there is nothing wrong about that. If the OS decides to use it
for its own purposes, then it's the job of higher-level code
to be aware of that. 

If we need to change something in GTK as a consequence of that
change, then so be it, but please let's not do strange stuff
to the quartz' backend's modifier mapping just to accommodate
some code in GTK that was never meant to handle the Mac, but
can easily be changed to simply do it.

--Mitch