Re: OS X: Change default key bindings of CMD and ALT

[Random832 <random832@fastmail.com>]

Adrian Robert <Adrian.B.Robert@gmail.com> writes:
> These are good points.  Of course, the problem is whichever key you choose
> to be meta, you are giving up some OS defaults; it is just a question of
> which ones are more important for how many users.  But it would also be
> good to take a parallel approach to Emacs on other platforms.  Currently
> under X or Windows, the Alt/Opt key goes to meta under Emacs, despite
> having other uses in the OS.

I think you've got to take a whole picture view of this.  With a
European keyboard layout selected in X, the right Alt key (or
whichever key, since this is customizable with xkb) won't send
"Alt", but instead will be "ISO_Level3_Shift" or "Mode_Switch".
So Emacs doesn't have to do any special handling to get the
desired behavior.  Meanwhile, on Windows, the right alt key on a
European keyboard layout sends a synthetic "Left Ctrl, Right
Alt" modifier combination that can be detected and can and
should be acted on specially.

> But IIRC it is only done on one side, so the
> Alt key on the other is still available for character selection use.  (And
> maybe menu shortcut use in Windows?)
>
> Would this be implementable in either the NS or Mac ports?  And if so would
> it allow natural / acceptable use by European users?

This is not what is done now, but it can certainly easily be
implemented. This is how I set up my own configuration, with
(setq ns-right-alternate-modifier 'none) - the current default
is 'left, which makes it defer to ns-alternate-modifier (which
is 'meta)

I am not European, but I think it would probably be natural for
European users because this is how MS Windows and I _think_ most
Linux distributions are set up by default, and the right alt key
alone is labeled AltGr on PC keyboards.

I was incidentally a bit confused by the original post calling
the desired functionality "compose" - this feature is not
compose, it's third level shift.