Re: display-mm-width return value off on Windows

[David Kastrup]

Ralf Angeli <address@hidden> writes:

> * Richard Stallman (2006-07-12) writes:
>
>> This approach has a problem: it assumes there is just one display
>> (or that all displays have the same size).  The right way to do
>> this is to let the user specify the size of each display
>> individually.  It could be done with a frame parameter.
>
> Okay.  Would it then suffice to pick an arbitrary frame on the
> display given as the argument of `display-mm-width' and check the
> parameter of that frame?  That could be done with something like
>
> (let ((frame-list (frames-on-display-list display)))
>   (when frame-list
>     (frame-parameter (car frame-list) 'display-mm-width)))
>
> assuming the frame parameter is called `display-mm-width'.

Hm.  I read:

(info "(elisp) Multiple Displays")

       A few Lisp variables are "terminal-local"; that is, they have a
    separate binding for each terminal.  The binding in effect at any time
    is the one for the terminal that the currently selected frame belongs
    to.  These variables include `default-minibuffer-frame',
    `defining-kbd-macro', `last-kbd-macro', and `system-key-alist'.  They
    are always terminal-local, and can never be buffer-local (*note
    Buffer-Local Variables::) or frame-local.

Would that not be a case for a terminal-local variable?

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum