Re: [patch] enhanced mac drag-n-drop

[Stefan Monnier <monnier@iro.umontreal.ca>]

>   "Perform the most common action for each type of item dropped
> onto Emacs on Mac OS X.  Currently, this means:
>     * File or directory -- call `find-file'.
>     * URL -- call `browse-url-browser-function'.
>     * Text -- insert text at point."

I use my MacOSX system pretty much exclusively as an X11 server, so maybe
I don't understand enough of Mac OS X's GUI philosophy, but I believe that
the behavior by default for URL should be the same as for Text, except maybe
when the browse-url function is configured to use one of the Emacs based
webbrowsers (like W3, or emacs-w3m).
The idea is that if I want to open a URL in Safari or Firefox, I'll
drag&drop it there, whereas if I drop it onto Emacs I most likely *don't*
intend it to go to my external browser.
Of course, if I have url-handlers-mode enabled, maybe I intend URL-drops to
call find-file as well ;-)

>   (interactive "e")
>   ;; Make sure the drop target has positive co-ords before setting the
>   ;; selected frame - otherwise it won't work.  <skx@tardis.ed.ac.uk>
>   (let* ((window (posn-window (event-start event)))
>          (coords (posn-x-y (event-start event)))
>          (x (car coords))
>          (y (cdr coords)))
>     (if (and (> x 0) (> y 0))
>         (set-frame-selected-window nil window))

Under which circumstances can X and/or Y be negative?

>     (mapcar
>      (lambda (name)
>        (case (car name)

Please use dolist instead of mapcar here.

>          (text (insert (cdr name)))
>          (url (funcall browse-url-browser-function (cdr name)))

Why not (browse-url (cdr name)) ?

>          (file
>           (setq name (cdr name))
>           (if (and (file-exists-p name)
>                    (not (string-match (image-file-name-regexp) name)))
>               (find-file name)
>               (insert name)))))

What is the rationale for the (image-file-name-regexp) exception?

>      (cadd event)))
>   (raise-frame)
>   (recenter))

Why are raise-frame and recenter necessary?

> (defun mac-secondary-dnd-function (event)

Please factor out the commonality between the two functions into an
auxiliary function.

> (global-set-key [shift drag-n-drop] 'mac-secondary-dnd-function)

Does this work?  Shouldn't it be [(shift drag-n-drop)]?


        Stefan


PS: When I ask a question about a piece of code, the answer should typically
    be either to change the code, or to add a comment answering
    the question.