What function does a button click call?

What function does a button click call?

[Raffaele Ricciardi]

Hello,

I am trying to determine what function gets called for a click on a
"Choose" button in a Customize buffer.

I have run "customize-face", then I have positioned point over a
"Choose" button, and then I have evaluated the expression:

     (button-at (point))

that has returned:

     #<marker (moves after insertion) at 477 in *Customize Face: Font
Lock Variable Name Face*>

This should mean that I am dealing with a button, shouldn't it?  Yet,
the expression:

     (button-get (button-at (point)) 'action)

has returned NIL.  Actually, the above expression has returned NIL for
all the button properties documented in the manual.

Any help?  Thanks.
--

Software:
  - GNU Emacs 24.3.1

Re: What function does a button click call?

[Michael Heerdegen]

Raffaele Ricciardi <rfflrccrd@gmail.com> writes:

> Any help?  Thanks.

I think the source of the confusion is the fact that customize uses
wid-edit.el, not button.el.

Both libraries use a 'button named overlay property, that's why
`button-at' doesn't fail although there is no button.el button there.

Try M-x debug-on-entry widget-button-click RET to find out what happens
when pressing the button.


HTH,

Michael.

Re: What function does a button click call?

[Michael Heerdegen]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Try M-x debug-on-entry widget-button-click RET to find out what
> happens when pressing the button.

BTW, a good strategy to find out what happens after hitting some key is
to use C-c k to see which command will be invoked, and then to M-x
debug-on-entry this command.  I do that so often that I wrote an own
command doing that, and bound it to a simple key:

(defun my-debug-on-next-key ()
  "Enter the debugger for the next command."
  (interactive)
  (let* ((keys (read-key-sequence "Debugging next key sequence..."))
         (cmd (key-binding keys)))
    (debug-on-entry cmd)
    (unwind-protect
         (call-interactively cmd keys)
      (cancel-debug-on-entry cmd))))


Regards,

Michael.