Function: mwheel--is-dir-p

mwheel--is-dir-p is a macro defined in mwheel.el.gz.

Signature

(mwheel--is-dir-p DIR BUTTON)

Source Code

;; Defined in /usr/src/emacs/lisp/mwheel.el.gz
(defmacro mwheel--is-dir-p (dir button)
  (declare (debug (sexp form)))
  (let ((custom-var (intern (format "mouse-wheel-%s-event" dir)))
        ;; N.B. that the direction `down' in a wheel event refers to
        ;; the movement of the section of the buffer the window is
        ;; displaying, that is to say, the direction `scroll-up' moves
        ;; it in.
        (event (intern (format "wheel-%s" (cond ((eq dir 'up)
                                                 'down)
                                                ((eq dir 'down)
                                                 'up)
                                                (t dir))))))
    (macroexp-let2 nil butsym button
      `(or (eq ,butsym ',event)
           ;; We presume here `button' is never nil.
           (eq ,butsym ,custom-var)))))