;; a function to have a delta functionnality with gwm

; how to use it: in your .profile, before any deco, do
; (load 'deltabutton)
; (: standard-behavior
;    (state-make
;       (on (buttonpress 1 alone) (if (deltabutton)
;                                     (progn (raise-window)(move-window))
;                                   (raise-window)))
;       standard-behavior				       
; ))
; (reparse-standard-behaviors)

(defaults-to deltabutton.delta 4)

(de abs (n)
    (if (> n 0) n
      (- n)))

(de deltabutton ()
    (if (and (> (current-event-code) 0)	; last event received
	     (< (current-event-modifier) 256)) ; is a buttonpress
	(tag DELTABUTTON
	     (: e-m (# (current-event-code) '(0 1 2 4)))
	     (: e-x (current-event-x))
	     (: e-y (current-event-y))
	     (: m-p (current-mouse-position))
	     (while (= (/ (# 2 m-p) 256) e-m) ; the button is still pressed
	       (: dx (abs (- (# 0 m-p) e-x)))
	       (: dy (abs (- (# 1 m-p) e-y)))
	       (if (or (> dx deltabutton.delta)
		       (> dy deltabutton.delta))
		   (exit DELTABUTTON t))
	       (: m-p (current-mouse-position)))
	     ()))
    )