scx/scheme/xlib/event.scm

;; Thread-safe event reading *****************************************

;; wait-event blocks the current thread until an event is available,
;; and then it returns this new event.

(define (wait-event dpy)
  (if (not (> (events-queued dpy (queued-mode after-flush)) 0))
      (block-on-message-inport dpy))
  (next-event dpy))

(define (block-on-message-inport dpy) ; needs ports, locks
  (let ((port (display-message-inport dpy)))
    (disable-interrupts!)
    (if (not (char-ready? port))
	(begin 
	  (obtain-lock (port-lock port))
	  (add-pending-channel (port->channel port))
	  (wait-for-channel (port->channel port)) ;; enables interrupts
	  (release-lock (port-lock port)))
	(enable-interrupts!))))

;;; Only here until scsh provides us with select
(import-lambda-definition add-pending-channel (channel)
  "scx_add_pending_channel")

;; How to find out if there are events available *********************

(define (event-ready? display)
  (or (> (events-queued display (queued-mode already)) 0)
      (char-ready? (display-message-inport display))))

(define (events-queued display mode)
  (%events-queued (display-Xdisplay display)
		  (queued-mode->integer mode)))

(import-lambda-definition %events-queued (Xdisplay mode)
  "scx_Events_Queued")

(define-enumerated-type queued-mode :queued-mode
  queued-mode? queued-modes queued-mode-name queued-mode-index
  (already after-reading after-flush))

(define (queued-mode->integer mode)
  (queued-mode-index mode))

;; events-pending is identical to events-pending with after-flush
;; mode.

(define (events-pending display)
  (%events-pending (display-Xdisplay display)))

(import-lambda-definition %events-pending (Xdisplay)
  "scx_Events_Pending")

;; Other event reading ***********************************************

(define (next-event display)
  (let ((r (%next-event (display-Xdisplay display))))
    (complete-event r)))

(import-lambda-definition %next-event (Xdisplay)
  "scx_Next_Event")

(define (peek-event display)
  (let ((r (%peek-event (display-Xdisplay display))))
    (complete-event r)))

(import-lambda-definition %peek-event (Xdisplay)
  "scx_Peek_Event")

(define (get-motion-events window from-time to-time)
  (%get-motion-events (display-Xdisplay (window-display window))
		      (window-Xwindow window)
		      from-time to-time))

(import-lambda-definition %get-motion-events (Xdisplay Xwindow from to)
  "scx_Get_Motion_Events")

;; Sending events ****************************************************

(define (send-event display window propagate? event-mask event)
  (let ((Xdisplay (display-Xdisplay display))
	(Xwindow (window-Xwindow window))
	(mask (event-mask->integer event-mask))
	(v (any-event->vector event))
	(type (event-type->integer (any-event-type event))))
    (%send-event Xdisplay Xwindow propagate? mask v type)))

(import-lambda-definition %send-event (Xdisplay Xwindow propagate mask v type)
  "scx_Send_Event")

;; Auxiliaries *******************************************************

;; creates an event type

(define (complete-event v)
  (vector-set! v 0 (integer->event-type (vector-ref v 0)))
  (let ((constructor (event-constructor (vector-ref v 0))))
    (apply constructor (vector->list v))))

(define (event-constructor type)
  (cond
   ((or (eq? type (event-type key-press))
	(eq? type (event-type key-release))) make-key-event)
   ((or (eq? type (event-type button-press))
	(eq? type (event-type button-release))) make-button-event)
   ((eq? type (event-type motion-notify)) make-motion-event)
   ((or (eq? type (event-type enter-notify))
	(eq? type (event-type leave-notify))) make-crossing-event)
   ((or (eq? type (event-type focus-in))
	(eq? type (event-type focus-out))) make-focus-change-event)
   ((eq? type (event-type keymap-notify)) make-keymap-event)
   ((eq? type (event-type expose)) make-expose-event)
   ((eq? type (event-type graphics-expose)) make-graphics-expose-event)
   ((eq? type (event-type no-expose)) make-no-expose-event)
   ((eq? type (event-type visibility-notify)) make-visibility-event)
   ((eq? type (event-type create-notify)) make-create-window-event)
   ((eq? type (event-type destroy-notify)) make-destroy-window-event)
   ((eq? type (event-type unmap-notify)) make-unmap-event)
   ((eq? type (event-type map-notify)) make-map-event)
   ((eq? type (event-type map-request)) make-map-request-event)
   ((eq? type (event-type reparent-notify)) make-reparent-event)
   ((eq? type (event-type configure-notify)) make-configure-event)
   ((eq? type (event-type configure-request)) make-configure-request-event)
   ((eq? type (event-type gravity-notify)) make-gravity-event)
   ((eq? type (event-type resize-request)) make-resize-request-event)
   ((eq? type (event-type circulate-notify)) make-circulate-event)
   ((eq? type (event-type circulate-request)) make-circulate-request-event)
   ((eq? type (event-type property-notify)) make-property-event)
   ((eq? type (event-type selection-clear)) make-selection-clear-event)
   ((eq? type (event-type selection-request)) make-selection-request-event)
   ((eq? type (event-type selection-notify)) make-selection-event)
   ((eq? type (event-type colormap-notify)) make-colormap-event)
   ((eq? type (event-type client-message)) make-client-message-event)
   ((eq? type (event-type mapping-notify)) make-mapping-event)
   (else (error "message type not supported" type))))

;;event-type-0 event-type-1 ;; those are not defined