71 lines
2.2 KiB
Scheme
71 lines
2.2 KiB
Scheme
;; Thread-safe event reading *****************************************
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;; wait-event blocks the current thread until an event is available,
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;; and then it returns this new event.
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(define (wait-event dpy)
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(if (> (events-queued dpy (queued-mode after-flush)) 0)
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(next-event dpy)
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(begin
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(really-wait-event dpy)
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(wait-event dpy))))
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(define (really-wait-event dpy . maybe-timeout)
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;; selects on the port to the X-server and on the internal wakeup
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;; pipe. We get woke up, if a Xlib-call reads events and puts them
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;; in the Xlib-internal event queue in our back. See
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;; general-after-function.
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(let* ((message-port (display-message-inport dpy))
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(wakeup-port (display-wakeup-inport dpy))
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(l (select-port-channels (if (null? maybe-timeout)
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#f
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(car maybe-timeout))
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message-port
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wakeup-port)))
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;; read all characters from the wakeup-port
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(if (member wakeup-port l)
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(let loop ()
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(if (char-ready? wakeup-port)
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(begin
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(read-char wakeup-port)
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(loop)))))
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(member message-port l)))
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;; How to find out if there are events available *********************
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(define-enumerated-type queued-mode :queued-mode
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queued-mode? queued-modes queued-mode-name queued-mode-index
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(already after-reading after-flush))
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(define-exported-binding "scx-queued-mode" :queued-mode)
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(import-xlib-function events-queued (display mode)
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"scx_Events_Queued")
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(define (event-ready? display)
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(or (> (events-queued display (queued-mode already)) 0)
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(char-ready? (display-message-inport display))))
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;; events-pending is identical to events-queued with after-flush
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;; mode.
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(import-xlib-function events-pending (display)
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"scx_Events_Pending")
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;; Other event reading ***********************************************
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(import-xlib-function next-event (display)
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"scx_Next_Event")
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(import-xlib-function peek-event (display)
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"scx_Peek_Event")
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;; returns a list of (time . (x . y)) elements
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(import-xlib-function get-motion-events (display window from to)
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"scx_Get_Motion_Events")
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;; Sending events ****************************************************
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(import-xlib-function send-event (display window propagate mask event)
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"scx_Send_Event")
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