#include "copyright.h"

/* $XConsortium: XChkTypWEv.c,v 11.6 88/09/06 16:09:13 jim Exp $ */
/* Copyright    Massachusetts Institute of Technology    1985, 1987	 */
#define NEED_EVENTS
#include "Xlibint.h"

extern _XQEvent *_qfree;

/*
 * Check existing events in queue to find if any match.  If so, return. If
 * not, flush buffer and see if any more events are readable. If one matches,
 * return.  If all else fails, tell the user no events found.
 */

Bool
XCheckTypedWindowEvent (dpy, w, type, event)
  register Display *dpy;
  Window w;			/* Selected window. */
  int type;			/* Selected event type. */
  register XEvent *event;	/* XEvent to be filled in. */
{
  register _XQEvent *prev, *qelt;
  int n;			/* time through count */

  LockDisplay (dpy);
  prev = NULL;
  for (n = 3; --n >= 0;) {
    for (qelt = prev ? prev->next : dpy->head;
	 qelt;
	 prev = qelt, qelt = qelt->next) {
      if ((qelt->event.xany.window == w) &&
	  (qelt->event.type == type)) {
	*event = qelt->event;
	if (prev) {
	  if ((prev->next = qelt->next) == NULL)
	    dpy->tail = prev;
	}
	else {
	  if ((dpy->head = qelt->next) == NULL)
	    dpy->tail = NULL;
	}
	qelt->next = _qfree;
	_qfree = qelt;
	dpy->qlen--;
	UnlockDisplay (dpy);
	return True;
      }
    }
    switch (n) {
    case 2:
      _XEventsQueued (dpy, QueuedAfterReading);
      break;
    case 1:
      _XFlush (dpy);
      break;
    }
  }
  UnlockDisplay (dpy);
  return False;
}