/* $XConsortium: XChkWinEv.c,v 11.21 91/02/20 18:48:51 rws Exp $ */ /* Copyright Massachusetts Institute of Technology 1985, 1987 */ /* Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of M.I.T. not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. M.I.T. makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. */ #define NEED_EVENTS #include "Xlibint.h" extern _XQEvent *_qfree; #if __STDC__ #define Const const #else #define Const /**/ #endif extern long Const _Xevent_to_mask[]; #define AllPointers (PointerMotionMask|PointerMotionHintMask|ButtonMotionMask) #define AllButtons (Button1MotionMask|Button2MotionMask|Button3MotionMask|\ Button4MotionMask|Button5MotionMask) /* * 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 XCheckWindowEvent (dpy, w, mask, event) register Display *dpy; Window w; /* Selected window. */ long mask; /* Selected event mask. */ 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 < LASTEvent) && (_Xevent_to_mask[qelt->event.type] & mask) && ((qelt->event.type != MotionNotify) || (mask & AllPointers) || (mask & AllButtons & qelt->event.xmotion.state))) { *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; }