WinEvent.c revision b4ee4795 
1/*
2
3Copyright 1985, 1998  The Open Group
4
5Permission to use, copy, modify, distribute, and sell this software and its
6documentation for any purpose is hereby granted without fee, provided that
7the above copyright notice appear in all copies and that both that
8copyright notice and this permission notice appear in supporting
9documentation.
10
11The above copyright notice and this permission notice shall be included in
12all copies or substantial portions of the Software.
13
14THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
17OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
18AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
19CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20
21Except as contained in this notice, the name of The Open Group shall not be
22used in advertising or otherwise to promote the sale, use or other dealings
23in this Software without prior written authorization from The Open Group.
24
25*/
26
27#define NEED_EVENTS
28#ifdef HAVE_CONFIG_H
29#include <config.h>
30#endif
31#include "Xlibint.h"
32
33extern long const _Xevent_to_mask[];
34#define AllPointers (PointerMotionMask|PointerMotionHintMask|ButtonMotionMask)
35#define AllButtons (Button1MotionMask|Button2MotionMask|Button3MotionMask|\
36		    Button4MotionMask|Button5MotionMask)
37
38/*
39 * Return the next event in the queue
40 * for the given window matching one of the events in the mask.
41 * Events earlier in the queue are not discarded.
42 * If none found, flush, and then wait until an event arrives which
43 * matches.
44 */
45
46int
47XWindowEvent (
48        register Display *dpy,
49	Window w,		/* Selected window. */
50	long mask,		/* Selected event mask. */
51	register XEvent *event)	/* XEvent to be filled in. */
52{
53	register _XQEvent *prev, *qelt;
54	unsigned long qe_serial = 0;
55
56        LockDisplay(dpy);
57
58	/* Delete unclaimed cookies */
59	_XFreeEventCookies(dpy);
60
61	prev = NULL;
62	while (1) {
63	    for (qelt = prev ? prev->next : dpy->head;
64		 qelt;
65		 prev = qelt, qelt = qelt->next) {
66		if ((qelt->event.xany.window == w) &&
67		    (qelt->event.type < GenericEvent) &&
68		    (_Xevent_to_mask[qelt->event.type] & mask) &&
69		    ((qelt->event.type != MotionNotify) ||
70		     (mask & AllPointers) ||
71		     (mask & AllButtons & qelt->event.xmotion.state))) {
72		    *event = qelt->event;
73		    _XDeq(dpy, prev, qelt);
74		    UnlockDisplay(dpy);
75		    return 0;
76		}
77	    }
78	    if (prev)
79		qe_serial = prev->qserial_num;
80	    _XReadEvents(dpy);
81	    if (prev && prev->qserial_num != qe_serial)
82		/* another thread has snatched this event */
83		prev = NULL;
84	}
85}
86