diff options
Diffstat (limited to 'nx-X11/lib/src/PeekIfEv.c')
-rw-r--r-- | nx-X11/lib/src/PeekIfEv.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/nx-X11/lib/src/PeekIfEv.c b/nx-X11/lib/src/PeekIfEv.c new file mode 100644 index 000000000..f2f2cede4 --- /dev/null +++ b/nx-X11/lib/src/PeekIfEv.c @@ -0,0 +1,84 @@ +/* + +Copyright 1986, 1998 The Open Group + +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. + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN +AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +Except as contained in this notice, the name of The Open Group shall not be +used in advertising or otherwise to promote the sale, use or other dealings +in this Software without prior written authorization from The Open Group. + +*/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" + +/* + * return the next event in the queue that satisfies the predicate. + * BUT do not remove it from the queue. + * If none found, flush, and then wait until one satisfies the predicate. + */ + +int +XPeekIfEvent ( + register Display *dpy, + register XEvent *event, + Bool (*predicate)( + Display* /* display */, + XEvent* /* event */, + char* /* arg */ + ), + char *arg) +{ + register _XQEvent *prev, *qelt; + unsigned long qe_serial = 0; + + LockDisplay(dpy); + prev = NULL; + while (1) { + for (qelt = prev ? prev->next : dpy->head; + qelt; + prev = qelt, qelt = qelt->next) { + if(qelt->qserial_num > qe_serial + && (*predicate)(dpy, &qelt->event, arg)) { + XEvent copy; + *event = qelt->event; + if (_XCopyEventCookie(dpy, &event->xcookie, ©.xcookie)) { + _XStoreEventCookie(dpy, ©); + *event = copy; + } + UnlockDisplay(dpy); + return 0; + } + } + if (prev) + qe_serial = prev->qserial_num; + _XReadEvents(dpy); + if (prev && prev->qserial_num != qe_serial) + /* another thread has snatched this event */ + prev = NULL; +#ifdef NX_TRANS_SOCKET + if (_XGetIOError(dpy)) { + UnlockDisplay(dpy); + return 0; + } +#endif + } +} + |