archie/tk4.2/doc/HandleEvent.3

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'\"
'\" Copyright (c) 1990-1992 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" SCCS: @(#) HandleEvent.3 1.6 96/03/26 18:13:34
'\"
.so man.macros
.TH Tk_HandleEvent 3 "" Tk "Tk Library Procedures"
.BS
.SH NAME
Tk_HandleEvent \- invoke event handlers for window system events
.SH SYNOPSIS
.nf
\fB#include <tk.h>\fR
.sp
\fBTk_HandleEvent\fR(\fIeventPtr\fR)
.SH ARGUMENTS
.AS XEvent *eventPtr
.AP XEvent *eventPtr in
Pointer to X event to dispatch to relevant handler(s).
.BE
.SH DESCRIPTION
.PP
\fBTk_HandleEvent\fR is a lower-level procedure that deals with window
events. It is called by \fBTk_ServiceEvent\fR (and indirectly by
\fBTk_DoOneEvent\fR), and in a few other cases within Tk.
It makes callbacks to any window event
handlers (created by calls to \fBTk_CreateEventHandler\fR)
that match \fIeventPtr\fR and then returns. In some cases
it may be useful for an application to bypass the Tk event
queue and call \fBTk_HandleEvent\fR directly instead of
calling \fBTk_QueueEvent\fR followed by
\fBTk_ServiceEvent\fR.
.PP
This procedure may be invoked recursively. For example,
it is possible to invoke \fBTk_HandleEvent\fR recursively
from a handler called by \fBTk_HandleEvent\fR. This sort
of operation is useful in some modal situations, such
as when a
notifier has been popped up and an application wishes to
wait for the user to click a button in the notifier before
doing anything else.
.SH KEYWORDS
callback, event, handler, window