+++ /dev/null
-'\"
-'\" 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: @(#) DoOneEvent.3 1.6 97/05/09 18:12:05
-'\"
-.so man.macros
-.TH Tcl_DoOneEvent 3 7.5 Tcl "Tcl Library Procedures"
-.BS
-.SH NAME
-Tcl_DoOneEvent \- wait for events and invoke event handlers
-.SH SYNOPSIS
-.nf
-\fB#include <tcl.h>\fR
-.sp
-int
-\fBTcl_DoOneEvent\fR(\fIflags\fR)
-.SH ARGUMENTS
-.AS int flags
-.AP int flags in
-This parameter is normally zero. It may be an OR-ed combination
-of any of the following flag bits:
-TCL_WINDOW_EVENTS,
-TCL_FILE_EVENTS, TCL_TIMER_EVENTS, TCL_IDLE_EVENTS, TCL_ALL_EVENTS, or
-TCL_DONT_WAIT.
-.BE
-
-.SH DESCRIPTION
-.PP
-This procedure is the entry point to Tcl's event loop; it is responsible for
-waiting for events and dispatching event handlers created with
-procedures such as \fBTk_CreateEventHandler\fR, \fBTcl_CreateFileHandler\fR,
-\fBTcl_CreateTimerHandler\fR, and \fBTcl_DoWhenIdle\fR.
-\fBTcl_DoOneEvent\fR checks to see if
-events are already present on the Tcl event queue; if so,
-it calls the handler(s) for the first (oldest) event, removes it from
-the queue, and returns.
-If there are no events ready to be handled, then \fBTcl_DoOneEvent\fR
-checks for new events from all possible sources.
-If any are found, it puts all of them on Tcl's event queue, calls
-handlers for the first event on the queue, and returns.
-If no events are found, \fBTcl_DoOneEvent\fR checks for \fBTcl_DoWhenIdle\fR
-callbacks; if any are found, it invokes all of them and returns.
-Finally, if no events or idle callbacks have been found, then
-\fBTcl_DoOneEvent\fR sleeps until an event occurs; then it adds any
-new events to the Tcl event queue, calls handlers for the first event,
-and returns.
-The normal return value is 1 to signify that some event
-was processed (see below for other alternatives).
-.PP
-If the \fIflags\fR argument to \fBTcl_DoOneEvent\fR is non-zero,
-it restricts the kinds of events that will be processed by
-\fBTcl_DoOneEvent\fR.
-\fIFlags\fR may be an OR-ed combination of any of the following bits:
-.TP 27
-\fBTCL_WINDOW_EVENTS\fR \-
-Process window system events.
-.TP 27
-\fBTCL_FILE_EVENTS\fR \-
-Process file events.
-.TP 27
-\fBTCL_TIMER_EVENTS\fR \-
-Process timer events.
-.TP 27
-\fBTCL_IDLE_EVENTS\fR \-
-Process idle callbacks.
-.TP 27
-\fBTCL_ALL_EVENTS\fR \-
-Process all kinds of events: equivalent to OR-ing together all of the
-above flags or specifying none of them.
-.TP 27
-\fBTCL_DONT_WAIT\fR \-
-Don't sleep: process only events that are ready at the time of the
-call.
-.LP
-If any of the flags \fBTCL_WINDOW_EVENTS\fR, \fBTCL_FILE_EVENTS\fR,
-\fBTCL_TIMER_EVENTS\fR, or \fBTCL_IDLE_EVENTS\fR is set, then the only
-events that will be considered are those for which flags are set.
-Setting none of these flags is equivalent to the value
-\fBTCL_ALL_EVENTS\fR, which causes all event types to be processed.
-If an application has defined additional event sources with
-\fBTcl_CreateEventSource\fR, then additional \fIflag\fR values
-may also be valid, depending on those event sources.
-.PP
-The \fBTCL_DONT_WAIT\fR flag causes \fBTcl_DoOneEvent\fR not to put
-the process to sleep: it will check for events but if none are found
-then it returns immediately with a return value of 0 to indicate
-that no work was done.
-\fBTcl_DoOneEvent\fR will also return 0 without doing anything if
-the only alternative is to block forever (this can happen, for example,
-if \fIflags\fR is \fBTCL_IDLE_EVENTS\fR and there are no
-\fBTcl_DoWhenIdle\fR callbacks pending, or if no event handlers or
-timer handlers exist).
-.PP
-\fBTcl_DoOneEvent\fR may be invoked recursively. For example,
-it is possible to invoke \fBTcl_DoOneEvent\fR recursively
-from a handler called by \fBTcl_DoOneEvent\fR. This sort
-of operation is useful in some modal situations, such
-as when a
-notification dialog has been popped up and an application wishes to
-wait for the user to click a button in the dialog before
-doing anything else.
-
-.SH KEYWORDS
-callback, event, handler, idle, timer
OSDN Git Service
