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diff --git a/tcl8.6/doc/update.n b/tcl8.6/doc/update.n new file mode 100644 index 0000000..ce0fb25 --- /dev/null +++ b/tcl8.6/doc/update.n @@ -0,0 +1,65 @@ +'\" +'\" 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. +'\" +.TH update n 7.5 Tcl "Tcl Built-In Commands" +.so man.macros +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +update \- Process pending events and idle callbacks +.SH SYNOPSIS +\fBupdate\fR ?\fBidletasks\fR? +.BE +.SH DESCRIPTION +.PP +This command is used to bring the application +.QW "up to date" +by entering the event loop repeatedly until all pending events +(including idle callbacks) have been processed. +.PP +If the \fBidletasks\fR keyword is specified as an argument to the +command, then no new events or errors are processed; only idle +callbacks are invoked. +This causes operations that are normally deferred, such as display +updates and window layout calculations, to be performed immediately. +.PP +The \fBupdate idletasks\fR command is useful in scripts where +changes have been made to the application's state and you want those +changes to appear on the display immediately, rather than waiting +for the script to complete. Most display updates are performed as +idle callbacks, so \fBupdate idletasks\fR will cause them to run. +However, there are some kinds of updates that only happen in +response to events, such as those triggered by window size changes; +these updates will not occur in \fBupdate idletasks\fR. +.PP +The \fBupdate\fR command with no options is useful in scripts where +you are performing a long-running computation but you still want +the application to respond to events such as user interactions; if +you occasionally call \fBupdate\fR then user input will be processed +during the next call to \fBupdate\fR. +.SH EXAMPLE +.PP +Run computations for about a second and then finish: +.PP +.CS +set x 1000 +set done 0 +after 1000 set done 1 +while {!$done} { + # A very silly example! + set x [expr {log($x) ** 2.8}] + + # Test to see if our time-limit has been hit. This would + # also give a chance for serving network sockets and, if + # the Tk package is loaded, updating a user interface. + \fBupdate\fR +} +.CE +.SH "SEE ALSO" +after(n), interp(n) +.SH KEYWORDS +asynchronous I/O, event, flush, handler, idle, update |