<HTML><HEAD><TITLE>Built-In Commands - tkwait manual page</TITLE></HEAD><BODY> <H3><A NAME="M2">NAME</A></H3> tkwait - Wait for variable to change or window to be destroyed <H3><A NAME="M3">SYNOPSIS</A></H3> <B>tkwait variable </B><I>name</I><BR> <B>tkwait visibility </B><I>name</I><BR> <B>tkwait window </B><I>name</I><BR> <H3><A NAME="M4">DESCRIPTION</A></H3> The <B>tkwait</B> command waits for one of several things to happen, then it returns without taking any other actions. The return value is always an empty string. If the first argument is <B><A HREF="../TkCmd/variable.htm">variable</A></B> (or any abbreviation of it) then the second argument is the name of a global variable and the command waits for that variable to be modified. If the first argument is <B>visibility</B> (or any abbreviation of it) then the second argument is the name of a window and the <B>tkwait</B> command waits for a change in its visibility state (as indicated by the arrival of a VisibilityNotify event). This form is typically used to wait for a newly-created window to appear on the screen before taking some action. If the first argument is <B>window</B> (or any abbreviation of it) then the second argument is the name of a window and the <B>tkwait</B> command waits for that window to be destroyed. This form is typically used to wait for a user to finish interacting with a dialog box before using the result of that interaction. <P> While the <B>tkwait</B> command is waiting it processes events in the normal fashion, so the application will continue to respond to user interactions. If an event handler invokes <B>tkwait</B> again, the nested call to <B>tkwait</B> must complete before the outer call can complete. <H3><A NAME="M5">KEYWORDS</A></H3> <A href="../Keywords/V.htm#variable">variable</A>, <A href="../Keywords/V.htm#visibility">visibility</A>, <A href="../Keywords/W.htm#wait">wait</A>, <A href="../Keywords/W.htm#window">window</A> <HR><PRE> <A HREF="../copyright.htm">Copyright</A> © 1992 The Regents of the University of California. <A HREF="../copyright.htm">Copyright</A> © 1994-1996 Sun Microsystems, Inc. <A HREF="../copyright.htm">Copyright</A> © 1995-1997 Roger E. Critchlow Jr.</PRE> </BODY></HTML>