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tkwait(3tk)


NAME

   tkwait - Wait for variable to change or window to be destroyed

SYNOPSIS

   tkwait variable name

   tkwait visibility name

   tkwait window name
______________________________________________________________________________

DESCRIPTION

   The  tkwait  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  variable  (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 visibility (or any abbreviation of it)  then  the
   second  argument  is  the name of a window and the tkwait 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 window (or any abbreviation of it) then the
   second argument is the name of a window and the  tkwait  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.

   While  the  tkwait 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 tkwait again, the nested
   call to tkwait must complete before the outer call can complete.

KEYWORDS

   variable, visibility, wait, window



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