after(n)                     Tk Built-In Commands                     after(n)



NAME
       after - Execute a command after a time delay

SYNOPSIS
       (after ms)

       (after ms thunk)

       (after 'cancel id)

       (after 'cancel thunk)

       (after 'idle ?thunk?)

       (after info)

       (after info id)


DESCRIPTION
       The after procedure is used to delay execution of the program or to
       execute a procedure in background after a delay.  It has several forms,
       depending on the first argument to the procedure:

       (after ms)
              Ms must be an integer giving a time in milliseconds.  The
              procedure sleeps for ms milliseconds and then returns.  While
              the procedure is sleeping the application does not respond to X
              events or any other events.

       (after ms thunk)
              In this form the procedure returns immediately, but it arranges
              for a STk procedure to be executed ms milliseconds later as a
              background event handler.  The procedure will be executed
              exactly once, at the given time.  The delayed procedure must be
              a thunk.  If an error occurs while executing the delayed
              procedure then the tkerror mechanism is used to report the
              error.  The after procedure returns a symbol that can be used to
              cancel the delayed procedure using after cancel.

       (after 'cancel id)
              Cancels the execution of a delayed procedure that was previously
              scheduled.  Id indicates which procedure should be canceled;  it
              must have been the return value from a previous after procedure.
              If the procedure given by id has already been executed then the
              after cancel procedure has no effect.

       (after 'cancel thunk)
              This procedure also cancels the execution of a delayed
              procedure. If there is a pending procedure that matches thunk,
              it is cancelled and will never be executed; if no such procedure
              is currently pending then the after cancel procedure has no
              effect.

       (after 'idle thunk)
              Arranges for the given thunk to be evaluated later as an idle
              handler The script will be run exactly once, the next time the
              Tk event loop is entered and there are no events to process.
              The procedure returns an identifier that can be used to cancel
              the delayed procedure using after cancel.  If an error occurs
              while executing the script then the tkerror mechanism is used to
              report the error.

       (after 'info id)

       (after 'info)
              This procedure returns information about existing event
              handlers.  If no id argument is supplied, then the procedure
              returns a list of the identifiers for all existing event
              handlers created by the after procedure for this interpreter.
              If id is supplied, it specifies an existing handler; id must
              have been the return value from some previous call to after and
              it must not have triggered yet or been cancelled.  In this case
              the procedure returns a list with two elements.  The first
              element of the list is the script associated with id, and the
              second element is either idle or timer to indicate what kind of
              event handler it is.



SEE ALSO
       tkerror



STk                                   3.1                             after(n)
