after - Execute a command after a time delay
after ms
after ms ?script script script ...?
after cancel id
after cancel command
after idle ?script script script ...?
This command is used to delay execution of the program or to execute
a command in background after a delay. It has several forms,
depending on the first argument to the command:
- after ms
-
Ms must be an integer giving a time in milliseconds.
The command sleeps for ms milliseconds and then returns.
While the command is sleeping the application does not respond to
X events or any other events.
- after ms ?script script script ...?
-
In this form the command returns immediately, but it arranges
for a Tcl command to be executed ms milliseconds later as a
background event handler.
The delayed command is formed by concatenating all the script
arguments in the same fashion as the concat command.
The command will be executed at global level (outside the context
of any Tcl procedure).
If an error occurs while executing the delayed command then the
tkerror mechanism is used to report the error.
The after command returns an identifier that can be used
to cancel the delayed command using after cancel.
- after cancel id
-
Cancels the execution of a delayed command that
was previously scheduled.
Id indicates which command should be canceled; it must have
been the return value from a previous after command.
If the command given by id has already been executed then
the after cancel command has no effect.
- after cancel command
-
This command also cancels the execution of a delayed command.
The command argument specifies the text of the command to
be cancelled.
If there exists such a command among those whose execution is
still pending, then it is cancelled and will never be executed;
if no such command is currently pending then the after cancel
command has no effect.
- after idle script ?script script ...?
-
Concatenates the script arguments together with space
separators (just as in the concat command), and arranges
for the resulting script to be evaluated later as an idle handler
(the script runs the next time the Tk event loop is entered
and there are no events to process).
The command returns an identifier that can be used
to cancel the delayed command using after cancel.
If an error occurs while executing the script then the
tkerror mechanism is used to report the error.
tkerror
cancel, delay, sleep, time
Copyright © 1990-1994 The Regents of the University of California.
Copyright © 1994-1995 Sun Microsystems, Inc.
Copyright © 1995 Roger E. Critchlow Jr.