Tk_CreateTimerHandler, Tk_DeleteTimerHandler - call a procedure at a
given time
#include <tk.h>
Tk_TimerToken
Tk_CreateTimerHandler(milliseconds, proc, clientData)
Tk_DeleteTimerHandler(token)
- int milliseconds (in)
-
How many milliseconds to wait before invoking proc.
- Tk_TimerProc *proc (in)
-
Procedure to invoke after milliseconds have elapsed.
- ClientData clientData (in)
-
Arbitrary one-word value to pass to proc.
- Tk_TimerToken token (in)
-
Token for previously-created timer handler (the return value
from some previous call to Tk_CreateTimerHandler).
Tk_CreateTimerHandler arranges for proc to be
invoked at a time milliseconds milliseconds in the
future.
The callback to proc will be made by Tk_DoOneEvent,
so Tk_CreateTimerHandler is only useful in
programs that dispatch events
through Tk_DoOneEvent or through other Tk procedures that
call Tk_DoOneEvent, such as Tk_MainLoop. The call
to proc may not be made at the exact time given by
milliseconds: it will be made at the next opportunity
after that time. For example, if Tk_DoOneEvent isn't
called until long after the time has elapsed, or if there
are other pending events to process before the call to
proc, then the call to proc will be delayed.
Proc should have arguments and return value that match
the type Tk_TimerProc:
typedef void Tk_TimerProc(ClientData clientData);
The clientData parameter to proc is a
copy of the clientData argument given to
Tcl_CreateTimerHandler when the callback
was created. Typically, clientData points to a data
structure containing application-specific information about
what to do in proc.
Tk_DeleteTimerHandler may be called to delete a
previously-created timer handler. It deletes the handler
indicated by token so that no call to proc
will be made; if that handler no longer exists
(e.g. because the time period has already elapsed and proc
has been invoked) then Tk_DeleteTimerHandler does nothing.
callback, clock, handler, timer
Copyright © 1990 The Regents of the University of California.
Copyright © 1994 Sun Microsystems, Inc.
Copyright © 1995 Roger E. Critchlow Jr.