Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!think.com!hsdndev!dartvax!ascutney!kurash
From: kurash@ascutney.dartmouth.edu (Mark Valence)
Newsgroups: comp.sys.mac.programmer
Subject: Re: ModalDialog question
Summary: refCon nullEvent Filter=true
Keywords: foo bar
Message-ID: <1991Mar18.204423.10887@dartvax.dartmouth.edu>
Date: 18 Mar 91 20:44:23 GMT
References: <1235@gagme.chi.il.us>
Sender: news@dartvax.dartmouth.edu (The News Manager)
Reply-To: kurash@ascutney (Mark Valence)
Organization: Dartmouth College
Lines: 35

>essam@gagme.chi.il.us (Essam Khairullah) writes:
> I have a modal dialog that pops up at a given time (installed with an INIT)
> and I want to be able to dismiss the dialog if the user doesn't do it
> himself after a half an hour.  How can I get ModalDialog to report null
> events (or in my filterProc) so that I can tell how much time has passed
> without the user having to cause an event?

As long as the dialog is "yours" (you're the one who called GetNewDialog
or NewDialog), you can use the "refCon" field of the DialogRecord for
the dialog (you can access this field with calls to GetWRefCon and
SetWRefCon).  Set the refCon of your DialogRecord to the time "one half
hour" from when you first display the dialog (use GetDateTime from
pascal or C to get the current time in seconds).  Then, every time
your filter proc gets an event (null or otherwise, if you like), check
the value in the refCon with the current time.  If the current time
is ever greater than what's in the refCon, set itemHit (passed as a var
parameter to the filter proc) to "ok" or "cancel", or whatever item
you want to be hit by your ghost user, and return "true" from the
filter proc.  Yup.  That'll do it.

Alternately, you could store a pointer to the "deadline" and other
stuff in the refCon.  More indirection, but you can then have access
to all of your INIT's global variables.

BTW, your INIT might crash under 7.0b1 and b2, but the bug (in the Finder)
that causes this crash is fixed in the b3 and b4 releases.

Also, just to emphasize the point, if you are not the one who called
GetNewDialog or NewDialog to post the dialog, you cannot use this scheme
and claim to be bug-free.  The "owner" of the dialog might be using
its refCon for its own purposes.

Sorry I had to post, but mail just bounced.

Mark.