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From: oster@well.sf.ca.us (David Phillip Oster)
Newsgroups: comp.sys.mac.programmer
Subject: Re: When to use a _real_ moda
Message-ID: <16785@well.sf.ca.us>
Date: 21 Mar 90 03:32:49 GMT
References: <38.26037AF7@imagery.FIDONET.ORG> <10853@hoptoad.uucp> <18601@boulder.Colorado.EDU>
Reply-To: oster@well.UUCP (David Phillip Oster)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 31

In article <10853@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes:
>A modeless dialog can configure a modal operation perfectly well.  The
>dialog comes up, but the operation doesn't happen until you click the
>equivalent of the OK button.  If you give the same command again (e.g.,
>Print or Open) before clicking OK or getting rid of the window, then
>the window simply comes to the front.  This would work perfectly well
>for both the Print dialogs and the Standard File dialogs, if the people

The general problem for modeless dialogs are that if _anything_ changes, then
you have to scan a list of potentially visible dialogs to see which ones _are_
visible, then change all relevant fields to be consistent with the new
information.  (You have to do this anyway, but in a world of modal dialogs,
the set of things that are potentially visible is much smaller.)

For example, suppose you have a database with three windows visible:
a main window showing many records, a data entry showing one record, where
the user can edit individual fields, and search window.

If the user deletes a record from the main window, if that record was
visible in the data entry you must clear it. If the user deleted _all_ the
records, then you must dim the "(Search)" button, since there is nothing to
search in (unless there is a partial record in the data window, and the
data window is "above" the main window (although it may be on a different CRT
even though it _is_ higher...))

Anybody have a good solution to this more general problem? I have particular
trouble getting Undo to set _everything_ back the way it was before, since
I like to give each window its own undo state.
-- 
-- David Phillip Oster - Note new address. Old one has gone Bye Bye.
-- oster@well.sf.ca.us = {backbone}!well!oster