Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!ncar!ames!uhccux!munnari.oz.au!murtoa.cs.mu.oz.au!jkjl
From: jkjl@cs.mu.oz.au (John Keong-Jin Lim)
Newsgroups: comp.sys.mac.programmer
Subject: Re: cdev question:  Why does GetDItem return bad value on closeDev?
Message-ID: <2809@murtoa.cs.mu.oz.au>
Date: 24 Jul 89 01:24:57 GMT
References: <783@kinetics.UUCP>
Reply-To: jkjl@murtoa.UUCP (John Keong-Jin Lim)
Organization: Comp Sci, Melbourne Uni, Australia
Lines: 32

In article <783@kinetics.UUCP> mahboud@kinetics.com (Mahboud Zabetian) writes:
>
>Does anyone know what state the Control Panel is in at the time of a closeDev
>call?  I do a GetDItem and SetIText when I get a closeDev call, but it never
>works, and sometimes it even crashes.
>

You need to do that before the cdev is closed ( i presume you mean GetIText -
SetIText seems pretty useless when closing a cdev !). What you need to do
is check for keyDown events and save the characters then. Alternately 
poll for keyDown events, then on the next null event do a GetIText; that
way you dont need to worry about backspace.

>In macsbug I notice that my DITL list is still pointed to by the Control Panel
>window and that my cdev file is still open.  So why am I not getting a valid
>Handle back from GetDItem?
>

If i recall, the TEHandle for your text has been disposed off already.

>On a related note- what happens when you get an updateDev call?  I do some
>drawing in the cdev window, which will get erased as soon as I get another
>message(other than a nulDev), but this drawing almost never is seen.  I know
>that the code for it gets executed, but the drawing seems to be wiped out with
>something.
>

Are you using BeginUpdate EndUpdate ? Have you set the nrct resource 
properly ?

	Have fun (i did when i wrote my first cdev !)
	john