Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!cs.dal.ca!aucs!850181f
From: 850181f@aucs.uucp (S. Ferguson-Parker)
Newsgroups: comp.sys.mac.programmer
Subject: Window Scrolling Problem
Message-ID: <1989Dec8.164905.13550@aucs.uucp>
Date: 8 Dec 89 16:49:05 GMT
Reply-To: 850860w@aucs.UUCP (VINCENT W. WHYNOT)
Distribution: na
Organization: School of Computer Science, Acadia Univ., Nova Scotia
Lines: 29


Having a problem scrolling windows.  I'm new at programming the Mac, but it
is proving to be challenging.

Here's the problem.  I'm using TrackControl() passing it an action procedure
to do continuous scrolling.  I should state that I am programming in 
LightSpeed C version 2.15.  Originally, no scrolling was taking place at all, 
but I fixed that problem by reversing the parameters of the action procedure.

Now I'll get to the problem.  After reversing the parameters of the action 
procedure, continuous scrolling would take place while the mouse was held
down in the scroll bar.  But it will only do it once!  If I release the mouse
button and try scrolling again, there is no result!  I cannot even move the 
thumb. 

After a little poking aroung I found that the toolbox routine TrackControl()
is returning a NULL pointer as the control handle instead of the handle to the
scroll bar being manipulated.

Also after scrolling once, if I try to zoom or grow the window, the system
crashes.  If it is of any help my action procedure is of type void.

I have tried everything I can think of to fix this problem, but have had no 
luck.  

  Does anyone have any suggestions?

Wade.
850860w@AcadiaU.CA