Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!fluke!ssc-vax!housen
From: housen@ssc-vax.UUCP (Kevin Housen)
Newsgroups: comp.sys.mac.programmer
Subject: Writing a simple CDEF
Message-ID: <2936@ssc-vax.UUCP>
Date: 23 Oct 89 20:13:33 GMT
Organization: Boeing Aerospace & Electronics, Seattle WA
Lines: 27
Keywords: Help, Im losing control.



I am trying to write a CDEF for a small slider control.
After reading through the Control Manager section of
IM, which is a little sketchy on CDEFs, and looking 
through back issues of MacTutor, I could use some hints.

The control has only one part, the indicator (i.e. the 
sliding knob).  The control is drawn properly, in response
to a drawCntl message.  But I can't get the slider to move.
My intention was to use the default method of dragging, so
the CDEF returns a result of 0 in response to a
dragCntl message.  I assumed that this would cause
TrackControl to drag the indicator about - but it doesn't.
In fact, the CDEF never receives a calcCRgns message, so
TrackControl couldnt know the region occupied by the
indicator.

I would really appreciate it if someone could send me an
example of source code for a CDEF, or outline the steps
needed to construct a simple control, like a slider.  I am
using Think Pascal 2.01, but source in any language
would be helpful.

Thanks heaps -

Kevin Housen