Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csmil.umich.edu
From: cash@csmil.umich.edu (Howard Cash)
Newsgroups: comp.sys.mac.programmer
Subject: Where to put window handling routines
Message-ID: <1067@mailrus.cc.umich.edu>
Date: 9 May 89 04:29:17 GMT
Sender: usenet@mailrus.cc.umich.edu
Reply-To: cash@csmil.umich.edu (Howard Cash)
Organization: Cognitive Science and Machine Intelligence Laboratory
Lines: 28

've been looking through some C code for the Mac, and I've noticed two 
fundamentally different philosophies on  the management of window 
events.  I want some votes on the prefered methodology.

Both cases use a struct of function pointers that handle various events in the
window (keyboard, mousedown, update, etc).  

  CASE 1:  The event handling struct is the first field in a bigger struct that
  includes window data.  A handle to the whole thing is in the window's RefCon
  so an event in the window looks in the RefCon for the appropriate handling 
  function.  The RefCon ends up pointing to a fairly bulky structure, but you
  always know where to find relevant functions or data.
  
  CASE 2:  The handling struct includes a window pointer to the window being 
  handled.  A list of such structs is maintained.  When the event arises, the
list 
  is searched for a "Window Handler" struct whose windowPtr field is the 
  same as the window where the event occurred.  This takes some search time,
  but the RefCon is free to carry only window-specific DATA and theJ
  management functions are isolated elsewhere.
  
How do all you experienced mac programmers deal with this issue?

Howard Cash
cash@csmil.umich.edu

This posting contains no opinions.