🚀 go-pugleaf

From: "Eric Berdahl" <Eric_Berdahl@taligent.com>
To: SANTADOG@ISYS.KING.AC.UK,
     "MacApp 3 Technical Discussion" <MACAPP3TECH$@AppleLink.Apple.COM>
 
        Reply to:   RE>pure virtual member functio
Hmm, there seems to be a simple problem, but I can't tell exactly which one i
s biting you.
 
There are two TIPCommand classes in the FotomatApp package. The one in FotoAp
p inherits from TServerCommand. The one in AEImage inherits from TClientComma
nd. They are not interchangable. From your citation of TIPCommand, I assume t
hat you are trying to compile AEImage. However, DoImageProcessing is a method
 of FotoApp's TIPCommand class, so obviously the compiler is seeing that class.
 
Is a puzzlement, said the King.
 
I would suggest getting the latest version of FotoApp, which has been revved
to fix some problems in older versions, one of which (I think) is the one you
're seeing. In early versions of FotoApp, I made DoImageProcessing pure virtu
al so C++ developers could get compile-time checking that they have implement
ed this method. I also gave it an implementation that would call SubClassResp
onsibility at runtime so Object Pascal developers would get checking too. As
newer compilers came online, that needed to be revved for the error you see.
 
The latest version of FotomatApp should be dated something like April, 1992,
and I think its in the MacApp3Tech$ archives (on ETO and AppleLink).
 
Hope this helps,
Eric
FotoApp author
eric_berdahl@taligent.com