Re: DocumentClass question?

William Tanksley (wtanksle@ucsd.edu)
Tue, 17 Sep 1996 11:06:33 -0700 (PDT)

On Tue, 17 Sep 1996, Falk Rehwagen wrote:

> Hello all GEOS-developers!
> Here now my first question to solve a problem for the next version of
> BitmapView.
> I need to subclass the GenDocumentClass to create my own document
> behavior. Here I subclass MSG_GEN_DOCUMENT_PHYSICAL_OPEN and
> MSG_GEN_DOCUMENT_PHYSICAL_CLOSE. After many hours fighting against
> strage results I locked in the header file gendocc.goh.
> Here seems to be some mistakes in message definitons. In all assembler
> definitions the CommonDocumentParams will give to the functions in the
> register ss:bp. In the GOH-file the parameter is defined as dx:bp. Is
> this an error or is this right?

Sounds like an error-- ss: is the default segment for bp, so ss:bp should
be right.

Ick!

> After I changed it to ss:bp it runs better but not perfect. There will
> be registers destroyed which the message needed. How I should
> understand the comment /* params must be a local variable */?
> Can anybody help me, I don`t see another way out!

Sounds like it has trouble copying other types of variables, and thus can
only work with the stack. They didn't implement the calling conventions
correctly.

Have you tried taking the comment literally, and making every parameter
to that message be a local variable within the function calling it?

> Falk

- -Billy