Re: Emacs and Gnome Canvas

[Óscar Fuentes]

Eli Zaretskii <address@hidden> writes:

>> I would use Qt, hence C++, not being shy about using advanced language
>> features if necessary. That is for getting a working system as soon as
>> possible.
>
> C++ is not the fastest language to get a job done.

That's very true. Unfortunately, AFAIK there is no Free high quality
cross platform GUI for Lisp :-)

> Plus, you'll have unrelated job on your hands of making Emacs
> C++-compliant, as discussed in another thread.

Only the Emacs header files that the display engine needs must be
acceptable by g++. The .c files would be compiled by gcc as usual.

> Unless you are rewriting the whole Emacs, that is ;-)

Others are already doing that :-)

>> > How you will be able to implement a new display engine without at
>> > least some familiarity with what the current one does?
>> 
>> I expect that if the internal layout of the data to be displayed is
>> clear enough, that is sufficient for the display engine writer. I mean,
>> knowing "this represents a text property" is what you need. Knowing how
>> the current display engine deals with it shouldn't be necessary.
>
> I said "knowing WHAT the current does", not HOW it does that.  The
> problem is, you cannot know WHAT it does without at least some study
> of the code, because there's no requirements document.
>
> Take the font-lock, for example -- it has special support in the
> display engine.  Without implementing the APIs for this support, JIT
> Lock, which is standard since Emacs 21.1, will not work.

I see. That's probably one instance of the "tight coupling" I was
talking about before.

Apart from reading all the source code, I hope that it is possible to
look into just a few header files for learning the interface of the
display engine.