Re: [Swarm-Modelling] Something Glen said

[Marcus G. Daniels]

Hi Paul,
> > Yes, Swarm gets dynamically linked into Firefox via a plugin.   The 
> > cost of a call to or from Swarm is the cost of the indirection 
> > through a pure virtual table in C++ (a COM interface), e.g. less than 
> > message dispatch in a pure Objective C model.  
> Is this a hypothetical "somebody could do this" kind of thing, or a 
> "this already works and you just have to learn how" kind of thing?
Somewhere in between, but much closer to the latter.  It needs dusting 
off as it has been some years.  (This was the last work I did as a 
SFI/SDG employee on Swarm.)  I got as far this weekend as building 
Firefox from source on Windows and Fedora 5 as environments for 
debugging.   Boy, computers are faster now then they were then.  :-)

Swarm knows how to write IDL in the form Mozilla/Firefox wants, Swarm 
has the callin/callout logic for XPCOM, and Swarm knows specifics about 
JavaScript objects in order to probe them and directly call them.  Left 
to be done is to package it up and adjust for whatever Mozilla interface 
changes have occurred in the last five years and probably some 
debugging.  I don't think there have really been that many, and Swarm 
doesn't use them in complex ways anyway.  

The packaging issue comes with some issues. Like whether to include 
whole Tcl/Tk/BLT gui thing (e.g. including Tcl files in the plugin tree 
and all those DLLs).  The last time I was working on this, when I 
created, say, a graph, a BLT window would popup beside the browser.   
That's not necessarily bad, but is kind of freaky.   It would be better 
to factor off those libraries and move toward browser based probes, for 
example.   Meanwhile, a curious/motivated person doesn't need to have 
these packaging issues addressed it if they are willing to build Firefox 
and Swarm from source.

One thing that has changed since this work is that Mozilla is no longer 
the whipping boy for open source projects!  :-)
It has bitmaps (canvas) and vector graphics (svg) builtin that are in 
working form and cross platform.