[Ros-talk] About GUI

[Simon Strandgaard]

On Fri, 2003-12-12 at 17:24, Shasckaw wrote:
> Simon Strandgaard wrote:
> >I have just been skipping through this XUL tutorial
> >http://www.xulplanet.com/tutorials/xultu/
> >I must admit thats its amazing.. what never had occured to me that CSS
> >could be used for GUI.  I see now that it works _very_ well.
> >
> >
> >I wonder how easy it will be to access via Ruby ?
> >Also if its easy to write custom widgets?
> >  
> >
> The fact is that the XUL community complain about a lack of XUL engine 
> for scripting langage as ruby, python, perl, and so on.

There exists Ruby bindings.. though a bit old.
http://rbxpcom.mozdev.org/

Im not sure if it requires more than xpcom bindings.


> The access via ruby, should be as easy as accessing XML. The scripting 
> of XUL should be written in ruby, when running with a XUL-ruby engine. I 
> don't think interpreting javascript with ruby would be fun! ;)

Then we will have to rewrite one of the XUL engines so it understands
Ruby. I have done some embedding of Ruby in C++. 



> About writing new widgets, I'm not sure.
> I know that XUL is not self-sufficient:
>     you need CSS
>     you need a scripting langage (for mozilla, its javascript)

javascript seems to be the only catch.


>     you should use RDF file for the content (eventually generated by a 
> PHP script)
>     you should use XPCOM elements for extensibility. XPCOM elements are 
> COM-like objects, extensions of mozilla (plugins in other words) and 
> written in C/C++ langage (in fact, it can be any langage because of IDL 
> interface).

>     you should use XBL (Xml Binding Langage). I don't understand exactly 
> what it is, but I know that XUL is not truly native in Mozilla: XUL is 
> in fact constructed with javascript, CSS and XBL. I know it by people 
> that wanted to refactor mozilla. Note that XBL is a standard of W3C: 
> http://www.w3.org/TR/xbl/

I don't either understand some things (read: most things).
Though an interesting link.


> As you see, it's a big piece! It can be really powerfull. But it can 
> also be an heavy and slow thing. We have to be carefull with that.

Its power and simplicity are seductive. 

Speedconcerns: If a machine are too slow.. is it then possible to select
between different levels of css [none, little, fancy, bloated]..
where the first has minimal demands for computing power, and the last
has maximum demands ?

--
Simon Strandgaard