Re: DOM Views confusion

On Wed, 22 Mar 2006, Cameron McCormack wrote:
> 
> Ian Hickson:
> > In typical desktop browsers, the defaultView attribute should point to an 
> > object which is all of the following:
> > 
> >    The ECMAScript global object
> >    An object implementing Window
> >    An object implementing AbstractView
> >    An object implementing ViewCSS
> 
> If this is what is desired, perhaps Window (or some related spec) should 
> require this.

The WHATWG and Window specs do, in conjunction with the CSSOM spec.


> > See the WHATWG spec (and the WebAPI Window spec, probably). ViewCSS is 
> > one of the interfaces implemented by Window.
> 
> Window doesn't seem to mention ViewCSS.

Well, it doesn't have to be ViewCSS. The expectation is that an instance 
of the ViewCSS interface can be obtained by using binding-specific casting 
methods on an instance of the AbstractView interface (Window being one 
such instance). It only applies to CSS UAs, not all Window UAs need 
implement CSS.


> Ok, but at the moment I don't see anything that requires ViewCSS to be 
> implemented on the same object as Window.

ViewCSS is from AbstractView:

   http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-ViewCSS

Window is an AbstractView (per Window or WHATWG).


> Just that if you are not allowed to assume that Window and ViewCSS are 
> both implemented on the same object, the default view, then it's 
> impossible to implement both Window and ViewCSS usefully.

Ah. Well, ViewCSS and Window are on the same object.


> > In practice there is rarely more than one. Opera is the only browser I 
> > know that actually supports multiple views, and it only has one View 
> > (you can't get to the computed styles in its aural view; indeed I'm 
> > not sure it even implements the concept of multiple media correctly).
> 
> Having only one view implemented is likely to be because there is no 
> proper way to get access to any other views...

Other than Opera's aural/screen duality, I don't know of any UA that 
actually does multi-view CSS at all, DOM or no DOM.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Wednesday, 22 March 2006 06:17:47 UTC