[whatwg] Re: media types

Ian Hickson ian at hixie.ch
Fri Aug 27 01:41:47 PDT 2004

On Sun, 22 Aug 2004, csant wrote:
> > >
> > > So basically there would probably be only media type active at the same
> > > time. However, there is a big problem when using a multimodal browser
> > > [1] which allows different modes visual/aural(/tactile) at the same
> > > time.
> > > 
> > > Different mediatypes would be mutually exclusive within a mode, e.g. you
> > > can't have screen and projection at the same time (they're in the same
> > > mode), but you can have projection and speech, or handheld and speech at
> > > the same time (they're in different modes).
> > 
> > At the moment the DOM doesn't support this kind of UA. There is only one
> > View -- the defaultView, which in Web Apps is defined as being the same as
> > the global window object -- and thus only one set of computed styles, and
> > thus only one set of stylesheets that apply.
> When two modes are running simultaneously (say 'screen' and 'speech'), there
> are two stylesheets applying, one to each mode (or, better: canvas), and they
> can have different computed styles.

Ok, fair enough.

The 'window' object, however, only applies to the current, default view 
(it's document.defaultView). At the moment, there is no way to get to the 
other view, the one with |window| set to something else.

So window.mediaMode only needs to be one media type at a time.

> > Frankly I would consider such a UA to be non-compliant if it used the
> > same window object for both rendering modes.
> Are you thus suggesting a UA would be less in breach when using two parallel
> DOM trees?

No, the DOM tree would be the same, but the window wouldn't. There would 
be two AbstractView interfaces, both with their |document| attribute set 
to the same object. One would be the global scope |window|, also 
accessible via document.defaultView. The other is the other view's window, 
which at the moment is not accessible via the DOM.

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

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