Re: [iSVG] Checking for the style interface

[Robin B. <ro...@kn...>]

On Tuesday 18 September 2001 18:51, Antoine Quint wrote:
> In the gradients module, there is a function called at init that looks
> up the DOM tree for the shapes filled with the gradients that are
> i:gradient enabled. So what I do is look through
> doc.getElementsByTagName('*') and I check each element's "fill" property
> to see if it refers to the specified gradient. 

This is extremely expensive, are you sure there's no better way ? Wouldn't 
you be able to specify the targets on the gradient or something like that ?

<i:gradient>
  <i:target xlink:href='#foo'>
  <i:target xlink:href='#bar'>
</i:gradient>

> Problem is that before I
> read the "fill" property I need to check if that particular element
> allows for the Style interface (getStyle()) to be called.
>
> Anybody knows how to do this?

I'm presently looking into ways of making E262 really OO, and it's not 
looking nice (it's even less OO than Java !). You might try 
element.prototype.hasOwnProperty('style'), that should normally tell you 
whether your object has a property called style, which is needed by 
getStyle(). However I wouldn't be surprised if it didn't work. Another option 
is to do the tricks people do in browsers (eval'ing to see if it works, 
testing the returned value to be an object, etc). Also note that it is 
possible -- though marginal -- that an element would have a getStyle() method 
that is not what you expect (this could happen with embedded XHTML for 
instance). That could have nasty side-effects (as most abuses of polymorphism 
would).

-- 
_______________________________________________________________________
Robin Berjon <ro...@kn...> -- CTO
k n o w s c a p e : // venture knowledge agency www.knowscape.com
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