- From: Thiago de Paiva <tcpaiva@gmail.com>
- Date: Wed, 21 Oct 2009 21:52:40 -0200
- To: www-svg@w3.org
- Message-ID: <30e795250910211652k4e9b9eb9o4a9438ea68a0e47c@mail.gmail.com>
Thank you all for responding. =) And Rob, I'm waiting for its implementation in Gecko! ;) Best! Thiago 2009/10/20 Paul Williams <pwilliams@infotrustgroup.com> > In other CSS paradigms (font rendering, for instance), a comma separated > list specifies the available options, and the UA uses the first value it can > handle: > > element { > font-family: Verdana,Helvetica,sans-serif; > } > > Something similar could be done for backgrounds (though I suppose that it's > not really the domain of the SVG working group): > > element { > background-image: url(foo.svg),url(foo.png); > } > > > -----Original Message----- > From: www-svg-request@w3.org [mailto:www-svg-request@w3.org] On Behalf Of > Erik Dahlstrom > Sent: Tuesday, October 20, 2009 7:06 AM > To: Helder Magalhães; Doug Schepers > Cc: robert@ocallahan.org; Thiago de Paiva; www-svg@w3.org > Subject: Re: ".svg" as background image using css > > On Sat, 17 Oct 2009 13:04:43 +0200, Helder Magalhães > <helder.magalhaes@gmail.com> wrote: > > ... > > I recall a (very ancient) way to set the pointer cursor in an IE4- [1] > > friendly way, something like: > > > > element{ > > /* for IE4 and before */ > > cursor:hand; > > /* standard value */ > > cursor:pointer; > > } > > > > As IE4 wouldn't recognize the second value, it would use the first, > > non-standard, one. > > Right, that's a bit different though, it's not using the same keywords (in > other words it's a different syntax). > > > So, following Thiago's example, I'd say this would be accomplished > > through something like: > > > > div{ > > /* fall-back for UA without support for SVG as CSS background > > image */ > > background-image: url('bg.png'); > > /* UA with support for SVG as CSS background image */ > > background-image: url('bg.svg'); > > } > > The last url() value is using valid syntax, and thus won't lead to that > being discarded by the UA per the CSS parsing rules. That an image format > isn't supported probably won't be discovered until the UA fetches the > resource, or when it tries to render it. > > > Therefore I'd way that an UA would ignore the second declaration, not > > only if it doesn't supports it but also if the SVG file could not be > > located. > > Nope, doesn't work. > > > I haven't checked for UA status on this approach, specially from an > > optimization point of view (I'd say a UA would try to optimize by > > attempting to use the overridden (second) "background-image" > > declaration before falling back and even downloading the raster (PNG) > > version. > > We'd need something like the image() syntax[1], or a format() specifier > that could be appended to existing url():s to give the UA the option of > ignoring unsupported formats early on. > > That said, it's still possible to do feature-detection in javascript and > add the corresponding CSS based on that[2]. Not as elegant as having > fallbacks in the CSS syntax maybe, but it works today (as long as > javascript is enabled). > > Cheers > /Erik > > [1] http://dev.w3.org/csswg/css3-images/ > [2] http://my.opera.com/Fyrd/blog/svg-image-and-background-image-replacer > > -- > Erik Dahlstrom, Core Technology Developer, Opera Software > Co-Chair, W3C SVG Working Group > Personal blog: http://my.opera.com/macdev_ed > >
Received on Wednesday, 21 October 2009 23:53:33 UTC