- From: Dean Jackson <dean@w3.org>
- Date: Fri, 16 Aug 2002 20:59:40 +1000
- To: Jim Ley <jim@jibbering.com>
- Cc: www-svg@w3.org
Hi Jim, On Fri, 16 Aug 2002, Jim Ley wrote: > The textLength attribute on SVG's textLength causes accesibility problems > for users who use their own stylesheets to overide author selections. > > Consider: > <text font-size="20px" textLength="38px" > lengthAdjust="spacingAndGlyphs">Hello</text> > > Which will work fine if the font-size is close to the 20px, the > adjustments whilst making the font slightly less clear shouldn't have too > much effect on legibility. > > However if the user takes advantage of CSS2 to increase the font-size to > something they find legible, the resulting narrow letters will likely be > unreadable for them. I do not see any mechanism for a user to override > the textLength property in their user stylesheet, yet a user would need > this ability to adjust font-size. > > If the lengthAdjust="spacing" then as a single character of the users > font could easily be 38px, I'm not sure what's supposed to happen then, > the spec. appears to be silent on the issue of what happens when the two > calculatated values are radically different, but Batik stacks the letters > on top of each other which seems reasonable. > > I do not have any ideas to propose as a solution unfortunately. It seems like we need some way to override the textLength. We'll discuss this and get back to you (www-svg). > The other is a little thing about use: > > http://www.w3.org/TR/SVG/struct.html#UseElement > | When a 'use' references another element which is another > | 'use' or whose content contains a 'use' element, then the > | deep cloning approach described above is recursive. > > I believe it should be made explicit what should be done in the situation > where a 'use' element, references a 'use' element which refers back to > the original one. ( http://jibbering.com/2002/8/use.test.svg ) as reading > it currently a conforming UA should keep on recursing forever... (and > Batik does!) We added wording to SVG 1.1 which describes that this in error. Basically as soon as the UA notices a self-reference (or reference loop) it goes into error - stops rendering. I think we should also publish an errata for this issue in SVG 1.0. Dean
Received on Friday, 16 August 2002 07:01:47 UTC