[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [cgmo-webcgm] SV, CV and CSS2-like inheritance [was: Re[2]: [cgmo-webcgm] Style properties]
Hi Lofton, See inline... Tuesday, May 17, 2005, 8:14:39 PM, Lofton wrote: LH> At 02:58 PM 5/17/2005 -0400, Benoit Bezaire wrote: >>[...] >>LH> A.) If the Computed Value of a style property involves "convert to >>LH> absolute", >>LH> B.) and if we inherit the Computed Value, >>LH> then .... it creates problems for CSS2-like inheritance of style >>LH> properties. >>What are these A) and B)? I'm not sure I'm following your line of >>thoughts here? LH> Okay, A and B are two factors or conditions that, taken together, make it LH> difficult to apply the CSS2 model, unmodified, to our style properties LH> inheritance. We are talking about inheritance down a tree of APSs. LH> A.) CSS2 says that convert-to-absolute happens at the Computed Value stage. LH> [Stroke-weight is a property of an APS. If convert-to-absolute for LH> stroke-weight means that you must convert % to NVDC, this cannot be done at LH> the APS level. Why can't this be done at the APS level? LH> So the CV of stroke-weight is ill-defined at the APS level, LH> if the CV requires convert-to-absolute.] LH> B.) CSS2 says that Computed Values are inherited. (CSS3 allows each LH> property to define which type of value is inherited.) LH> Condition A and condition B taken together makes it problematic to apply LH> the CSS2 inheritance model exactly to our style properties inheritance. Why is it problematic? -- Benoit mailto:benoit@itedo.com LH> If we relax condition B, i.e., if we say that SV is inherited down APS LH> branches (for style properties) instead of CV, as allowed by CSS3, then LH> that inheritance model works. (But it leaves CV pretty much unused in the LH> model, and doesn't solve the problem of uncomputable CV at the APS level.) LH> If we relax condition A -- i.e., convert-to-absolute happens after CV, LH> e.g., at the Used Value stage -- then CV is the same as SV (except for LH> resolution of the values 'inherit', which we don't allow anyway for style LH> properties.) And inheritance down APS branches works, CSS2-like. LH> -Lofton.
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]