- From: Ilya Streltsyn via GitHub <sysbot+gh@w3.org>
- Date: Thu, 21 Mar 2019 14:55:33 +0000
- To: public-css-archive@w3.org
The newest definition of the `width` property that I could find (in [[css-sizing-3]](https://drafts.csswg.org/css-sizing-3/#propdef-width)) says that its animation type is "by computed value type", and computed value is "as specified, _with `<length-percentage>` values computed_". The [css-animations] spec seems to have no exact rules of length interpolation, instead it has an [issue](https://drafts.csswg.org/css-animations/#issue-73aacf21) linking to the [[css-transitions] rules](https://drafts.csswg.org/css-transitions/#application) as an example. These rules imply that interpolation happens between the start and end values only, i.e. Firefox's behavior seems to be correct according to them (though it might be counter-intuitive). Interestingly, the MDN page for the `width` property currently [reports](https://developer.mozilla.org/en-US/docs/Web/CSS/width#Specifications) its animation type as "a length, percentage _or calc();_", apparently implying that `calc()` is a separate animation type, so interpolations between `10em` and `20em` and between `calc(10em)` and `calc(20em)` would probably happen in different spaces. But I haven't found any justification for such distinction in neither [[css-values-4]](https://drafts.csswg.org/css-values-4/#calc-calculation) nor animations nor transitions spec. With all that said, I wouldn't consider either behavior a bug until the [css-animations] spec resolves its issue about the interpolation rules between keyframes. -- GitHub Notification of comment by SelenIT Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/3751#issuecomment-475262979 using your GitHub account
Received on Thursday, 21 March 2019 14:55:38 UTC