- From: Nigel Megitt via GitHub <sysbot+gh@w3.org>
- Date: Fri, 01 Jun 2018 13:15:17 +0000
- To: public-tt@w3.org
nigelmegitt has just created a new issue for https://github.com/w3c/ttml2: == Disallow `offset-position-v` as a one component position == See also #711 and #769. Currently two options are available for one component `<position>` values: ``` <position> : offset-position-h // single component value | offset-position-v // single component value ... offset-position-h : position-keyword-h | <length> offset-position-v : position-keyword-v | <length> ... position-keyword-h : "center" | edge-keyword-h position-keyword-v : "center" | edge-keyword-v edge-keyword-h : "left" | "right" edge-keyword-v : "top" | "bottom" ``` And the table explaining the equivalents of the one component values maps: * `center` -> `center center` * `<length>` -> `<length> center` Both of those mappings indicates that a valid value for an `offset-position-v` of `center` or `<length>` will be interpreted as an `offset-position-h`. So in those cases the spec is actively misleading in suggesting that a vertical offset value can be used on its own. The only one component values that are unambiguously vertical positions are `top` and `bottom`. Rather than handling those two specific values (which I guess would be rarely used because mostly authors leave a gap at the top or the bottom of the root container region), for simplicity I propose that we remove `offset-position-v` from the permitted set of one component values. Please view or discuss this issue at https://github.com/w3c/ttml2/issues/809 using your GitHub account
Received on Friday, 1 June 2018 13:15:19 UTC