[css-overflow-3] Updated Working Draft of the CSS Overflow Module Level 3

The CSS Working Group has published an updated Working Draft of the CSS Overflow Module Level 3.

    https://www.w3.org/TR/css-overflow-3/

This module contains the features of CSS relating to scrollable overflow handling in visual media. This level is focused on completing a precise specification for the existing overflow features, including the 'overflow' property and its longhands; 'line-clamp', its longhands, and its legacy pre-standard syntax; and the 'text-overflow' property. A few additional features introduced in support of the CSS Containment Module (see https://www.w3.org/TR/css-contain-2/) are also defined: 'overflow: clip' and the 'overflow-clip-margin' property.

It has been quite a while since the last update, so there is a fair amount of changes. The main changes can be broadly grouped in 3 categories:

 * More details about what is and isn't included in the scrollable overflow of a box. These changes are driven by trying to find the best balance between desirable behavior and compatibility constraints.

 * Significant revisions to the definition of the 'line-clamp' property and its longhands. The behavior is more precisely defined, takes into account ease-of-implementation concerns raised by interested browser vendors, and covers compatibility with the pre-standard '-webkit-line-clamp' property. Implementation experience is still limited, but the design is considered roughly complete. Detailed review and feedback is strongly encouraged at this point.

 * Introduction of the 'overflow-clip-margin' property, which determines how far outside its bounds the element is allowed to paint before being clipped when using 'overflow: clip' or the related 'contain: paint' from the CSS Containment Module (https://www.w3.org/TR/css-contain)

See the Changes section for further details:

    https://www.w3.org/TR/2020/WD-css-overflow-3-20200603/#changes-since-2018-07-31

Please send any comments to the mailing list <www-style@w3.org>, prefixed with [css-overflow-3] (as I did on this message) or (preferably) file them in the GitHub repository at https://github.com/w3c/csswg-drafts/issues with the spec code [css-overflow-3] and your comment topic in the subject line.

For the CSS WG,
—Florian Rivoal

Received on Friday, 5 June 2020 04:51:12 UTC