W3C Invites Implementations of CSS Painting API Level 1

The CSS Working Group invites implementations of a Candidate Recommendation of CSS Painting API Level 1, an API for allowing web developers to define a custom CSS <image> with javascript, which will respond to style and size changes. See EXPLAINER.

W3C Invites Implementations of Timed Text Markup Language 1 (TTML1) (Third Edition)

The Timed Text Working Group invites implementations of an updated Candidate Recommendation of Timed Text Markup Language 1 (TTML1) (Third Edition). This document specifies Timed Text Markup Language (TTML), Version 1, also known as TTML1, in terms of a vocabulary and semantics thereof.

The Timed Text Markup Language is a content type that represents timed text media for the purpose of interchange among authoring systems. Timed text is textual information that is intrinsically or extrinsically associated with timing information.

It is intended to be used for the purpose of transcoding or exchanging timed text information among legacy distribution content formats presently in use for subtitling and captioning functions.

In addition to being used for interchange among legacy distribution content formats, TTML Content may be used directly as a distribution format, for example, providing a standard content format to reference from a <track> element in an HTML5 document, or a <text> or <textstream> media element in a [SMIL 2.1] document.

New version of the Roadmap of Web Applications on Mobile

W3C has published a new version of its Roadmap of Web Applications on Mobile, an overview of the various technologies developed in W3C that increase the capabilities of Web applications, and how they apply more specifically to the mobile context.

The contents of the roadmap have been updated to follow the evolution of the Web platform since April 2018. See the Change history for details. Most of these updates focused on mechanisms that allow mobile web applications to tweak performance settings and gain finer-grained control over the browser’s default behavior. In particular, new exploratory work and technologies in progress mentioned in the Performance and Tuningpage include:

• the CSS Animation Worklet API to create scripted animations in a dedicated thread,
• the CSS contain property to indicate that an element’s subtree is independent of the rest of the page,
• the proposed CSS overscroll-behavior property to control the behavior of a scroll container when its scrollport reaches the boundary of its scroll box,
• the Event Timing Web Perf API to measure the latency of events triggered by user interaction,
• the Identifiers for WebRTC’s Statistics API to monitor the performance of the network and media pipeline in peer-to-peer scenarios, and
• Priority Hints to let developers signal the priority of each resource they need to download.

The roadmap did not mention WebDriver, recently published as a W3C Recommendation, a key technology for mobile web developers as it enables automated testing across browsers and devices. This was an oversight, fixed in this new version.

The implementation info rendered in tables now also embeds information from the MDN Browser Compatibility Dataproject. A new “partial” badge also indicates that an implementation may be incomplete, either because it is, or because implementation data is not complete enough to assess support of the entire specification.

Sponsored by Beihang University, this project is part of a set of roadmaps under development in a GitHub repository to document existing standards, highlight ongoing standardization efforts, point out topics under incubation, and discuss technical gaps that may need to be addressed in the future. New versions will be published on a quarterly basis, or as needed depending on progress of key technologies of the Web platform. We encourage the community to review them and raise comments, or suggest new ones, in the repository’s issue tracker.