Intent to Prototype: Transitions on specified discrete properties

[Robert Flack]

Contact emails

fla...@chromium.org

Explainer

https://github.com/w3c/csswg-drafts/issues/4441#issuecomment-1329749962

Specification

Summary

Allows transitions of discrete properties to be started on properties explicitly listed in the transition-property list. These transitions run using the same logic as an animation on those properties performing a flip at 50% by default but can be customized through the use of the transitionstart event and web-animations-1 APIs for modifying transition animations.

Blink component

Blink>Animation

Motivation

The web-animations allows developers to define custom transitions by modifying those animations. In theory, this would let a developer define a transition for property types which are animation type Discrete, however css-transitions-1 defines discrete animations as not transitionable which prevents this. Additionally, there are use cases for transitioning discrete properties (e.g. visibility, display, etc) which currently require developers to create an animation or use javascript to control. By allowing transitions on discrete properties, developers can: * Implement custom transitions for any animateable property * Use transitions for hiding components

Initial public proposal

https://github.com/w3c/csswg-drafts/issues/4441

TAG review

TAG review status

Pending

Risks

Interoperability and Compatibility

This is unlikely to have a big compatibility risk since the transition-property: all keyword does not include discrete properties. This will only affect sites which have explicitly listed discrete properties in transition-property. However given this used to be unsupported, it is unlikely to have been specified on most sites. This will also now be doing what the developer requested.

Gecko: No signal

WebKit: No signal

Web developers: No signals

Other signals:

Security

This does not do anything that the developer could not have set with their own stylesheets or script and shouldn't have any risks.

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

Debuggability

This feature would be consistent with existing CSS transitions, showing up the dev tools animation timeline and generating transition events. No new interfaces should be needed.

Is this feature fully tested by web-platform-tests?

No

Flag name

Requires code in //chrome?

False

Tracking bug

https://bugs.chromium.org/p/chromium/issues/detail?id=1399631

Estimated milestones

No milestones specified

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5071230636392448

This intent message was generated by Chrome Platform Status.