Intent to Prototype: View transitions: layered capture

[Chromestatus]

Contact emails

nrose...@chromium.org, vmp...@chromium.org, khusha...@chromium.org

Explainer

https://github.com/WICG/view-transitions/blob/main/nested-explainer.md#capture-modes

Specification

None

Summary

In its current form, we capture the view transition into an old&new snapshot and then cross-fade between them, also animating the transform to simulate motion. With layered capture, more CSS properties are captured as style instead of being baked into the snapshot: opacity, clipping, border, box-shadow, background, 3D, mask, filters, border-radius. This allows displaying a more correct animation when using nested view transitions, and also allows more expressiveness for view-transitions in general, as borders & shadow would animate logically rather than cross-fade.

Blink component

Blink>CSS

Motivation

The main need arises from nested view transitions. When there is a tree hierarchy of transitioning elements, suddenly tree effects like opacity/mask/3D/filter are rendered differently, as well as decorations that respond to overflow like border-radius & box-shadow. Without capturing the transitioning elements differently, those nested animations would look broken. In addition, it allows implementing view transitions that were not easily possible before regardless of nesting, such as animating the border-radius of a transitioning shared element. This was brought up by partner designs.

Initial public proposal

https://github.com/w3c/csswg-drafts/issues/10585

TAG review

None

TAG review status

Pending

Risks

Interoperability and Compatibility

None

Gecko: No signal

WebKit: No signal

Web developers: No signals

Other signals:

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?

None

Debuggability

None

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

No

Flag name on chrome://flags

None

Finch feature name

None

Non-finch justification

None

Requires code in //chrome?

False

Estimated milestones

No milestones specified

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5159227115700224?gate=5184991819202560

This intent message was generated by Chrome Platform Status.