Intent to Prototype: ContentVisibilityAutoStateChanged event
Vladimir Levin
Contact emails
vmp...@chromium.org
Explainer
https://github.com/vmpstr/web-proposals/blob/main/explainers/cv-auto-event.md
Specification
Summary
This proposal is to add an event that would fire on a content-visibility: auto element when the rendering state of the element changes due to any of the attributes that make the element relevant to the user (https://www.w3.org/TR/css-contain-2/#relevant-to-the-user)
Blink component
Blink
Motivation
The use-case for this is to let developers have greater control over when to stop or start rendering in response to the user-agent stopping or starting rendering of the content-visibility subtree. For example, the developer may want to stop React updates in a subtree that is not rendered by the user-agent. Similarly, the developer may want to stop any other script updates (e.g. canvas updates) when the user-agent is not rendering the element.
Initial public proposal
https://github.com/w3c/csswg-drafts/issues/7384#issuecomment-1176847043
TAG review
https://github.com/w3ctag/design-reviews/issues/756
TAG review status
Not applicable
Risks
Interoperability and Compatibility
This is a new feature that enhances `content-visibility: auto` use. It poses minimal interop and compat risks, and can be feature detected and polyfilled
Gecko: No signal (https://github.com/mozilla/standards-positions/issues/664)
WebKit: No signal (https://github.com/WebKit/standards-positions/issues/33)
Web developers: No signals
Other signals:
This is a new feature that enhances `content-visibility: auto` use. It poses minimal interop and compat risks, and can be feature detected and polyfilled
Gecko: No signal (https://github.com/mozilla/standards-positions/issues/664)
WebKit: No signal (https://github.com/WebKit/standards-positions/issues/33)
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?
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 can be debugged similarly to other events
Is this feature fully tested by web-platform-tests?
Yes
Flag name
ContentVisibilityAutoStateChangedEvent
Requires code in //chrome?
False
Tracking bug
https://bugs.chromium.org/p/chromium/issues/detail?id=1343432
Estimated milestones
No milestones specified