On Wednesday, December 10, 2025 at 5:09:57 PM UTC+1 Rick Byers wrote:
Hey David, This seems fairly straightforward to me, but I imagine there's probably some developer signals here, right? Somebody who has said why they want this? Hi, it’s me! :) This is needed when applying scroll-triggered animations that use selectors which match multiple elements. Without trigger-scope, the last element that declares the trigger would “win”, thereby breaking all other matched element that use the same name for its trigger. With trigger-scope, the name can be contained to a specific subtree, allowing name reuse. See https://codepen.io/bramus/pen/dPMVoYR/2e5fd8b6a35cc77cfb8faf0f16caf1e3 (Canary with flags) for an example: each image animates individually, each with their own trigger-timeline named --t. Without timeline-trigger scope, all images would animate using the timeline-trigger of the very last element – which is not what you want. tl;dr Without trigger-scope, it would be near impossible for authors to properly implement scroll-triggered animations. Thanks, Rick On Tue, Dec 9, 2025 at 4:40 PM David Awogbemila <[email protected]> wrote: *Contact emails* [email protected] *Explainer* https://github.com/explainers-by-googlers/scroll-triggered-animations/blob/main/TRIGGER_SCOPE.md *Specification* https://drafts.csswg.org/css-animations-2/#trigger-scope *Summary* trigger-scope gives authors the ability to limit the names of animation triggers declared by trigger-instantiating properties. Trigger-Instantiating properties, such as timeline-trigger, declare names which can be referenced by the animation-trigger property in order to attach animations to triggers. However, these names are global by default (similar to anchor-name) and it is often useful for author to limit the visibility of the names so as to isolate animation-to-trigger interactions. *Blink component* Blink>Animation <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EAnimation%22> *Web Feature ID* Missing feature *Motivation* Similar to anchor-scope[1], trigger-instantiating properties need a mechanism for limiting the visibility of the names declared by the trigger-instantiating property. [1] https://drafts.csswg.org/css-anchor-position-1/#anchor-scope *Initial public proposal* *No information provided* *TAG review* https://github.com/w3ctag/design-reviews/issues/1175 *TAG review status* Pending *Risks* *Interoperability and Compatibility* *No information provided* *Gecko*: No signal ( https://github.com/mozilla/standards-positions/issues/1327) *WebKit*: No signal ( https://github.com/WebKit/standards-positions/issues/589) *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? *No information provided* *Debuggability* *No information provided* *Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?* Yes *Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* Yes https://wpt.fyi/results/?label=master&label=experimental&aligned&q=trigger-scope (As of this writing, only the parsing tests are present on the dashboard but functional tests[1] are quickly following) [1] https://github.com/web-platform-tests/wpt/pull/56601 *Flag name on about://flags* *No information provided* *Finch feature name* *No information provided* *Non-finch justification* *No information provided* *Rollout plan* Will ship enabled for all users *Requires code in //chrome?* False *Tracking bug* https://crbug.com/466134208 *Estimated milestones* Shipping on desktop145Shipping on Android145Shipping on WebView145 *Anticipated spec changes* Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way). *No information provided* *Link to entry on the Chrome Platform Status* https://chromestatus.com/feature/5152759609425920?gate=5794840308744192 This intent message was generated by Chrome Platform Status <https://chromestatus.com/>. -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAA6pwF59XSB2N2b1bx-26%2BJX2Feunn7Zv7s2aUvD6AkjqfTjmg%40mail.gmail.com <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAA6pwF59XSB2N2b1bx-26%2BJX2Feunn7Zv7s2aUvD6AkjqfTjmg%40mail.gmail.com?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/67b029e2-0b62-405d-931c-de81449757a0n%40chromium.org.
