Oh, it was just pointed out that the spec is essentially "TODO: spec
this" (at least that's my read on the second Note).
https://drafts.csswg.org/css-animations-2/#trigger-scope
I'd prefer to rescind my LGTM until we at least have a spec PR up to
actually define trigger-scope. Can you please prioritize that work?
On 12/15/25 9:38 a.m., Mike Taylor wrote:
LGTM2
On 12/11/25 1:32 a.m., Yoav Weiss (@Shopify) wrote:
LGTM1
On Wednesday, December 10, 2025 at 8:02:23 PM UTC+1 Bramus Van Damme
wrote:
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
<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.
I'm hearing similar arguments from devs inside of Shopify.
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
<https://github.com/explainers-by-googlers/scroll-triggered-animations/blob/main/TRIGGER_SCOPE.md>
*Specification*
https://drafts.csswg.org/css-animations-2/#trigger-scope
<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
<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
<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
<https://github.com/mozilla/standards-positions/issues/1327>)
/WebKit/: No
signal (https://github.com/WebKit/standards-positions/issues/589
<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
<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
<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
<https://chromestatus.com/feature/5152759609425920?gate=5794840308744192>
This intent message was generated by Chrome Platform
Status <https://chromestatus.com/>.
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