2033130 - Rework KeyframesStep and generate Gecko Keyframes to include timeline range name

Status: RESOLVED FIXED

(Core :: CSS Transitions and Animations, task)

Description

[Boris Chiou [:boris]]

In KeyframesAnimation::from_keyframes(), we convert the Keyframe into KeyframesStep, and sort it. We also add the missing 0% and 100% if needed.

Also, in Servo_StyleSet_GetKeyframesForName(), we iterate the KeyframesStep in the reverse order. We may rewrite everywhere to make sure we could handle range names well before we start to resolve and use the range names in Bug 1824875.

Comment 1

[Boris Chiou [:boris]]

After checking the implementation of WebKit and Chromium, I think we need to do the following things:

1. Extend KeyframesStep to include range names.
2. Move the generation of implicit keyframes (i.e. 0% and 100%) later. Perhaps in GetKeyframes() and BuildProperties(), because we need to know which timeline type the animation uses, and we have to resolve the computed offsets before filling the implicit keyframes.
   • However, this has impact when we group the keyframes, so need to tweak it as well.
3. Sort the keyframes in the computed order for GetKeyframe() and in the used order for BuildProperties(). It's probably fine to sort it earlier in KeyframesAnimation::from_keyframes() for keyframes with percentage offset.
4. Check some edge cases when using getKeyframes() for the document timeline (e.g. if there are only keyframes with range names).
5. Resolve the keyframe computed offset in Bug 1824875.

Comment 4

[Boris Chiou [:boris]]

Attachment: Bug 2033130 - Rewrite ComputeMissingKeyframeOffsets() for timeline range offsets.

The spec doesn't change this section for TimelineRangeOffset when
computing the missing keyframe offsets, so we still follow
[web-animations-1]: distribute the keyframes from double offsets only.

Also, the distribution code doesn't have impact on CSS Animations because
we always generate keyframes with an offset, but the computation of
computedOffset for TimelineRangeOffset will be used for both CSS
Animations and Web Animations, so we still have to implement this now.

Comment 5

[Boris Chiou [:boris]]

Attachment: Bug 2033130 - Generate mozilla::Keyframes with timeline range offsets.

Comment 6

[Boris Chiou [:boris]]

Attachment: Bug 2033130 - Use NaN to represent the unresolved computed offset.

Keyframe::mComputedOffset could be negative or any real number larger
than 1.0, so we use NaN to represent its unresolved value.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/8703a41947ba
https://hg.mozilla.org/integration/autoland/rev/c85e91002fd7
Extend Keyframe offset with range names. r=layout-scroll-driven-animation-reviewers,firefox-style-system-reviewers,dshin
https://github.com/mozilla-firefox/firefox/commit/0ff36869a962
https://hg.mozilla.org/integration/autoland/rev/b8a1e79fee9d
Rewrite ComputeMissingKeyframeOffsets() for timeline range offsets. r=layout-scroll-driven-animation-reviewers,firefox-style-system-reviewers,dshin
https://github.com/mozilla-firefox/firefox/commit/884caf0caa5c
https://hg.mozilla.org/integration/autoland/rev/316f574e4ab9
Use NaN to represent the unresolved computed offset. r=layout-scroll-driven-animation-reviewers,firefox-style-system-reviewers,dshin
https://github.com/mozilla-firefox/firefox/commit/22fe786988c9
https://hg.mozilla.org/integration/autoland/rev/e033b4740763
Extend KeyframesStep to use timeline range name. r=layout-scroll-driven-animation-reviewers,firefox-style-system-reviewers,dshin
https://github.com/mozilla-firefox/firefox/commit/96fbdcd2020f
https://hg.mozilla.org/integration/autoland/rev/e7055180be08
Generate mozilla::Keyframes with timeline range offsets. r=firefox-style-system-reviewers,layout-scroll-driven-animation-reviewers,dshin

Comment 8

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/c85e91002fd7
https://hg.mozilla.org/mozilla-central/rev/b8a1e79fee9d
https://hg.mozilla.org/mozilla-central/rev/316f574e4ab9
https://hg.mozilla.org/mozilla-central/rev/e033b4740763
https://hg.mozilla.org/mozilla-central/rev/e7055180be08