194938 2019-02-22 01:20:16 -0800 Changing the transition-duration of an-flight transition should not alter or cancel it 2019-02-22 01:41:20 -0800 1 1 1 Unclassified WebKit Animations WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 graouts webkit-unassigned dino webkit-bug-importer oldest_to_newest 1508940 0 362706 graouts 2019-02-22 01:20:16 -0800 Created attachment 362706 Test case See the attached test case. In this example we start a transition by setting transition-duration to a positive value and then setting a "margin-left" style which triggers a transition for the duration set. Then, one second after the transition has started, we remove the transition-duration which reverts back to 0. In our current implementation this cancels the transition, but the spec says that it shouldn't, per the note at the bottom of https://drafts.csswg.org/css-transitions-1/#starting: "Note that once the transition of a property has started (including being in its delay phase), it continues running based on the original timing function, duration, and delay, even if the transition-timing-function, transition-duration, or transition-delay property changes before the transition is complete. However, if the transition-property property changes such that the transition would not have started, the transition stops (and the property immediately changes to its final value)." While this is informative text, there are no normative steps that would indicate otherwise. 1508948 1 webkit-bug-importer 2019-02-22 01:41:20 -0800 <rdar://problem/48305929> 362706 2019-02-22 01:20:16 -0800 2019-02-22 01:20:16 -0800 Test case transition-shoud-not-cancel-when-changing-transition-duration.html text/html 864 graouts PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KPG1ldGEgY2hhcnNldD0idXRmLTgiPgo8c3R5 bGU+CgpkaXYgewogICAgdG9wOiAwOwogICAgbGVmdDogMDsKICAgIHdpZHRoOiAyMDBweDsKICAg IGhlaWdodDogMjAwcHg7CiAgICBiYWNrZ3JvdW5kLWNvbG9yOiBibGFjazsKfQoKPC9zdHlsZT4K PC9oZWFkPgo8Ym9keT4KPGRpdj48L2Rpdj4KPHNjcmlwdD4KCiAgICBjb25zdCB0YXJnZXQgPSBk b2N1bWVudC5xdWVyeVNlbGVjdG9yKCJkaXYiKTsKICAgIHRhcmdldC5zdHlsZS50cmFuc2l0aW9u RHVyYXRpb24gPSAiNXMiOwoKICAgIHNldFRpbWVvdXQoXyA9PiB7CiAgICAgICAgdGFyZ2V0LmFk ZEV2ZW50TGlzdGVuZXIoInRyYW5zaXRpb25ydW4iLCBldmVudCA9PiB7CiAgICAgICAgICAgIHNl dFRpbWVvdXQoXyA9PiB7CiAgICAgICAgICAgICAgICBjb25zb2xlLmxvZygiUmVtb3ZpbmcgdGhl ICd0cmFuc2l0aW9uJyBwcm9wZXJ0eSBhZnRlciB0aGUgdHJhbnNpdGlvbiBoYXMgYmVlbiBydW5u aW5nIGZvciBhIHNlY29uZC4iKTsKICAgICAgICAgICAgICAgIHRhcmdldC5zdHlsZS5yZW1vdmVQ cm9wZXJ0eSgidHJhbnNpdGlvbi1kdXJhdGlvbiIpOwogICAgICAgICAgICAgICAgY29uc29sZS5s b2coYE51bWJlciBvZiBydW5uaW5nIGFuaW1hdGlvbnM6ICR7dGFyZ2V0LmdldEFuaW1hdGlvbnMo KS5sZW5ndGh9LmApOwogICAgICAgICAgICB9LCAxMDAwKTsKICAgICAgICB9KTsKCiAgICAgICAg Y29uc29sZS5sb2coIlN0YXJ0aW5nIGluaXRpYWwgdHJhbnNpdGlvbi4iKTsKICAgICAgICB0YXJn ZXQuc3R5bGUubWFyZ2luTGVmdCA9ICI1MDBweCI7CiAgICB9KTsKCjwvc2NyaXB0Pgo8L2JvZHk+ CjwvaHRtbD4K