1917602 - CSS zoom property is animatable contrary to what spec says

Status: REOPENED

(Core :: CSS Transitions and Animations, defect, P3)

Description

[Vadim Makeev]

Attachment: zoom-animation.html

The CSS Viewport Module Level 1 spec lists the zoom property as not animatable. Though it can be animated in Firefox:

p {
    zoom: 2;
    animation: zoom 1s linear infinite alternate;
}

@keyframes zoom {
    from {
        zoom: 2;
    }
    to {
        zoom: 4;
    }
}

Chrome does discrete animation without transitions in between, while Safari doesn’t do anything at all. I’m not sure which behavior is correct (Chrome or Safari), but according to the spec, there should be no smooth animation.

Comment 1

[Vadim Makeev]

Emilio, I believe you were involved in the implementation.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Hmm, well, I guess.

I think we should at least do discrete animation. I don't think it matters much in practice.

This should be a matter of adding animation_type="discrete" to here, and adding a test.

Comment 3

[Brian Birtles (:birtles)]

Filed https://github.com/w3c/csswg-drafts/issues/10872 to clarify if the spec really intends this property to be non-animatable. Once that's resolved I might have a contributor I'm looking to onboard who can take this.

Comment 4

[tannal2409]

Attachment: Bug 1917602 - Make CSS zoom property discrete animatable. r?emilio

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f3cc65f111ef
Make CSS zoom property discrete animatable. r=emilio

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/48339 for changes under testing/web-platform/tests

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d5d237db3e73
Fix test_transitions_per_property.html

Comment 8

[Brian Birtles (:birtles)]

Shouldn't we have gotten the spec fixed or at least agreed upon before landing this?

Comment 9

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/f3cc65f111ef
https://hg.mozilla.org/mozilla-central/rev/d5d237db3e73

Comment 10

[Emilio Cobos Álvarez (:emilio)]

(In reply to Brian Birtles (:birtles) from comment #8)

Shouldn't we have gotten the spec fixed or at least agreed upon before landing this?

Yeah sorry, I had missed your csswg issue. I added it to the agenda.

Comment 11

[Cristina Horotan [:chorotan]]

Backed out on request by emilio
Backout: https://hg.mozilla.org/integration/autoland/rev/2bb69969f239b6fd2ef2bec51b3596959db863da

Comment 12

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR was closed without merging

Comment 13

[Cristina Horotan [:chorotan]]

Backout merged to central: https://hg.mozilla.org/integration/autoland/rev/2bb69969f239b6fd2ef2bec51b3596959db863da

Comment 14

[Emilio Cobos Álvarez (:emilio)]

No need to do anything yet, let's wait for the spec issue.