877294 - [Meta] Implement border box mask (mask-border-*) support

Status: NEW

(Core :: Layout, enhancement, P3)

Description

[Jared Wein [:jaws] (please needinfo? me)]

https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-mask-box-image details the webkit implementation, and this is a link to the spec, https://dvcs.w3.org/hg/FXTF/raw-file/default/masking/index.html#the-mask-box-image

Comment 1

[Jared Wein [:jaws] (please needinfo? me)]

Assigning as per https://groups.google.com/d/msg/mozilla.dev.platform/jB6I6EvcbH0/wq0TutTan2oJ

Comment 2

[Jared Wein [:jaws] (please needinfo? me)]

See https://groups.google.com/d/msg/mozilla.dev.platform/-23mG3x2vdk/ReOWo9_sIAkJ for the original discussion that brought about this bug.

Comment 3

[Jared Wein [:jaws] (please needinfo? me)]

Still want, but not part of Australis project.

Comment 4

[eric]

Any chance of having this in the next versions?

Comment 5

[Jared Wein [:jaws] (please needinfo? me)]

Unassigning due to lack of activity.

Comment 6

[Daniel Holbert [:dholbert]]

This test is exercising these properties & happens to be part of the interop-2023-cssmasking test set:
https://wpt.fyi/results/css/css-masking/inheritance.sub.html

Comment 7

[Boris Chiou [:boris]]

I suspect there are only parsing and serialization tests for mask-border-* in interop-2023-masking WPT list. We could support them in style first (because they could be added quickly), and leave the layout/painting support later.

Comment 8

[Daniel Holbert [:dholbert]]

(In reply to Boris Chiou [:boris] from comment #7)

I suspect there are only parsing and serialization tests for mask-border-* in interop-2023-masking WPT list. We could support them in style first (because they could be added quickly), and leave the layout/painting support later.

Yup, it makes sense to start with style-system bits first. But note that it won't make a difference for interop2023 scoring until we're ready to enable the properties by default on Nightly, and presumably that would be when we've got some useful portion of the layout/painting support enabled.

(When we're partway through implementing something and we have opt-in pref flips in the testing/web-platform/meta/.../*.ini files, those prefs still aren't activated for upstream wpt.fyi test-runs. wpt.fyi runs essentially "stock" versions of Nightly/release, with only a few prefs toggled for test-harness-stability type purposes.)