236153 2022-02-04 12:46:01 -0800 Implement overflow-clip-margin 2026-03-09 09:21:45 -0700 1 1 1 Unclassified WebKit CSS WebKit Nightly Build Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=308522 BrowserCompat, InRadar, WPTImpact P2 Normal --- 1 rbuis webkit-unassigned 709922234 ahmad.saleem792 contact fotis.papadogeorgopoulos karlcow kyle.bavender pinkhominid sebastianzartner webkit-bug-importer woodlxf00 oldest_to_newest 1837561 0 rbuis 2022-02-04 12:46:01 -0800 Implement overflow-clip-margin: https://drafts.csswg.org/css-overflow/#overflow-clip-margin 1840495 1 webkit-bug-importer 2022-02-11 12:46:16 -0800 <rdar://problem/88830478> 1921950 2 karlcow 2022-12-26 16:53:45 -0800 https://wpt.fyi/results/css/css-overflow?label=master&label=experimental&aligned&view=subtest&q=overflow-clip%20safari%3Afail 2165855 3 contact 2025-12-15 01:58:13 -0800 I would like to take a stab at implementing this feature. I’m working on familiarizing myself with how clipping is implemented in the WebKit codebase. 2165861 4 ahmad.saleem792 2025-12-15 02:32:49 -0800 (In reply to Suraj from comment #3) > I would like to take a stab at implementing this feature. I’m working on > familiarizing myself with how clipping is implemented in the WebKit codebase. Sure, please go ahead and also join Open Source WebKit slack to ask any question in #dev channel. How to join - https://webkit.org/getting-started/#staying-in-touch 2167378 5 contact 2025-12-19 12:48:52 -0800 Quick update for anyone tracking this feature - I made some progress in implementing this feature. To implement this feature, most likely, the dimensions calculated in RenderBox::overflowClipRect need to be updated based on the value of the overflow clip margin property - https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderBox.cpp#2265. I started by implementing the parsing logic for this property. I defined a new CSS property in CSSProperties.json file and created a new RenderStyle class named "OverflowClipMargin". I managed to compile the code and get it running. More than half of the WPT parsing tests defined here are passing - http://wpt.live/css/css-overflow/parsing/overflow-clip-margin.html. All the failing tests are due to the error "serialization should be canonical". I'm working through such errors by trying to understand how CSS style serialization is implemented and make changes to the OverflowClipMargin RenderStyle class accordingly. 2167394 6 ahmad.saleem792 2025-12-19 13:35:03 -0800 (In reply to Suraj from comment #5) > Quick update for anyone tracking this feature - > > I made some progress in implementing this feature. To implement this > feature, most likely, the dimensions calculated in > RenderBox::overflowClipRect need to be updated based on the value of the > overflow clip margin property - > https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderBox. > cpp#2265. I started by implementing the parsing logic for this property. I > defined a new CSS property in CSSProperties.json file and created a new > RenderStyle class named "OverflowClipMargin". I managed to compile the code > and get it running. More than half of the WPT parsing tests defined here are > passing - > http://wpt.live/css/css-overflow/parsing/overflow-clip-margin.html. All the > failing tests are due to the error "serialization should be canonical". I'm > working through such errors by trying to understand how CSS style > serialization is implemented and make changes to the OverflowClipMargin > RenderStyle class accordingly. Thanks for an update, if you want feedback and input while you iterate, you can do draft PR and tag engineers. You should join our Open Source WebKit Slack channel as well, where in #dev or #help channel, you can ask for inputs as well. How to join - https://webkit.org/getting-started/#staying-in-touch 2167415 7 contact 2025-12-19 15:15:51 -0800 Sure, I didn’t know we could draft PRs. Thanks for letting me know. 2179751 8 contact 2026-02-09 22:18:38 -0800 Pull request: https://github.com/WebKit/WebKit/pull/58276 2179753 9 contact 2026-02-09 22:25:04 -0800 I'm back after a long hiatus. I submitted a Draft PR for feedback. The PR comment has information about what works and doesn't. I'm currently working through fixing the failing WPT tests