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Re: [csswg-drafts] [cssom-view] {element, elements, nodes}FromPoint but without restricting to the viewport clip? (#4122)

From: Chris Harrelson via GitHub <sysbot+gh@w3.org>
Date: Mon, 29 Jul 2019 21:12:28 +0000
To: public-css-archive@w3.org
Message-ID: <issue_comment.created-516164348-1564434747-sysbot+gh@w3.org>
Just like Firefox, Chromium has non-web-exposed use-cases for skipping the clip. Our use cases are:

* Visually positioning carets and selection ranges
* Detecting colors underneath elements in DevTools
* IntersectionObserver occlusion testing

I'd like to understand better the required web-exposed use cases before we agree to this API, because as Tab mentioned there are some performance downsides, and this API could end up being a new footgun in practice.

In particular, for the use case you mentioned @emilio of measuring on-screen-ness: is IntersectionObserver awkward for that use-case?

Regarding detecting whether two elements intersect at an arbitrary point, or overlap that point: I'm not sure what that's for?

-- 
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Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4122#issuecomment-516164348 using your GitHub account
Received on Monday, 29 July 2019 21:12:30 UTC

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