w3c/csswg-drafts

[cssom-view] elementFromPoint etc need to be defined in terms of layout and visual viewports

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#1,378 opened on May 15, 2017

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Help Wantedcssom-view-1

Description

https://www.w3.org/TR/cssom-view-1/#dom-document-elementfrompoint

elementFromPoint(), elementsFromPoint() and caretPositionFromPoint() need to define whether the arguments are relative to the layout or visual viewports. Other "client" coordinates are being defined as being in terms of the layout viewport (e.g. getBoundingClientRects(), getClientRects(), event.clientX/y [citation needed]).

The spec also needs to define whether the clipping to the the viewport uses the layout or visual viewports for clipping.

Contributor guide

Tech stack
htmlcss
Domain
documentation
Issue type
documentation
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
CSSOM View specificationunderstanding of layout and visual viewports
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Review the CSSOM View specification sections on elementFromPoint, elementsFromPoint, and caretPositionFromPoint. Examine existing comments in the issue for proposed definitions. Consider how other 'client' coordinates are defined in terms of layout viewport. Propose text that clarifies whether arguments are relative to layout or visual viewports and whether clipping uses layout or visual viewports.