1949953 - Show offsetParent of fixed position element if it is not the viewport

Status: RESOLVED FIXED

(DevTools :: Inspector: Layout, defect, P3)

Description

[James Stuckey Weber]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Steps to reproduce:

I used the DevTools > Layout > Box Model > Box Model Properties to inspect a fixed position element that was inside of a <DIV> with a style of transform: translate(0,0). The transform creates a containing block / offsetParent for the fixed position element that is not the viewport.

Reproduction: https://codepen.io/jamessw/pen/OPJXyYW

<div style="transform: translate(0);">
<div style="position: fixed;">Fixed, but offsetParent is the parent div</div>
</div>

Actual results:

No Offset Parent of the selected element is shown.

Expected results:

The offset parent of the element should have been shown, in the same way as for absolute and relative positioned elements. This will help users understand why a fixed position element is not fixed to the viewport.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'DevTools::General' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[James Stuckey Weber]

Attachment: Bug 1949953 - Show offset parent of fixed position elements if not root. r?#devtools-reviewers

Shows in DevTools > Layout > Box Model > Box Model Properties.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/32e80692f39f
Show offset parent of fixed position elements if not root. r=devtools-reviewers,nchevobbe

Comment 4

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/32e80692f39f