1634153 - focus({preventScroll: true}); does not work on textareas

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[caleb]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1 Safari/605.1.15

Steps to reproduce:

Probably just skip to the fiddle here:

https://jsfiddle.net/xya79cqL/

Summary of the repro:

1. Scroll a textarea out of view
2. Call el.focus({preventScroll: true}) where el is an HTMLTextareaElement
3. Page scrolls even though it shouldn't.

Other notes:

• Nightly is affected
• It works correctly for <input>
• I haven't tested any other kinds of elements.
• Chrome does this correctly.

Actual results:

Page scrolls.

Expected results:

Page should not have scrolled.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

This is because bug 353539 introduced back in the day a way to scroll to the caret of the textarea, but that doesn't restrict the scrolling to the textarea, and also tries to scroll the textarea into view.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1634153 - Make textarea focus code not unconditionally scroll. r=masayuki

Bug 353539 introduced a ScrollOnFocusEvent to scroll the caret on focus
whenever the form control was focused.

However ScrollOnFocusEvent::Run was forgetting to pass
nsISelectionController::SCROLL_FIRST_ANCESTOR_ONLY, so it was also
scrolling the document, which is pretty unexpected when you use
.focus({ preventScroll: true }) for example.

Use ScrollSelectionIntoView instead, does the right thing and is what
the original bug intended anyhow.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1634153 - Rename and devirtualize nsITextControlFrame::ScrollSelectionIntoView. r=masayuki

To make clear it happens async.

Depends on D73181

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/04108f403e7b
Make textarea focus code not unconditionally scroll. r=masayuki
https://hg.mozilla.org/integration/autoland/rev/86989c06d090
Rename and devirtualize nsITextControlFrame::ScrollSelectionIntoView. r=masayuki

Comment 5

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/23345 for changes under testing/web-platform/tests

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 7

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/04108f403e7b
https://hg.mozilla.org/mozilla-central/rev/86989c06d090

Comment 8

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot