Bug 9581 – REGRESSION: The new NativeTextArea scrolls to the top when the control is unfocused.

• Component: Forms
• Status: RESOLVED FIXED

[Rosyna]

If I have a lot of text In a textarea control, such that it makes the textarea get a scroll bar and I scroll to the bottom of the textarea control, then click on another control (such as a checkbox, radio control, or push button), the textarea scrolls to the top. This seems to be really "jarring". Especially if I'm trying to copy and paste something into the textarea from the webpage I'm commenting on. Since it means I have to scroll all the way down to the bottom again to find the location I was *just* at in order to paste the thing I am going to quote.

[Rosyna]

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[Adele Peterson]

Created attachment 9096 [details]
patch

[Adele Peterson]

Comment on attachment 9096 [details]
patch

clearing review flag. this isn't quite right.

[Adele Peterson]

That patch fixes some common cases of this problem, but RenderLayer::updateScrollInfoAfterLayout is still sometimes causing the layer to scroll back to the top.

I'm not sure I understand this code.... we're calculating a new scroll position (line 1036):

        int newY = max(0, min(m_scrollY, scrollHeight() - m_object->clientHeight()));

where m_scrollY is 26... which seems to be valid, but gets clobbered by this calculation.

[Simon Raboczi]

A more severe (and presumably related) problem with the scrolling of textareas is that touching the scrollbar instantly and reproducibly crashes the browser.

[Adele Peterson]

Simon, please file a new bug about the crash, so we can fix that separately from this issue.  Thanks!

[David Kilzer (:ddkilzer)]

This is a regression from production Safari, so adding Regression keyword.  Regressions are P1, and should have a Radar associated with them (adding NeedsRadar).

[David Kilzer (:ddkilzer)]

Bug 9942 may be related to this bug since it exhibits similar behavior.

*** Bug 10670 has been marked as a duplicate of this bug. ***

[Jon]

Highlight scrolling is still crazy as of r16831. Major usability (i.e. testing) problem

[Adele Peterson]

Comment on attachment 9096 [details]
patch

I actually do think this patch is right.  The problem I was seeing before is caused by the flexbox double layout bugs.  Now that we've moved textareas off of RenderFlexibleBox, this change should fully fix this scrolling problem.

[Adele Peterson]

Comment on attachment 9096 [details]
patch

oh, and of course, I'll update this patch so RenderTextField --> RenderTextControl

[Anders Carlsson]

Comment on attachment 9096 [details]
patch

r=me

[Adele Peterson]

Committed revision 17560.