Bug 218538 – [macOS] Toggling dark mode does not update the scrollbar appearance in overflow: scroll elements

• Status: RESOLVED
• Resolution: FIXED
• Component: Scrolling

[Aditya Keerthi]

The only way to update the scrollbar's appearance is by hovering over it.

[Aditya Keerthi]

<rdar://problem/68953006>

[Aditya Keerthi]

Created attachment 413113 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 413113 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=413113&action=review

> Source/WebCore/platform/ScrollableArea.cpp:370
>      m_scrollbarOverlayStyle = overlayStyle;
> +    updateScrollbarOverlayStyle();

Can you only call updateScrollbarOverlayStyle() if it changed?

[Aditya Keerthi]

(In reply to Simon Fraser (smfr) from comment #3)
> Comment on attachment 413113 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=413113&action=review
> 
> > Source/WebCore/platform/ScrollableArea.cpp:370
> >      m_scrollbarOverlayStyle = overlayStyle;
> > +    updateScrollbarOverlayStyle();
> 
> Can you only call updateScrollbarOverlayStyle() if it changed?

I think it should be fine to make that change here, but it would be unrelated to the solution.

Note that I've made RenderLayer::styleChanged unconditionally call updateScrollbarOverlayStyle(). This is because the scrollbar's overlay style is always ScrollbarOverlayStyleDefault (regardless of dark/light mode) and we need to call into `[NSScrollerImp setNeedsDisplay:]` to trigger the appearance change.

[Simon Fraser (smfr)]

Comment on attachment 413113 [details]
Patch

r- because it invalidates scrollbars on every style change which will be a perf hit.

[Aditya Keerthi]

Created attachment 413237 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 413237 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=413237&action=review

> Source/WebCore/platform/ScrollableArea.cpp:384
>          if (ScrollAnimator* scrollAnimator = existingScrollAnimator())

auto

> Source/WebCore/platform/ScrollableArea.cpp:390
>          if (ScrollAnimator* scrollAnimator = existingScrollAnimator())

auto

[Aditya Keerthi]

Created attachment 413295 [details]
Patch for landing

[Aditya Keerthi]

Created attachment 413301 [details]
Patch for landing

[EWS]

Committed r269437: <https://trac.webkit.org/changeset/269437>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 413301 [details].