Bug 211895 – [Wheel event region] Invalidation when changing listeners on elements

• Component: Compositing
• Status: RESOLVED FIXED

[Antti Koivisto]

Listener changes should update the region.

[Antti Koivisto]

Created attachment 399362 [details]
patch

[Simon Fraser (smfr)]

Comment on attachment 399362 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=399362&action=review

> LayoutTests/fast/scrolling/mac/wheel-event-listener-region-element-invalidation.html:20
> +

extra line

> LayoutTests/fast/scrolling/mac/wheel-event-listener-region-element-invalidation.html:29
> +    function listener() {
> +        results.textContent += 'wheel\n';
> +    }

This is never called, right? It could be an empty function.

> LayoutTests/fast/scrolling/mac/wheel-event-listener-region-element-invalidation.html:33
> +    if (window.internals)
> +        results.textContent += internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_EVENT_REGION | internals.LAYER_TREE_INCLUDES_ROOT_LAYER_PROPERTIES);

Beware of setting element contents here then fetching layers again later; layout will change making the two trees hard to compare.

I prefer to store the first layer tree in a variable then set textContent once at the end.

> LayoutTests/fast/scrolling/mac/wheel-event-listener-region-element-invalidation.html:36
> +    passive.addEventListener('wheel', () => { results.textContent += 'passive wheel\n' }, { passive: true });

Ditto

> Source/WebCore/rendering/RenderLayer.cpp:-6973
> -    // FIXME: This should not be conditioned on PLATFORM(IOS_FAMILY). See <https://webkit.org/b/210216>.

Can https://webkit.org/b/210216 be closed after this?

> Source/WebCore/rendering/RenderLayer.cpp:6973
> +#if ENABLE(ASYNC_SCROLLING)

This doesn't feel like quite the right #ifdef; isn't it also if we have touch events or editable regions?

[Antti Koivisto]

> This doesn't feel like quite the right #ifdef; isn't it also if we have
> touch events or editable regions?

It doesn't, but it is the #ifdef currently used for RenderLayerBacking::updateEventRegion and this should match.

[Antti Koivisto]

Created attachment 399474 [details]
patch

[EWS]

Committed r261742: <https://trac.webkit.org/changeset/261742>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 399474 [details].

[Radar WebKit Bug Importer]

<rdar://problem/63270443>