Bug 233788 – Implement CSS overscroll-behavior for iOS

• Component: New Bugs
• Status: RESOLVED FIXED

[Nikos Mouchtaris]

Implement CSS overscroll-behavior for iOS

[Nikos Mouchtaris]

Created attachment 445791 [details]
Patch

[Radar WebKit Bug Importer]

<rdar://problem/86126776>

[Nikos Mouchtaris]

Created attachment 446239 [details]
Patch

[Nikos Mouchtaris]

Created attachment 446255 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 446255 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=446255&action=review

Why is there no layout test with this?

> Source/WebKit/ChangeLog:10
> +        to UIKit by Russell Ladd, to allow controlling of scroll chaining.

I don't think this level of detail needs to be in the webkit changelog.

> Source/WebKit/UIProcess/RemoteLayerTree/ios/ScrollingTreeScrollingNodeDelegateIOS.mm:261
> +            scrollView.bouncesHorizontally = params.horizontalOverscrollBehavior == OverscrollBehavior::None ? NO : YES;
> +            scrollView.bouncesVertically = scrollingStateNode.scrollableAreaParameters().verticalOverscrollBehavior == OverscrollBehavior::None ? NO : YES;
> +            scrollView._allowsParentToBeginHorizontally = scrollingStateNode.scrollableAreaParameters().horizontalOverscrollBehavior != OverscrollBehavior::Auto ? NO : YES;
> +            scrollView._allowsParentToBeginVertically = scrollingStateNode.scrollableAreaParameters().verticalOverscrollBehavior != OverscrollBehavior::Auto ? NO : YES;

params vs scrollingStateNode.scrollableAreaParameters() ?

[Nikos Mouchtaris]

Created attachment 446588 [details]
Patch

[Nikos Mouchtaris]

Created attachment 446615 [details]
Patch

[Darin Adler]

Comment on attachment 446615 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=446615&action=review

> Source/WebKit/UIProcess/RemoteLayerTree/ios/ScrollingTreeScrollingNodeDelegateIOS.mm:261
> +            scrollView.bouncesHorizontally = params.horizontalOverscrollBehavior == OverscrollBehavior::None ? NO : YES;
> +            scrollView.bouncesVertically = params.verticalOverscrollBehavior == OverscrollBehavior::None ? NO : YES;
> +            scrollView._allowsParentToBeginHorizontally = params.horizontalOverscrollBehavior != OverscrollBehavior::Auto ? NO : YES;
> +            scrollView._allowsParentToBeginVertically = params.verticalOverscrollBehavior != OverscrollBehavior::Auto ? NO : YES;

Since this is all Boolean logic, we could rewrite it to not use ? NO : YES so much, like this:

     scrollView.bouncesHorizontally = params.horizontalOverscrollBehavior != OverscrollBehavior::None;

Fine to land what was reviewed, but I would prefer the more direct boolean style rather than one that implements "!" using "? NO : YES" syntax.

[Nikos Mouchtaris]

Created attachment 446625 [details]
overscroll-behavior ios

[Nikos Mouchtaris]

Created attachment 450302 [details]
Patch

[EWS]

Committed r288782 (246559@main): <https://commits.webkit.org/246559@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 450302 [details].

[Nikos Mouchtaris]

*** Bug 233787 has been marked as a duplicate of this bug. ***