Bug 141001

Summary: Scroll snap points do not work in the vertical direction
Product: WebKit Reporter: Brent Fulgham <bfulgham>
Component: Layout and RenderingAssignee: Brent Fulgham <bfulgham>
Status: RESOLVED FIXED    
Severity: Normal CC: bdakin, bfulgham, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Example of horizontal and vertical scroll snap points
none
Patch bdakin: review+

Brent Fulgham
Reported 2015-01-28 10:02:53 PST
Created attachment 245550 [details] Example of horizontal and vertical scroll snap points Scroll snap points work properly in the horizontal direction, but not in the vertical. See the attached example page. The top example works properly, but the bottom fails.
Attachments
Example of horizontal and vertical scroll snap points (2.72 KB, text/html)
2015-01-28 10:02 PST, Brent Fulgham 		no flags
Details
Patch (5.87 KB, patch)
2015-01-28 16:44 PST, Brent Fulgham 		bdakin: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Brent Fulgham
Comment 1 2015-01-28 10:04:16 PST
The problem seems to be in EventHandler::defaultWheelEventHandler: When scrolling in the horizontal direction, we do not mark the wheelEvent as 'default handled', which allows the event to bubble up and get handled by the snap logic. When scrolling in the vertical direction, we do mark the event as 'default handled', which prevents us from bubbling the event up to the snap logic.
Radar WebKit Bug Importer
Comment 2 2015-01-28 10:04:37 PST
<rdar://problem/19632089>
Brent Fulgham
Comment 3 2015-01-28 10:21:26 PST
Actually, it looks like the difference might be in ScrollAnimatorMac::handleWheelEvent. We ask the ScrollAnimator to handle the wheel event directly in the vertical case, rather than passing it along to the scroll elasticity controller.
Brent Fulgham
Comment 4 2015-01-28 16:44:59 PST
Created attachment 245580 [details] Patch
Beth Dakin
Comment 5 2015-01-28 16:51:53 PST
Comment on attachment 245580 [details] Patch R=me assuming this does not break rubber-banding in overflow areas and iframes.
Brent Fulgham
Comment 6 2015-01-28 18:15:45 PST
Committed r179324: <http://trac.webkit.org/changeset/179324>
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