Bug 210618

Summary: A slow-starting swipe always latches on the root node
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: ScrollingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: cmarcelo, ews-watchlist, fred.wang, jamesr, luiz, simon.fraser, thorton, tonikitoo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
testcase
none
Patch none

Description Simon Fraser (smfr) 2020-04-16 14:25:32 PDT
Created attachment 396698 [details]
testcase

Start a slow swipe over an overflow:scroll, and we'll always latch on the main frame by mistake.

The first event we get has zero deltas, so ScrollingTreeScrollingNode::canScrollWithWheelEvent() returns false for non-root nodes, and true for root nodes. Then we latch on the root node for the rest of the gesture.
Comment 1 Radar WebKit Bug Importer 2020-04-16 14:25:49 PDT
<rdar://problem/61903663>
Comment 2 Simon Fraser (smfr) 2020-04-16 15:05:51 PDT
Created attachment 396703 [details]
Patch
Comment 3 EWS 2020-04-16 16:05:33 PDT
Committed r260224: <https://trac.webkit.org/changeset/260224>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 396703 [details].