RESOLVED WORKSFORME 232738
A sideways rubber band can break a vertical scroll snap animation 
https://bugs.webkit.org/show_bug.cgi?id=232738
Summary A sideways rubber band can break a vertical scroll snap animation
Simon Fraser (smfr)
Reported 2021-11-04 17:26:11 PDT
In a vertically document with snap points, if your vertical scroll gesture has some horizontal component, we can start a rubberband animation in X which kills the scroll snap momentum animation: ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController::applyScrollDeltaWithStretching() - stretchScrollForce width=4 height=0 move delta width=0 height=0 dampedDelta width=1 height=0 ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController::applyScrollDeltaWithStretching() - stretchScrollForce width=4 height=0 move delta width=0 height=0 dampedDelta width=1 height=0 ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController::applyScrollDeltaWithStretching() - stretchScrollForce width=5 height=0 move delta width=1 height=0 dampedDelta width=1 height=0 ScrollingEffectsController::applyScrollDeltaWithStretching() - stretchScrollForce width=6 height=0 move delta width=1 height=0 dampedDelta width=1 height=0 ScrollingEffectsController 0x31062c180 updateRubberBandingState - isRubberBanding 0 ScrollingEffectsController 0x31062c180 startMomentumScrollWithInitialVelocity width=0 height=0 from (1,319) ScrollingEffectsController 0x31062c180 scrollAnimationWillStart ScrollAnimation 0x3106124b0 momentum active 1 current offset (0,0) ScrollingEffectsController::startRubberBandAnimationIfNecessary() - rubberBandAnimationRunning 0 stretchAmount width=1 height=0 targetOffset (1,319) ScrollingEffectsController 0x31062c180 scrollAnimationDidEnd ScrollAnimation 0x3106124b0 momentum active 0 current offset (0,0) ScrollingEffectsController 0x31062c180 stopAnimatedScroll ScrollingEffectsController::startRubberBandAnimation() - starting rubbberband with targetOffset (0,319) initialVelocity width=0 height=0 initialOverscroll width=1 height=0 ScrollingEffectsController 0x31062c180 scrollAnimationWillStart ScrollAnimation 0x31f8bf240 rubber-band active 1 current offset (0,0) ScrollingEffectsController 0x31062c180 updateRubberBandingState - isRubberBanding 1 ScrollingEffectsController 0x31062c180 scrollAnimationDidUpdate ScrollAnimation 0x31f8bf240 rubber-band active 1 current offset (1,319) (main thread 0) scrolling to (1,319) ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController 0x31062c180 scrollAnimationDidUpdate ScrollAnimation 0x31f8bf240 rubber-band active 1 current offset (1,319) (main thread 0) scrolling to (1,319) ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController 0x31062c180 scrollAnimationDidUpdate ScrollAnimation 0x31f8bf240 rubber-band active 1 current offset (1,319) (main thread 0) scrolling to (1,319) ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ScrollingEffectsController 0x31062c180 scrollAnimationDidUpdate ScrollAnimation 0x31f8bf240 rubber-band active 1 current offset (0,319) (main thread 0) scrolling to (0,319) ScrollingEffectsController 0x31062c180 updateRubberBandingState - isRubberBanding 0 ScrollingEffectsController 0x31062c180 scrollAnimationDidEnd ScrollAnimation 0x31f8bf240 rubber-band active 0 current offset (0,319) ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 1 ThreadedScrollingTree::willStartRenderingUpdate - scrollingThreadIsActive 0
Attachments
Test case (614 bytes, text/html)
2021-11-09 08:56 PST, Simon Fraser (smfr) 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2021-11-04 17:46:08 PDT
<rdar://problem/85041566>
Simon Fraser (smfr)
Comment 2 2021-11-04 17:57:56 PDT
This will be a regression from the scroll animation refactoring.
Simon Fraser (smfr)
Comment 3 2021-11-09 08:56:34 PST
Created attachment 443694 [details] Test case
Brent Fulgham
Comment 4 2022-02-12 22:21:43 PST
QA is unable to reproduce this.
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