| Summary: | [iOS] scroll snap points are animating to the wrong position. | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Product: | WebKit | Reporter: | Brent Fulgham <bfulgham> | ||||||||||
| Component: | Layout and Rendering | Assignee: | Brent Fulgham <bfulgham> | ||||||||||
| Status: | RESOLVED FIXED | ||||||||||||
| Severity: | Critical | CC: | benjamin, bfulgham, buildbot, cmarcelo, commit-queue, dino, jamesr, luiz, rniwa, simon.fraser, thorton, tonikitoo, webkit-bug-importer | ||||||||||
| Priority: | P2 | Keywords: | InRadar | ||||||||||
| Version: | 528+ (Nightly build) | ||||||||||||
| Hardware: | iPhone / iPad | ||||||||||||
| OS: | All | ||||||||||||
| See Also: | https://bugs.webkit.org/show_bug.cgi?id=142706 | ||||||||||||
| Attachments: |
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Description
Brent Fulgham
2015-03-14 20:31:36 PDT
Created attachment 248664 [details]
Patch
Scroll snapping was landing in the wrong place on iOS because of two problems:
(1) It was searching for the closest snap offset point using unscaled 'screen' pixels,
which caused it to always choose one of the earliest snap point options.
(2) It was then selecting a scaled snap point coordinate and passing it back to UIKit
to animate the snap. This caused it to select a target point beyond the 'screen'
pixel we want to hit.
The solution to both problems are to scale the scroll destination UIKit suggests so that
we search among the scaled points with a valid value. Then, we need to scale the returned
value back to screen units before handing it back to UIKit to process.
Comment on attachment 248664 [details] Patch Attachment 248664 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/5213893995528192 New failing tests: css3/scroll-snap/scroll-snap-position-values.html css3/scroll-snap/scroll-snap-initial.html Created attachment 248665 [details]
Archive of layout-test-results from ews105 for mac-mavericks-wk2
The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews105 Port: mac-mavericks-wk2 Platform: Mac OS X 10.9.5
I will correct the test expectations when landing. Comment on attachment 248664 [details] Patch Attachment 248664 [details] did not pass mac-ews (mac): Output: http://webkit-queues.appspot.com/results/6102462599528448 New failing tests: css3/scroll-snap/scroll-snap-position-values.html css3/scroll-snap/scroll-snap-initial.html Created attachment 248666 [details]
Archive of layout-test-results from ews100 for mac-mavericks
The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews100 Port: mac-mavericks Platform: Mac OS X 10.9.5
Created attachment 248669 [details]
Patch v2 (Revised to correct test crash)
Committed r181504: <http://trac.webkit.org/changeset/181504> |