226354 2021-05-27 13:38:39 -0700 VisualViewport fires lots scroll events for 0.5px offsets when scrolling on Retina iOS device 2021-06-07 10:22:54 -0700 1 1 1 Unclassified WebKit DOM Safari Technology Preview Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=218465 InRadar P2 Normal --- 1 simon.fraser webkit-unassigned john.crim simon.fraser webkit-bug-importer oldest_to_newest 1764482 0 429921 simon.fraser 2021-05-27 13:38:39 -0700 Created attachment 429921 Testcase When not zoomed, we should not be firing scroll events on the VisualViewport. However, we do, because of some 0.5px difference between the layout viewport and visual viewport, probably due to rounding. See testcase, test on iPad. 1764483 1 webkit-bug-importer 2021-05-27 13:38:58 -0700 <rdar://problem/78584763> 1764484 2 simon.fraser 2021-05-27 13:39:21 -0700 We also fire events on rubberbanding. 429921 2021-05-27 13:38:39 -0700 2021-05-27 13:38:39 -0700 Testcase visual-viewport-scroll-handler.html text/html 1551 simon.fraser PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KICAgIDxtZXRhIG5hbWU9InZpZXdwb3J0IiBj b250ZW50PSJ3aWR0aD1kZXZpY2Utd2lkdGgsIGluaXRpYWwtc2NhbGU9MSwgc2hyaW5rLXRvLWZp dD1ubyI+CiAgICA8c3R5bGU+CiAgICAgICAgYm9keSB7CiAgICAgICAgICAgIGhlaWdodDogNTAw MHB4OwogICAgICAgICAgICBiYWNrZ3JvdW5kLWltYWdlOiByZXBlYXRpbmctbGluZWFyLWdyYWRp ZW50KHRyYW5zcGFyZW50LCBzaWx2ZXIgMzAwcHgpOwogICAgICAgIH0KICAgICAgICAKICAgICAg ICAjb3V0cHV0IHsKICAgICAgICAgICAgcG9zaXRpb246IGZpeGVkOwogICAgICAgICAgICB3aWR0 aDogNTAwcHg7CiAgICAgICAgICAgIGhlaWdodDogMjAwcHg7CiAgICAgICAgICAgIHRvcDogMTBw eDsKICAgICAgICAgICAgbGVmdDogMTBweDsKICAgICAgICAgICAgYmFja2dyb3VuZC1jb2xvcjog cmdiYSgyNTUsIDI1NSwgMjU1LCAwLjcpOwogICAgICAgICAgICB3aGl0ZS1zcGFjZTogcHJlOwog ICAgICAgICAgICBvdmVyZmxvdzogc2Nyb2xsOwogICAgICAgICAgICBwYWRkaW5nOiAxMHB4Owog ICAgICAgIH0KICAgIDwvc3R5bGU+CiAgICA8c2NyaXB0PgogICAgICAgIAogICAgICAgIGZ1bmN0 aW9uIGxvZ1N0cmluZyhzKQogICAgICAgIHsKICAgICAgICAgICAgY29uc3Qgb3V0cHV0ID0gZG9j dW1lbnQuZ2V0RWxlbWVudEJ5SWQoJ291dHB1dCcpOwogICAgICAgICAgICBvdXRwdXQuaW5uZXJU ZXh0ICs9IHMgKyAnXG4nOwogICAgICAgICAgICBvdXRwdXQuc2Nyb2xsVG9wID0gOTk5OTk5OTsK ICAgICAgICB9CiAgICAgICAgCiAgICAgICAgd2luZG93LmFkZEV2ZW50TGlzdGVuZXIoJ2xvYWQn LCAoKSA9PiB7CiAgICAgICAgICAgIGxvZ1N0cmluZygnbG9hZCcpOwogICAgICAgICAgICAKICAg ICAgICAgICAgaWYgKCEoJ3Zpc3VhbFZpZXdwb3J0JyBpbiB3aW5kb3cpKSB7CiAgICAgICAgICAg ICAgICBsb2dTdHJpbmcoJ3Zpc3VhbFZpZXdwb3J0IG5vdCBzdXBwb3J0ZWQnKTsKICAgICAgICAg ICAgICAgIHJldHVybjsKICAgICAgICAgICAgfQogICAgICAgICAgICAgICAgCiAgICAgICAgICAg IHdpbmRvdy52aXN1YWxWaWV3cG9ydC5hZGRFdmVudExpc3RlbmVyKCdzY3JvbGwnLCAoZXZ0KSA9 PiB7CiAgICAgICAgICAgICAgICBsb2dTdHJpbmcoJ3Njcm9sbCAnICsgIHdpbmRvdy52aXN1YWxW aWV3cG9ydC5vZmZzZXRUb3ApOwogICAgICAgICAgICB9KTsKCiAgICAgICAgICAgIHdpbmRvdy52 aXN1YWxWaWV3cG9ydC5hZGRFdmVudExpc3RlbmVyKCdyZXNpemUnLCAoZXZ0KSA9PiB7CiAgICAg ICAgICAgICAgICBsb2dTdHJpbmcoJ3Jlc2l6ZSAnICsgIHdpbmRvdy52aXN1YWxWaWV3cG9ydC5v ZmZzZXRUb3AgKyAnICcgKyB3aW5kb3cudmlzdWFsVmlld3BvcnQud2lkdGgpOwogICAgICAgICAg ICB9KTsKCiAgICAgICAgICAgIAogICAgICAgIH0sIGZhbHNlKTsKICAgIDwvc2NyaXB0Pgo8L2hl YWQ+Cjxib2R5PgogICAgPGRpdiBpZD0ib3V0cHV0Ij4KICAgICAgICAKICAgIDwvZGl2Pgo8L2Jv ZHk+CjwvaHRtbD4K