257910 2023-06-09 13:54:52 -0700 [GTK] No key modifier present in wheel event 2023-06-12 23:08:39 -0700 1 1 1 Unclassified WebKit WebKitGTK Other PC Linux RESOLVED FIXED P2 Normal --- 1 elidoset mcatanzaro bugs-noreply mcatanzaro oldest_to_newest 1960825 0 466656 elidoset 2023-06-09 13:54:52 -0700 Created attachment 466656 test case of the bug The modifier key (ctrlKey, shiftKey,...) properties of the WheelEvent are always false when read from a wheel event callback. Tested in Epiphany 44.3-1 and in an embedded application using Webkit2gtk 2.40.2-1, on Arch Linux. A test case is provided as an attachement. When scrolling over the red square while the Ctrl key is held down, should turn green. Passes on Firefox 114.0. 1960928 1 elidoset 2023-06-10 02:25:33 -0700 I've done a first investigation myself on the question, and I found the problem to be here : https://github.com/WebKit/WebKit/blob/ef93c1b412c09e10975907c8fd683269eb36a413/Source/WebKit/Shared/gtk/NativeWebWheelEventGtk.cpp#LL41C13-L41C13 The modifier events that could have been extracted from the GtkEventScroll are not transmitted to the constructor of WebEvent. This is handled better for key presses (https://github.com/WebKit/WebKit/blob/ef93c1b412c09e10975907c8fd683269eb36a413/Source/WebKit/Shared/gtk/WebEventFactory.cpp#L259), where a factory function parses the GtkEventScroll.state property and transmits the modifier keys using the modifiersForEvent(const GdkEvent*) function. This is my first time delving into the Webkit codebase and I'm not a professional programmer so I don't really want to make the change myself, but I can try if nobody's up for it... 1960929 2 elidoset 2023-06-10 02:35:09 -0700 See also https://github.com/WebKit/WebKit/blob/ef93c1b412c09e10975907c8fd683269eb36a413/Source/WebKit/UIProcess/API/gtk/WebKitWebViewBase.cpp#L1409 for where the event is handled on the Gtk side and first dispatched to the page Proxy. Strangely enough the key modifiers are even queried a few lines up (l402), but never checked again further down the call stack. 1960933 3 mcatanzaro 2023-06-10 07:15:55 -0700 Nice investigation. This probably explains why all those "hold Ctrl to scroll" maps on various websites do not work. 1961046 4 mcatanzaro 2023-06-12 08:19:58 -0700 Pull request: https://github.com/WebKit/WebKit/pull/14863 1961247 5 ews-feeder 2023-06-12 23:08:36 -0700 Committed 265104@main (c313668f2cf7): <https://commits.webkit.org/265104@main> Reviewed commits have been landed. Closing PR #14863 and removing active labels. 466656 2023-06-09 13:54:52 -0700 2023-06-09 13:54:52 -0700 test case of the bug testbug.html text/html 686 elidoset PCFET0NUWVBFIGh0bWw+CjxodG1sIGxhbmc9ImVuIj4KCjxoZWFkPgogICAgPG1ldGEgY2hhcnNl dD0iVVRGLTgiPgogICAgPG1ldGEgbmFtZT0idmlld3BvcnQiIGNvbnRlbnQ9IndpZHRoPWRldmlj ZS13aWR0aCwgaW5pdGlhbC1zY2FsZT0xLjAiPgogICAgPHRpdGxlPlRlc3Qgd2hlZWw8L3RpdGxl Pgo8L2hlYWQ+Cgo8Ym9keT4KICAgIDxkaXYgaWQ9InRlc3QiPjwvZGl2PgoKICAgIDxzY3JpcHQ+ CgoKICAgICAgICBjb25zb2xlLmxvZygibmlrIikKICAgICAgICBkb2N1bWVudC5xdWVyeVNlbGVj dG9yKCIjdGVzdCIpLmFkZEV2ZW50TGlzdGVuZXIoIndoZWVsIiwgKGUpID0+IHsKICAgICAgICAg ICAgZS5wcmV2ZW50RGVmYXVsdCgpOwogICAgICAgICAgICBjb25zb2xlLmxvZyhlLnR5cGUpCiAg ICAgICAgICAgIGlmIChlLmN0cmxLZXkpCiAgICAgICAgICAgICAgICBlLnRhcmdldC5jbGFzc0xp c3QuYWRkKCJwYXNzZWQiKQogICAgICAgIH0pCgogICAgPC9zY3JpcHQ+CjwvYm9keT4KCjxzdHls ZT4KICAgICN0ZXN0IHsKICAgICAgICB3aWR0aDogMTAwcHg7CiAgICAgICAgaGVpZ2h0OiAxMDBw eDsKICAgICAgICBiYWNrZ3JvdW5kLWNvbG9yOiByZWQ7CiAgICB9CgogICAgI3Rlc3QucGFzc2Vk IHsKICAgICAgICBiYWNrZ3JvdW5kLWNvbG9yOiBncmVlbjsKICAgIH0KPC9zdHlsZT4KCjwvaHRt bD4=