257039 2023-05-19 10:28:37 -0700 [GTK] Overlay scrollbar does not properly hide itself when drag released outside window 2024-09-10 22:02:01 -0700 1 1 1 Unclassified WebKit WebKitGTK WebKit Nightly Build PC Linux NEW https://bugs.webkit.org/show_bug.cgi?id=238327 P2 Normal --- 210100 1 mcatanzaro webkit-unassigned bugs-noreply mcatanzaro muziknavi oldest_to_newest 1956530 0 mcatanzaro 2023-05-19 10:28:37 -0700 When dragging the scrollbar and releasing it with the pointer outside the window, the overlay scrollbar gets stuck in the active/exposed state when it should be hidden. This is related to bug #238327, except this one is only a visual bug. 1956563 1 mcatanzaro 2023-05-19 12:58:56 -0700 I think the problem is we are failing to call ScrollbarsControllerGeneric::mouseExitedContentArea in this case. That's supposed to be handled by EventHandler::notifyScrollableAreasOfMouseEvents. 1956595 2 mcatanzaro 2023-05-19 14:45:39 -0700 I'm having trouble investigating this one. Here's what I've done so far: * In EventHandler::handleMouseReleaseEvent, I changed all the FireMouseOverOut::No to FireMouseOverOut::Yes. Not sure what the consequences of that is, but it's required so that EventHandler::updateMouseEventTargetNode will call EventHandler::notifyScrollableAreasOfMouseEvents. * In EventHandler::notifyScrollableAreasOfMouseEvents, I applied some sabotage that I don't understand (below) in order to ensure that ScrollableArea::mouseExitedContentArea gets called diff --git a/Source/WebCore/page/EventHandler.cpp b/Source/WebCore/page/EventHandler.cpp index 44afaa401827..fe617acc2e91 100644 --- a/Source/WebCore/page/EventHandler.cpp +++ b/Source/WebCore/page/EventHandler.cpp @@ -2769,9 +2769,9 @@ void EventHandler::notifyScrollableAreasOfMouseEvents(const AtomString& eventTyp } if (!movedBetweenScrollableaAreas) - return; +// return; - if (scrollableAreaForLastNode && scrollableAreaForLastNode != frameView) + if (scrollableAreaForLastNode /*&& scrollableAreaForLastNode != frameView*/) scrollableAreaForLastNode->mouseExitedContentArea(); if (scrollableAreaForNodeUnderMouse && scrollableAreaForNodeUnderMouse != frameView) Now ScrollbarsControllerGeneric::hideOverlayScrollbars gets called like I want it to, but it doesn't actually work. The function bails immediately because m_overlayScrollbarAnimationTimer.isActive() and m_overlayScrollbarAnimationTarget == 0, meaning it's _already_ trying to hide the scrollbars for some unknown reason, but fails. (This is only true after my changes above, not normally.) I need to investigate more to see what's going wrong. If I sabotage this further to immediately hide the scrollbars, then the scrollbars stay hidden permanently, so something's up here.