[Bug]: MouseEvent: mouseDownTime > eventTime

[fyzix]

Detailed steps on how to reproduce the bug

It is possible that the eventTime of, e.g., a mouseUp event is overtaken by the mouseDownTime when the MouseEvent is created.

How to reproduce/debug: Put this assertion into the body of MouseEvent::MouseEvent

jassert (time >= mouseDownTime);

and start a juce app in the debugger, then click around a lot. You should break into the debugger then.

My suspicion is that this happens because the lastMouseDownTime in MouseInputSource is updated before other mouse events are processed. MouseInputSourceImpl::handleAsyncUpdate might have something to do with it, as it forms jmax (lastTime, Time::getCurrentTime()) which is not a value coming out of any OS timestamp, and if this asyncUpdate is processed before the mouse events, I suspect something like this could happen.

EDIT: Could be partly be related to the function getMouseTime (also mentioned in #1587)

   static int64 getMouseTime (NSEvent* e) noexcept
    {
        return (Time::currentTimeMillis() - Time::getMillisecondCounter())
                 + (int64) ([e timestamp] * 1000.0);
    }

The difference Time::currentTimeMillis() - Time::getMillisecondCounter() oscillates by at least 1 ms (proved this with DBG printouts). The reason is that getMillisecondCounteris a rounded value, and forming the difference after rounding makes it an unstable offset. Maybe it would be a good idea to cache a stable offset once that is then used consistently in order not to break monotony of timestamps that are causally connected such as mouseDown / mouseUp.

What is the expected behaviour?

I would expect a mouseUp event (and others) to always have an eventTime that is >= the corresponding mouseDownTime.

Operating systems

macOS

What versions of the operating systems?

Sequoia 15.5
macOS 26.0.1

Architectures

Arm64/aarch64

Stacktrace

TouchGestureTests!juce::MouseEvent::MouseEvent(juce::MouseInputSource, juce::Point<float>, juce::ModifierKeys, float, float, float, float, float, juce::Component*, juce::Component*, juce::Time, juce::Point<float>, juce::Time, int, bool) (JUCE/modules/juce_gui_basics/mouse/juce_MouseEvent.cpp:69)
TouchGestureTests!juce::MouseEvent::MouseEvent(juce::MouseInputSource, juce::Point<float>, juce::ModifierKeys, float, float, float, float, float, juce::Component*, juce::Component*, juce::Time, juce::Point<float>, juce::Time, int, bool) (JUCE/modules/juce_gui_basics/mouse/juce_MouseEvent.cpp:68)
TouchGestureTests!juce::detail::makeMouseEvent(juce::MouseInputSource, juce::detail::PointerState const&, juce::ModifierKeys, juce::Component*, juce::Component*, juce::Time, juce::Point<float>, juce::Time, int, bool) (JUCE/modules/juce_gui_basics/detail/juce_PointerState.h:96)
TouchGestureTests!juce::Component::internalMouseUp(juce::Component::SafePointer<juce::Component>, juce::MouseInputSource, juce::detail::PointerState const&, juce::Time, juce::ModifierKeys) (JUCE/modules/juce_gui_basics/components/juce_Component.cpp:2287)
TouchGestureTests!juce::detail::MouseInputSourceImpl::sendMouseUp(juce::Component&, juce::detail::PointerState const&, juce::Time, juce::ModifierKeys) (JUCE/modules/juce_gui_basics/detail/juce_MouseInputSourceImpl.h:165)
TouchGestureTests!juce::detail::MouseInputSourceImpl::setButtons(juce::detail::PointerState const&, juce::Time, juce::ModifierKeys) (JUCE/modules/juce_gui_basics/detail/juce_MouseInputSourceImpl.h:221)
TouchGestureTests!juce::detail::MouseInputSourceImpl::handleEvent(juce::ComponentPeer&, juce::Point<float>, juce::Time, juce::ModifierKeys, float, float, juce::PenDetails) (JUCE/modules/juce_gui_basics/detail/juce_MouseInputSourceImpl.h:348)
TouchGestureTests!juce::MouseInputSource::handleEvent(juce::ComponentPeer&, juce::Point<float>, long long, juce::ModifierKeys, float, float, juce::PenDetails const&) (JUCE/modules/juce_gui_basics/mouse/juce_MouseInputSource.cpp:89)
TouchGestureTests!juce::ComponentPeer::handleMouseEvent(juce::MouseInputSource::InputSourceType, juce::Point<float>, juce::ModifierKeys, float, float, long long, juce::PenDetails, int) (JUCE/modules/juce_gui_basics/windows/juce_ComponentPeer.cpp:99)
TouchGestureTests!juce::NSViewComponentPeer::sendMouseEvent(NSEvent*) (JUCE/modules/juce_gui_basics/native/juce_NSViewComponentPeer_mac.mm:868)
TouchGestureTests!juce::NSViewComponentPeer::redirectMouseUp(NSEvent*) (JUCE/modules/juce_gui_basics/native/juce_NSViewComponentPeer_mac.mm:741)
TouchGestureTests!void juce::JuceNSViewClass::callOnOwner<void (juce::NSViewComponentPeer::*)(NSEvent*), NSEvent*&>(objc_object*, void (juce::NSViewComponentPeer::*&&)(NSEvent*), NSEvent*&) (JUCE/modules/juce_gui_basics/native/juce_NSViewComponentPeer_mac.mm:2673)
TouchGestureTests!juce::JuceNSViewClass::asyncMouseUp(objc_object*, objc_selector*, NSEvent*) (JUCE/modules/juce_gui_basics/native/juce_NSViewComponentPeer_mac.mm:2678)
TouchGestureTests!juce::JuceNSViewClass::mouseUp(objc_object*, objc_selector*, NSEvent*) (JUCE/modules/juce_gui_basics/native/juce_NSViewComponentPeer_mac.mm:2702)
AppKit!_routeMouseUpEvent (Unknown Source:0)
AppKit!-[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:] (Unknown Source:0)
AppKit!-[NSWindow(NSEventRouting) sendEvent:] (Unknown Source:0)
AppKit!-[NSApplication(NSEventRouting) sendEvent:] (Unknown Source:0)
AppKit!-[NSApplication _handleEvent:] (Unknown Source:0)
AppKit!-[NSApplication run] (Unknown Source:0)
TouchGestureTests!juce::MessageManager::runDispatchLoop() (JUCE/modules/juce_events/native/juce_MessageManager_mac.mm:347)
TouchGestureTests!juce::JUCEApplicationBase::main() (JUCE/modules/juce_events/messages/juce_ApplicationBase.cpp:277)
TouchGestureTests!juce::JUCEApplicationBase::main(int, char const**) (JUCE/modules/juce_events/messages/juce_ApplicationBase.cpp:255)
TouchGestureTests!main (.../TouchGestureTests/Main.cpp:104)
start (Unknown Source:0)

Plug-in formats (if applicable)

No response

Plug-in host applications (DAWs) (if applicable)

No response

Testing on the develop branch

The bug is present on the develop branch

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