stdin.diff

commit ae32c14edccae744c3a66d9384caa62b15e66194
Author: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Date:   Mon Dec 11 16:17:30 2017 +0100

    macOS: Transition to momentum-based wheel scrolling without Qt::ScrollEnd
    
    We detect if there's an upcoming momentum phase, and if so skip sending
    Qt::ScrollEnd. The event is not guaranteed to be in the queue, but in
    practice it is. This is the same trick used by e.g. Mozilla in their
    event handling.
    
    See also http://bit.ly/2BA77uq
    
    Task-number: QTBUG-63026
    Change-Id: I80191a472f6fa892387004c199166a6350124274

diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 2e64204fb7..0490dc90ee 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -1470,8 +1470,13 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
         m_scrolling = true;
     } else if (phase == NSEventPhaseEnded || phase == NSEventPhaseCancelled ||
                momentumPhase == NSEventPhaseEnded || momentumPhase == NSEventPhaseCancelled) {
-        ph = Qt::ScrollEnd;
-        m_scrolling = false;
+        bool upcomingMomentumPhase = phase == NSEventPhaseEnded &&
+            [NSApp nextEventMatchingMask:NSScrollWheelMask untilDate:[NSDate distantPast]
+                inMode:@"QtMomementumEventSearchMode" dequeue:NO].momentumPhase == NSEventPhaseBegan;
+        if (!upcomingMomentumPhase) {
+            ph = Qt::ScrollEnd;
+            m_scrolling = false;
+        }
     } else if (phase == NSEventPhaseNone && momentumPhase == NSEventPhaseNone) {
         ph = Qt::NoScrollPhase;
     }