tdf#151423 Only allow modifiers for mouse scrollwheel events

The Command modifier converts scrollwheel events into
magnification events and the Shift modifier converts vertical
scrollwheel events into horizontal scrollwheel events. This
behavior is reasonable for mouse scrollwheel events since many
mice only have a single, vertical scrollwheel but trackpads
already have specific gestures for magnification and horizontal
scrolling. So, behave like most macOS applications and ignore
all modifiers if this a trackpad scrollwheel event.

Also, ignore all modifiers for swipe events since it appears
that devices that generate swipe events can generate both
vertical and horizontal swipe events.

Change-Id: I3c0c726759ef010d528f221c63d1e7e401726db5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/176410
Tested-by: Jenkins
Reviewed-by: Patrick Luby <guibomacdev@gmail.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/vcl/osx/salframeview.mm b/vcl/osx/salframeview.mm
index 6b812fe00ec1..ebbf112f1176 100644
--- a/vcl/osx/salframeview.mm
+++ b/vcl/osx/salframeview.mm
@@ -238,6 +238,11 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
     }
 }
 
+static bool isMouseScrollWheelEvent( NSEvent *pEvent )
+{
+    return ( pEvent && [pEvent type] == NSEventTypeScrollWheel && [pEvent phase] == NSEventPhaseNone && [pEvent momentumPhase] == NSEventPhaseNone );
+}
+
 @interface NSResponder (SalFrameWindow)
 -(BOOL)accessibilityIsIgnored;
 @end
@@ -1145,7 +1150,7 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
         {
             dX += [pEvent deltaX];
             dY += [pEvent deltaY];
-            NSEvent* pNextEvent = [NSApp nextEventMatchingMask: NSEventMaskScrollWheel
+            NSEvent* pNextEvent = [NSApp nextEventMatchingMask: NSEventMaskSwipe
             untilDate: nil inMode: NSDefaultRunLoopMode dequeue: YES ];
             if( !pNextEvent )
                 break;
@@ -1159,7 +1164,11 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
         aEvent.mnTime           = mpFrame->mnLastEventTime;
         aEvent.mnX = static_cast<tools::Long>(aPt.x) - mpFrame->GetUnmirroredGeometry().x();
         aEvent.mnY = static_cast<tools::Long>(aPt.y) - mpFrame->GetUnmirroredGeometry().y();
-        aEvent.mnCode           = ImplGetModifierMask( mpFrame->mnLastModifierFlags );
+        // tdf#151423 Ignore all modifiers for swipe events
+        // It appears that devices that generate swipe events can generate
+        // both veritical and horizontal swipe events. So, behave like most
+        // macOS applications and ignore all modifiers if this a swipe event.
+        aEvent.mnCode           = 0;
         aEvent.mbDeltaIsPixel   = true;
 
         if( AllSettings::GetLayoutRTL() )
@@ -1185,6 +1194,9 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
             aEvent.mnScrollLines = SAL_WHEELMOUSE_EVENT_PAGESCROLL;
             mpFrame->CallCallback( SalEvent::WheelMouse, &aEvent );
         }
+
+        // tdf#155266 force flush after scrolling
+        mpFrame->mbForceFlush = true;
     }
 }
 
@@ -1200,13 +1212,14 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
         // merge pending scroll wheel events
         CGFloat dX = 0.0;
         CGFloat dY = 0.0;
+        bool bAllowModifiers = isMouseScrollWheelEvent( pEvent );
         for(;;)
         {
             dX += [pEvent deltaX];
             dY += [pEvent deltaY];
             NSEvent* pNextEvent = [NSApp nextEventMatchingMask: NSEventMaskScrollWheel
                 untilDate: nil inMode: NSDefaultRunLoopMode dequeue: YES ];
-            if( !pNextEvent )
+            if( !pNextEvent || ( isMouseScrollWheelEvent( pNextEvent ) != bAllowModifiers ) )
                 break;
             pEvent = pNextEvent;
         }
@@ -1218,7 +1231,16 @@ static void freezeWindowSizeAndReschedule( NSWindow *pWindow )
         aEvent.mnTime         = mpFrame->mnLastEventTime;
         aEvent.mnX = static_cast<tools::Long>(aPt.x) - mpFrame->GetUnmirroredGeometry().x();
         aEvent.mnY = static_cast<tools::Long>(aPt.y) - mpFrame->GetUnmirroredGeometry().y();
-        aEvent.mnCode         = ImplGetModifierMask( mpFrame->mnLastModifierFlags );
+        // tdf#151423 Only allow modifiers for mouse scrollwheel events
+        // The Command modifier converts scrollwheel events into
+        // magnification events and the Shift modifier converts vertical
+        // scrollwheel events into horizontal scrollwheel events. This
+        // behavior is reasonable for mouse scrollwheel events since many
+        // mice only have a single, vertical scrollwheel but trackpads
+        // already have specific gestures for magnification and horizontal
+        // scrolling. So, behave like most macOS applications and ignore
+        // all modifiers if this a trackpad scrollwheel event.
+        aEvent.mnCode         = bAllowModifiers ? ImplGetModifierMask( mpFrame->mnLastModifierFlags ) : 0;
         aEvent.mbDeltaIsPixel = false;
 
         if( AllSettings::GetLayoutRTL() )