SYNERGY-988 Mac client does not scroll in natural direction (#7012)

* SYNERGY-988 - Use system preferences for horizontal scrolling

* Update changelog

* SYNERGY-988 - Invert xscroll direction

* Also revert system event xscroll

* SYNERGY-988 - Update directions

* SYNERGY-988 - Update changelog

* SYNERGY-988 - Update scrolling direction and y scrolling

* SYNERGY-988 - Update variable comment

Co-authored-by: SerhiiGadzhilov <71632867+SerhiiGadzhilov@users.noreply.github.com>

ChangeLog

@@ -3,6 +3,7 @@ v1.14.1-snapshot
 Bug fixes:
 - #7016 Fix script that generates version number
 - #7006 Resolve code scanning issues
+- #7012 Fix natural horizontal scrolling on Mac client
 
 Enhancements:
 

src/lib/platform/OSXScreen.h

@@ -339,6 +339,9 @@ private:
     
     Thread*                m_getDropTargetThread;
     String                    m_dropTarget;
+
+    // -1 for natural scrolling direction, 1 otherwise
+    SInt32                    m_scrollDirection = 1;
     
 #if defined(MAC_OS_X_VERSION_10_7)
     Mutex*                    m_carbonLoopMutex;

src/lib/platform/OSXScreen.mm

@@ -681,8 +681,8 @@ OSXScreen::fakeMouseWheel(SInt32 xDelta, SInt32 yDelta) const
 		CGEventRef scrollEvent = CGEventCreateScrollWheelEvent(
 			NULL, kCGScrollEventUnitLine, 2,
 			mapScrollWheelFromSynergy(yDelta),
-			-mapScrollWheelFromSynergy(xDelta));
-		
+			mapScrollWheelFromSynergy(xDelta));
+
         // Fix for sticky keys
         CGEventFlags modifiers = m_keyState->getModifierStateAsOSXFlags();
         CGEventSetFlags(scrollEvent, modifiers);
@@ -840,6 +840,8 @@ OSXScreen::enter()
 		setZeroSuppressionInterval();
 	}
 	else {
+		m_scrollDirection = [[[NSUserDefaults standardUserDefaults] objectForKey:@"com.apple.swipescrolldirection"] boolValue] ? -1 : 1;
+
 		// reset buttons
 		m_buttonState.reset();
 
@@ -1448,7 +1450,7 @@ OSXScreen::mapScrollWheelFromSynergy(SInt32 x) const
 {
 	// use server's acceleration with a little boost since other platforms
 	// take one wheel step as a larger step than the mac does.
-	return static_cast<SInt32>(3.0 * x / 120.0);
+	return static_cast<SInt32>(m_scrollDirection * 3.0 * x / 120.0);
 }
 
 double