Unify behaviour of mouse-wheel and mouse-drag image scrolling

Horos/Sources/BrowserController.m

@@ -9263,10 +9263,11 @@ - (void)scrollWheel: (NSEvent *)theEvent
 {
     float reverseScrollWheel;
 
-    if ([[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"])
-        reverseScrollWheel = -1.0;
-    else
-        reverseScrollWheel = 1.0;
+	if ([imageView shouldReverseScrollDirectionForMouseWheel]) {
+		reverseScrollWheel = -1.0;
+    } else {
+		reverseScrollWheel = 1.0;
+	}
 
     float change = reverseScrollWheel * [theEvent deltaY];
 

Horos/Sources/CPRMPRDCMView.m

@@ -1977,30 +1977,30 @@ - (void) mouseUp:(NSEvent *)theEvent
 	dontCheckRoiChange = NO;
 }
 
+
+// Probably could use MPRDCMView's method if refactored to a shared parent class as code is identical
+
 - (void) mouseDraggedImageScroll:(NSEvent *) event
 {
 	[self checkCursor];
 
 	NSPoint current = [self currentPointInView: event];
-
-	if( scrollMode == 0)
+	if (scrollMode == ScrollModeReady)
 	{
-		if( fabs( start.x - current.x) < fabs( start.y - current.y))
-		{
-			if( fabs( start.y - current.y) > 3) scrollMode = 1;
-		}
-		else if( fabs( start.x - current.x) >= fabs( start.y - current.y))
-		{
-			if( fabs( start.x - current.x) > 3) scrollMode = 2;
-		}
+		[self establishScrollModeFromInitialDragWithPoint: current];
 	}
 
-	float delta;
+	float delta = 0.0;
 
-	if( scrollMode == 1)
-		delta = ((previous.y - current.y) * 512. )/ ([self convertSizeToBacking: self.frame.size].width/2);
-	else
+	if (scrollMode == ScrollModeVertical) {
+		delta = ((previous.y - current.y) * 512. )/ ([self convertSizeToBacking: self.frame.size].height/2);
+	} else if (scrollMode == ScrollModeHorizontal) {
 		delta = ((current.x - previous.x) * 512. )/ ([self convertSizeToBacking: self.frame.size].width/2);
+	}
+
+	if ([self shouldReverseScrollDirectionForMouseDrag]) {
+        delta *= -1.0;
+	}
 
 	[self restoreCamera];
 	windowController.lowLOD = YES;

Horos/Sources/DCMView.h

@@ -96,6 +96,12 @@ typedef NS_ENUM(short, ToolMode)
     //tOvalAngle                  //  31
 };
 
+typedef NS_ENUM(NSUInteger, ScrollMode) {
+	ScrollModeReady				=	0,
+	ScrollModeVertical,
+	ScrollModeHorizontal
+};
+
 extern NSString * const HorosPasteboardType;
 extern NSString * const HorosPasteboardTypePlugin;
 // these older pasteboard keys are deprecated, but they still work
@@ -582,6 +588,9 @@ typedef enum {DCMViewTextAlignLeft, DCMViewTextAlignCenter, DCMViewTextAlignRigh
 - (void)mouseDraggedZoom:(NSEvent *)event;
 - (void)mouseDraggedTranslate:(NSEvent *)event;
 - (void)mouseDraggedRotate:(NSEvent *)event;
+- (void) establishScrollModeFromInitialDragWithPoint: (NSPoint) currentPoint;
+- (BOOL) shouldReverseScrollDirectionForMouseWheel;
+- (BOOL) shouldReverseScrollDirectionForMouseDrag;
 - (void)mouseDraggedImageScroll:(NSEvent *)event;
 - (void)mouseDraggedBlending:(NSEvent *)event;
 - (void)mouseDraggedWindowLevel:(NSEvent *)event;

Horos/Sources/DCMView.m

@@ -4311,7 +4311,7 @@ - (void) mouseDown:(NSEvent *)event
             startScaleValue = scaleValue;
             rotationStart = rotation;
             blendingFactorStart = blendingFactor;
-            scrollMode = 0;
+            scrollMode = ScrollModeReady;
             resizeTotal = 1;
 
             originStart = origin;
@@ -4913,10 +4913,12 @@ - (void)scrollWheel:(NSEvent *)theEvent
 
     if( [[NSUserDefaults standardUserDefaults] boolForKey: @"ZoomWithHorizonScroll"] == NO) deltaX = 0;
 
-    if ([[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"])
-        reverseScrollWheel = -1.0;
-    else
+	if ([self shouldReverseScrollDirectionForMouseWheel])
+	{
+		reverseScrollWheel = -1.0;
+    } else {
         reverseScrollWheel = 1.0;
+	}
 
     if( flippedData) reverseScrollWheel *= -1.0;
 
@@ -5576,36 +5578,69 @@ - (void)mouseDraggedRotate:(NSEvent *)event
     self.rotation = rot;
 }
 
-//Scrolling through images with Mouse
+- (void) establishScrollModeFromInitialDragWithPoint: (NSPoint) currentPoint
+{
+	if (fabs(start.x - currentPoint.x) < fabs(start.y - currentPoint.y))
+	{
+		if (fabs(start.y - currentPoint.y) > 3) { scrollMode = ScrollModeVertical; }
+	}
+	else if (fabs(start.x - currentPoint.x) >= fabs(start.y - currentPoint.y))
+	{
+		if (fabs(start.x - currentPoint.x) > 3) { scrollMode = ScrollModeHorizontal; }
+	}
+}
+
+
+- (BOOL) shouldReverseScrollDirectionForMouseWheel
+{
+	if ([[NSUserDefaults standardUserDefaults] boolForKey: @"com.apple.swipescrolldirection"]) {
+		return NO;		// System scroll setting "natural" - no need to reverse.
+	}
+
+	// System scroll setting "normal", use app's scroll setting, which defaults to YES.
+
+	return [[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"];
+}
+
+
+- (BOOL) shouldReverseScrollDirectionForMouseDrag
+{
+	if ([[NSUserDefaults standardUserDefaults] boolForKey: @"com.apple.swipescrolldirection"]) {
+		return YES;		// System scroll setting "natural" - reverse mouse drag to complement mouse-wheel.
+	}
+
+	// System scroll setting "normal", use app's scroll setting, to match mouse-wheel.
+
+	return [[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"];
+}
+
+
+// Scrolling through images with mouse
 // could be cleaned up by subclassing DCMView
-- (void)mouseDraggedImageScroll:(NSEvent *)event
+- (void) mouseDraggedImageScroll: (NSEvent *)event
 {
-    short   previmage;
+    short   previmage = curImage;
     BOOL	movie4Dmove = NO;
     NSPoint current = [self currentPointInView:event];
-    if( scrollMode == 0)
+    if (scrollMode == ScrollModeReady)
     {
-        if( fabs( start.x - current.x) < fabs( start.y - current.y))
-        {
-            if( fabs( start.y - current.y) > 3) scrollMode = 1;
-        }
-        else if( fabs( start.x - current.x) >= fabs( start.y - current.y))
-        {
-            if( fabs( start.x - current.x) > 3) scrollMode = 2;
-        }
+        [self establishScrollModeFromInitialDragWithPoint: current];
     }
 
-    if( movie4Dmove == NO)
+    if (movie4Dmove == NO)				// Currently always called.  For future functionality.
     {
-        previmage = curImage;
-
-        if( scrollMode == 2)
+        CGFloat scrollWheelDirection = 1.0;
+		if ([self shouldReverseScrollDirectionForMouseDrag]) {
+			scrollWheelDirection = -1.0;
+		}
+
+        if (scrollMode == ScrollModeHorizontal)
         {
-            curImage = startImage + ((current.x - start.x) * [dcmPixList count] )/ ([self frame].size.width/2);
+            curImage = startImage + ((current.x - start.x) * [dcmPixList count] * scrollWheelDirection) / ([self frame].size.width/2);
         }
-        else if( scrollMode == 1)
+        else if (scrollMode == ScrollModeVertical)
         {
-            curImage = startImage + ((start.y - current.y) * [dcmPixList count] )/ ([self frame].size.height/2);
+            curImage = startImage + ((start.y - current.y) * [dcmPixList count] * scrollWheelDirection) / ([self frame].size.height/2);
         }
 
         if( curImage < 0) curImage = 0;
@@ -5632,6 +5667,8 @@ - (void)mouseDraggedImageScroll:(NSEvent *)event
     }
 }
 
+#pragma mark -
+
 - (void)mouseDraggedBlending:(NSEvent *)event
 {
     float WWAdapter = bdstartWW / 100.0;

Horos/Sources/MPRDCMView.m

@@ -1764,24 +1764,20 @@ - (void) mouseDraggedImageScroll:(NSEvent *) event
 
 	NSPoint current = [self currentPointInView: event];
 
-	if( scrollMode == 0)
-	{
-		if( fabs( start.x - current.x) < fabs( start.y - current.y))
-		{
-			if( fabs( start.y - current.y) > 3) scrollMode = 1;
-		}
-		else if( fabs( start.x - current.x) >= fabs( start.y - current.y))
-		{
-			if( fabs( start.x - current.x) > 3) scrollMode = 2;
-		}
+	if (scrollMode == ScrollModeReady) {
+		[self establishScrollModeFromInitialDragWithPoint: current];
 	}
 
-	float delta;
-
-	if( scrollMode == 1)
-		delta = ((previous.y - current.y) * 512. )/ ([self convertSizeToBacking: self.frame.size].width/2);
-	else
-		delta = ((current.x - previous.x) * 512. )/ ([self convertSizeToBacking: self.frame.size].width/2);
+	float delta = 0.0;
+	if (scrollMode == ScrollModeVertical) {
+		delta = ((previous.y - current.y) * 512. ) / ([self convertSizeToBacking: self.frame.size].height/2);
+	} else if (scrollMode == ScrollModeHorizontal) {
+		delta = ((current.x - previous.x) * 512. ) / ([self convertSizeToBacking: self.frame.size].width/2);
+	}
+
+	if ([self shouldReverseScrollDirectionForMouseDrag]) {
+        delta *= -1.0;
+	}
 
 	[self restoreCamera];
 	windowController.lowLOD = YES;

Horos/Sources/OrthogonalMPRView.m

@@ -101,13 +101,14 @@ - (void)scrollWheel:(NSEvent *)theEvent
 
 	if( [[NSUserDefaults standardUserDefaults] boolForKey: @"ZoomWithHorizonScroll"] == NO) deltaX = 0;
 
-	if ([[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"])
-		reverseScrollWheel = -1.0;
-	else
-		reverseScrollWheel = 1.0;
+	if ([self shouldReverseScrollDirectionForMouseWheel]) {
+        reverseScrollWheel = 1.0;
+	} else {
+        reverseScrollWheel = -1.0;
+    }
 
 	if( flippedData) reverseScrollWheel *= -1.0;
-	
+
     if( dcmPixList)
 	{
 		[[self controller] saveCrossPositions];
@@ -1037,49 +1038,42 @@ - (void)mouseDraggedCrosshair:(NSEvent *)event
 	}
 }
 
-- (void)mouseDraggedImageScroll:(NSEvent *) event {
-	short   now, prev;
+- (void) mouseDraggedImageScroll: (NSEvent*) event
+{
 	BOOL	movie4Dmove = NO;
 	NSPoint current = [self currentPointInView:event];
-	if( scrollMode == 0)
+	if (scrollMode == ScrollModeReady)
 	{
-		if( fabs( start.x - current.x) < fabs( start.y - current.y))
-		{
-			prev = start.y/2;
-			now = current.y/2;
-			if( fabs( start.y - current.y) > 3) scrollMode = 1;
-		}
-		else if( fabs( start.x - current.x) >= fabs( start.y - current.y))
-		{
-			prev = start.x/2;
-			now = current.x/2;
-			if( fabs( start.x - current.x) > 3) scrollMode = 2;
-		}
-
-	//	NSLog(@"scrollMode : %d", scrollMode);
+		[self establishScrollModeFromInitialDragWithPoint: current];
 	}
 
 
- if( movie4Dmove == NO)
+	if (movie4Dmove == NO)				// Currently always passes, for future development.
 	{
 		long from, to;
-		if( scrollMode == 2)
+		if (scrollMode == ScrollModeHorizontal)
 		{
-			from = current.x;
-			to = start.x;
+			from = start.x;
+			to = current.x;
 		}
-		else if( scrollMode == 1)
+		else if (scrollMode == ScrollModeVertical)
 		{
-			from = start.y;
-			to = current.y;
+			from = current.y;
+			to = start.y;
 		}
 		else
 		{
 			from = 0;
 			to = 0;
 		}
+
+		if ([self shouldReverseScrollDirectionForMouseDrag]) {
+			long temp = to;
+			to = from;
+			from = temp;
+		}
 
-		if ( abs((int)(from-to)) >= 1) {
+		if (abs((int)(from-to)) >= 1) {
 			[self scrollTool: from : to];
 		}
 	}

Horos/Sources/VRView.mm

@@ -2983,7 +2983,15 @@ - (void) scrollWheel:(NSEvent *)theEvent
 {
     if ([self eventToPlugins:theEvent]) return;
 
-    return [self scrollInStack: [theEvent deltaY]];
+	float delta = [theEvent deltaY];
+	// Match behaviour of -[DCMView shouldReverseScrollDirectionForMouseWheel]
+ 	if ([[NSUserDefaults standardUserDefaults] boolForKey: @"com.apple.swipescrolldirection"]) {
+ 		delta *= -1.0;
+	} else if (![[NSUserDefaults standardUserDefaults] boolForKey: @"Scroll Wheel Reversed"]) {
+		delta *= -1.0;
+	}
+
+    return [self scrollInStack: delta];
 }
 
 - (void)otherMouseDown:(NSEvent *)theEvent