cocoa: Revised synthesized mouse/touch event strategy.

I _think_ I understand what Sylvain is working on here now, so hopefully I
got this right.

Fixes Bugzilla #4576.

(I think!)

src/events/SDL_mouse.c

@@ -103,7 +103,11 @@ SDL_TouchMouseEventsChanged(void *userdata, const char *name, const char *oldVal
     if (hint && (*hint == '0' || SDL_strcasecmp(hint, "false") == 0)) {
         mouse->touch_mouse_events = SDL_FALSE;
     } else {
+#if defined(__MACOSX__)  /* macOS synthesizes its own events for this. */
+        mouse->touch_mouse_events = SDL_FALSE;
+#else
         mouse->touch_mouse_events = SDL_TRUE;
+#endif
     }
 }
 

src/video/cocoa/SDL_cocoamouse.m

@@ -408,8 +408,7 @@ Cocoa_HandleMouseEvent(_THIS, NSEvent *event)
         DLog("Motion was (%g, %g), offset to (%g, %g)", [event deltaX], [event deltaY], deltaX, deltaY);
     }
 
-    const SDL_MouseID mouseID = ([event subtype] == NSEventSubtypeTouch) ? SDL_TOUCH_MOUSEID : mouse->mouseID;
-    SDL_SendMouseMotion(mouse->focus, mouseID, 1, (int)deltaX, (int)deltaY);
+    SDL_SendMouseMotion(mouse->focus, mouse->mouseID, 1, (int)deltaX, (int)deltaY);
 }
 
 void
@@ -437,8 +436,8 @@ Cocoa_HandleMouseWheel(SDL_Window *window, NSEvent *event)
     } else if (y < 0) {
         y = SDL_floor(y);
     }
-    const SDL_MouseID mouseID = ([event subtype] == NSEventSubtypeTouch) ? SDL_TOUCH_MOUSEID : mouse->mouseID;
-    SDL_SendMouseWheel(window, mouseID, x, y, direction);
+
+    SDL_SendMouseWheel(window, mouse->mouseID, x, y, direction);
 }
 
 void

src/video/cocoa/SDL_cocoawindow.m

@@ -933,14 +933,8 @@ SetWindowStyle(SDL_Window * window, NSUInteger style)
 
     clicks = (int) [theEvent clickCount];
 
-    SDL_MouseID mouseID;
-    if ([theEvent subtype] == NSEventSubtypeTouch) {
-        mouseID = SDL_TOUCH_MOUSEID;
-    } else {
-        SDL_Mouse *mouse = SDL_GetMouse();
-        mouseID = mouse ? mouse->mouseID : 0;
-    }
-
+    const SDL_Mouse *mouse = SDL_GetMouse();
+    const SDL_MouseID mouseID = mouse ? mouse->mouseID : 0;
     SDL_SendMouseButtonClicks(_data->window, mouseID, SDL_PRESSED, button, clicks);
 }
 
@@ -986,14 +980,8 @@ SetWindowStyle(SDL_Window * window, NSUInteger style)
 
     clicks = (int) [theEvent clickCount];
 
-    SDL_MouseID mouseID;
-    if ([theEvent subtype] == NSEventSubtypeTouch) {
-        mouseID = SDL_TOUCH_MOUSEID;
-    } else {
-        SDL_Mouse *mouse = SDL_GetMouse();
-        mouseID = mouse ? mouse->mouseID : 0;
-    }
-
+    const SDL_Mouse *mouse = SDL_GetMouse();
+    const SDL_MouseID mouseID = mouse ? mouse->mouseID : 0;
     SDL_SendMouseButtonClicks(_data->window, mouseID, SDL_RELEASED, button, clicks);
 }
 
@@ -1058,8 +1046,7 @@ SetWindowStyle(SDL_Window * window, NSUInteger style)
         }
     }
 
-    const SDL_MouseID mouseID = ([theEvent subtype] == NSEventSubtypeTouch) ? SDL_TOUCH_MOUSEID : mouse->mouseID;
-    SDL_SendMouseMotion(window, mouseID, 0, x, y);
+    SDL_SendMouseMotion(window, mouse->mouseID, 0, x, y);
 }
 
 - (void)mouseDragged:(NSEvent *)theEvent
@@ -1093,8 +1080,7 @@ SetWindowStyle(SDL_Window * window, NSUInteger style)
         }
     }
     if (existingTouchCount == 0) {
-        const BOOL ismouse = ([theEvent subtype] == NSEventSubtypeMouseEvent);
-        const SDL_TouchID touchID = ismouse ? SDL_MOUSE_TOUCHID : (SDL_TouchID)(intptr_t)[[touches anyObject] device];
+        const SDL_TouchID touchID = (SDL_TouchID)(intptr_t)[[touches anyObject] device];
         int numFingers = SDL_GetNumTouchFingers(touchID);
         DLog("Reset Lost Fingers: %d", numFingers);
         for (--numFingers; numFingers >= 0; --numFingers) {
@@ -1124,11 +1110,10 @@ SetWindowStyle(SDL_Window * window, NSUInteger style)
 
 - (void)handleTouches:(NSTouchPhase) phase withEvent:(NSEvent *) theEvent
 {
-    const BOOL ismouse = ([theEvent subtype] == NSEventSubtypeMouseEvent);
     NSSet *touches = [theEvent touchesMatchingPhase:phase inView:nil];
 
     for (NSTouch *touch in touches) {
-        const SDL_TouchID touchId = ismouse ? SDL_MOUSE_TOUCHID : (SDL_TouchID)(intptr_t)[touch device];
+        const SDL_TouchID touchId = (SDL_TouchID)(intptr_t)[touch device];
         SDL_TouchDeviceType devtype = SDL_TOUCH_DEVICE_INDIRECT_ABSOLUTE;
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 101202 /* Added in the 10.12.2 SDK. */