cocoa: removed relative mode handling on focus change

This is now being done at a higher level, so we don't want to duplicate it here.

Fixes the mouse cursor staying hidden if you enable relative mode, alt-tab away and then alt-tab back.

src/video/cocoa/SDL_cocoamouse.m

@@ -316,11 +316,19 @@ static int Cocoa_WarpMouse(SDL_Window *window, float x, float y)
 
 static int Cocoa_SetRelativeMouseMode(SDL_bool enabled)
 {
-    SDL_Window *window = SDL_GetKeyboardFocus();
     CGError result;
-    SDL_CocoaWindowData *data;
+
     if (enabled) {
+        SDL_Window *window = SDL_GetKeyboardFocus();
         if (window) {
+            /* We will re-apply the relative mode when the window finishes being moved,
+             * if it is being moved right now.
+             */
+            SDL_CocoaWindowData *data = (__bridge SDL_CocoaWindowData *)window->internal;
+            if ([data.listener isMovingOrFocusClickPending]) {
+                return 0;
+            }
+
             /* make sure the mouse isn't at the corner of the window, as this can confuse things if macOS thinks a window resize is happening on the first click. */
             const CGPoint point = CGPointMake((float)(window->x + (window->w / 2)), (float)(window->y + (window->h / 2)));
             Cocoa_HandleMouseWarp(point.x, point.y);
@@ -336,21 +344,6 @@ static int Cocoa_SetRelativeMouseMode(SDL_bool enabled)
         return SDL_SetError("CGAssociateMouseAndMouseCursorPosition() failed");
     }
 
-    /* We will re-apply the non-relative mode when the window gets focus, if it
-     * doesn't have focus right now.
-     */
-    if (!window) {
-        return 0;
-    }
-
-    /* We will re-apply the non-relative mode when the window finishes being moved,
-     * if it is being moved right now.
-     */
-    data = (__bridge SDL_CocoaWindowData *)window->internal;
-    if ([data.listener isMovingOrFocusClickPending]) {
-        return 0;
-    }
-
     /* The hide/unhide calls are redundant most of the time, but they fix
      * https://bugzilla.libsdl.org/show_bug.cgi?id=2550
      */

src/video/cocoa/SDL_cocoawindow.m

@@ -1166,18 +1166,13 @@ static NSCursor *Cocoa_GetDesiredCursor(void)
 - (void)windowDidBecomeKey:(NSNotification *)aNotification
 {
     SDL_Window *window = _data.window;
-    SDL_Mouse *mouse = SDL_GetMouse();
 
     /* We're going to get keyboard events, since we're key. */
     /* This needs to be done before restoring the relative mouse mode. */
     Cocoa_SetKeyboardFocus(_data.keyboard_focus ? _data.keyboard_focus : window);
 
-    if (mouse->relative_mode && !mouse->relative_mode_warp && ![self isMovingOrFocusClickPending]) {
-        mouse->SetRelativeMouseMode(SDL_TRUE);
-    }
-
     /* If we just gained focus we need the updated mouse position */
-    if (!mouse->relative_mode) {
+    if (!(window->flags & SDL_WINDOW_MOUSE_RELATIVE_MODE)) {
         NSPoint point;
         float x, y;
 
@@ -1205,11 +1200,6 @@ static NSCursor *Cocoa_GetDesiredCursor(void)
 
 - (void)windowDidResignKey:(NSNotification *)aNotification
 {
-    SDL_Mouse *mouse = SDL_GetMouse();
-    if (mouse->relative_mode && !mouse->relative_mode_warp) {
-        mouse->SetRelativeMouseMode(SDL_FALSE);
-    }
-
     /* Some other window will get mouse events, since we're not key. */
     if (SDL_GetMouseFocus() == _data.window) {
         SDL_SetMouseFocus(NULL);