cocoa: Add keyboard grab support

CGSSetGlobalHotKeyOperatingMode() is not a public API, so we will only
compile this in if SDL_MAC_NO_SANDBOX=1 is defined during compilation.

src/video/cocoa/SDL_cocoakeyboard.h

@@ -31,6 +31,8 @@ extern void Cocoa_StartTextInput(_THIS);
 extern void Cocoa_StopTextInput(_THIS);
 extern void Cocoa_SetTextInputRect(_THIS, SDL_Rect *rect);
 
+extern void Cocoa_SetWindowKeyboardGrab(_THIS, SDL_Window * window, SDL_bool grabbed);
+
 #endif /* SDL_cocoakeyboard_h_ */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/video/cocoa/SDL_cocoakeyboard.m

@@ -602,6 +602,23 @@ Cocoa_QuitKeyboard(_THIS)
 {
 }
 
+typedef int CGSConnection;
+typedef enum {
+    CGSGlobalHotKeyEnable = 0,
+    CGSGlobalHotKeyDisable = 1,
+} CGSGlobalHotKeyOperatingMode;
+
+extern CGSConnection _CGSDefaultConnection(void);
+extern CGError CGSSetGlobalHotKeyOperatingMode(CGSConnection connection, CGSGlobalHotKeyOperatingMode mode);
+
+void
+Cocoa_SetWindowKeyboardGrab(_THIS, SDL_Window * window, SDL_bool grabbed)
+{
+#if SDL_MAC_NO_SANDBOX
+    CGSSetGlobalHotKeyOperatingMode(_CGSDefaultConnection(), grabbed ? CGSGlobalHotKeyDisable : CGSGlobalHotKeyEnable);
+#endif
+}
+
 #endif /* SDL_VIDEO_DRIVER_COCOA */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/video/cocoa/SDL_cocoavideo.m

@@ -103,6 +103,7 @@ Cocoa_CreateDevice(int devindex)
     device->SetWindowGammaRamp = Cocoa_SetWindowGammaRamp;
     device->GetWindowGammaRamp = Cocoa_GetWindowGammaRamp;
     device->SetWindowMouseGrab = Cocoa_SetWindowMouseGrab;
+    device->SetWindowKeyboardGrab = Cocoa_SetWindowKeyboardGrab;
     device->DestroyWindow = Cocoa_DestroyWindow;
     device->GetWindowWMInfo = Cocoa_GetWindowWMInfo;
     device->SetWindowHitTest = Cocoa_SetWindowHitTest;