Cocoa : implement opening .blend file by double-clicking on it in OSX Finder

When the user double-clicks on a document file in the Finder, OSX doesn't simply give the filename as a command-line argument when calling Blender, as it is done in other OSes.
Instead, it launches the app if needed, and then sends an "openFile" event.

The user can also open a document file by dropping its icon on the app dock icon. But as this is not real Drag'n'drop, I've renamed the Ghost event to a less confusing "GHOST_kEventOpenMainFile" name.

DND Ghost wiki page updated : http://wiki.blender.org/index.php/BlenderDev/Blender2.5/DragnDrop

source/blender/windowmanager/intern/wm_window.c

@@ -34,6 +34,7 @@
 #include "DNA_listBase.h"	
 #include "DNA_screen_types.h"
 #include "DNA_windowmanager_types.h"
+#include "RNA_access.h"
 
 #include "MEM_guardedalloc.h"
 
@@ -714,6 +715,28 @@ static int ghost_event_proc(GHOST_EventHandle evt, GHOST_TUserDataPtr private)
 				}
 				break;
 			}
+				
+			case GHOST_kEventOpenMainFile:
+			{
+				PointerRNA props_ptr;
+				wmWindow *oldWindow;
+				char *path = GHOST_GetEventData(evt);
+				
+				if (path) {
+					/* operator needs a valid window in context, ensures
+					 it is correctly set */
+					oldWindow = CTX_wm_window(C);
+					CTX_wm_window_set(C, win);
+					
+					WM_operator_properties_create(&props_ptr, "WM_OT_open_mainfile");
+					RNA_string_set(&props_ptr, "path", path);
+					WM_operator_name_call(C, "WM_OT_open_mainfile", WM_OP_EXEC_DEFAULT, &props_ptr);
+					WM_operator_properties_free(&props_ptr);
+					
+					CTX_wm_window_set(C, oldWindow);
+				}
+				break;
+			}
 			case GHOST_kEventDraggingDropDone:
 			{
 				wmEvent event= *(win->eventstate);	/* copy last state, like mouse coords */