Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 50475)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 50476)
@@ -35,4 +35,7 @@
 #include <Carbon/Carbon.h>
 #include "DarwinKeyboard.h"
+
+/** Easy way of dynamical call for 10.7 AppKit functionality we do not yet support. */
+#define NSWindowCollectionBehaviorFullScreenPrimary (1 << 7)
 
 NativeNSWindowRef darwinToNativeWindowImpl(NativeNSViewRef pView)
@@ -180,4 +183,9 @@
 //    [[NSApplication sharedApplication] deactivate];
 //    [pWindow performMiniaturize:nil];
+}
+
+void darwinEnableFullscreenSupport(NativeNSWindowRef pWindow)
+{
+    [pWindow setCollectionBehavior :NSWindowCollectionBehaviorFullScreenPrimary];
 }
 
Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp	(revision 50475)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp	(revision 50476)
@@ -137,4 +137,9 @@
 {
     return ::darwinMinaturizeWindow(::darwinToNativeWindow(pWidget));
+}
+
+void darwinEnableFullscreenSupport(QWidget *pWidget)
+{
+    return ::darwinEnableFullscreenSupport(::darwinToNativeWindow(pWidget));
 }
 
Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 50475)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 50476)
@@ -79,4 +79,5 @@
 bool darwinIsWindowMaximized(NativeNSWindowRef pWindow);
 void darwinMinaturizeWindow(NativeNSWindowRef pWindow);
+void darwinEnableFullscreenSupport(NativeNSWindowRef pWindow);
 
 bool darwinOpenFile(NativeNSStringRef pstrFile);
@@ -240,4 +241,5 @@
 bool darwinIsWindowMaximized(QWidget *pWidget);
 void darwinMinaturizeWindow(QWidget *pWidget);
+void darwinEnableFullscreenSupport(QWidget *pWidget);
 bool darwinOpenFile(const QString &strFile);