Bug-fix: Cocoa menus work in aircraft with custom dialogs.

Restarting the GUI could cause Cocoa menus to misbehave, due to
destruction behaviour of SGBinding. Use new clear() helper in the
short term to work around this.

src/GUI/FGCocoaMenuBar.mm

@@ -24,6 +24,41 @@ typedef std::map<NSMenuItem*, SGBindingList> MenuItemBindings;
 
 @class CocoaMenuDelegate;
 
+namespace {
+    
+    class CocoaEnabledListener : public SGPropertyChangeListener
+    {
+    public:
+        CocoaEnabledListener(SGPropertyNode_ptr prop, NSMenuItem* i) :
+            property(prop->getNode("enabled")),
+            item(i)
+        {
+            if (property.get()) {
+                property->addChangeListener(this);
+            }
+        }
+        
+        ~CocoaEnabledListener()
+        {
+            if (property.get()) {
+                property->removeChangeListener(this);
+            }
+        }
+        
+        
+        virtual void valueChanged(SGPropertyNode *node)
+        {
+            CocoaAutoreleasePool pool;
+            BOOL b = node->getBoolValue();
+            [item setEnabled:b];
+        }
+        
+    private:
+        SGPropertyNode_ptr property;
+        NSMenuItem* item;
+    };
+} // of anonymous namespace
+
 class FGCocoaMenuBar::CocoaMenuBarPrivate
 {
 public:
@@ -38,7 +73,7 @@ public:
   CocoaMenuDelegate* delegate;
   
   MenuItemBindings itemBindings;
-    std::vector<SGPropertyChangeListener*> listeners;
+    std::vector<CocoaEnabledListener*> listeners;
 };
 
 // prior to the 10.6 SDK, NSMenuDelegate was an informal protocol
@@ -126,35 +161,6 @@ static void setItemShortcutFromString(NSMenuItem* item, const string& s)
   [item setKeyEquivalentModifierMask:modifiers];
 }
 
-namespace {
-
-  class CocoaEnabledListener : public SGPropertyChangeListener
-  {
-  public:
-    CocoaEnabledListener(NSMenuItem* i) :
-      item(i)
-    {
-    
-    }
-      
-      ~CocoaEnabledListener()
-      {
-          
-      }
-    
-    
-    virtual void valueChanged(SGPropertyNode *node) 
-    {
-      CocoaAutoreleasePool pool;
-      BOOL b = node->getBoolValue();
-      [item setEnabled:b];
-    }
-    
-  private:
-    NSMenuItem* item;
-  };
-} // of anonymous namespace
-
 FGCocoaMenuBar::CocoaMenuBarPrivate::CocoaMenuBarPrivate()
 {
   delegate = [[CocoaMenuDelegate alloc] init];
@@ -195,9 +201,9 @@ void FGCocoaMenuBar::CocoaMenuBarPrivate::menuFromProps(NSMenu* menu, SGProperty
           setItemShortcutFromString(item, shortcut);
         }
         
-        SGPropertyChangeListener* enableListener = new CocoaEnabledListener(item);
-        listeners.push_back(enableListener);
-        n->getNode("enabled")->addChangeListener(enableListener);
+        CocoaEnabledListener* cl = new CocoaEnabledListener(n, item);
+        listeners.push_back(cl);
+          
         [item setTarget:delegate];
         [item setAction:@selector(itemAction:)];
       }
@@ -243,10 +249,18 @@ FGCocoaMenuBar::~FGCocoaMenuBar()
         [topLevelItem.submenu removeAllItems];
     }
     
-    std::vector<SGPropertyChangeListener*>::iterator it;
+    std::vector<CocoaEnabledListener*>::iterator it;
     for (it = p->listeners.begin(); it != p->listeners.end(); ++it) {
         delete *it;
     }
+    
+    // owing to the bizarre destructor behaviour of SGBinding, we need
+    // to explicitly clear these bindings. (PUIMenuBar takes a different
+    // approach, and copies each binding into /sim/bindings)
+    MenuItemBindings::iterator j;
+    for (j = p->itemBindings.begin(); j != p->itemBindings.end(); ++j) {
+        clearBindingList(j->second);
+    }
 }
 
 void FGCocoaMenuBar::init()
@@ -291,9 +305,8 @@ void FGCocoaMenuBar::init()
       n->setBoolValue("enabled", true);
     }
     
-    SGPropertyChangeListener* l = new CocoaEnabledListener(item);
+    CocoaEnabledListener* l = new CocoaEnabledListener( n, item);
     p->listeners.push_back(l);
-    n->getNode("enabled")->addChangeListener(l);
   }
 }
 

src/GUI/new_gui.cxx

@@ -63,23 +63,18 @@ NewGUI::~NewGUI ()
 void
 NewGUI::init ()
 {
-#if defined(SG_MAC)
-    if (fgGetBool("/sim/menubar/native", true)) {
-        _menubar.reset(new FGCocoaMenuBar);
-    }
-#endif
-    if (!_menubar.get()) {
-        _menubar.reset(new FGPUIMenuBar);
-    }
-    
+    createMenuBarImplementation();
     fgTie("/sim/menubar/visibility", this,
           &NewGUI::getMenuBarVisible, &NewGUI::setMenuBarVisible);
     
     setStyle();
     SGPath p(globals->get_fg_root(), "gui/dialogs");
     readDir(p);
-    const std::string aircraft_dir(fgGetString("/sim/aircraft-dir"));
-    readDir( SGPath(aircraft_dir, "gui/dialogs") );
+    
+    SGPath aircraftDialogDir(string(fgGetString("/sim/aircraft-dir")), "gui/dialogs");
+    if (aircraftDialogDir.exists()) {
+        readDir(aircraftDialogDir);
+    }
     
     // Fix for http://code.google.com/p/flightgear-bugs/issues/detail?id=947
     fgGetNode("sim/menubar")->setAttribute(SGPropertyNode::PRESERVE, true);
@@ -107,6 +102,19 @@ NewGUI::redraw ()
     reset(false);
 }
 
+void
+NewGUI::createMenuBarImplementation()
+{
+#if defined(SG_MAC)
+    if (fgGetBool("/sim/menubar/native", true)) {
+        _menubar.reset(new FGCocoaMenuBar);
+    }
+#endif
+    if (!_menubar.get()) {
+        _menubar.reset(new FGPUIMenuBar);
+    }
+}
+
 void
 NewGUI::reset (bool reload)
 {
@@ -122,15 +130,13 @@ NewGUI::reset (bool reload)
     setStyle();
 
     unbind();
-#if !defined(SG_MAC)
-    _menubar.reset(new FGPUIMenuBar);
-#endif
 
     if (reload) {
         _dialog_props.clear();
         _dialog_names.clear();
         init();
     } else {
+        createMenuBarImplementation();
         _menubar->init();
     }
 

src/GUI/new_gui.hxx

@@ -201,6 +201,8 @@ protected:
     virtual void reset (bool reload);
 
 private:
+    void createMenuBarImplementation();
+    
     struct ltstr
     {
         bool operator()(const char* s1, const char* s2) const {