Fix CPPopUpButton menu support.

- Added enumerateObjectsUsingBlock: to CPArray
- Fixed a remaining case of [] being used instead of objectAtIndex: in CPMutableArray.
- Added KVO support for menu items array in menus.
- Changed CPPopUpButton to use KVO to sync up with menu instead of notifications.
- Removed extra menu encoding in CPPopUpButton.
- Removed extra mainMenu object from CPApplication.
- Use setters in CPResponder instead of direct ivar access in initWithCoder:.

Closes #298.
Closes $1059.

Reviewed by me.

AppKit/CPApplication.j

@@ -90,7 +90,6 @@ CPRunContinuesResponse  = -1002;
     CPWindow                _previousKeyWindow;
     CPWindow                _previousMainWindow;
 
-    CPMenu                  _mainMenu;
     CPDocumentController    _documentController;
 
     CPModalSession          _currentSession;
@@ -530,7 +529,7 @@ CPRunContinuesResponse  = -1002;
 - (BOOL)_handleKeyEquivalent:(CPEvent)anEvent
 {
     return  [[self keyWindow] performKeyEquivalent:anEvent] ||
-            [_mainMenu performKeyEquivalent:anEvent];
+            [[self mainMenu] performKeyEquivalent:anEvent];
 }
 
 /*!
@@ -637,7 +636,7 @@ CPRunContinuesResponse  = -1002;
 */
 - (CPMenu)mainMenu
 {
-    return _mainMenu;
+    return [self menu];
 }
 
 /*!
@@ -645,16 +644,21 @@ CPRunContinuesResponse  = -1002;
     @param aMenu the menu to set for the application
 */
 - (void)setMainMenu:(CPMenu)aMenu
+{
+    [self setMenu:aMenu];
+}
+
+- (void)setMenu:(CPMenu)aMenu
 {
     if ([aMenu _menuName] === "CPMainMenu")
     {
-        if (_mainMenu === aMenu)
+        if ([self menu] === aMenu)
             return;
 
-        _mainMenu = aMenu;
+        [super setMenu:aMenu];
 
         if ([CPPlatform supportsNativeMainMenu])
-            window.cpSetMainMenu(_mainMenu);
+            window.cpSetMainMenu([self menu]);
     }
     else
         [aMenu _setMenuName:@"CPMainMenu"];

AppKit/CPMenu/CPMenu.j

@@ -274,22 +274,7 @@ var _CPMenuBarVisible               = NO,
 */
 - (void)insertItem:(CPMenuItem)aMenuItem atIndex:(unsigned)anIndex
 {
-    var menu = [aMenuItem menu];
-
-    if (menu)
-        if (menu !== self)
-            [CPException raise:CPInternalInconsistencyException reason:@"Attempted to insert item into menu that was already in another menu."];
-        else
-            return;
-
-    [aMenuItem setMenu:self];
-    [_items insertObject:aMenuItem atIndex:anIndex];
-
-    [[CPNotificationCenter defaultCenter]
-        postNotificationName:CPMenuDidAddItemNotification
-                      object:self
-                    userInfo:[CPDictionary dictionaryWithObject:anIndex forKey:@"CPMenuItemIndex"]];
-
+    [self insertObject:aMenuItem inItemsAtIndex:anIndex];
 }
 
 /*!
@@ -346,16 +331,7 @@ var _CPMenuBarVisible               = NO,
 */
 - (void)removeItemAtIndex:(unsigned)anIndex
 {
-    if (anIndex < 0 || anIndex >= _items.length)
-        return;
-
-    [_items[anIndex] setMenu:nil];
-    [_items removeObjectAtIndex:anIndex];
-
-    [[CPNotificationCenter defaultCenter]
-        postNotificationName:CPMenuDidRemoveItemNotification
-                      object:self
-                    userInfo:[CPDictionary dictionaryWithObject:anIndex forKey:@"CPMenuItemIndex"]];
+    [self removeObjectFromItemsAtIndex:anIndex];
 }
 
 /*!
@@ -364,9 +340,11 @@ var _CPMenuBarVisible               = NO,
 */
 - (void)itemChanged:(CPMenuItem)aMenuItem
 {
-    if ([aMenuItem menu] != self)
+    if ([aMenuItem menu] !== self)
         return;
 
+    [aMenuItem setValue:[aMenuItem valueForKey:@"changeCount"] + 1 forKey:@"changeCount"];
+
     [[CPNotificationCenter defaultCenter]
         postNotificationName:CPMenuDidChangeItemNotification
                       object:self
@@ -1035,6 +1013,61 @@ var _CPMenuBarVisible               = NO,
 
 @end
 
+@implementation CPMenu (CPKeyValueCoding)
+
+- (CPUInteger)countOfItems
+{
+    return [_items count];
+}
+
+- (CPMenuItem)objectInItemsAtIndex:(CPUInteger)anIndex
+{
+    return [_items objectAtIndex:anIndex];
+}
+
+- (CPArray)itemsAtIndexes:(CPIndexSet)indexes
+{
+    return [_items objectsAtIndexes:indexes];
+}
+
+@end
+
+@implementation CPMenu (CPKeyValueObserving)
+
+- (void)insertObject:(CPMenuItem)aMenuItem inItemsAtIndex:(CPUInteger)anIndex
+{
+    var menu = [aMenuItem menu];
+
+    if (menu)
+        if (menu !== self)
+            [CPException raise:CPInternalInconsistencyException reason:@"Attempted to insert item into menu that was already in another menu."];
+        else
+            return;
+
+    [aMenuItem setMenu:self];
+    [_items insertObject:aMenuItem atIndex:anIndex];
+
+    [[CPNotificationCenter defaultCenter]
+        postNotificationName:CPMenuDidAddItemNotification
+                      object:self
+                    userInfo:[CPDictionary dictionaryWithObject:anIndex forKey:@"CPMenuItemIndex"]];
+}
+
+- (void)removeObjectFromItemsAtIndex:(CPUInteger)anIndex
+{
+    if (anIndex < 0 || anIndex >= [_items count])
+        return;
+
+    [[_items objectAtIndex:anIndex] setMenu:nil];
+    [_items removeObjectAtIndex:anIndex];
+
+    [[CPNotificationCenter defaultCenter]
+        postNotificationName:CPMenuDidRemoveItemNotification
+                      object:self
+                    userInfo:[CPDictionary dictionaryWithObject:anIndex forKey:@"CPMenuItemIndex"]];
+}
+
+@end
 
 var CPMenuTitleKey              = @"CPMenuTitleKey",
     CPMenuNameKey               = @"CPMenuNameKey",

AppKit/CPMenuItem/CPMenuItem.j

@@ -77,6 +77,8 @@
     id              _representedObject;
     CPView          _view;
 
+    int             _changeCount;
+
     _CPMenuItemView _menuItemView;
 }
 
@@ -98,12 +100,14 @@
 
     if (self)
     {
+        _changeCount = 0;
         _isSeparator = NO;
 
         _title = aTitle;
         _action = anAction;
 
         _isEnabled = YES;
+        _isHidden = NO;
 
         _tag = 0;
         _state = CPOffState;
@@ -890,6 +894,7 @@ var CPMenuItemIsSeparatorKey                = @"CPMenuItemIsSeparatorKey",
 
     if (self)
     {
+        _changeCount = 0;
         _isSeparator = [aCoder containsValueForKey:CPMenuItemIsSeparatorKey] && [aCoder decodeBoolForKey:CPMenuItemIsSeparatorKey];
 
         _title = [aCoder decodeObjectForKey:CPMenuItemTitleKey];

AppKit/CPPopUpButton.j

@@ -38,10 +38,8 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 @implementation CPPopUpButton : CPButton
 {
-    int         _selectedIndex;
+    CPUInteger  _selectedIndex;
     CPRectEdge  _preferredEdge;
-
-    CPMenu      _menu;
 }
 
 + (CPString)defaultThemeClass
@@ -76,6 +74,14 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
         [self setMenu:[[CPMenu alloc] initWithTitle:@""]];
 
         [self setPullsDown:shouldPullDown];
+
+        var options =   CPKeyValueObservingOptionNew |
+                        CPKeyValueObservingOptionOld;/* |
+                        CPKeyValueObservingOptionInitial;
+*/
+        [self addObserver:self forKeyPath:@"menu.items" options:options context:nil];
+        [self addObserver:self forKeyPath:@"_firstItem.changeCount" options:options context:nil];
+        [self addObserver:self forKeyPath:@"selectedItem.changeCount" options:options context:nil];
     }
 
     return self;
@@ -103,7 +109,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
     if (!changed)
         return;
 
-    var items = [_menu itemArray];
+    var items = [[self menu] itemArray];
 
     if ([items count] <= 0)
         return;
@@ -128,7 +134,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (void)addItem:(CPMenuItem)anItem
 {
-    [_menu addItem:anItem];
+    [[self menu] addItem:anItem];
 }
 
 /*!
@@ -137,7 +143,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (void)addItemWithTitle:(CPString)aTitle
 {
-    [_menu addItemWithTitle:aTitle action:NULL keyEquivalent:nil];
+    [[self menu] addItemWithTitle:aTitle action:NULL keyEquivalent:nil];
 }
 
 /*!
@@ -167,7 +173,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
         if ([items[count] title] == aTitle)
             [self removeItemAtIndex:count];
 
-    [_menu insertItemWithTitle:aTitle action:NULL keyEquivalent:nil atIndex:anIndex];
+    [[self menu] insertItemWithTitle:aTitle action:NULL keyEquivalent:nil atIndex:anIndex];
 }
 
 /*!
@@ -175,10 +181,11 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (void)removeAllItems
 {
-    var count = [_menu numberOfItems];
+    var menu = [self menu],
+        count = [menu numberOfItems];
 
     while (count--)
-        [_menu removeItemAtIndex:0];
+        [menu removeItemAtIndex:0];
 }
 
 /*!
@@ -197,7 +204,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (void)removeItemAtIndex:(int)anIndex
 {
-    [_menu removeItemAtIndex:anIndex];
+    [[self menu] removeItemAtIndex:anIndex];
     [self synchronizeTitleAndSelectedItem];
 }
 
@@ -207,10 +214,12 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPMenuItem)selectedItem
 {
-    if (_selectedIndex < 0 || _selectedIndex > [self numberOfItems] - 1)
+    var indexOfSelectedItem = [self indexOfSelectedItem];
+
+    if (indexOfSelectedItem < 0 || indexOfSelectedItem > [self numberOfItems] - 1)
         return nil;
 
-    return [_menu itemAtIndex:_selectedIndex];
+    return [[self menu] itemAtIndex:indexOfSelectedItem];
 }
 
 /*!
@@ -270,7 +279,9 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (void)selectItemAtIndex:(int)anIndex
 {
-    if (_selectedIndex == anIndex)
+    anIndex = +anIndex;
+
+    if (_selectedIndex === anIndex)
         return;
 
     [self willChangeValueForKey:@"selectedIndex"];
@@ -316,74 +327,13 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 }
 
 // Getting Menu Items
-/*!
-    Returns the button's menu of items.
-*/
-- (CPMenu)menu
-{
-    return _menu;
-}
-
-/*!
-    Sets the menu for the button
-*/
-- (void)setMenu:(CPMenu)aMenu
-{
-    if (_menu === aMenu)
-        return;
-
-    var defaultCenter = [CPNotificationCenter defaultCenter];
-
-    if (_menu)
-    {
-        [defaultCenter
-            removeObserver:self
-                      name:CPMenuDidAddItemNotification
-                    object:_menu];
-
-        [defaultCenter
-            removeObserver:self
-                      name:CPMenuDidChangeItemNotification
-                    object:_menu];
-
-        [defaultCenter
-            removeObserver:self
-                      name:CPMenuDidRemoveItemNotification
-                    object:_menu];
-    }
-
-    _menu = aMenu;
-
-    if (_menu)
-    {
-        [defaultCenter
-            addObserver:self
-              selector:@selector(menuDidAddItem:)
-                  name:CPMenuDidAddItemNotification
-                object:_menu];
-
-        [defaultCenter
-            addObserver:self
-              selector:@selector(menuDidChangeItem:)
-                  name:CPMenuDidChangeItemNotification
-                object:_menu];
-
-        [defaultCenter
-            addObserver:self
-              selector:@selector(menuDidRemoveItem:)
-                  name:CPMenuDidRemoveItemNotification
-                object:_menu];
-    }
-
-    [self synchronizeTitleAndSelectedItem];
-}
 
 /*!
     Returns a count of the number of items in the button's menu.
 */
 - (int)numberOfItems
 {
-    return [_menu numberOfItems];
+    return [[self menu] numberOfItems];
 }
 
 /*!
@@ -391,7 +341,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPArray)itemArray
 {
-    return [_menu itemArray];
+    return [[self menu] itemArray];
 }
 
 /*!
@@ -400,7 +350,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPMenuItem)itemAtIndex:(unsigned)anIndex
 {
-    return [_menu itemAtIndex:anIndex];
+    return [[self menu] itemAtIndex:anIndex];
 }
 
 /*!
@@ -409,7 +359,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPString)itemTitleAtIndex:(unsigned)anIndex
 {
-    return [[_menu itemAtIndex:anIndex] title];
+    return [[[self menu] itemAtIndex:anIndex] title];
 }
 
 /*!
@@ -434,7 +384,9 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPMenuItem)itemWithTitle:(CPString)aTitle
 {
-    return [_menu itemAtIndex:[_menu indexOfItemWithTitle:aTitle]];
+    var menu = [self menu];
+
+    return [menu itemAtIndex:[menu indexOfItemWithTitle:aTitle]];
 }
 
 /*!
@@ -442,7 +394,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (CPMenuItem)lastItem
 {
-    return [[_menu itemArray] lastObject];
+    return [[[self menu] itemArray] lastObject];
 }
 
 // Getting the Indices of Menu Items
@@ -452,7 +404,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (int)indexOfItem:(CPMenuItem)aMenuItem
 {
-    return [_menu indexOfItem:aMenuItem];
+    return [[self menu] indexOfItem:aMenuItem];
 }
 
 /*!
@@ -461,7 +413,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (int)indexOfItemWithTag:(int)aTag
 {
-    return [_menu indexOfItemWithTag:aTag];
+    return [[self menu] indexOfItemWithTag:aTag];
 }
 
 /*!
@@ -470,7 +422,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (int)indexOfItemWithTitle:(CPString)aTitle
 {
-    return [_menu indexOfItemWithTitle:aTitle];
+    return [[self menu] indexOfItemWithTitle:aTitle];
 }
 
 /*!
@@ -481,7 +433,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (int)indexOfItemWithRepresentedObject:(id)anObject
 {
-    return [_menu indexOfItemWithRepresentedObject:anObject];
+    return [[self menu] indexOfItemWithRepresentedObject:anObject];
 }
 
 /*!
@@ -493,7 +445,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 */
 - (int)indexOfItemWithTarget:(id)aTarget action:(SEL)anAction
 {
-    return [_menu indexOfItemWithTarget:aTarget action:anAction];
+    return [[self menu] indexOfItemWithTarget:aTarget action:anAction];
 }
 
 // Setting the Cell Edge to Pop out in Restricted Situations
@@ -529,7 +481,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 
     if ([self pullsDown])
     {
-        var items = [_menu itemArray];
+        var items = [[self menu] itemArray];
 
         if ([items count] <= 0)
             [self addItemWithTitle:aTitle];
@@ -577,7 +529,7 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
 
     if ([self pullsDown])
     {
-        var items = [_menu itemArray];
+        var items = [[self menu] itemArray];
 
         if ([items count] > 0)
             item = items[0];
@@ -589,73 +541,117 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
     [super setTitle:[item title]];
 }
 
-//
-/*!
-    Called when the menu has a new item added to it.
-    @param aNotification information about the event
-*/
-- (void)menuDidAddItem:(CPNotification)aNotification
+- (void)observeValueForKeyPath:(CPString)aKeyPath ofObject:(id)anObject change:(CPDictionary)changes context:(id)aContext
 {
-    var index = [[aNotification userInfo] objectForKey:@"CPMenuItemIndex"];
+    var pullsDown = [self pullsDown];
 
-    if (_selectedIndex < 0)
-        [self selectItemAtIndex:0];
-
-    else if (index == _selectedIndex)
+    if (!pullsDown && aKeyPath === @"selectedItem.changeCount" ||
+        pullsDown && (aKeyPath === @"_firstItem" || aKeyPath === @"_firstItem.changeCount"))
         [self synchronizeTitleAndSelectedItem];
 
-    else if (index < _selectedIndex)
-        ++_selectedIndex;
-
-    if (index == 0 && [self pullsDown])
+    // FIXME: This is due to a bug in KVO, we should never get it for "menu".
+    if (aKeyPath === @"menu")
     {
-        var items = [_menu itemArray];
+        aKeyPath = @"menu.items";
 
-        [items[0] setHidden:YES];
-
-        if (items.length > 0)
-            [items[1] setHidden:NO];
+        [changes setObject:CPKeyValueChangeSetting forKey:CPKeyValueChangeKindKey];
+        [changes setObject:[[self menu] itemArray] forKey:CPKeyValueChangeNewKey];
     }
 
-    var item = [_menu itemArray][index],
-        action = [item action];
-
-    if (!action || (action === @selector(_popUpItemAction:)))
+    if (aKeyPath === @"menu.items")
     {
-        [item setTarget:self];
-        [item setAction:@selector(_popUpItemAction:)];
+        var changeKind = [changes objectForKey:CPKeyValueChangeKindKey],
+            indexOfSelectedItem = [self indexOfSelectedItem];
+
+        if (changeKind === CPKeyValueChangeRemoval)
+        {
+            var index = CPNotFound,
+                indexes = [changes objectForKey:CPKeyValueChangeIndexesKey];
+
+            if ([indexes containsIndex:0] && [self pullsDown])
+                [self _firstItemDidChange];
+
+            // See whether the index has changed, despite the actual item not changing.
+            while ((index = [indexes indexGreaterThanIndex:index]) !== CPNotFound &&
+                    index <= indexOfSelectedItem)
+                --indexOfSelectedItem;
+
+            [self selectItemAtIndex:indexOfSelectedItem];
+        }
+
+        else if (changeKind === CPKeyValueChangeReplacement)
+        {
+            var indexes = [changes objectForKey:CPKeyValueChangeIndexesKey];
+
+            if (pullsDown && [indexes containsIndex:0] ||
+                !pullsDown && [indexes containsIndex:indexOfSelectedItem])
+                [self synchronizeTitleAndSelectedItem];
+        }
+
+        else
+        {
+            // No matter what, we want to prepare the new items.
+            var newItems = [changes objectForKey:CPKeyValueChangeNewKey];
+
+            [newItems enumerateObjectsUsingBlock:function(aMenuItem)
+            {
+                var action = [aMenuItem action];
+
+                if (!action)
+                    [aMenuItem setAction:action = @selector(_popUpItemAction:)];
+
+                if (action === @selector(_popUpItemAction:))
+                    [aMenuItem setTarget:self];
+            }];
+
+            if (changeKind === CPKeyValueChangeSetting)
+            {
+                [self _firstItemDidChange];
+
+                _selectedIndex = -2;
+                [self selectItemAtIndex:MIN([newItems count] - 1, indexOfSelectedItem)];
+            }
+
+            else //if (changeKind === CPKeyValueChangeInsertion)
+            {
+                var indexes = [changes objectForKey:CPKeyValueChangeIndexesKey];
+
+                if ([self pullsDown] && [indexes containsIndex:0])
+                {
+                    [self _firstItemDidChange];
+
+                    if ([self numberOfItems] > 1)
+                    {
+                        var index = CPNotFound,
+                            originalIndex = 0;
+
+                        while ((index = [indexes indexGreaterThanIndex:index]) !== CPNotFound &&
+                                index <= originalIndex)
+                            ++originalIndex;
+
+                        [[self itemAtIndex:originalIndex] setHidden:NO];
+                    }
+                }
+
+                if (indexOfSelectedItem < 0)
+                    [self selectItemAtIndex:0];
+
+                else
+                {
+                    var index = CPNotFound;
+
+                    // See whether the index has changed, despite the actual item not changing.
+                    while ((index = [indexes indexGreaterThanIndex:index]) !== CPNotFound &&
+                            index <= indexOfSelectedItem)
+                        ++indexOfSelectedItem;
+
+                    [self selectItemAtIndex:indexOfSelectedItem];
+                }
+            }
+        }
     }
-}
 
-/*!
-    Called when a menu item has changed.
-    @param aNotification information about the event
-*/
-- (void)menuDidChangeItem:(CPNotification)aNotification
-{
-    var index = [[aNotification userInfo] objectForKey:@"CPMenuItemIndex"];
-
-    if ([self pullsDown] && index != 0)
-        return;
-
-    if (![self pullsDown] && index != _selectedIndex)
-        return;
-
-    [self synchronizeTitleAndSelectedItem];
-}
-
-/*!
-    Called when an item was removed from the menu.
-    @param aNotification information about the event
-*/
-- (void)menuDidRemoveItem:(CPNotification)aNotification
-{
-    var numberOfItems = [self numberOfItems];
-
-    if (numberOfItems <= _selectedIndex && numberOfItems > 0)
-        [self selectItemAtIndex:numberOfItems - 1];
-    else
-        [self synchronizeTitleAndSelectedItem];
+//    [super observeValueForKeyPath:aKeyPath ofObject:anObject change:changes context:aContext];
 }
 
 - (void)mouseDown:(CPEvent)anEvent
@@ -735,6 +731,22 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
     [self sendAction:[self action] to:[self target]];
 }
 
+- (void)_firstItemDidChange
+{
+    [self willChangeValueForKey:@"_firstItem"];
+    [self didChangeValueForKey:@"_firstItem"];
+
+    [[self _firstItem] setHidden:YES];
+}
+
+- (CPMenuItem)_firstItem
+{
+    if ([self numberOfItems] <= 0)
+        return nil;
+
+    return [[self menu] itemAtIndex:0];
+}
+
 - (void)takeValueFromKeyPath:(CPString)aKeyPath ofObjects:(CPArray)objects
 {
     var count = objects.length,
@@ -744,18 +756,13 @@ CPPopUpButtonStatePullsDown = CPThemeState("pulls-down");
     [self setEnabled:YES];
 
     while (count-- > 1)
-    {
         if (value !== [objects[count] valueForKeyPath:aKeyPath])
-        {
             [[self selectedItem] setState:CPOffState];
-        }
-    }
 }
 
 @end
 
-var CPPopUpButtonMenuKey            = @"CPPopUpButtonMenuKey",
-    CPPopUpButtonSelectedIndexKey   = @"CPPopUpButtonSelectedIndexKey",
+var CPPopUpButtonSelectedIndexKey   = @"CPPopUpButtonSelectedIndexKey",
     CPPopUpButtonPullsDownKey       = @"CPPopUpButtonPullsDownKey";
 
 @implementation CPPopUpButton (CPCoding)
@@ -773,10 +780,17 @@ var CPPopUpButtonMenuKey            = @"CPPopUpButtonMenuKey",
     if (self)
     {
         // Nothing is currently selected
-        _selectedIndex = -1;
+        _selectedIndex = CPNotFound;
 
-        [self setMenu:[aCoder decodeObjectForKey:CPPopUpButtonMenuKey]];
         [self selectItemAtIndex:[aCoder decodeObjectForKey:CPPopUpButtonSelectedIndexKey]];
+
+        var options =   CPKeyValueObservingOptionNew |
+                        CPKeyValueObservingOptionOld;/* |
+                        CPKeyValueObservingOptionInitial;
+*/
+        [self addObserver:self forKeyPath:@"menu.items" options:options context:nil];
+        [self addObserver:self forKeyPath:@"_firstItem.changeCount" options:options context:nil];
+        [self addObserver:self forKeyPath:@"selectedItem.changeCount" options:options context:nil];
     }
 
     return self;
@@ -791,7 +805,6 @@ var CPPopUpButtonMenuKey            = @"CPPopUpButtonMenuKey",
 {
     [super encodeWithCoder:aCoder];
 
-    [aCoder encodeObject:_menu forKey:CPPopUpButtonMenuKey];
     [aCoder encodeInt:_selectedIndex forKey:CPPopUpButtonSelectedIndexKey];
 }
 

AppKit/CPResponder.j

@@ -358,8 +358,8 @@ var CPResponderNextResponderKey = @"CPResponderNextResponderKey",
 
     if (self)
     {
-        _nextResponder = [aCoder decodeObjectForKey:CPResponderNextResponderKey];
-        _menu = [aCoder decodeObjectForKey:CPResponderMenuKey];
+        [self setNextResponder:[aCoder decodeObjectForKey:CPResponderNextResponderKey]];
+        [self setMenu:[aCoder decodeObjectForKey:CPResponderMenuKey]];
     }
 
     return self;

Foundation/CPArray/CPArray.j

@@ -517,6 +517,14 @@ var concat = Array.prototype.concat,
             objj_msgSend([self objectAtIndex:index], aSelector);
 }
 
+- (void)enumerateObjectsUsingBlock:(Function)aFunction
+{
+    var index = 0,
+        count = [self count];
+
+    for (; index < count; ++index)
+        aFunction([self objectAtIndex:index], index);
+}
 
 // Comparing arrays
 /*!

Foundation/CPArray/CPMutableArray.j

@@ -136,15 +136,15 @@
     @param anIndexSet the set of indices to array positions that will be replaced
     @param objects the array of objects to place in the specified indices
 */
-- (void)replaceObjectsAtIndexes:(CPIndexSet)anIndexSet withObjects:(CPArray)objects
+- (void)replaceObjectsAtIndexes:(CPIndexSet)indexes withObjects:(CPArray)objects
 {
     var i = 0,
-        index = [anIndexSet firstIndex];
+        index = [indexes firstIndex];
 
     while (index !== CPNotFound)
     {
-        [self replaceObjectAtIndex:index withObject:objects[i++]];
-        index = [anIndexSet indexGreaterThanIndex:index];
+        [self replaceObjectAtIndex:index withObject:[objects objectAtIndex:i++]];
+        index = [indexes indexGreaterThanIndex:index];
     }
 }
 

Tests/AppKit/CPPopUpButtonTest.j

@@ -12,6 +12,77 @@
     button = [CPPopUpButton new];
 }
 
+- (void)testMenuSynchronization
+{
+    var popUpButton = [[CPPopUpButton alloc] initWithFrame:CGRectMake(0.0, 0.0, 100.0, 28.0) pullsDown:NO];
+
+    [self assert:CPNotFound equals:[popUpButton indexOfSelectedItem]];
+
+    [popUpButton addItemWithTitle:@"one"];
+
+    [self assert:0 equals:[popUpButton indexOfSelectedItem]];
+
+    [popUpButton addItemWithTitle:@"two"];
+    [popUpButton addItemWithTitle:@"three"];
+    [popUpButton addItemWithTitle:@"four"];
+    [popUpButton addItemWithTitle:@"five"];
+    [popUpButton addItemWithTitle:@"six"];
+
+    [self assert:0 equals:[popUpButton indexOfSelectedItem]];
+
+    [popUpButton insertItemWithTitle:@"negative one" atIndex:0];
+
+    [self assert:1 equals:[popUpButton indexOfSelectedItem]];
+
+    var items = [
+        [[CPMenuItem alloc] initWithTitle:@"negative five" action:nil keyEquivalent:@""],
+        [[CPMenuItem alloc] initWithTitle:@"negative four" action:nil keyEquivalent:@""],
+        [[CPMenuItem alloc] initWithTitle:@"negative three" action:nil keyEquivalent:@""],
+        [[CPMenuItem alloc] initWithTitle:@"negative two" action:nil keyEquivalent:@""]
+                ],
+        indexes = [CPIndexSet indexSetWithIndexesInRange:CPMakeRange(0, 4)],
+        mutableItemsArray = [[popUpButton menu] mutableArrayValueForKey:@"items"];
+
+    [mutableItemsArray insertObjects:items atIndexes:indexes];
+
+    [self assert:5 equals:[popUpButton indexOfSelectedItem]];
+
+    [[popUpButton menu] removeItemAtIndex:5];
+
+    [self assert:4 equals:[popUpButton indexOfSelectedItem]];
+
+    [[popUpButton menu] removeItemAtIndex:0];
+
+    [self assert:3 equals:[popUpButton indexOfSelectedItem]];
+
+    [popUpButton selectItemAtIndex:1];
+
+    indexes = [CPIndexSet indexSetWithIndexesInRange:CPMakeRange(1, 3)];
+    [mutableItemsArray removeObjectsAtIndexes:indexes];
+
+    [self assert:0 equals:[popUpButton indexOfSelectedItem]];
+
+    var pullDownButton = [[CPPopUpButton alloc] initWithFrame:CGRectMake(0.0, 0.0, 100.0, 28.0) pullsDown:YES];
+
+    [pullDownButton addItemWithTitle:@"First Item"];
+
+    [self assert:YES equals:[[pullDownButton itemAtIndex:0] isHidden]];
+
+    [pullDownButton addItemWithTitle:@"Second Item"];
+
+    [self assert:YES equals:[[pullDownButton itemAtIndex:0] isHidden]];
+    [self assert:NO equals:[[pullDownButton itemAtIndex:1] isHidden]];
+
+    [pullDownButton removeItemAtIndex:0];
+
+    [self assert:YES equals:[[pullDownButton itemAtIndex:0] isHidden]];
+
+    [pullDownButton insertItemWithTitle:@"A Title" atIndex:0];
+
+    [self assert:YES equals:[[pullDownButton itemAtIndex:0] isHidden]];
+    [self assert:NO equals:[[pullDownButton itemAtIndex:1] isHidden]];
+}
+
 - (void)testItemTitles
 {
     [self assert:[] equals:[button itemTitles]];