Fixed: token field autocomplete menu remaining after window closed.

Without this change, closing the window containing a token field showing an autocomplete menu would result in a detached autocomplete menu hanging around.

This fix checks for window close notifications and makes sure to dismiss the menu if the window closes.

AppKit/CPView.j

@@ -651,6 +651,9 @@ var CPViewFlags                     = { },
     if (_window === aWindow)
         return;
 
+    // Unlike in Cocoa you can observe the window of a view.
+    [self willChangeValueForKey:@"window"];
+
     [[self window] _dirtyKeyViewLoop];
 
     // Clear out first responder if we're the first responder and leaving.
@@ -678,6 +681,8 @@ var CPViewFlags                     = { },
     [self viewDidMoveToWindow];
 
     [[self window] _dirtyKeyViewLoop];
+
+    [self didChangeValueForKey:@"window"];
 }
 
 /*!

AppKit/_CPAutocompleteMenu.j

@@ -38,6 +38,7 @@ var _CPAutocompleteMenuMaximumHeight = 307;
     float           widestItemWidth;
 
     CPWindow        _menuWindow;
+    CPWindow        _parentWindow @accessors(property=parentWindow);
     CPScrollView    scrollView;
     CPTableView     tableView;
 
@@ -48,7 +49,8 @@ var _CPAutocompleteMenuMaximumHeight = 307;
 {
     if (self = [super init])
     {
-        textField = aTextField;
+        [self bind:@"parentWindow" toObject:self withKeyPath:@"textField.window" options:nil];
+        [self setTextField:aTextField];
 
         _menuWindow = [[CPWindow alloc] initWithContentRect:CGRectMake(0, 0, 100, 100) styleMask:CPBorderlessWindowMask];
 
@@ -258,6 +260,25 @@ var _CPAutocompleteMenuMaximumHeight = 307;
     [textField _complete:self];
 }
 
+- (void)setParentWindow:(CPWindow)aWindow
+{
+    if (aWindow === _parentWindow)
+        return;
+
+    if (_parentWindow)
+        [[CPNotificationCenter defaultCenter] removeObserver:self];
+
+    _parentWindow = aWindow;
+
+    if (_parentWindow)
+        [[CPNotificationCenter defaultCenter] addObserver:self selector:@selector(parentWindowWillClose:) name:CPWindowWillCloseNotification object:_parentWindow];
+}
+
+- (void)parentWindowWillClose:(CPNotification)aNotification
+{
+    [self _hideCompletions];
+}
+
 @end