public FlayoutNavigationItem(string caption, NSAction tapped, UIImage image, string controller)
     : base(caption, tapped, image)
 {
     Controller = controller;
     Image = image;
     Callback = tapped;
 }

 public static void Invoke(NSAction action)
 {
     if (_app != null)
     {
         _app.InvokeOnMainThread(action);
     }
 }

 public FilterElement(IssuesFiltersViewModel.FilterModel filterModel, NSAction action, Action accessory)
     : base(filterModel.IssueModel.FilterName, action)
 {
     Accessory = UITableViewCellAccessory.DetailButton;
     AccessoryTapped += () => accessory();
     FilterModel = filterModel;
 }

		public void BeginSheet (NSWindow window, NSAction onEnded)
		{
			BeginSheetForResponse (window, r => {
				if (onEnded != null)
					onEnded ();
			});
		}

        public NSActionDispatcher(NSAction action)
        {
            if (action == null)
                throw new ArgumentNullException ("action");

            this.action = action;
        }

 public ImageLoaderStringElement(string caption,  NSAction tapped, NSUrl imageUrl, UIImage placeholder)
     : base(caption, tapped)
 {
     Placeholder = placeholder;
     ImageUrl = imageUrl;
     this.Accessory = UITableViewCellAccessory.None;
 }

		public static CADisplayLink Create (NSAction action)
		{
			var dispatcher = new NSActionDispatcher (action);
			var rv = Create (dispatcher, NSActionDispatcher.Selector);
			rv.dispatcher = dispatcher;
			return rv;
		}

 public StyledElement(string caption,  NSAction tapped, UIImage image)
     : base(caption, tapped)
 {
     Init();
     Image = image;
     Accessory = UITableViewCellAccessory.DisclosureIndicator;
 }

 public UIRaisedTabBar(UIImage normal, UIImage highlighted, NSAction tapped)
     : base()
 {
     normalState = normal;
     highlightedState = highlighted;
     if (tapped != null)
         Tapped += tapped;
 }

 public BikeElement(BikeLocation bike, NSAction action)
     : base("","",action)
 {
     Bike = bike;
     Caption = bike.Name;
     Value = GetValueString();
     Accessory = UITableViewCellAccessory.DisclosureIndicator;
 }

		public BadgeElement (UIImage badgeImage, string cellText, NSAction tapped) : base (cellText)
		{
			if (badgeImage == null)
				throw new ArgumentNullException ("badgeImage");
			
			image = badgeImage;
			if (tapped != null)
				Tapped += tapped;
		}		

        public ButtonElement(string caption, NSAction tapped)
            : base(caption)
        {
            this.tapped = tapped;

            NormalColor = UIColor.Gray;
            NormalTextColor = UIColor.Black;

            HighlightedColor = UIColor.Blue;
            HighlightedTextColor = UIColor.White;

            DisabledColor = UIColor.Gray;
            DisabledTextColor = UIColor.DarkGray;
        }

        public void AddAccount(DialogViewController dvc, NSAction action)
        {
            var oauth = new OAuthAuthorizer (TwitterAccount.OAuthConfig);

            if (useXauth)
                NewAccountXAuth (dvc, action);
            else {
                if (oauth.AcquireRequestToken ()){
                    oauth.AuthorizeUser (dvc, delegate {
                        SetDefaultAccount (oauth);
                        action ();
                    });
                }
            }
        }

		public BadgeElement (UIImage badgeImage, string cellText, NSAction tapped) 
            : base (cellText)
		{
            LineBreakMode = UILineBreakMode.TailTruncation;
            ContentMode = UIViewContentMode.Left;
            Lines = 1;
            Accessory = UITableViewCellAccessory.None;

            if (badgeImage == null)
				throw new ArgumentNullException ("badgeImage");
			
			_image = badgeImage;

			if (tapped != null)
				Tapped += tapped;
		}		

		private RootElement GetRoot()
		{
			IList<Series> coll = AppManifest.Current.Collections;
			
			var root = new RootElement("Collections");
			var section = new Section();
			
			for(var i = 0; i < coll.Count; i++)
			{
				Series series = coll[i];
				var rounded = ImageFactory.LoadRoundedThumbnail(series.Pieces[0]);
				var viewAction = new NSAction(() => { LoadSeries (series); });
				
				var element = new StyledStringElement(series.Title, viewAction) { Image = rounded };
				element.New = series.New.GetValueOrDefault();
				section.Add(element);
			}
			
			root.Add(section);			
			return root;
		}

		private RootElement GetRoot()
		{
			IList<Piece> pieces = _parent.Series.Pieces;			
						
			var root = new RootElement("");
			_section = new Section(string.Concat(_parent.Series.Title, " (", _parent.Series.Years , ")"));
									
			for(var i = 0; i < pieces.Count; i++)
			{
				var page = i;
				var piece = pieces[page];
				
				var viewAction = new NSAction(() =>
				{
					GoToPage(page);
				});				
				
				var element = new StyledStringElement(piece.Title, viewAction);		
				element.Activity = true;
				_section.Add(element);
								
				ThreadPool.QueueUserWorkItem(s =>
				{
					var rounded = ImageFactory.LoadRoundedThumbnail(piece);
					InvokeOnMainThread(()=>
					{
						element.Image = rounded;	
						element.Reload();
					});
				});											
			}
						
			// Set the default check box
			CheckPiece(0);
			root.Add(_section);		
			
			View.SetNeedsDisplay();
			return root;
		}

 public NSActionDispatcher(NSAction action)
 {
     this.action = action;
 }

		public CustomImageStringElement (string caption, NSAction tapped, UIImage image) : base (caption, tapped, image)
		{
			_image = image;
		}		

 public GameInstanceElement(NetworkBrowserModel.GameInstanceInfo gameInstanceInfo, NSAction tapped)
     : base(gameInstanceInfo.GameInstance.Name, tapped)
 {
     this.GameInstanceInfo = gameInstanceInfo;
 }

		public void BeginSheet (NSPrintInfo printInfo, NSWindow docWindow, NSAction onEnded)
		{
			var obj = OneShotTracker.Create (onEnded);
			BeginSheet (printInfo, docWindow, obj, NSActionDispatcher.Selector, IntPtr.Zero);
		}