WPF: A TimeLineControl

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;

namespace TimeLineControl
{
    /// <summary>
    /// Displays year of <c>ITemLineItem</c>s
    /// </summary>
    public partial class YearView : UserControl
    {
        #region Data
        Dictionary<Int32, List<ITimeLineItem>> itemsByKey = new Dictionary<int, List<ITimeLineItem>>();
        private Boolean initialised = false;
        #endregion

        #region Ctor
        public YearView()
        {
            InitializeComponent();
        }
        #endregion

        #region Public Properties

        public Int32 StartYear { get; set; }

        #region ItemsDataTemplate

        /// <summary>
        /// ItemsDataTemplate Dependency Property
        /// </summary>
        public static readonly DependencyProperty ItemsDataTemplateProperty =
            DependencyProperty.Register("ItemsDataTemplate", typeof(DataTemplate),
            typeof(YearView),
                new FrameworkPropertyMetadata((DataTemplate)null,
                    new PropertyChangedCallback(OnItemsDataTemplateChanged)));

        /// <summary>
        /// Gets or sets the ItemsDataTemplate property.  
        /// </summary>
        public DataTemplate ItemsDataTemplate
        {
            get { return (DataTemplate)GetValue(ItemsDataTemplateProperty); }
            set { SetValue(ItemsDataTemplateProperty, value); }
        }

        /// <summary>
        /// Handles changes to the ItemsDataTemplate property.
        /// </summary>
        private static void OnItemsDataTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
        }
        #endregion

        #region TimeLineItems

        /// <summary>
        /// TimeLineItems Dependency Property
        /// </summary>
        public static readonly DependencyProperty TimeLineItemsProperty =
            DependencyProperty.Register("TimeLineItems", typeof(List<ITimeLineItem>),
            typeof(YearView),
                new FrameworkPropertyMetadata((List<ITimeLineItem>)null,
                    new PropertyChangedCallback(OnTimeLineItemsChanged)));

        /// <summary>
        /// Gets or sets the TimeLineItems property.  
        /// </summary>
        public List<ITimeLineItem> TimeLineItems
        {
            get { return (List<ITimeLineItem>)GetValue(TimeLineItemsProperty); }
            set { SetValue(TimeLineItemsProperty, value); }
        }

        /// <summary>
        /// Handles changes to the TimeLineItems property.
        /// </summary>
        private static void OnTimeLineItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {


        }
        #endregion
        #endregion

        #region Public Methods
        public void Draw()
        {
            if (TimeLineItems.Count() == 0)
                return;

            if (initialised)
                return;

            grid.Children.Clear();
            Int32 barHeightToDrawIn = (Int32)this.Height - 35;

            Double barWidth = (this.ActualWidth / 10) > 50.0 ? this.ActualWidth / 10 : 50.0;
            foreach (ColumnDefinition col in grid.ColumnDefinitions)
            {
                col.Width = new GridLength(barWidth,GridUnitType.Pixel);
            }

            Int32 maximumItemsForGraphAcrossAllBars = 0;
            

            for (int i = 0; i < 10; i++)
            {
                Int32 checkingForYear = StartYear+i;
                List<ITimeLineItem> items =
                 (from t in TimeLineItems 
                  where t.ItemTime.Year == checkingForYear 
                  select t).ToList();

                if (items != null && items.Count > 0)
                    itemsByKey.Add(checkingForYear, items);

            }

            if (itemsByKey.Count > 0)
                maximumItemsForGraphAcrossAllBars = 
                    (from x in itemsByKey 
                     select x.Value.Count).Max();

            for (int i = 0; i < 10; i++)
            {
                Int32 checkingForYear = StartYear + i;
                List<ITimeLineItem> items = null;


                Double columnWidth = grid.ActualWidth / 10; 

                if (itemsByKey.TryGetValue(checkingForYear, out items))
                {

                    ItemsBar bar = new ItemsBar();
                    bar.ItemsDataTemplate = this.ItemsDataTemplate;
                    bar.Height = barHeightToDrawIn;
                    bar.Width = columnWidth;
                    bar.TimeLineItems = items;
                    bar.MaximumItemsForGraphAcrossAllBars = maximumItemsForGraphAcrossAllBars;
                    bar.Loaded += (s, e) =>
                    {
                        bar.Draw();
                    };
                    bar.SetValue(Grid.ColumnProperty, i);
                    bar.SetValue(Grid.RowProperty, 0);
                    grid.Children.Add(bar);
                }

                //Need to build up buttons now
                grid.Children.Add(CreateButton(checkingForYear, i));
            }

            initialised = true;
        }
        #endregion

        #region Events
        public event EventHandler<DateEventArgs> ViewDateEvent;
        #endregion

        #region Private Methods
        private void OnViewDateEvent(DateTime currentViewingDate)
        {
            // Copy to a temporary variable to be thread-safe.
            EventHandler<DateEventArgs> temp = ViewDateEvent;
            if (temp != null)
                temp(this, new DateEventArgs(currentViewingDate));
        }

        private Button CreateButton(Int32 year, Int32 column)
        {
            Button btn = new Button();
            btn.Content = year;
            Style style = (Style)this.Resources["graphSectionButtonStyle"];
            if (style != null) { btn.Style = style; }
            btn.Click += Button_Click;
            btn.IsEnabled = itemsByKey.ContainsKey(year);
            btn.SetValue(Grid.RowProperty, 1);
            btn.SetValue(Grid.ColumnProperty, column);
            return btn;
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Button btn = (Button)sender;
            OnViewDateEvent(new DateTime(Int32.Parse(btn.Content.ToString()), 1, 1));
        }
        #endregion
    }
}