Equation Calculator with Graphing

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;
using CommonUtils;

namespace Calculator
{
	/// <summary>
	/// Interaction logic for FunctionList.xaml
	/// </summary>
	public partial class FunctionList : UserControl
	{
		public FunctionList()
		{
			InitializeComponent();
		}
	}
	public class FunctionListPopup : ListPopup
	{
		public FunctionListPopup()
		{
			List = new ObservableCollection<string>();
			foreach (string f in CommonUtils.EquationParser.FunctionsList)
				List.Add(f);

			Child = new FunctionList();
			((FunctionList)Child).DataContext = this;
			((FunctionList)Child).Loaded += new RoutedEventHandler(OnListLoaded);
			Width = 100;
			Height = 150;
			StaysOpen = false;
		}
		void OnListLoaded(object sender, RoutedEventArgs e)
		{
			AttachListBox();
		}
	}
	public class ListPopup : System.Windows.Controls.Primitives.Popup
	{
		ListBox m_listBox = null;
		public static DependencyProperty SelectedItemProperty = DependencyProperty.Register("SelectedItem", typeof(string), typeof(ListPopup));
		ObservableCollection<string> m_list;
		public bool PopupResult {get; protected set;}
		public string SelectedItem 
		{
			get { return (string)GetValue(SelectedItemProperty); }
			set { SetValue(SelectedItemProperty, value); }
		}
		public ObservableCollection<string> List 
		{
			get { return m_list;}
			set
			{
				m_list = value;
				DataContext = this;
			}
		}
		public ListPopup()
		{
			SelectedItem = string.Empty;
			Loaded += new RoutedEventHandler(OnLoaded);
		}
		protected virtual void AttachListBox()
		{
			if (m_listBox != null)
				return;
			m_listBox = VisualTreeUtils.FindVisualChildByName<ListBox>(Child, "m_listBox");
			if (m_listBox != null)
			{
				// cool, attach and receive event even if it has been handled (true)
				m_listBox.AddHandler(ListBox.MouseLeftButtonDownEvent,
					(RoutedEventHandler)OnLeftButtonDown,
					true);
			}
		}
		void OnLoaded(object sender, RoutedEventArgs e)
		{
			AttachListBox();
		}
		void OnLeftButtonDown(object sender, RoutedEventArgs e)
		{
			Close(SelectedItem.Length > 0);
		}
		public virtual void Open(string curText)
		{
			SelectedItem = curText;
			IsOpen = true;
			if (m_listBox != null)
			{
				m_listBox.Focus();
				ListBoxItem item = m_listBox.ItemContainerGenerator.ContainerFromItem(m_listBox.SelectedItem) as ListBoxItem;
				if (item != null)
					item.Focus();
				else if (List.Count > 0)
					item = m_listBox.ItemContainerGenerator.ContainerFromItem(List[0]) as ListBoxItem;
				if (item != null)
					item.Focus();
			}
		}
		public virtual void Close(bool result)
		{
			PopupResult = result;
			IsOpen = false;
			UIElement target = PlacementTarget;
			if (target != null)
				target.Focus();
		}
		protected override void OnOpened(EventArgs e)
		{
			PopupResult = false;
			base.OnOpened(e);
		}
		protected override void OnPreviewKeyDown(KeyEventArgs e)
		{
			base.OnPreviewKeyDown(e);
			if (e.Key == Key.Escape)
			{
				Close(false);
				return;
			}
			if (e.Key == Key.Enter)
			{
				Close(true);
				return;
			}
		}
	}
}