WebBrowserControl for the .NET Framework 1.1

using System;
using System.Drawing;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;
using System.ComponentModel;

namespace Pajocomo.Drawing.Design
{
	/// <summary>
	/// Implements a custom type editor for selecting an enumeration from in a list.
	/// <seealso cref="U:http://www.codeproject.com/cs/miscctrl/flagseditor.asp">A flag editor</seealso>
	/// </summary>
	public class FlagsEditor : System.Drawing.Design.UITypeEditor
	{
		/// <summary>
		/// Internal class used for storing custom data in listviewitems
		/// </summary>
		internal class FlagItem
		{
			/// <summary>
			/// Initializes a new instance of the <see cref="FlagItem"/> class.
			/// </summary>
			/// <param name="str">The string to display in the <c>ToString</c> method. 
			/// It will contains the name of the flag</param>
			/// <param name="value">The integer value of the flag</param>
			/// <param name="tooltip">The tooltip to display in the <see cref="CheckedListBox"/></param>
			public FlagItem(string str, uint value, string tooltip)
			{
				this.str = str;
				this.value = value;
				this.tooltip = tooltip;
			}

			private string str;

			private uint value;
			/// <summary>
			/// Gets the int value for this item
			/// </summary>
			public uint Value
			{
				get{return value;}
			}

			private string tooltip;

			/// <summary>
			/// Gets the tooltip for this item
			/// </summary>
			public string Tooltip
			{
				get{return tooltip;}
			}

			/// <summary>
			/// Gets the name of this item
			/// </summary>
			/// <returns>The name passed in the constructor</returns>
			public override string ToString()
			{
				return str;
			}
		}

		private IWindowsFormsEditorService flagsEditorService = null;
		private CheckedListBox flagsListBox;
		private ToolTip tooltipControl;
		private bool handleLostfocus = false;

		/// <summary>
		/// Overrides the method used to provide basic behaviour for selecting editor.
		/// Shows our custom control for editing the value.
		/// </summary>
		/// <param name="context">The context of the editing control</param>
		/// <param name="provider">A valid service provider</param>
		/// <param name="value">The current value of the object to edit</param>
		/// <returns>The new value of the object</returns>
		public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value) 
		{
			if ((context != null) && (context.Instance != null) && (provider != null)) 
			{

				this.flagsEditorService = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));

				if (this.flagsEditorService != null) 
				{					
					// Create a CheckedListBox and populate it with all the enum values
					this.flagsListBox = new CheckedListBox();
					this.flagsListBox.BorderStyle = BorderStyle.FixedSingle;
					this.flagsListBox.CheckOnClick = true;
					this.flagsListBox.MouseDown += new MouseEventHandler(this.FlagsListBox_MouseDown);
					this.flagsListBox.MouseMove += new MouseEventHandler(this.FlagsListBox_MouseMoved);

					this.tooltipControl = new ToolTip();
					this.tooltipControl.ShowAlways = true;

					// Get the int value of the current enum value (the one being edited)
					uint uintEdited = (uint)Convert.ChangeType(value, typeof(uint));

					foreach(string flagName in Enum.GetNames(context.PropertyDescriptor.PropertyType))
					{
						// Get the enum value
						object flagValue = Enum.Parse(context.PropertyDescriptor.PropertyType, flagName);
						// Get the uint value 
						uint uintValue = (uint) Convert.ChangeType(flagValue, typeof(uint));
					
						if (uintValue != 0)
						{
						// Get the description attribute for this field
							System.Reflection.FieldInfo fi = context.PropertyDescriptor.PropertyType.GetField(flagName);
						DescriptionAttribute[] attrs = (DescriptionAttribute[]) fi.GetCustomAttributes(typeof(DescriptionAttribute), false);

						// Store the the description
							string tooltip = attrs.Length > 0 ? attrs[0].Description : null;

							// Creates a FlagItem that stores the name, the int value and the tooltip
							FlagItem flagItem = new FlagItem(flagValue.ToString(), uintValue, tooltip);

						// Get the checkstate from the value being edited
							bool checkedItem = (uintEdited & uintValue) > 0;

						// Add the item with the right check state
							this.flagsListBox.Items.Add(flagItem, checkedItem);
						}
					}					

					// Show our CheckedListbox as a DropDownControl. 
					// This methods returns only when the dropdowncontrol is closed
					this.flagsEditorService.DropDownControl(this.flagsListBox);

					// Get the sum of all checked flags
					uint uintResult = 0;
					foreach(FlagItem flagItem in this.flagsListBox.CheckedItems)
					{
						uintResult |= flagItem.Value;
					}
				
					// return the right enum value corresponding to the result
					return Enum.ToObject(context.PropertyDescriptor.PropertyType, uintResult);
				}
			}

			return value;
		}

		/// <summary>
		/// Shows a dropdown icon in the property editor
		/// </summary>
		/// <param name="context">The context of the editing control</param>
		/// <returns><see cref="UITypeEditorEditStyle.DropDown"/></returns>
		public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context) 
		{
			return UITypeEditorEditStyle.DropDown;			
		}

		/// <summary>
		/// When got the focus, handle the lost focus event.
		/// </summary>
		/// <param name="sender">The sender.</param>
		/// <param name="e">The <see cref="System.Windows.Forms.MouseEventArgs"/> instance containing the event data.</param>
		private void FlagsListBox_MouseDown(object sender, MouseEventArgs e) 
		{
			if(!this.handleLostfocus && this.flagsListBox.ClientRectangle.Contains(this.flagsListBox.PointToClient(new Point(e.X, e.Y))))
			{
				this.flagsListBox.LostFocus += new EventHandler(this.FlagsListBox_LostFocus);
				this.handleLostfocus = true;
			}
		}

		/// <summary>
		/// Occurs when the mouse is moved over the checkedlistbox. 
		/// Sets the tooltip of the item under the pointer
		/// </summary>
		/// <param name="sender">The sender.</param>
		/// <param name="e">The <see cref="System.Windows.Forms.MouseEventArgs"/> instance containing the event data.</param>
		private void FlagsListBox_MouseMoved(object sender, MouseEventArgs e) 
		{			
			int index = this.flagsListBox.IndexFromPoint(e.X, e.Y);
			if(index >= 0)
			{
				this.tooltipControl.SetToolTip(this.flagsListBox, ((FlagItem)(this.flagsListBox.Items[index])).Tooltip);
			}
		}

		/// <summary>
		/// Close the dropdowncontrol when the user has selected a value
		/// </summary>
		/// <param name="sender">The sender.</param>
		/// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
		private void FlagsListBox_LostFocus(object sender, EventArgs e) 
		{
			if (this.flagsEditorService != null) 
			{
				this.flagsEditorService.CloseDropDown();
			}
		}
	}
}