RSS 2.0 Framework

// Copyright � 2006 by Christoph Richner. All rights are reserved.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
//
// website http://www.raccoom.net, email support@raccoom.net, msn chrisdarebell@msn.com

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

namespace Actions.Design
{
	/// <summary>
	/// The base class for the UITypeEditor for an index in an ImageList.
	/// </summary>
	public abstract class ImageIndexEditorBase : UITypeEditor
	{
		/// <summary>
		/// Indicates whether the specified context supports painting a representation of an object's value within the specified context.
		/// </summary>
		/// <param name="context">An ITypeDescriptorContext that can be used to gain additional context information.</param>
		/// <returns>true if PaintValue is implemented; otherwise, false.</returns>
		public override bool GetPaintValueSupported(ITypeDescriptorContext context)
		{
			return true;
		}
		/// <summary>
		/// Paints a representation of the value of an object using the specified PaintValueEventArgs.
		/// </summary>
		/// <param name="pe">A PaintValueEventArgs that indicates what to paint and where to paint it.</param>
		public override void PaintValue(PaintValueEventArgs pe)
		{
			if (!(pe.Value is int))
			{
				return;
			}
			Image img = GetImage(pe.Context, (int)pe.Value);
			if (img != null)
			{
				pe.Graphics.DrawImage(img, pe.Bounds);
			}
		}
		/// <summary>
		/// Get the image corresponding to the corresponding index. The imageList is determined firstly by looking at property of type ImageList among the instance properties,
		/// secondly by looking at the properties of the "Parent" property of the instance
		/// </summary>
		/// <param name="context">The context of the call</param>
		/// <param name="index">The index of the image</param>
		/// <returns>The corresponding image or null</returns>
		private Image GetImage(ITypeDescriptorContext context, int index)
		{
			ImageList		il = GetImageList(context);
			if (il == null || index < 0 || index >= il.Images.Count)
			{
				return null;
			}
			return il.Images[index];
		}
		/// <summary>
		/// Abstract method which allow to find the ImageList for the given context
		/// </summary>
		/// <param name="context">The context of the call</param>
		/// <returns>An ImageList</returns>
		protected abstract ImageList GetImageList(ITypeDescriptorContext context);
	}
	
	/// <summary>
	/// An UITypeEditor for an index in an ImageList. There is one in System.Windows.Form.Design but unfortunately it's a private class.
	/// </summary>
	public class ImageIndexEditor : ImageIndexEditorBase
	{
		/// <summary>
		/// Finds the ImageList for the given context by looking first at property of type ImageList among the instance properties,
		/// and if the search was unsuccessful by looking at the properties of the "Parent" property of the instance
		/// </summary>
		/// <param name="context">The context of the call</param>
		/// <returns>An ImageList</returns>
		protected override ImageList GetImageList(ITypeDescriptorContext context)
		{
			// try first to find a property of type ImageList among the instance properties
			ImageList		il = null;
			PropertyInfo[]	props = context.Instance.GetType().GetProperties();
			foreach(PropertyInfo prop in props)
			{
				if (prop.PropertyType == typeof(ImageList) && prop.CanRead)
				{
					il = (ImageList)prop.GetValue(context.Instance, null);
					break;
				}
			}
			// if not found, look for a "Parent" property and do the same search on the parent
			if (il == null)
			{
				PropertyInfo parentprop = context.Instance.GetType().GetProperty("Parent");
				if (parentprop != null)
				{
					object parent = parentprop.GetValue(context.Instance, null);
					if (parent != null)
					{
						props = parent.GetType().GetProperties();
						foreach(PropertyInfo prop in props)
						{
							if (prop.PropertyType == typeof(ImageList) && prop.CanRead)
							{
								il = (ImageList)prop.GetValue(parent, null);
								break;
							}
						}
					}
				}
			}
			return il;
		}
	}
}