Adding XP Themes to Custom .NET Controls

/////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2003 - Don Kackman
//
// Distribute and change freely, but please don't remove my name from the source 
//
// No warrantee of any kind, express or implied, is included with this
// software; use at your own risk, responsibility for damages (if any) to
// anyone resulting from the use of this software rests entirely with the
// user. 
//
// questions - contact me at dkackman_2000@yahoo.com
//

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

using System.Windows.Forms.Themes;

namespace System.Windows.Forms
{
	/// <summary>
	/// Abstract base Panel control to help out with rendering while themed and not themed
	/// </summary>
	public class ThemeablePanel : Panel
	{
		private ThemeInfo m_ThemeInfo;
		private string m_WindowClassName;

		/// <summary>
		/// Initializes the ThemeablePanel class
		/// </summary>
		/// <param name="windowClassName">The window class name that will be used to retreive ThemeParts</param>
		protected ThemeablePanel( string windowClassName ) 
		{
			m_WindowClassName = windowClassName;
			m_ThemeInfo = new ThemeInfo();

			BackColor = SystemColors.ControlLightLight;
			SetStyle( ControlStyles.Selectable, false );
		}

		/// <summary>
		/// This contructor is needed so derived classes can be used
		/// by the designer. It shouldn't be called otherise
		/// </summary>
		protected ThemeablePanel() : this( "" )
		{
		}

		/// <summary>
		/// ThemeInfo instance for the control
		/// </summary>
		protected ThemeInfo ThemeInfo
		{
			get { return m_ThemeInfo; }
		}

		/// <summary>
		/// Get the current window theme for the panel using the window class name
		/// If the app is not themed returns null
		/// </summary>
		/// <returns>ThemeInfo object or null</returns>
		protected WindowTheme GetCurrentWindowTheme()
		{
			WindowTheme theme = null;

			// try and get the window theme
			// If we can't catch the error and return null
			try
			{
				// don't get a the window theme if the app isn't themed or we are in design mode
				if ( UxTheme.IsAppThemed && !DesignMode )
					theme = m_ThemeInfo[m_WindowClassName];
			}
			catch ( IndexOutOfRangeException )
			{
			}

			return theme;
		}

		protected override void OnPaintBackground(PaintEventArgs pevent)
		{
			WindowTheme theme = GetCurrentWindowTheme();

			if ( theme == null )
			{
				base.OnPaintBackground( pevent );
				OnPaintUnthemedBackground(pevent);
			}
			else
			{
				OnPaintThemedBackground( pevent );
			}
		}

		/// <summary>
		/// Derived classes should override this method if they need to do custom
		/// rendering on the background when the app isn't themed.
		/// The base class implementation does nothing
		/// </summary>
		/// <param name="pevent">Paint event arguments</param>
		protected virtual void OnPaintUnthemedBackground( PaintEventArgs pevent )
		{
			// base class implementation is a no-op
		}

		/// <summary>
		/// Derived classes should override this method if the need to do
		/// custom background rendering when the app is themed.
		/// The base class implementation just does a nomral background paint
		/// </summary>
		/// <param name="pevent">Paint event arguments</param>
		protected virtual void OnPaintThemedBackground( PaintEventArgs pevent )
		{
			//base class implementation just does a normal background paint
			base.OnPaintBackground (pevent);
		}

		/// <summary>
		/// Draw the specified theme part
		/// </summary>
		/// <param name="graphics">Graphics object used for painting</param>
		/// <param name="bounds">Rectangle to pain into</param>
		/// <param name="partName">The name of the part to paint</param>
		/// <returns>The ThemePart object that is painted</returns>
		protected ThemePart DrawPart( Graphics graphics, Rectangle bounds, string partName )
		{
			WindowTheme theme = GetCurrentWindowTheme();

			ThemePart part = theme.Parts[partName];
			part.DrawBackground( graphics, bounds );

			return part;
		}
		/// <summary>
		/// Draw the specified theme part
		/// </summary>
		/// <param name="graphics">Graphics object used for painting</param>
		/// <param name="bounds">Rectangle to pain into</param>
		/// <param name="partName">The name of the part to paint</param>
		/// <param name="stateName">The name of the part's state to paint</param>
		/// <returns>The ThemePartState object used to paint</returns>
		protected ThemePartState DrawPart( Graphics graphics, Rectangle bounds, string partName, string stateName )
		{
			WindowTheme theme = GetCurrentWindowTheme();

			ThemePart part = theme.Parts[partName];
			ThemePartState state = part.States[stateName];
			state.DrawBackground( graphics, bounds );

			return state;
		}

		/// <summary>
		/// Draws the specified part onto the control
		/// </summary>
		/// <param name="graphics">Graphics object used for painting</param>
		/// <param name="control">The control who's bounds will be used to paint</param>
		/// <param name="partName">The name of the part to paint</param>
		/// <returns>The ThemePart object that is painted</returns>
		protected ThemePart DrawPart( Graphics graphics, Control control, string partName )
		{
			return DrawPart( graphics, new Rectangle( 0, 0, control.Width, control.Height ), partName );
		}

		/// <summary>
		/// Draws the specified part and state onto the control
		/// </summary>
		/// <param name="graphics">Graphics object used for painting</param>
		/// <param name="control">The control who's bounds will be used to paint</param>
		/// <param name="partName">The name of the part to paint</param>
		/// <param name="stateName">The name of the part's state to paint</param>
		/// <returns>The ThemePartState object used to paint</returns>
		protected ThemePartState DrawPart( Graphics graphics, Control control, string partName, string stateName )
		{
			return DrawPart( graphics, new Rectangle( 0, 0, control.Width, control.Height ), partName, stateName );
		}
	}

}