XPTable - .NET ListView meets Java's JTable

/*
 * Copyright � 2005, Mathew Hall
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 *    - Redistributions of source code must retain the above copyright notice, 
 *      this list of conditions and the following disclaimer.
 * 
 *    - Redistributions in binary form must reproduce the above copyright notice, 
 *      this list of conditions and the following disclaimer in the documentation 
 *      and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 */


using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

using XPTable.Events;
using XPTable.Models;
using XPTable.Renderers;


namespace XPTableDemo.MediaPlayerStyle
{
	/// <summary>
	/// A CellRenderer that draws Cell contents as rating stars
	/// </summary>
	public class RatingCellRenderer : CellRenderer
	{
		#region Constructor
		
		/// <summary>
		/// Initializes a new instance of the RatingCellRenderer class with 
		/// default settings
		/// </summary>
		public RatingCellRenderer() : base()
		{
			
		}

		#endregion


		#region Methods

		/// <summary>
		/// Gets the Rectangle that specifies the Size and Location of 
		/// the Image contained in the current Cell
		/// </summary>
		/// <param name="image">The Image to be drawn</param>
		/// <param name="rowAlignment">The alignment of the current Cell's row</param>
		/// <returns>A Rectangle that specifies the Size and Location of 
		/// the Image contained in the current Cell</returns>
		protected Rectangle CalcImageRect(Image image, RowAlignment rowAlignment)
		{
			Rectangle imageRect = this.ClientRectangle;

			if (image.Width < imageRect.Width)
			{
				imageRect.Width = image.Width;
			}

			if (image.Height < imageRect.Height)
			{
				imageRect.Height = image.Height;
			}
			

			if (rowAlignment == RowAlignment.Center)
			{
				imageRect.Y += (this.ClientRectangle.Height - imageRect.Height) / 2;
			}
			else if (rowAlignment == RowAlignment.Bottom)
			{
				imageRect.Y = this.ClientRectangle.Bottom - imageRect.Height;
			}

			return imageRect;
		}

		#endregion
		

		#region Events

		#region Paint
		
		/// <summary>
		/// Raises the PaintCell event
		/// </summary>
		/// <param name="e">A PaintCellEventArgs that contains the event data</param>
		public override void OnPaintCell(PaintCellEventArgs e)
		{
			base.OnPaintCell(e);
		}


		/// <summary>
		/// Raises the Paint event
		/// </summary>
		/// <param name="e">A PaintCellEventArgs that contains the event data</param>
		protected override void OnPaint(PaintCellEventArgs e)
		{
			base.OnPaint(e);
			
			// don't bother if the Cell is null or doesn't have an image
			if (e.Cell == null || e.Cell.Text == null || e.Cell.Image == null)
			{
				return;
			}

			int stars = Convert.ToInt32(e.Cell.Text);

			// work out the size and location of the image
			Rectangle imageRect = this.CalcImageRect(e.Cell.Image, this.LineAlignment);

			float alpha;
			
			for (int i=1; i<=5; i++)
			{
				alpha = (i <= stars) ? 1f : 0.4f;
				
				this.DrawImage(e.Graphics, e.Cell.Image, imageRect, alpha);

				imageRect.X += imageRect.Width;
			}
			
			if (e.Focused)
			{
				ControlPaint.DrawFocusRectangle(e.Graphics, this.ClientRectangle);
			}
		}


		/// <summary>
		/// Draws the Image contained in the Cell
		/// </summary>
		/// <param name="g">The Graphics used to paint the Image</param>
		/// <param name="image">The Image to be drawn</param>
		/// <param name="imageRect">A rectangle that specifies the Size and 
		/// Location of the Image</param>
		/// <param name="alpha">Specifies the opacity of the image</param>
		protected void DrawImage(Graphics g, Image image, Rectangle imageRect, float alpha)
		{
			if (alpha == 1f)
			{
				g.DrawImage(image, imageRect);
			}
			else
			{
				float[][] ptsArray = {new float[] {1, 0, 0, 0, 0},
										 new float[] {0, 1, 0, 0, 0},
										 new float[] {0, 0, 1, 0, 0},
										 new float[] {0, 0, 0, alpha, 0}, 
										 new float[] {0, 0, 0, 0, 1}}; 

				ColorMatrix colorMatrix = new ColorMatrix(ptsArray);
				ImageAttributes imageAttributes = new ImageAttributes();
				imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

				g.DrawImage(image, imageRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, imageAttributes);
			}
		}

		#endregion

		#endregion
	}
}