/*=============================================================================

  Project:   SharpImage
  Module:    siRepaintablePanel.cs
  Language:  C#
  Author:    Dan Mueller
  Date:      $Date: 2007-07-06 10:57:00 +1000 (Fri, 06 Jul 2007) $
  Revision:  $Revision: 2 $

  Copyright (c) Queensland University of Technology (QUT) 2007.
  All rights reserved.

  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.  See the above copyright notices for more information.
  
=============================================================================*/

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

namespace SharpImage.Rendering
{
    class siRepaintablePanel : Panel
    {
        /// <summary>
        /// Default constructor.
        /// </summary>
        public siRepaintablePanel() : base()
        {

        }

        /// <summary>
        /// Force the panel to paint to an offscreen bitmap before drawing this bitmap to the actual control.
        /// </summary>
        public void Repaint()
        {
            // Create a bitmap to allow double buffer rendering
            Bitmap imgOffscreen = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height, PixelFormat.Format32bppArgb);
            Graphics gOffscreen = Graphics.FromImage(imgOffscreen);
            gOffscreen.Clear(this.BackColor);

            // Fire the Paint event using the offscreen bitmap
            this.OnPaint(new PaintEventArgs(gOffscreen, this.ClientRectangle));

            // All the panel event handlers have had their chance to paint to the
            // offscreen bitmap, now draw the bitmap to the control
            Graphics gPanel = this.CreateGraphics();
            gPanel.DrawImage(imgOffscreen, 0, 0);
        }
    }
}