.NET Regular Expressions Find and Replace Add-In for Visual Studio 2008

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.ComponentModel;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
using System.IO;

namespace RegexFindAndReplace
{
    public class CollapsibleGroupBox : GroupBox
    {
        #region Fields

        private Rectangle m_toggleRect = new Rectangle( 8, 2, 11, 11 );
        private Boolean m_collapsed = false;
        private Boolean m_bResizingFromCollapse = false;

        private const int m_collapsedHeight = 20;
        private Size m_FullSize = Size.Empty;

        private System.ComponentModel.IContainer components = null;
        private Bitmap plusBitmap;
        private Bitmap minusBitmap;

        #endregion

        #region Events & Delegates

        /// <summary>Fired when the Collapse Toggle button is pressed</summary>
        public delegate void CollapseBoxClickedEventHandler( object sender );
        public event CollapseBoxClickedEventHandler CollapseBoxClickedEvent;

        #endregion

        #region Constructor

        public CollapsibleGroupBox()
        {
            InitializeComponent();
        }

        #endregion

        #region Public Properties

        [Browsable( false ), DesignerSerializationVisibility( DesignerSerializationVisibility.Hidden )]
        public int FullHeight
        {
            get
            {
                return m_FullSize.Height;
            }
        }

        [DefaultValue( false ), Browsable( false ), DesignerSerializationVisibility( DesignerSerializationVisibility.Hidden )]
        public bool IsCollapsed
        {
            get
            {
                return m_collapsed;
            }
            set
            {
                if ( value != m_collapsed )
                {
                    m_collapsed = value;

                    if ( !value )
                    {
                        // Expand
                        this.Size = m_FullSize;
                    }
                    else
                    {
                        // Collapse
                        m_bResizingFromCollapse = true;
                        this.Height = m_collapsedHeight;
                        m_bResizingFromCollapse = false;
                    }

                    foreach ( Control c in Controls )
                    {
                        c.Visible = !value;
                    }

                    Invalidate();
                }
            }
        }

        [Browsable( false ), DesignerSerializationVisibility( DesignerSerializationVisibility.Hidden )]
        public int CollapsedHeight
        {
            get
            {
                return m_collapsedHeight;
            }
        }

        #endregion

        #region Overrides

        protected override void OnMouseUp( MouseEventArgs e )
        {
            if ( m_toggleRect.Contains( e.Location ) )
            {
                ToggleCollapsed();
            }
            else
            {
                base.OnMouseUp( e );
            }
        }

        protected override void OnPaint( PaintEventArgs e )
        {
            HandleResize();
            DrawGroupBox( e.Graphics );
            DrawToggleButton( e.Graphics );
        }

        #endregion

        #region Implimentation

        void DrawGroupBox( Graphics g )
        {
            // Get windows to draw the GroupBox
            Rectangle bounds = new Rectangle( ClientRectangle.X, ClientRectangle.Y + 6, ClientRectangle.Width, ClientRectangle.Height - 6 );
            GroupBoxRenderer.DrawGroupBox( g, bounds, Enabled ? GroupBoxState.Normal : GroupBoxState.Disabled );

            // Text Formating positioning & Size
            StringFormat sf = new StringFormat();
            int i_textPos = ( bounds.X + 8 ) + m_toggleRect.Width + 2;
            int i_textSize = (int)g.MeasureString( Text, this.Font ).Width;
            i_textSize = i_textSize < 1 ? 1 : i_textSize;
            int i_endPos = i_textPos + i_textSize + 1;

            // Draw a line to cover the GroupBox border where the text will sit
            g.DrawLine( SystemPens.Control, i_textPos, bounds.Y, i_endPos, bounds.Y );

            // Draw the GroupBox text
            using ( SolidBrush drawBrush = new SolidBrush( SystemColors.ActiveCaption ) )
            {
                g.DrawString( Text, this.Font, drawBrush, i_textPos, 0 );
            }
        }

        void DrawToggleButton( Graphics g )
        {
            if ( IsCollapsed )
                g.DrawImage( plusBitmap, m_toggleRect );
            else
                g.DrawImage( minusBitmap, m_toggleRect );
        }

        void ToggleCollapsed()
        {
            IsCollapsed = !IsCollapsed;

            if ( CollapseBoxClickedEvent != null )
                CollapseBoxClickedEvent( this );
        }

        void HandleResize()
        {
            if ( !m_bResizingFromCollapse && !m_collapsed )
                m_FullSize = this.Size;
        }

        #endregion

        /// <summary> 
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose( bool disposing )
        {
            if ( disposing && ( components != null ) )
            {
                components.Dispose();
            }
            base.Dispose( disposing );
        }

        #region Component Designer generated code

        /// <summary> 
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager( typeof( CollapsibleGroupBox ) );
            this.SuspendLayout();
            // 
            // CollapsibleGroupBox
            // 
            this.Name = "CollapsibleGroupBox";
            this.ResumeLayout( false );

            Stream plusBitmapStream = null;
            Stream minusBitmapStream = null;

            plusBitmapStream = this.GetType().Assembly.GetManifestResourceStream( "RegexFindAndReplace.plus.bmp" );
            minusBitmapStream = this.GetType().Assembly.GetManifestResourceStream( "RegexFindAndReplace.minus.bmp" );

            plusBitmap = new Bitmap( plusBitmapStream );
            plusBitmap.MakeTransparent( Color.White );

            minusBitmap = new Bitmap( minusBitmapStream );
            minusBitmap.MakeTransparent( Color.White );
        }

        #endregion
    }
}