Another Flexible ListView Control

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Windows.Forms.VisualStyles;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.IO;

namespace Guide.Controls
{
	/// <summary>
	/// An enhanced ListBox which correctly handles and provides better control over horizontal scrolling.
	/// </summary>
	public class ProperListBox : ListBox
	{
		private int horzScrollBarValue = 0;

		public ProperListBox()
		{
			this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.ResizeRedraw, true);
			// this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint | ControlStyles.ResizeRedraw, true);
		}

		protected override void OnPaint(PaintEventArgs e)
		{
			Region iRegion = new Region(e.ClipRectangle);
			e.Graphics.FillRegion(new SolidBrush(this.BackColor), iRegion);

			for (int i = 0; i < this.Items.Count; ++i)
			{
				System.Drawing.Rectangle irect = this.GetItemRectangle(i);
				if (e.ClipRectangle.IntersectsWith(irect))
				{
					if ((this.SelectionMode == SelectionMode.One && this.SelectedIndex == i)
					|| (this.SelectionMode == SelectionMode.MultiSimple && this.SelectedIndices.Contains(i))
					|| (this.SelectionMode == SelectionMode.MultiExtended && this.SelectedIndices.Contains(i)))
					{
						OnDrawItem(new DrawItemEventArgs(e.Graphics, this.Font,
							irect, i,
							DrawItemState.Selected, this.ForeColor,
							this.BackColor));
					}
					else
					{
						OnDrawItem(new DrawItemEventArgs(e.Graphics, this.Font,
							irect, i,
							DrawItemState.Default, this.ForeColor,
							this.BackColor));
					}

					iRegion.Complement(irect);
				}
			}

			base.OnPaint(e);
		}

		protected override void WndProc(ref Message m)
		{
			base.WndProc(ref m);

			if (this.HorizontalScrollbar && m.Msg == PInvokeHelp.WM_HSCROLL || m.Msg == PInvokeHelp.WM_MOUSEWHEEL)
			{
				//					Debug.WriteLine("WParam = " + m.WParam.ToInt32().ToString() + " LParam = " + m.LParam.ToInt32().ToString());

				// Update Scroll position
				PInvokeHelp.SCROLLINFO si = new PInvokeHelp.SCROLLINFO();
				si.cbSize = Marshal.SizeOf(si);
				si.fMask = PInvokeHelp.SIF_ALL;

				if (PInvokeHelp.GetScrollInfo(m.HWnd, PInvokeHelp.SB_HORZ, ref si))
					horzScrollBarValue = si.nPos;

				//					Debug.WriteLine("Position = " + si.nPos.ToString() + "; " + si.nTrackPos.ToString());

				// Callback
				if (this.HorizontalScrolled != null)
					this.HorizontalScrolled(this, EventArgs.Empty);
			}
		}

		public new bool HorizontalScrollbar
		{
			get
			{
				return base.HorizontalScrollbar;
			}
			set
			{
				base.HorizontalScrollbar = value;
				if (!base.HorizontalScrollbar)
				{
					base.HorizontalExtent = 0;
					this.HScrollPosition = 0;
				}

				ForceUpdateHScroll();
			}
		}

		/// <summary>
		/// Gets or sets the width by which the horizontal scroll bar of a ListBox
		/// </summary>
		/// <returns>
		/// The width, in pixels, that the horizontal scroll bar can scroll the control. The default is zero.
		/// </returns>
		[DefaultValue(0)]
		[Localizable(true)]
		public new int HorizontalExtent
		{
			get
			{
				return base.HorizontalExtent;
			}
			set
			{
				base.HorizontalExtent = value;

				ForceUpdateHScroll();
			}
		}

		/// <summary>
		/// Gets or sets the width by which the horizontal scroll bar of a ListBox can scroll.
		/// </summary>
		/// <returns>
		/// The width, in pixels, that the horizontal scroll bar can scroll the control. The default is zero.
		/// </returns>
		[DefaultValue(0)]
		[Localizable(true)]
		public int HScrollPosition
		{
			get
			{
				return horzScrollBarValue;
			}
			set
			{
				PInvokeHelp.SCROLLINFO si = new PInvokeHelp.SCROLLINFO();
				si.cbSize = Marshal.SizeOf(si);
				si.fMask = PInvokeHelp.SIF_POS;
				si.nPos = value;

				horzScrollBarValue = PInvokeHelp.SetScrollInfo(this.Handle, PInvokeHelp.SB_HORZ, ref si, true);

				ForceUpdateHScroll();
			}
		}

		protected void ForceUpdateHScroll()
		{
			PInvokeHelp.SendMessage(this.Handle, PInvokeHelp.WM_HSCROLL, PInvokeHelp.MakeDWord(PInvokeHelp.SB_THUMBPOSITION, this.HScrollPosition), 0);
		}

		/// <summary>
		/// Occurs when the horizontal scroll bar scrolls.
		/// </summary>
		public event EventHandler HorizontalScrolled;

		class PInvokeHelp
		{
			public const int WM_HSCROLL = 0x0114;
			public const int WM_MOUSEWHEEL = 0x20A;

			public static int HiWord(int value)
			{
				return (int)(value & 0xFFFF0000) >> 16;
			}

			public static int LoWord(int value)
			{
				return (int)(value & 0x0000FFFF);
			}

			public static long MakeDWord(int lo, int hi)
			{
				return (lo | (hi << 16));
			}

			[StructLayout(LayoutKind.Sequential)]
			public struct SCROLLINFO
			{
				public int cbSize;
				public uint fMask;
				public int nMin;
				public int nMax;
				public uint nPage;
				public int nPos;
				public int nTrackPos;
			}

			// ScrollBarDirection
			public const int SB_HORZ = 0;
			public const int SB_VERT = 1;
			public const int SB_CTL = 2;
			public const int SB_BOTH = 3;

			// ScrollInfoMask
			public const int SIF_RANGE = 0x1;
			public const int SIF_PAGE = 0x2;
			public const int SIF_POS = 0x4;
			public const int SIF_DISABLENOSCROLL = 0x8;
			public const int SIF_TRACKPOS = 0x10;
			public const int SIF_ALL = SIF_RANGE + SIF_PAGE + SIF_POS + SIF_TRACKPOS;

			// ScrollBarCommands
			public const int SB_LINEUP = 0;
			public const int SB_LINELEFT = 0;
			public const int SB_LINEDOWN = 1;
			public const int SB_LINERIGHT = 1;
			public const int SB_PAGEUP = 2;
			public const int SB_PAGELEFT = 2;
			public const int SB_PAGEDOWN = 3;
			public const int SB_PAGERIGHT = 3;
			public const int SB_THUMBPOSITION = 4;
			public const int SB_THUMBTRACK = 5;
			public const int SB_TOP = 6;
			public const int SB_LEFT = 6;
			public const int SB_BOTTOM = 7;
			public const int SB_RIGHT = 7;
			public const int SB_ENDSCROLL = 8;

			[DllImport("user32.dll")]
			public static extern int SendMessage(IntPtr hWnd, uint Msg, long wParam, long lParam);

			[DllImport("user32.dll")]
			[return: MarshalAs(UnmanagedType.Bool)]
			public static extern bool GetScrollInfo(IntPtr hwnd, int fnBar, ref SCROLLINFO lpsi);

			[DllImport("user32.dll")]
			public static extern int SetScrollInfo(IntPtr hwnd, int fnBar, [In] ref SCROLLINFO lpsi, bool fRedraw);
		}
	}
}