using System;

using System.Text;

using System.Drawing;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using MsdnMag;			// For LocalCbtHook

using Microsoft.Win32;	// For RegKey



namespace MsgBoxCheck

{

	public class MessageBox

	{

		protected LocalCbtHook m_cbt;

		protected IntPtr m_hwnd = IntPtr.Zero;

		protected IntPtr m_hwndBtn = IntPtr.Zero;

		protected bool m_bInit = false;

		protected bool m_bCheck = false;

		protected string m_strCheck;



		public MessageBox()

		{

			m_cbt = new LocalCbtHook();

			m_cbt.WindowCreated += new LocalCbtHook.CbtEventHandler(WndCreated);

			m_cbt.WindowDestroyed += new LocalCbtHook.CbtEventHandler(WndDestroyed);

			m_cbt.WindowActivated += new LocalCbtHook.CbtEventHandler(WndActivated);

		}



		public DialogResult Show(string strKey, string strValue, DialogResult dr, string strCheck, string strText, string strTitle, MessageBoxButtons buttons, MessageBoxIcon icon)

		{

			RegistryKey regKey = Registry.CurrentUser.CreateSubKey(strKey);

			try

			{

				if(Convert.ToBoolean(regKey.GetValue(strValue,false)))

					return dr;

			}

			catch 

			{

				// No processing needed...the convert might throw an exception,

				// but if so we proceed as if the value was false.

			}



			m_strCheck = strCheck;

			m_cbt.Install();

			dr = System.Windows.Forms.MessageBox.Show(strText, strTitle, buttons, icon);

			m_cbt.Uninstall();



			regKey.SetValue(strValue,m_bCheck);

			return dr;

		}



		public DialogResult Show(string strKey, string strValue, DialogResult dr, string strCheck, string strText, string strTitle, MessageBoxButtons buttons)

		{

			return Show(strKey, strValue, dr, strCheck, strText, strTitle, buttons, MessageBoxIcon.None);

		}

		

		public DialogResult Show(string strKey, string strValue, DialogResult dr, string strCheck, string strText, string strTitle)

		{

			return Show(strKey, strValue, dr, strCheck, strText, strTitle, MessageBoxButtons.OK, MessageBoxIcon.None);

		}

		

		public DialogResult Show(string strKey, string strValue, DialogResult dr, string strCheck, string strText)

		{

			return Show(strKey, strValue, dr, strCheck, strText, "", MessageBoxButtons.OK, MessageBoxIcon.None);

		}



		private void WndCreated(object sender, CbtEventArgs e)

		{

			if (e.IsDialogWindow)

			{

				m_bInit = false;

				m_hwnd = e.Handle;

			}

		}

	

		private void WndDestroyed(object sender, CbtEventArgs e)

		{

			if (e.Handle == m_hwnd)

			{

				m_bInit = false;

				m_hwnd = IntPtr.Zero;

				if(BST_CHECKED == (int)SendMessage(m_hwndBtn,BM_GETCHECK,IntPtr.Zero,IntPtr.Zero))

					m_bCheck = true;

			}

		}



		private void WndActivated(object sender, CbtEventArgs e)

		{

			if (m_hwnd != e.Handle)

				return;



			// Not the first time

			if (m_bInit)

				return;

			else

				m_bInit = true;



			// Get the current font, either from the static text window

			// or the message box itself

			IntPtr hFont;

			IntPtr hwndText = GetDlgItem(m_hwnd, 0xFFFF);

			if(hwndText != IntPtr.Zero)

				hFont = SendMessage(hwndText, WM_GETFONT, IntPtr.Zero, IntPtr.Zero);			

			else

				hFont = SendMessage(m_hwnd, WM_GETFONT, IntPtr.Zero, IntPtr.Zero);			

			Font fCur = Font.FromHfont(hFont);

	

			// Get the x coordinate for the check box.  Align it with the icon if possible,

			// or one character height in

			int x = 0;

			IntPtr hwndIcon = GetDlgItem(m_hwnd, 0x0014);

			if(hwndIcon != IntPtr.Zero)

			{

				RECT rcIcon = new RECT();

				GetWindowRect(hwndIcon, rcIcon);

				POINT pt = new POINT();

				pt.x = rcIcon.left;

				pt.y = rcIcon.top;

				ScreenToClient(m_hwnd, pt);

				x = pt.x;

			}

			else

				x = (int)fCur.GetHeight();



			// Get the y coordinate for the check box, which is the bottom of the

			// current message box client area

			RECT rc = new RECT();

			GetClientRect(m_hwnd, rc);

			int y = rc.bottom - rc.top;



			// Resize the message box with room for the check box

			GetWindowRect(m_hwnd, rc);

			MoveWindow(m_hwnd,rc.left,rc.top,rc.right-rc.left,rc.bottom-rc.top + (int)fCur.GetHeight()*2,true);



			m_hwndBtn = CreateWindowEx(0, "button", m_strCheck, BS_AUTOCHECKBOX|WS_CHILD|WS_VISIBLE|WS_TABSTOP, 

				x, y , rc.right-rc.left-x, (int)fCur.GetHeight(),

				m_hwnd, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);



			SendMessage(m_hwndBtn, WM_SETFONT, hFont, new IntPtr(1));			

		}



		#region Win32 Imports

		private const int WS_VISIBLE		= 0x10000000;

		private const int WS_CHILD			= 0x40000000;

		private const int WS_TABSTOP        = 0x00010000;

		private const int WM_SETFONT		= 0x00000030;

		private const int WM_GETFONT		= 0x00000031;

		private const int BS_AUTOCHECKBOX	= 0x00000003; 

		private const int BM_GETCHECK       = 0x00F0;

		private const int BST_CHECKED       = 0x0001;



		[DllImport("user32.dll")]

		protected static extern void DestroyWindow(IntPtr hwnd);

	

		[DllImport("user32.dll")]

		protected static extern IntPtr GetDlgItem(IntPtr hwnd, int id);

		

		[DllImport("user32.dll")]

		protected static extern int GetWindowRect(IntPtr hwnd, RECT rc);

		

		[DllImport("user32.dll")]

		protected static extern int GetClientRect(IntPtr hwnd, RECT rc);

		

		[DllImport("user32.dll")]

		protected static extern void MoveWindow(IntPtr hwnd, int x, int y, int nWidth, int nHeight, bool bRepaint);

		

		[DllImport("user32.dll")]

		protected static extern int ScreenToClient(IntPtr hwnd, POINT pt);

		

		[DllImport("user32.dll", EntryPoint="MessageBox")]

		protected static extern int _MessageBox(IntPtr hwnd, string text, string caption,

			int options);

	

		[DllImport("user32.dll")]

		protected static extern IntPtr SendMessage(IntPtr hwnd, 

			int msg, IntPtr wParam, IntPtr lParam);



		[DllImport("user32.dll")]

		protected static extern IntPtr CreateWindowEx(

			int dwExStyle,			// extended window style

			string lpClassName,		// registered class name

			string lpWindowName,	// window name

			int dwStyle,			// window style

			int x,					// horizontal position of window

			int y,					// vertical position of window

			int nWidth,				// window width

			int nHeight,			// window height

			IntPtr hWndParent,      // handle to parent or owner window

			IntPtr hMenu,			// menu handle or child identifier

			IntPtr hInstance,		// handle to application instance

			IntPtr lpParam			// window-creation data

			);

	

		[StructLayout(LayoutKind.Sequential)]

		public class POINT

		{ 

			public int x;

			public int y;

		}



		[StructLayout(LayoutKind.Sequential)]

		public class RECT

		{ 

			public int left; 

			public int top; 

			public int right; 

			public int bottom; 

		}



		#endregion

	}

}