Dual Pane File Manager

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using Win32API;

namespace JGFSControls
{
	/// <summary>
	/// Shows the Explorer Context Menu
	/// </summary>
	public class JContextMenu
	{
		public const int MAX_SHELL_ID = 0x7FFF;
		public const int MIN_SHELL_ID = 1;

		private JContextMenu()
		{
			//
			// No instances, all static
			//
		}

		/// <summary>
		/// Takes an ArrayList of IntPtr and returns an IntPtr[]
		/// </summary>
		/// <param name="alPIDLS">ArrayList of PIDLs</param>
		/// <returns>IntPtr[]</returns>
		private static IntPtr[] ArrayListToIPArray(System.Collections.ArrayList alPIDLS)
		{
			int count = 0;
			IntPtr[] resultArray = null;

			if (alPIDLS != null && alPIDLS.Count > 0)
			{
				resultArray = new IntPtr[alPIDLS.Count];
				count = 0;
				foreach (IntPtr current in alPIDLS)
				{
					resultArray[count] = (IntPtr)alPIDLS[count];
					count++;
				}
			}
			return resultArray;
		}

		/// <summary>
		/// Creates an IntPtr[] from a List of file/folder paths
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// <param name="listPaths">List of file/folder paths</param>
		/// <param name="ParentFolder">IShellFolder to be returned</param>
		/// <returns>An IntPtr[] of ItemIDLists for strFiles</returns>
		private static IntPtr[] CreatePIDLList(IntPtr hwnd, List<string> listPaths, ref IShellFolder parentSF)
		{
			System.Collections.ArrayList alPIDLS = new System.Collections.ArrayList();

			IntPtr ipChild = new IntPtr();

			foreach (string current in listPaths)
			{
				ipChild = GetChildIDList(hwnd, current, ref parentSF);
				alPIDLS.Add(ipChild);
			}
			return ArrayListToIPArray(alPIDLS);
		}

		/// <summary>
		/// Gets an IntPtr to an ItemIDList for a file/folder and sets ParentFolder
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// <param name="objectPath">File/Folder path</param>
		/// <param name="parentShellFolder">IShellFolder to be set</param>
		/// <returns>An IntPtr to the objectPath ItemIDList</returns>
		public static IntPtr GetChildIDList(IntPtr hwnd, string objectPath, ref IShellFolder parentShellFolder)
		{
			string parentName = "", childName = "";

			//	Don't use Path.GetDirectoryName(objectPath) as the objectPath could be anything
			SplitObjectPath(objectPath, out parentName, out childName);

			uint pchEaten = 0, dwAttributes = 0;

			IntPtr ipParent, ipChild;

			IntPtr[] ipArray = new IntPtr[0];

			IShellFolder desktopSF = null;

			Guid IID_IShellFolder = new Guid(JInterfaces.IShellFolder);

			SHGetDesktopFolder(ref desktopSF);

			//	ParseDisplayName - parent
			//	Translates a file object's or folder's display name into an item identifier list
			pchEaten = 1;
			dwAttributes = 0;
			ipParent = new IntPtr();
			desktopSF.ParseDisplayName(hwnd, IntPtr.Zero, parentName, ref pchEaten, ref ipParent, ref dwAttributes);

			//	BindToObject
			//	Retrieves an IShellFolder object for a subfolder	
			parentShellFolder = null;
			desktopSF.BindToObject(ipParent, IntPtr.Zero, ref IID_IShellFolder, ref parentShellFolder);

			//	ParseDisplayName - child
			//	Translates a file object's or folder's display name into an item identifier list
			pchEaten = 1;
			dwAttributes = 0;
			ipChild = new IntPtr();
			parentShellFolder.ParseDisplayName(hwnd, IntPtr.Zero, childName, ref pchEaten, ref ipChild, ref dwAttributes);

			//	Release the desktopSF
			Marshal.ReleaseComObject(desktopSF);

			return ipChild;
		}

		private static int MAKEINTRESOURCE(int res)
		{
			return 0x0000FFFF & res;
		}

		/// <summary>
		/// Shows Explorer Context Menu for an object whose PIDL is known
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// <param name="ipPIDL">IntPtr to the object's ItemIDList</param>
		/// <param name="pt">Position where context menu should be shown</param>
		/// <param name="icm3">IContextMenu3 to be set for owner draw items on context menu</param>
		/// <returns>true</returns>
		public static bool ShowContextMenu(IntPtr hwnd, IntPtr ipPIDL, Point pt, ref IContextMenu3 icm3)
		{
			uint rgfReserved = 0;

			IntPtr ipParent = new IntPtr();
			IntPtr[] ipPIDLArray = new IntPtr[1];

			IShellFolder desktopSF = null;
			IShellFolder parentSF = null;

			IUnknown iu;

			Guid IID_IShellFolder = new Guid(JInterfaces.IShellFolder);
			Guid IID_IContextMenu = new Guid(JInterfaces.IContextMenu);

			SHGetDesktopFolder(ref desktopSF);

			//	BindToObject
			//	Retrieves an IShellFolder object for a subfolder
			//	If ipPIDL is the DeskTop then parentSF will be null
			parentSF = null;
			desktopSF.BindToObject(ipParent, IntPtr.Zero, ref IID_IShellFolder, ref parentSF);

			ipPIDLArray[0] = ipPIDL;
			iu = null;
			object obTemp = new object();
			if (parentSF != null)
				parentSF.GetUIObjectOf(hwnd, 1, ipPIDLArray, ref IID_IContextMenu, ref rgfReserved, ref obTemp);
			else
				desktopSF.GetUIObjectOf(hwnd, 1, ipPIDLArray, ref IID_IContextMenu, ref rgfReserved, ref obTemp);

			iu = (IUnknown)obTemp;
			Marshal.ReleaseComObject(desktopSF);

			return ShowMenu(hwnd, pt, iu, ref icm3);
		}

		/// <summary>
		/// Shows Context Menu for one file/folder
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// <param name="filePath">Full path of object for which context menu is to be displayed</param>
		/// <param name="pt">Position where context menu should be shown</param>
		/// <param name="icm3">IContextMenu3 to be set for owner draw items on context menu</param>
		/// <returns>true</returns>
		public static bool ShowContextMenu(IntPtr hwnd, string filePath, Point pt, ref IContextMenu3 icm3)
		{
			uint rgfReserved = 0;

			IntPtr ipChild = new IntPtr();

			IShellFolder parentSF = null;

			IUnknown iu;

			Guid IID_IContextMenu = new Guid(JInterfaces.IContextMenu);

			ipChild = GetChildIDList(hwnd, filePath, ref parentSF);
			IntPtr[] ipChildArray = new IntPtr[1];
			ipChildArray[0] = ipChild;

			iu = null;
			object obTemp = new object();
			parentSF.GetUIObjectOf(hwnd, 1, ipChildArray, ref IID_IContextMenu, ref rgfReserved, ref obTemp);
			iu = (IUnknown)obTemp;

			Marshal.ReleaseComObject(parentSF);

			return ShowMenu(hwnd, pt, iu, ref icm3);
		}


		/// <summary>
		/// Shows Context Menu for String Array of files/folders
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// <param name="filePath">List of full paths of objects for which context menu is to be displayed</param>
		/// <param name="pt">Position where context menu should be shown</param>
		/// <param name="icm3">IContextMenu3 to be set for owner draw items on context menu</param>
		/// <returns>true</returns>
		public static bool ShowContextMenu(IntPtr hwnd, List<string> fileArray, Point pt, ref IContextMenu3 icm3)
		{
			if (fileArray == null || fileArray.Count < 1)
				return false;

			uint rgfReserved = 0;

			IShellFolder parentFolder = null;

			IUnknown iu = null;

			Guid IID_IContextMenu = new Guid(JInterfaces.IContextMenu);

			IntPtr[] ipList = CreatePIDLList(hwnd, fileArray, ref parentFolder);

			if (ipList.GetUpperBound(0) < 0)
				return false;

			object obTemp = new object();
			parentFolder.GetUIObjectOf(hwnd, (uint)ipList.GetUpperBound(0) + 1, ipList, ref IID_IContextMenu, ref rgfReserved, ref obTemp);
			iu = (IUnknown)obTemp;

			Marshal.ReleaseComObject(parentFolder);

			return ShowMenu(hwnd, pt, iu, ref icm3);
		}

		/// <summary>
		/// Shows the context menu after all the background work is complete
		/// </summary>
		/// <param name="hwnd">Parent window handle</param>
		/// /// <param name="pt">Position where context menu should be shown</param>
		/// <param name="iu">IUnknown created during background work</param>
		/// <param name="icm3">IContextMenu3 to be set for owner draw items on context menu</param>
		/// <returns>true</returns>
		public static bool ShowMenu(IntPtr hwnd, Point pt, IUnknown iu, ref IContextMenu3 icm3)
		{
			//	Casting to an IcontextMenu2 does this: pContextMenu->QueryInterface(IID_IContextMenu2, (VOID**)&pContextMenu2);
			//	Advice provided by Mattias Sj�gren [MVP] http://www.msjogren.net/dotnet/
			//	We need this to deal with 'Send To' and 'Open With' which have owner draw sub menus

			CMINVOKECOMMANDINFO cmInvoke = new CMINVOKECOMMANDINFO();
			icm3 = (IContextMenu3)iu;
			RECT mRect;
			//string menuText = new string('\0', 255);
			//int result;

			if (icm3 != null)
			{
				IntPtr hMenu = CreatePopupMenu();
				icm3.QueryContextMenu(hMenu, 0, MIN_SHELL_ID, MAX_SHELL_ID, (ushort)(CMF.CMF_EXPLORE | CMF.CMF_CANRENAME));

				int cmdID = TrackPopupMenu(hMenu, ((int)TPM.TPM_RETURNCMD | (int)TPM.TPM_LEFTALIGN), pt.X, pt.Y, 0, hwnd, out mRect);

				if (cmdID != 0)
				{
					//	This will identify the command selected
					//itemInfo.fMask = (uint)MIIM.MIIM_STRING;
					//itemInfo.fType = (uint)MFT.MFT_STRING;
					//itemInfo.dwTypeData = menuText;
					//itemInfo.cch = 255;
					//itemInfo.cbSize = (uint)Marshal.SizeOf(itemInfo);
					//result = JDll.GetMenuItemInfoA(hMenu, (uint)(cmdID - 0), false, ref itemInfo);

					cmInvoke.cbSize = (uint)Marshal.SizeOf(cmInvoke);
					cmInvoke.hwnd = hwnd;
					cmInvoke.lpVerb = MAKEINTRESOURCE(cmdID - 1);
					cmInvoke.lpParameters = "";
					cmInvoke.lpDirectory = "";
					cmInvoke.nShow = (int)SW.SW_SHOWNORMAL;
					icm3.InvokeCommand(ref cmInvoke);
				}
			}
			return true;
		}

		/// <summary>
		/// Splits a file/folder fully qualified path into its parent directory and the object name
		/// </summary>
		/// <param name="strFQPath">Fully qualified path of object</param>
		/// <param name="strParent">Parent folder</param>
		/// <param name="strChild">Object name</param>
		/// <returns>true on success, false otherwise</returns>
		public static bool SplitObjectPath(string pathIN, out string parentPart, out string childPart)
		{
			parentPart = "";
			childPart = "";

			try
			{
				FileInfo fInfo = new FileInfo(pathIN);

				if (fInfo.Exists)
				{
					childPart = fInfo.Name;
					parentPart = fInfo.DirectoryName;
				}
				else
				{
					DirectoryInfo dInfo = new DirectoryInfo(pathIN);
					if (dInfo.Exists)
					{
						try
						{
							childPart = dInfo.Name;
							parentPart = dInfo.Parent.FullName;
						}
						catch
						{
							parentPart = "";
						}
					}
					else
					{
						parentPart = "";
						childPart = pathIN;
					}
				}
			}
			catch
			{
				return false;
			}
			return true;
		}


		//	CreatePopupMenu
		[DllImport("user32.dll", EntryPoint = "CreatePopupMenu", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
		public static extern IntPtr CreatePopupMenu();

		//	TrackPopupMenu
		[DllImport("user32.dll", EntryPoint = "TrackPopupMenu", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
		public static extern int TrackPopupMenu(IntPtr hMenu, int wFlags, int x, int y, int nReserved, IntPtr hwnd, out RECT lprc);

		//	SHGetDesktopFolder
		[DllImport("shell32.dll", EntryPoint = "SHGetDesktopFolder", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
		public static extern void SHGetDesktopFolder(ref IShellFolder sf);


	}

}