Dual Pane File Manager

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

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

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

		/// <summary>
		/// Takes an ArrayList of IntPtr and returns an array of IntPtr
		/// </summary>
		/// <param name="alPIDLS">ArrayList of PIDLs</param>
		/// <returns>IntPtr[]</returns>
		private static IntPtr[] ArrayListToIPArray(ArrayList alPIDLS)
		{
			int intPos = 0;
			IntPtr[] ipReturn = null;

			if (alPIDLS.Count > 0)
			{
				ipReturn = new IntPtr[alPIDLS.Count];
				IEnumerator ie = alPIDLS.GetEnumerator();
				while (ie.MoveNext())
					ipReturn[intPos++] = (IntPtr)ie.Current;
			}
			return ipReturn;
		}

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

			int intCount;

			IntPtr ipChild = new IntPtr();
			IntPtr[] ipList = new IntPtr[0];

			string strParent = "";
			string strChild = "";

			for (intCount = 0; intCount <= strFiles.GetUpperBound(0); intCount++)
			{
				cCommon.SplitObjectPath(strFiles[intCount], out strParent, out strChild);
				ipChild = cCommon.GetChildIDList(hwnd, strParent, strChild, ref ParentFolder);
				alPIDLS.Add(ipChild);
			}
			return ArrayListToIPArray(alPIDLS);
		}


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

		/// <summary>
		/// Shows Explorer Context Menu for an object who's 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();

			IShellFolder DesktopFolder = null;
			IShellFolder ParentFolder = null;

			IUnknown iu;

			REFIID IID_IShellFolder = new REFIID("000214E6-0000-0000-c000-000000000046");
			REFIID IID_IContextMenu = new REFIID("000214E4-0000-0000-c000-000000000046");

			cCommon.SHGetDesktopFolder(ref DesktopFolder);

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

			iu = null;
			if (ParentFolder != null)
				ParentFolder.GetUIObjectOf(hwnd, 1, ref ipPIDL, ref IID_IContextMenu, out rgfReserved, ref iu);
			else
				DesktopFolder.GetUIObjectOf(hwnd, 1, ref ipPIDL, ref IID_IContextMenu, out rgfReserved, ref iu);

			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="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, string strFQFileName, Point pt, ref IContextMenu3 icm3)
		{
			uint rgfReserved = 0;

			IntPtr ipChild = new IntPtr();

			IShellFolder ParentFolder = null;

			IUnknown iu;

			REFIID IID_IContextMenu = new REFIID("000214E4-0000-0000-c000-000000000046");

			string strParent = "";
			string strChild = "";

			bool blnOK = cCommon.SplitObjectPath(strFQFileName, out strParent, out strChild);
			if (!blnOK)
				return false;

			ipChild = cCommon.GetChildIDList(hwnd, strParent, strChild, ref ParentFolder);

			iu = null;
			ParentFolder.GetUIObjectOf(hwnd, 1, ref ipChild, ref IID_IContextMenu, out rgfReserved, ref iu);

			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="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, string[] strFiles, Point pt, ref IContextMenu3 icm3)
		{
			if (strFiles.GetUpperBound(0) < 0)
				return false;

			uint rgfReserved = 0;

			IShellFolder ParentFolder = null;

			IUnknown iu = null;

			REFIID IID_IContextMenu = new REFIID("000214E4-0000-0000-c000-000000000046");

			IntPtr[] ipList = CreatePIDLList(hwnd, strFiles, ref ParentFolder);

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

			ParentFolder.GetUIObjectOf(hwnd, (uint)ipList.GetUpperBound(0) + 1, ref ipList[0], ref IID_IContextMenu, out rgfReserved, ref iu);

			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>
		private 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 CI = new CMINVOKECOMMANDINFO();
			icm3 = (IContextMenu3)iu;
			RECT mRect;

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

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

				if (cmdID != 0)
				{
					CI.cbSize = (uint)Marshal.SizeOf(CI);
					CI.hwnd = hwnd;
					CI.lpVerb = (IntPtr)MAKEINTRESOURCE(cmdID - 1);
					CI.lpParameters = IntPtr.Zero;
					CI.lpDirectory = IntPtr.Zero;
					CI.nShow = (int)SW.SW_SHOWNORMAL;
					icm3.InvokeCommand(ref CI);
				}
			}
			return true;
		}

	}
}