SQL Editor for Database Developers

/*
SqlBuilder - an intelligent database tool
 
This file is part of SqlBuilder.
www.netcult.ch/elmue

This program is free software; you can redistribute it and/or modify it 
under the terms of the GNU General Public License as published by the 
Free Software Foundation; either version 2 of the License, or 
(at your option) any later version. 
 
This program is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details. 
 
You find the GNU General Public License in the subfolder GNU
if not, write to the Free Software Foundation, 
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/


using System;
using System.IO;
using System.Threading;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using SqlBuilder.Forms;

namespace SqlBuilder
{
	/// <summary>
	/// The stupid Windows Recycle Bin needs 30 seconds to move ONE file 
	/// into the recyler if there are 500 files in the recycler.
	/// During these 30 seconds the application will completely hang if you dont execute this in another thread!
	/// </summary>
	public class Recycler
	{
		#region Win32 API

		[StructLayout(LayoutKind.Sequential, Pack = 4, CharSet = CharSet.Unicode)]
		struct SHFILEOPSTRUCTW
		{
			public IntPtr          hwnd;
			public uint            wFunc;
			public string          pFrom;
			public string          pTo;
			public uint            fFlags;
			public bool            fAnyOperationsAborted;
			public IntPtr          hNameMappings;
			public string          lpszProgressTitle;
		};

		[StructLayout(LayoutKind.Sequential, Pack = 4, CharSet = CharSet.Ansi)]
		struct SHFILEOPSTRUCTA
		{
			public IntPtr          hwnd;
			public uint            wFunc;
			public string          pFrom;
			public string          pTo;
			public uint            fFlags;
			public bool            fAnyOperationsAborted;
			public IntPtr          hNameMappings;
			public string          lpszProgressTitle;
		};

		[DllImport("shell32.dll", EntryPoint="SHFileOperationW")]
		static extern int SHFileOperationW(ref SHFILEOPSTRUCTW k_FileOp);

		[DllImport("shell32.dll", EntryPoint="SHFileOperationA")]
		static extern int SHFileOperationA(ref SHFILEOPSTRUCTA k_FileOp);

		#endregion

		frmWait mi_WaitForm;
		string  ms_File;
		int     ms32_Error = 0;

		/// <summary>
		/// s_File must be a FULL path (not relative)!
		/// </summary>
		public bool MoveToRecycleBin(Form i_Owner, string s_File)
		{
			ms_File = s_File;

			if (!File.Exists(s_File))
				return true;

			mi_WaitForm = new frmWait(); // ORDER FIRST!

			Thread i_Thread = new Thread(new ThreadStart(WorkThread));
			i_Thread.Start(); // ORDER AFTER!

			int s32_Tick = Environment.TickCount;
			// The following command will block until the file is in the recycler or the user aborted
			DialogResult Res = mi_WaitForm.ShowDialog(i_Owner);
			s32_Tick = Environment.TickCount - s32_Tick;

			if (ms32_Error != 0)
				frmMsgBox.Err(i_Owner, string.Format("The following file could not be moved to the recycle bin:\n{0}\n{1}", s_File, Functions.ExplainApiError(ms32_Error)));
	
			if (s32_Tick > 2000)
				frmMsgBox.Warn(i_Owner, "You should clean up your recycle bin!!\nWindows needed "+(s32_Tick/1000)+" seconds to move only ONE file into your recycler!");

			return (Res == DialogResult.OK && ms32_Error == 0);
		}

		private void WorkThread()
		{
			mi_WaitForm.SetLabelText("Moving to recycler...");

			const int  FO_DELETE         = 0x0003;
			const int FOF_SILENT         = 0x0004;
			const int FOF_ALLOWUNDO      = 0x0040;
			const int FOF_NOERRORUI      = 0x0400;
			const int FOF_NOCONFIRMATION = 0x0010;

			Functions.RemoveWriteProtection(ms_File);

			uint u32_Flags = FOF_ALLOWUNDO |     // move to recycle bin
			                 FOF_SILENT    |     // don't show progress bar
			                 FOF_NOERRORUI |     // don't show error MessageBoxes
			                 FOF_NOCONFIRMATION; // don't ask for confirmation

			if (Environment.OSVersion.Platform == PlatformID.Win32NT)
			{
				SHFILEOPSTRUCTW k_File = new SHFILEOPSTRUCTW();
				k_File.hwnd   = IntPtr.Zero;         // not used
				k_File.wFunc  = FO_DELETE;
				k_File.pFrom  = ms_File + "\0";      // requires !TWO! terminating zeroes
				k_File.pTo    = null;
				k_File.fFlags = u32_Flags;

				ms32_Error = SHFileOperationW(ref k_File);
			}
			else
			{
				SHFILEOPSTRUCTA k_File = new SHFILEOPSTRUCTA();
				k_File.hwnd   = IntPtr.Zero;         // not used
				k_File.wFunc  = FO_DELETE;
				k_File.pFrom  = ms_File + "\0";      // requires !TWO! terminating zeroes
				k_File.pTo    = null;
				k_File.fFlags = u32_Flags;

				ms32_Error = SHFileOperationA(ref k_File);
			}

			mi_WaitForm.Close(); // DialogResult.OK
		}
	}
}