FileDatObject.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using System.Windows.Forms;
using Sayuri.IO;
using FILETIME = System.Runtime.InteropServices.ComTypes.FILETIME;
using IDataObject = System.Runtime.InteropServices.ComTypes.IDataObject;

namespace Sayuri.Windows{
	static class UnsafeNativeMethods{
		[DllImport("Kernel32.dll", SetLastError=true)]
		public static extern IntPtr GlobalAlloc( int uFlags, int dwBytes );
		[DllImport("Kernel32.dll")]
		public static extern IntPtr GlobalFree( IntPtr hMem );
		[DllImport("Kernel32.dll", SetLastError=true)]
		public static extern IntPtr GlobalLock( IntPtr hMem );
		[DllImport("Kernel32.dll")]
		[return: MarshalAs(UnmanagedType.Bool)]
		public static extern bool GlobalUnlock( IntPtr hMem );
	}

	static class HResults{
		public const int S_OK = 0;
		public const int S_FALSE = 1;
		public const int E_UNEXPECTED             = unchecked((int)0x8000FFFF);
		public const int OLE_E_ADVISENOTSUPPORTED = unchecked((int)0x80040003);
		public const int DV_E_FORMATETC           = unchecked((int)0x80040064);
		public const int DV_E_TYMED               = unchecked((int)0x80040069);
	}

	[StructLayout(LayoutKind.Sequential, Pack=4, CharSet=CharSet.Unicode)]
	struct FILEDESCRIPTORW{
		public int dwFlags;
		public Guid clsid;
		public long sizel;
		public long pointl;
		public int dwFileAttributes;
		public FILETIME ftCreationTime;
		public FILETIME ftLastAccessTime;
		public FILETIME ftLastWriteTime;
		public int nFileSizeHigh;
		public int nFileSizeLow;
		[MarshalAs(UnmanagedType.ByValTStr, SizeConst=260)]
		public string cFileName;
	}

	[StructLayout(LayoutKind.Sequential, Pack=4, CharSet=CharSet.Unicode)]
	struct FILEGROUPDESCRIPTORW{
		public int cItems;
		[MarshalAs(UnmanagedType.ByValArray)]
		public FILEDESCRIPTORW[] fgd;
	}

	public sealed class FileDataObject: IDataObject, IEnumFORMATETC{
		public FileDataObject( IFile[] files ){
			this.files = files;
		}

		static readonly DataFormats.Format CFSTR_FILEDESCRIPTORW = DataFormats.GetFormat( "FileGroupDescriptorW" );
		static readonly DataFormats.Format CFSTR_FILECONTENTS    = DataFormats.GetFormat( "FileContents" );

		int current;
		readonly IFile[] files;

		void GetFileDescriptor( out STGMEDIUM medium ){
			Debug.WriteLine( "GetFileContents()" );

			IntPtr hFileDescriptor = UnsafeNativeMethods.GlobalAlloc( 0x0002|0x0040/*GHND*/, sizeof(int) + Marshal.SizeOf( typeof(FILEDESCRIPTORW) ) * files.Length );
			if( hFileDescriptor == IntPtr.Zero )
				throw Marshal.GetExceptionForHR( Marshal.GetHRForLastWin32Error() );
			IntPtr pGroupDescriptor = UnsafeNativeMethods.GlobalLock( hFileDescriptor );
			if( pGroupDescriptor == IntPtr.Zero ){
				UnsafeNativeMethods.GlobalFree( hFileDescriptor );
				throw Marshal.GetExceptionForHR( Marshal.GetHRForLastWin32Error() );
			}
			FILEGROUPDESCRIPTORW fgd = new FILEGROUPDESCRIPTORW{
				cItems = files.Length,
				fgd = ( from file in files
						select new FILEDESCRIPTORW{
							dwFlags = 0x0040/*FD_FILESIZE*/|0x0004/*FD_ATTRIBUTES*/,
							nFileSizeLow = file.Length,
							nFileSizeHigh = 0,
							dwFileAttributes = 0x00000080/*FILE_ATTRIBUTE_NORMAL*/,
							cFileName = Path.GetFileName( file.Path ),
						} ).ToArray()
			};
			Marshal.StructureToPtr( fgd, pGroupDescriptor, false );
			UnsafeNativeMethods.GlobalUnlock( hFileDescriptor );

			medium.tymed = TYMED.TYMED_HGLOBAL;
			medium.unionmember = hFileDescriptor;
			medium.pUnkForRelease = null;
		}

		void GetFileContents( FORMATETC format, out STGMEDIUM medium ){
			Debug.WriteLine( string.Format( "GetFileContents({0},{1})", format.tymed, format.lindex ) );

			// TODO: サイズが大きい場合、HGLOBALに押し込むのは無理がある
			if( (format.tymed & TYMED.TYMED_HGLOBAL) != TYMED.TYMED_HGLOBAL )
				throw Marshal.GetExceptionForHR( HResults.DV_E_TYMED );
			IntPtr hFileContents = UnsafeNativeMethods.GlobalAlloc( 0x0002/*GMEM_MOVEABLE*/, files[ format.lindex ].Length );
			if( hFileContents == IntPtr.Zero )
				throw Marshal.GetExceptionForHR( Marshal.GetHRForLastWin32Error() );
			IntPtr pFileContents = UnsafeNativeMethods.GlobalLock( hFileContents );
			if( pFileContents == IntPtr.Zero ){
				UnsafeNativeMethods.GlobalFree( hFileContents );
				throw Marshal.GetExceptionForHR( Marshal.GetHRForLastWin32Error() );
			}
			Marshal.Copy( files[ format.lindex ].GetBytes(), 0, pFileContents, files[ format.lindex ].Length );

			medium.tymed = TYMED.TYMED_HGLOBAL;
			medium.unionmember = hFileContents;
			medium.pUnkForRelease = null;
		}

		int IDataObject.DAdvise( ref FORMATETC pFormatetc, ADVF advf, IAdviseSink adviseSink, out int connection ){
			throw Marshal.GetExceptionForHR( HResults.OLE_E_ADVISENOTSUPPORTED );
		}

		void IDataObject.DUnadvise( int connection ){
			throw Marshal.GetExceptionForHR( HResults.OLE_E_ADVISENOTSUPPORTED );
		}

		int IDataObject.EnumDAdvise( out IEnumSTATDATA enumAdvise ){
			throw Marshal.GetExceptionForHR( HResults.OLE_E_ADVISENOTSUPPORTED );
		}

		IEnumFORMATETC IDataObject.EnumFormatEtc( DATADIR direction ){
			Debug.WriteLine( string.Format( "IDataObject.EnumFormatEtc({0})", direction ) );

			if( direction != DATADIR.DATADIR_GET )
				throw new NotImplementedException();
			return this;
		}

		int IDataObject.GetCanonicalFormatEtc( ref FORMATETC formatIn, out FORMATETC formatOut ){
			Debug.WriteLine( string.Format( "IDataObject.GetCanonicalFormatEtc({0})", formatIn.cfFormat ) );
			throw Marshal.GetExceptionForHR( HResults.E_UNEXPECTED );
		}

		void IDataObject.GetData( ref FORMATETC format, out STGMEDIUM medium ){
			Debug.WriteLine( string.Format( "IDataObject.GetData({0})", format.cfFormat ) );

			if( format.dwAspect == DVASPECT.DVASPECT_CONTENT && format.ptd == IntPtr.Zero )
				if( format.cfFormat == unchecked( (short)CFSTR_FILEDESCRIPTORW.Id ) ){
					if( (format.tymed & TYMED.TYMED_HGLOBAL) != TYMED.TYMED_NULL )
						if( format.lindex == 0 || format.lindex == -1 ){
								GetFileDescriptor( out medium );
								return;
							}
				}else if( format.cfFormat == unchecked( (short)CFSTR_FILECONTENTS.Id ) )
					if( (format.tymed & (TYMED.TYMED_HGLOBAL|TYMED.TYMED_ISTREAM)) != TYMED.TYMED_NULL ){
						GetFileContents( format, out medium );
						return;
					}
			throw Marshal.GetExceptionForHR( HResults.DV_E_FORMATETC );
		}

		void IDataObject.GetDataHere( ref FORMATETC format, ref STGMEDIUM medium ){
			Debug.WriteLine( string.Format( "IDataObject.GetDataHere({0})", format.cfFormat ) );
			throw Marshal.GetExceptionForHR( HResults.E_UNEXPECTED );
		}

		int IDataObject.QueryGetData( ref FORMATETC format ){
			Debug.WriteLine( string.Format( "IDataObject.QueryGetData({0})", format.cfFormat ) );

			int result = HResults.DV_E_FORMATETC;
			if( format.dwAspect == DVASPECT.DVASPECT_CONTENT && format.ptd == IntPtr.Zero )
				if( format.cfFormat == unchecked( (short)CFSTR_FILEDESCRIPTORW.Id ) ){
					if( (format.tymed & TYMED.TYMED_HGLOBAL) != TYMED.TYMED_NULL )
						if( format.lindex == 0 || format.lindex == -1 )
							result = HResults.S_OK;
				}else if( format.cfFormat == unchecked( (short)CFSTR_FILECONTENTS.Id ) )
					if( (format.tymed & (TYMED.TYMED_HGLOBAL|TYMED.TYMED_ISTREAM)) != TYMED.TYMED_NULL )
						result = HResults.S_OK;
			Debug.WriteLine( string.Format( " result: {0}", result ) );
			return result;
		}

		void IDataObject.SetData( ref FORMATETC formatIn, ref STGMEDIUM medium, bool release ){
			Debug.WriteLine( string.Format( "IDataObject.SetData({0})", formatIn.cfFormat ) );
			throw new NotImplementedException();
		}

		void IEnumFORMATETC.Clone( out IEnumFORMATETC newEnum ){
			Debug.WriteLine( "IEnumFORMATETC.Clone(): not impremented." );
			throw Marshal.GetExceptionForHR( HResults.E_UNEXPECTED );
		}

		int IEnumFORMATETC.Next( int celt, FORMATETC[] rgelt, int[] pceltFetched ){
			Debug.WriteLine( string.Format( "IEnumFORMATETC0.Next({0}): {1} read.", celt, current ) );

			int i = 0;
			if( current == 0 && celt > 0 ){
				rgelt[i].cfFormat = unchecked( (short)CFSTR_FILEDESCRIPTORW.Id );
				rgelt[i].ptd = IntPtr.Zero;
				rgelt[i].dwAspect = DVASPECT.DVASPECT_CONTENT;
				rgelt[i].lindex = -1;
				rgelt[i].tymed = TYMED.TYMED_HGLOBAL;
				i++;
				current++;
				celt--;
			}
			if( current == 1 && celt > 0 ){
				rgelt[i].cfFormat = unchecked( (short)CFSTR_FILECONTENTS.Id );
				rgelt[i].ptd = IntPtr.Zero;
				rgelt[i].dwAspect = DVASPECT.DVASPECT_CONTENT;
				rgelt[i].lindex = -1;
				rgelt[i].tymed = TYMED.TYMED_HGLOBAL|TYMED.TYMED_ISTREAM;
				i++;
				current++;
				celt--;
			}
			if( i == 0 )
				return HResults.S_FALSE;

			// celt=1のときNULLが許されるため、チェックが必要
			if( pceltFetched != null )
				pceltFetched[0] = i;
			return HResults.S_OK;
		}

		int IEnumFORMATETC.Reset(){
			Debug.WriteLine( "IEnumFORMATETC.Reset()" );
			current = 0;
			return HResults.S_OK;
		}

		int IEnumFORMATETC.Skip( int celt ){
			Debug.WriteLine( string.Format( "IEnumFORMATETC.Skip({0})", celt ) );

			if( current + celt < 2 ){
				current += celt;
				return HResults.S_OK;
			}
			return HResults.S_FALSE;
		}
	}
}