// Name: clipbrd.cpp
// Purpose: Clipboard functionality
// Author: Julian Smart
-// Modified by:
+// Modified by: Mattia Barbon (added support for generic wxDataObjects)
// Created: 17/09/98
// RCS-ID: $Id$
// Copyright: (c) Julian Smart
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-#ifdef __GNUG__
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation
#pragma implementation "clipbrd.h"
#endif
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __VMS
+#include "wx/vms_x_fix.h"
+#define XtWindow XTWINDOW
+#define XtScreen XTSCREEN
+#define XtParent XTPARENT
+#define XtIsRealized XTISREALIZED
+#define XtDisplay XTDISPLAY
+#endif
+
#include "wx/defs.h"
#if wxUSE_CLIPBOARD
#include "wx/app.h"
-#include "wx/frame.h"
#include "wx/bitmap.h"
#include "wx/utils.h"
-#include "wx/metafile.h"
#include "wx/clipbrd.h"
#include "wx/dataobj.h"
+#include "wx/ptr_scpd.h"
#ifdef __VMS__
#pragma message disable nosimpint
+
#endif
#include <Xm/Xm.h>
#include <Xm/CutPaste.h>
#pragma message enable nosimpint
#endif
-#include <string.h>
-
-#if !USE_SHARED_LIBRARY
-// IMPLEMENT_DYNAMIC_CLASS(wxClipboard, wxObject)
-// IMPLEMENT_ABSTRACT_CLASS(wxClipboardClient, wxObject)
-#endif
-
-static bool gs_clipboardIsOpen = FALSE;
+#include "wx/motif/private.h"
bool wxOpenClipboard()
{
- if (!gs_clipboardIsOpen)
- {
- gs_clipboardIsOpen = TRUE;
- return TRUE;
- }
- else
- return FALSE;
+ return wxTheClipboard->Open();
}
bool wxCloseClipboard()
{
- if (gs_clipboardIsOpen)
- {
- gs_clipboardIsOpen = FALSE;
- return TRUE;
- }
- else
- return FALSE;
+ wxTheClipboard->Close();
+
+ return true;
}
bool wxEmptyClipboard()
{
- // No equivalent in Motif
- return TRUE;
+ wxTheClipboard->Clear();
+ return true;
}
bool wxClipboardOpen()
{
- return gs_clipboardIsOpen;
+ return wxTheClipboard->IsOpened();
}
bool wxIsClipboardFormatAvailable(wxDataFormat dataFormat)
{
- // Only text is supported.
- if (dataFormat != wxDF_TEXT)
- return FALSE;
+ return wxTheClipboard->IsSupported( dataFormat );
+}
- unsigned long numBytes = 0;
- long privateId = 0;
-
- Window window = (Window) 0;
- if (wxTheApp->GetTopWindow())
- window = XtWindow( (Widget) wxTheApp->GetTopWindow()->GetTopWidget() );
+bool wxSetClipboardData(wxDataFormat dataFormat, wxObject *obj,
+ int WXUNUSED(width), int WXUNUSED(height))
+{
+ wxDataObject* dobj = NULL;
- int success = XmClipboardRetrieve((Display*) wxGetDisplay(),
- window, "TEXT", (XtPointer) 0, 0, & numBytes, & privateId) ;
+ if( dataFormat == wxDF_TEXT )
+ {
+ wxChar* data = (wxChar*)obj;
+ dobj = new wxTextDataObject( data );
+ }
+ else if( dataFormat = wxDF_BITMAP )
+ {
+ wxBitmap* data = (wxBitmap*)obj;
+ dobj = new wxBitmapDataObject( *data );
+ }
- // Assume only text is supported. If we have anything at all,
- // or the clipboard is locked so we're not sure, we say we support it.
- if (success == ClipboardNoData)
- return FALSE;
- else
- return TRUE;
-}
+ if( !dobj )
+ return false;
-bool wxSetClipboardData(wxDataFormat dataFormat, wxObject *obj, int WXUNUSED(width), int WXUNUSED(height))
-{
- if (dataFormat != wxDF_TEXT)
- return FALSE;
-
- char* data = (char*) obj;
-
- XmString text = XmStringCreateSimple ("CLIPBOARD");
- Window window = (Window) 0;
- if (wxTheApp->GetTopWindow())
- window = XtWindow( (Widget) wxTheApp->GetTopWindow()->GetTopWidget() );
-
- long itemId = 0;
- int result = 0;
-
- while ((result =
- XmClipboardStartCopy((Display*) wxGetDisplay(),
- window,
- text,
- XtLastTimestampProcessed((Display*) wxGetDisplay()),
- (Widget) 0,
- (XmCutPasteProc) 0,
- & itemId)) != ClipboardSuccess)
-
- ;
-
- XmStringFree (text);
-
- long dataId = 0;
- while ((result =
- XmClipboardCopy((Display*) wxGetDisplay(),
- window,
- itemId,
- "TEXT",
- (XtPointer) data,
- strlen(data) + 1,
- 0,
- & dataId)) != ClipboardSuccess)
-
- ;
-
- while (( result =
- XmClipboardEndCopy((Display*) wxGetDisplay(),
- window, itemId) ) != ClipboardSuccess)
-
- ;
-
- return TRUE;
+ return wxTheClipboard->SetData( dobj );
}
wxObject *wxGetClipboardData(wxDataFormat dataFormat, long *len)
{
- if (dataFormat != wxDF_TEXT)
- return (wxObject*) NULL;
+ wxDataObject* dobj = NULL;
+ wxTextDataObject* tobj = NULL;
+ wxBitmapDataObject* bobj = NULL;
- bool done = FALSE;
- long id = 0;
- unsigned long numBytes = 0;
- int result = 0;
- Window window = (Window) 0;
- if (wxTheApp->GetTopWindow())
- window = XtWindow( (Widget) wxTheApp->GetTopWindow()->GetTopWidget() );
+ if( dataFormat == wxDF_TEXT )
+ {
+ dobj = tobj = new wxTextDataObject;
+ }
+ else if( dataFormat = wxDF_BITMAP )
+ {
+ dobj = bobj = new wxBitmapDataObject;
+ }
- int currentDataSize = 256;
- char* data = new char[currentDataSize];
+ if( !dobj || !wxTheClipboard->GetData( *dobj ) )
+ return NULL;
- while (!done)
+ if( tobj )
{
- if (result == ClipboardTruncate)
- {
- delete[] data;
- currentDataSize = 2*currentDataSize;
- data = new char[currentDataSize];
- }
- result = XmClipboardRetrieve((Display*) wxGetDisplay(),
- window,
- "TEXT",
- (XtPointer) data,
- currentDataSize,
- &numBytes,
- &id);
-
- switch (result)
- {
- case ClipboardSuccess:
- {
- if (len)
- *len = strlen(data) + 1;
- return (wxObject*) data;
- break;
- }
- case ClipboardTruncate:
- case ClipboardLocked:
- {
- break;
- }
- default:
- case ClipboardNoData:
- {
- return (wxObject*) NULL;
- break;
- }
- }
-
+ wxString text = tobj->GetText();
+ wxChar* buf = new wxChar[text.length() + 1];
+
+ if( len ) *len = text.length();
+ return (wxObject*)wxStrcpy( buf, text.c_str() );
+ }
+ else if( bobj )
+ {
+ if( len ) *len = 0;
+ return new wxBitmap( bobj->GetBitmap() );
}
- return NULL;
+ return NULL; // just in case...
}
-wxDataFormat wxEnumClipboardFormats(wxDataFormat dataFormat)
+wxDataFormat wxEnumClipboardFormats(wxDataFormat dataFormat)
{
// Only wxDF_TEXT supported
if (dataFormat == wxDF_TEXT)
return wxDF_INVALID;
}
-wxDataFormat wxRegisterClipboardFormat(char *WXUNUSED(formatName))
+wxDataFormat wxRegisterClipboardFormat(char *WXUNUSED(formatName))
{
// Not supported
- return (wxDataFormat) wxDF_INVALID;
+ return wxDF_INVALID;
}
-bool wxGetClipboardFormatName(wxDataFormat dataFormat, char *formatName, int WXUNUSED(maxCount))
+bool wxGetClipboardFormatName(wxDataFormat dataFormat, char *formatName,
+ int maxCount)
{
- // Only wxDF_TEXT supported
- if (dataFormat == wxDF_TEXT)
- {
- strcpy(formatName, "TEXT");
- return TRUE;
- }
- else
- return FALSE;
+ wxStrncpy( formatName, dataFormat.GetId().c_str(), maxCount );
+
+ return true;
}
//-----------------------------------------------------------------------------
// wxClipboard
//-----------------------------------------------------------------------------
+struct wxDataIdToDataObject
+{
+ wxDataIdToDataObject( wxDataObject* o, long d, size_t s )
+ : object( o ), size( s ), dataId( d ) { }
+
+ wxDataObject* object;
+ size_t size;
+ long dataId;
+};
+
+#include "wx/listimpl.cpp"
+
+WX_DEFINE_LIST(wxDataObjectList);
+WX_DEFINE_LIST(wxDataIdToDataObjectList);
+
+#if wxCHECK_LESSTIF()
+static void wxClipboardCallback( Widget widget, int* data_id,
+ int* priv, int* reason );
+#else
+static void wxClipboardCallback( Widget widget, long* data_id,
+ long* priv, int* reason );
+#endif
+
IMPLEMENT_DYNAMIC_CLASS(wxClipboard,wxObject)
wxClipboard::wxClipboard()
{
- m_open = FALSE;
+ m_open = false;
}
wxClipboard::~wxClipboard()
void wxClipboard::Clear()
{
- wxNode* node = m_data.First();
+ wxDataObjectList::compatibility_iterator node = m_data.GetFirst();
while (node)
{
- wxDataObject* data = (wxDataObject*) node->Data();
- delete data;
- node = node->Next();
+ delete node->GetData();
+ node = node->GetNext();
}
m_data.Clear();
+
+ for( wxDataIdToDataObjectList::compatibility_iterator node2 = m_idToObject.GetFirst();
+ node2; node2 = node2->GetNext() )
+ {
+ delete node2->GetData();
+ }
+ m_idToObject.Clear();
}
bool wxClipboard::Open()
{
- wxCHECK_MSG( !m_open, FALSE, "clipboard already open" );
+ wxCHECK_MSG( !m_open, false, "clipboard already open" );
- m_open = TRUE;
+ m_open = true;
- return wxOpenClipboard();
+ return true;
}
bool wxClipboard::SetData( wxDataObject *data )
{
- wxCHECK_MSG( data, FALSE, "data is invalid" );
- wxCHECK_MSG( m_open, FALSE, "clipboard not open" );
+ wxCHECK_MSG( data, false, "data is invalid" );
+ wxCHECK_MSG( m_open, false, "clipboard not open" );
Clear();
return AddData( data );
}
-bool wxClipboard::AddData( wxDataObject *data )
-{
- wxCHECK_MSG( data, FALSE, "data is invalid" );
- wxCHECK_MSG( m_open, FALSE, "clipboard not open" );
+wxDECLARE_SCOPED_ARRAY( wxDataFormat, wxDataFormatScopedArray );
+wxDEFINE_SCOPED_ARRAY( wxDataFormat, wxDataFormatScopedArray );
- wxDataFormat::NativeFormat format = data->GetPreferredFormat().GetType();
- switch ( format )
+#if wxCHECK_LESSTIF()
+void wxClipboardCallback( Widget xwidget, int* data_id,
+ int* priv, int* reason )
+#else
+void wxClipboardCallback( Widget xwidget, long* data_id,
+ long* priv, int* reason )
+#endif
+{
+ Display* xdisplay = XtDisplay( xwidget );
+ Window xwindow = XtWindow( xwidget );
+ wxDataObject* dobj = NULL;
+ size_t size = 0;
+
+ for( wxDataIdToDataObjectList::compatibility_iterator node2 =
+ wxTheClipboard->m_idToObject.GetFirst();
+ node2; node2 = node2->GetNext() )
{
- case wxDF_TEXT:
- case wxDF_OEMTEXT:
- {
- wxTextDataObject* textDataObject = (wxTextDataObject*) data;
- wxString str(textDataObject->GetText());
- return wxSetClipboardData(format, (wxObject*) (const char*) str);
- }
-#if 0
- case wxDF_BITMAP:
- case wxDF_DIB:
+ wxDataIdToDataObject* dido = node2->GetData();
+ if( dido->dataId == *data_id )
{
- wxBitmapDataObject* bitmapDataObject = (wxBitmapDataObject*) data;
- wxBitmap bitmap(bitmapDataObject->GetBitmap());
- return wxSetClipboardData(data->GetType(), & bitmap);
+ dobj = dido->object;
+ size = dido->size;
break;
}
-#endif // 0
}
-
- return FALSE;
-}
-void wxClipboard::Close()
-{
- wxCHECK_RET( m_open, "clipboard not open" );
-
- m_open = FALSE;
- wxCloseClipboard();
-}
+ if( !dobj ) return;
-bool wxClipboard::IsSupported( const wxDataFormat& format)
-{
- return wxIsClipboardFormatAvailable(format);
+ wxCharBuffer buffer(size);
+ size_t count = dobj->GetFormatCount( wxDataObject::Get );
+ wxDataFormatScopedArray dfarr( new wxDataFormat[count] );
+ dobj->GetAllFormats( dfarr.get(), wxDataObject::Get );
+
+ if( !dobj->GetDataHere( dfarr[*priv], buffer.data() ) )
+ return;
+
+ while( XmClipboardCopyByName( xdisplay, xwindow, *data_id,
+ buffer.data(), size, 0 )
+ == XmClipboardLocked );
}
-bool wxClipboard::GetData( wxDataObject& data )
+bool wxClipboard::AddData( wxDataObject *data )
{
- wxCHECK_MSG( m_open, FALSE, "clipboard not open" );
-
- wxDataFormat::NativeFormat format = data.GetPreferredFormat().GetType();
- switch ( format )
- {
- case wxDF_TEXT:
- case wxDF_OEMTEXT:
- {
- wxTextDataObject& textDataObject = (wxTextDataObject &) data;
- char* s = (char*) wxGetClipboardData(format);
- if (s)
- {
- textDataObject.SetText(s);
- delete[] s;
- return TRUE;
- }
- else
- return FALSE;
- break;
- }
-/*
- case wxDF_BITMAP:
- case wxDF_DIB:
- {
- wxBitmapDataObject* bitmapDataObject = (wxBitmapDataObject*) data;
- wxBitmap* bitmap = (wxBitmap*) wxGetClipboardData(data->GetType());
- if (bitmap)
- {
- bitmapDataObject->SetBitmap(* bitmap);
- delete bitmap;
- return TRUE;
- }
- else
- return FALSE;
- break;
- }
-*/
- default:
- {
- return FALSE;
- }
- }
- return FALSE;
-}
+ wxCHECK_MSG( data, false, "data is invalid" );
+ wxCHECK_MSG( m_open, false, "clipboard not open" );
-#if 0
+ m_data.Append( data );
-/*
-* Old clipboard implementation by Matthew Flatt
-*/
+ Display* xdisplay = wxGlobalDisplay();
+ Widget xwidget = (Widget)wxTheApp->GetTopLevelRealizedWidget();
+ Window xwindow = XtWindow( xwidget );
+ wxXmString label( wxTheApp->GetAppName() );
+ Time timestamp = XtLastTimestampProcessed( xdisplay );
+ long itemId;
-wxClipboard *wxTheClipboard = NULL;
+ int retval;
-void wxInitClipboard()
-{
- if (!wxTheClipboard)
- wxTheClipboard = new wxClipboard;
-}
+ while( ( retval = XmClipboardStartCopy( xdisplay, xwindow, label(),
+ timestamp, xwidget,
+ wxClipboardCallback,
+ &itemId ) )
+ == XmClipboardLocked );
+ if( retval != XmClipboardSuccess )
+ return false;
-wxClipboard::wxClipboard()
-{
- clipOwner = NULL;
- cbString = NULL;
-}
+ size_t count = data->GetFormatCount( wxDataObject::Get );
+ wxDataFormatScopedArray dfarr( new wxDataFormat[count] );
+ data->GetAllFormats( dfarr.get(), wxDataObject::Get );
-wxClipboard::~wxClipboard()
-{
- if (clipOwner)
- clipOwner->BeingReplaced();
- if (cbString)
- delete[] cbString;
+ for( size_t i = 0; i < count; ++i )
+ {
+ size_t size = data->GetDataSize( dfarr[i] );
+ long data_id;
+ wxString id = dfarr[i].GetId();
+
+ while( ( retval = XmClipboardCopy( xdisplay, xwindow, itemId,
+ wxConstCast(id.c_str(), char),
+ NULL, size, i, &data_id ) )
+ == XmClipboardLocked );
+
+ m_idToObject.Append( new wxDataIdToDataObject( data, data_id, size ) );
+ }
+
+ while( XmClipboardEndCopy( xdisplay, xwindow, itemId )
+ == XmClipboardLocked );
+
+ return true;
}
-static int FormatStringToID(char *str)
+void wxClipboard::Close()
{
- if (!strcmp(str, "TEXT"))
- return wxDF_TEXT;
+ wxCHECK_RET( m_open, "clipboard not open" );
- return wxRegisterClipboardFormat(str);
+ m_open = false;
}
-void wxClipboard::SetClipboardClient(wxClipboardClient *client, long time)
+bool wxClipboard::IsSupported(const wxDataFormat& format)
{
- bool got_selection;
-
- if (clipOwner)
- clipOwner->BeingReplaced();
- clipOwner = client;
- if (cbString) {
- delete[] cbString;
- cbString = NULL;
- }
-
- if (wxOpenClipboard()) {
- char **formats, *data;
- int i;
- int ftype;
- long size;
-
- formats = clipOwner->formats.ListToArray(FALSE);
- for (i = clipOwner->formats.Number(); i--; ) {
- ftype = FormatStringToID(formats[i]);
- data = clipOwner->GetData(formats[i], &size);
- if (!wxSetClipboardData(ftype, (wxObject *)data, size, 1)) {
- got_selection = FALSE;
+ Display* xdisplay = wxGlobalDisplay();
+ Window xwindow = XtWindow( (Widget)wxTheApp->GetTopLevelRealizedWidget() );
+ bool isSupported = false;
+ int retval, count;
+ unsigned long max_name_length;
+ wxString id = format.GetId();
+
+ while( ( retval = XmClipboardLock( xdisplay, xwindow ) )
+ == XmClipboardLocked );
+ if( retval != XmClipboardSuccess )
+ return false;
+
+ if( XmClipboardInquireCount( xdisplay, xwindow, &count, &max_name_length )
+ == XmClipboardSuccess )
+ {
+ wxCharBuffer buf( max_name_length + 1 );
+ unsigned long copied;
+
+ for( int i = 0; i < count; ++i )
+ {
+ if( XmClipboardInquireFormat( xdisplay, xwindow, i + 1,
+ (XtPointer)buf.data(),
+ max_name_length, &copied )
+ != XmClipboardSuccess )
+ continue;
+
+ buf.data()[copied] = '\0';
+
+ if( buf == id )
+ {
+ isSupported = true;
break;
}
}
-
- if (i < 0)
- got_selection = wxCloseClipboard();
- } else
- got_selection = FALSE;
-
- got_selection = FALSE; // Assume another process takes over
-
- if (!got_selection) {
- clipOwner->BeingReplaced();
- clipOwner = NULL;
}
-}
-wxClipboardClient *wxClipboard::GetClipboardClient()
-{
- return clipOwner;
+ XmClipboardUnlock( xdisplay, xwindow, False );
+
+ return isSupported;
}
-void wxClipboard::SetClipboardString(char *str, long time)
+class wxClipboardEndRetrieve
{
- bool got_selection;
-
- if (clipOwner) {
- clipOwner->BeingReplaced();
- clipOwner = NULL;
- }
- if (cbString)
- delete[] cbString;
-
- cbString = str;
-
- if (wxOpenClipboard()) {
- if (!wxSetClipboardData(wxDF_TEXT, (wxObject *)str))
- got_selection = FALSE;
- else
- got_selection = wxCloseClipboard();
- } else
- got_selection = FALSE;
-
- got_selection = FALSE; // Assume another process takes over
-
- if (!got_selection) {
- delete[] cbString;
- cbString = NULL;
+public:
+ wxClipboardEndRetrieve( Display* display, Window window )
+ : m_display( display ), m_window( window ) { }
+ ~wxClipboardEndRetrieve()
+ {
+ while( XmClipboardEndRetrieve( m_display, m_window )
+ == XmClipboardLocked );
}
-}
+private:
+ Display* m_display;
+ Window m_window;
+};
-char *wxClipboard::GetClipboardString(long time)
+bool wxClipboard::GetData( wxDataObject& data )
{
- char *str;
- long length;
+ wxCHECK_MSG( m_open, false, "clipboard not open" );
+
+ Display* xdisplay = wxGlobalDisplay();
+ Window xwindow = XtWindow( (Widget)wxTheApp->GetTopLevelRealizedWidget() );
+ Time timestamp = XtLastTimestampProcessed( xdisplay );
+
+ wxDataFormat chosenFormat;
+ int retval;
+
+ ///////////////////////////////////////////////////////////////////////////
+ // determine if the cliboard holds any format we like
+ ///////////////////////////////////////////////////////////////////////////
+ while( ( retval = XmClipboardStartRetrieve( xdisplay, xwindow,
+ timestamp ) )
+ == XmClipboardLocked );
+ if( retval != XmClipboardSuccess )
+ return false;
+
+ wxClipboardEndRetrieve endRetrieve( xdisplay, xwindow );
+
+ int count;
+ unsigned long max_name_length;
+ size_t dfcount = data.GetFormatCount( wxDataObject::Set );
+ wxDataFormatScopedArray dfarr( new wxDataFormat[dfcount] );
+ data.GetAllFormats( dfarr.get(), wxDataObject::Set );
- str = GetClipboardData("TEXT", &length, time);
- if (!str) {
- str = new char[1];
- *str = 0;
- }
-
- return str;
-}
+ if( XmClipboardInquireCount( xdisplay, xwindow, &count, &max_name_length )
+ == XmClipboardSuccess )
+ {
+ wxCharBuffer buf( max_name_length + 1 );
+ unsigned long copied;
-char *wxClipboard::GetClipboardData(char *format, long *length, long time)
-{
- if (clipOwner) {
- if (clipOwner->formats.Member(format))
- return clipOwner->GetData(format, length);
- else
- return NULL;
- } else if (cbString) {
- if (!strcmp(format, "TEXT"))
- return copystring(cbString);
- else
- return NULL;
- } else {
- if (wxOpenClipboard()) {
- receivedString = (char *)wxGetClipboardData(FormatStringToID(format),
- length);
- wxCloseClipboard();
- } else
- receivedString = NULL;
-
- return receivedString;
+ for( int i = 0; i < count; ++i )
+ {
+ if( XmClipboardInquireFormat( xdisplay, xwindow, i + 1,
+ (XtPointer)buf.data(),
+ max_name_length, &copied )
+ != XmClipboardSuccess )
+ continue;
+
+ buf.data()[copied] = '\0';
+
+ // try preferred format
+ if( buf == data.GetPreferredFormat( wxDataObject::Set ).GetId() )
+ {
+ chosenFormat = data.GetPreferredFormat( wxDataObject::Set );
+ break;
+ }
+
+ // try all other formats
+ for( size_t i = 0; i < dfcount; ++i )
+ {
+ if( buf == dfarr[i].GetId() )
+ chosenFormat = dfarr[i];
+ }
+ }
}
+
+ if( chosenFormat == wxDF_INVALID )
+ return false;
+
+ ///////////////////////////////////////////////////////////////////////////
+ // now retrieve the data
+ ///////////////////////////////////////////////////////////////////////////
+ unsigned long length, dummy1;
+ long dummy2;
+ wxString id = chosenFormat.GetId();
+
+ while( ( retval = XmClipboardInquireLength( xdisplay, xwindow,
+ wxConstCast(id.c_str(), char),
+ &length ) )
+ == XmClipboardLocked );
+ if( retval != XmClipboardSuccess )
+ return false;
+
+ wxCharBuffer buf(length);
+
+ while( ( retval = XmClipboardRetrieve( xdisplay, xwindow,
+ wxConstCast(id.c_str(), char),
+ (XtPointer)buf.data(),
+ length, &dummy1, &dummy2 ) )
+ == XmClipboardLocked );
+ if( retval != XmClipboardSuccess )
+ return false;
+
+ if( !data.SetData( chosenFormat, length, buf.data() ) )
+ return false;
+
+ return true;
}
-#endif
#endif // wxUSE_CLIPBOARD
projects / wxWidgets.git / blobdiff