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add support for custom controls in file dialog in wxGTK and generic versions; also...
[wxWidgets.git] / src / gtk / clipbrd.cpp
index f0110301a8dd5681ec4a76057c8da384d5274daa..3e64f825153b82bd5e2c68eed846c972a894f786 100644 (file)
 /////////////////////////////////////////////////////////////////////////////
-// Name:        clipbrd.cpp
-// Purpose:
-// Author:      Robert Roebling
+// Name:        src/gtk/clipbrd.cpp
+// Purpose:     wxClipboard implementation for wxGTK
+// Author:      Robert Roebling, Vadim Zeitlin
 // Id:          $Id$
 // Copyright:   (c) 1998 Robert Roebling
-// Licence:    wxWindows licence
+//              (c) 2007 Vadim Zeitlin
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "clipbrd.h"
-#endif
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#if wxUSE_CLIPBOARD
 
 #include "wx/clipbrd.h"
 
-//-----------------------------------------------------------------------------
-// data
-//-----------------------------------------------------------------------------
+#ifndef WX_PRECOMP
+    #include "wx/log.h"
+    #include "wx/utils.h"
+    #include "wx/dataobj.h"
+#endif
 
-wxClipboard *wxTheClipboard = (wxClipboard*) NULL;
+#include "wx/ptr_scpd.h"
+#include "wx/scopeguard.h"
 
-GdkAtom  g_textAtom        = 0;
-GdkAtom  g_clipboardAtom   = 0;
-GdkAtom  g_targetsAtom     = 0;
+#include "wx/gtk/private.h"
 
-//-----------------------------------------------------------------------------
-// reminder
-//-----------------------------------------------------------------------------
+wxDECLARE_SCOPED_ARRAY(wxDataFormat, wxDataFormatArray)
+wxDEFINE_SCOPED_ARRAY(wxDataFormat, wxDataFormatArray)
+
+// ----------------------------------------------------------------------------
+// data
+// ----------------------------------------------------------------------------
 
-/* The contents of a selection are returned in a GtkSelectionData
-   structure. selection/target identify the request. 
-   type specifies the type of the return; if length < 0, and
-   the data should be ignored. This structure has object semantics -
-   no fields should be modified directly, they should not be created
-   directly, and pointers to them should not be stored beyond the duration of
-   a callback. (If the last is changed, we'll need to add reference
-   counting)
+static GdkAtom  g_clipboardAtom   = 0;
+static GdkAtom  g_targetsAtom     = 0;
+static GdkAtom  g_timestampAtom   = 0;
 
-struct _GtkSelectionData
+#if wxUSE_UNICODE
+extern GdkAtom g_altTextAtom;
+#endif
+
+// the trace mask we use with wxLogTrace() - call
+// wxLog::AddTraceMask(TRACE_CLIPBOARD) to enable the trace messages from here
+// (there will be a *lot* of them!)
+#define TRACE_CLIPBOARD _T("clipboard")
+
+// ----------------------------------------------------------------------------
+// wxClipboardSync: used to perform clipboard operations synchronously
+// ----------------------------------------------------------------------------
+
+// constructing this object on stack will wait wait until the latest clipboard
+// operation is finished on block exit
+//
+// notice that there can be no more than one such object alive at any moment,
+// i.e. reentrancies are not allowed
+class wxClipboardSync
 {
-  GdkAtom selection;
-  GdkAtom target;
-  GdkAtom type;
-  gint   format;
-  guchar *data;
-  gint   length;
+public:
+    wxClipboardSync(wxClipboard& clipboard)
+    {
+        wxASSERT_MSG( !ms_clipboard, _T("reentrancy in clipboard code") );
+        ms_clipboard = &clipboard;
+    }
+
+    ~wxClipboardSync()
+    {
+        while ( ms_clipboard )
+            gtk_main_iteration();
+    }
+
+    // this method must be called by GTK+ callbacks to indicate that we got the
+    // result for our clipboard operation
+    static void OnDone(wxClipboard * WXUNUSED_UNLESS_DEBUG(clipboard))
+    {
+        wxASSERT_MSG( clipboard == ms_clipboard,
+                        _T("got notification for alien clipboard") );
+
+        ms_clipboard = NULL;
+    }
+
+    // this method should be called if it's possible that no async clipboard
+    // operation is currently in progress (like it can be the case when the
+    // clipboard is cleared but not because we asked about it), it should only
+    // be called if such situation is expected -- otherwise call OnDone() which
+    // would assert in this case
+    static void OnDoneIfInProgress(wxClipboard *clipboard)
+    {
+        if ( ms_clipboard )
+            OnDone(clipboard);
+    }
+
+private:
+    static wxClipboard *ms_clipboard;
+
+    DECLARE_NO_COPY_CLASS(wxClipboardSync)
 };
 
-*/
+wxClipboard *wxClipboardSync::ms_clipboard = NULL;
+
+// ============================================================================
+// clipboard ca;backs implementation
+// ============================================================================
 
 //-----------------------------------------------------------------------------
 // "selection_received" for targets
 //-----------------------------------------------------------------------------
 
+extern "C" {
 static void
-targets_selection_received( GtkWidget *WXUNUSED(widget), 
-                            GtkSelectionData *selection_data, 
-                           wxClipboard *clipboard )
+targets_selection_received( GtkWidget *WXUNUSED(widget),
+                            GtkSelectionData *selection_data,
+                            guint32 WXUNUSED(time),
+                            wxClipboard *clipboard )
 {
-    if (!wxTheClipboard) return;
-  
-    if (selection_data->length <= 0) return;
-  
-    // make sure we got the data in the correct form 
-    if (selection_data->type != GDK_SELECTION_TYPE_ATOM) return;
-  
-    // the atoms we received, holding a list of targets (= formats) 
-    GdkAtom *atoms = (GdkAtom *)selection_data->data;
-
-    for (unsigned int i=0; i<selection_data->length/sizeof(GdkAtom); i++)
+    if ( !clipboard )
+        return;
+
+    wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
+
+    if ( !selection_data || selection_data->length <= 0 )
+        return;
+
+    // make sure we got the data in the correct form
+    GdkAtom type = selection_data->type;
+    if ( type != GDK_SELECTION_TYPE_ATOM )
     {
-        if (atoms[i] == clipboard->m_targetRequested)
+        if ( strcmp(wxGtkString(gdk_atom_name(type)), "TARGETS") != 0 )
         {
-            clipboard->m_formatSupported = TRUE;
+            wxLogTrace( TRACE_CLIPBOARD,
+                        _T("got unsupported clipboard target") );
+
             return;
         }
     }
 
-    return;
+#ifdef __WXDEBUG__
+    // it's not really a format, of course, but we can reuse its GetId() method
+    // to format this atom as string
+    wxDataFormat clip(selection_data->selection);
+    wxLogTrace( TRACE_CLIPBOARD,
+                wxT("Received available formats for clipboard %s"),
+                clip.GetId().c_str() );
+#endif // __WXDEBUG__
+
+    // the atoms we received, holding a list of targets (= formats)
+    const GdkAtom * const atoms = (GdkAtom *)selection_data->data;
+    for ( size_t i = 0; i < selection_data->length/sizeof(GdkAtom); i++ )
+    {
+        const wxDataFormat format(atoms[i]);
+
+        wxLogTrace(TRACE_CLIPBOARD, wxT("\t%s"), format.GetId().c_str());
+
+        if ( clipboard->GTKOnTargetReceived(format) )
+            return;
+    }
+}
+}
+
+bool wxClipboard::GTKOnTargetReceived(const wxDataFormat& format)
+{
+    if ( format != m_targetRequested )
+        return false;
+
+    m_formatSupported = true;
+    return true;
 }
 
 //-----------------------------------------------------------------------------
 // "selection_received" for the actual data
 //-----------------------------------------------------------------------------
 
-static void 
-selection_received( GtkWidget *WXUNUSED(widget), 
-                    GtkSelectionData *selection_data, 
-                   wxClipboard *clipboard )
+extern "C" {
+static void
+selection_received( GtkWidget *WXUNUSED(widget),
+                    GtkSelectionData *selection_data,
+                    guint32 WXUNUSED(time),
+                    wxClipboard *clipboard )
 {
-    if (!wxTheClipboard) return;
-  
-    wxDataObject *data_object = clipboard->m_receivedData;
-    
-    if (!data_object) return;
-    
-    if (selection_data->length <= 0) return;
-  
-    // make sure we got the data in the correct format
-    
-    if (data_object->m_formatAtom != selection_data->target) return;
-    
-    // make sure we got the data in the correct form (selection type).
-    // if so, copy data to target object
-    
-    switch (data_object->GetFormat())
-    {
-        case wxDF_TEXT:
-       {
-            if (selection_data->type != GDK_SELECTION_TYPE_STRING) return;
-           
-           wxTextDataObject *text_object = (wxTextDataObject *) data_object;
-           
-           wxString text = (const char*) selection_data->data;
-           
-           text_object->SetText( text );
-           
-           break;
-       }
-       
-       case wxDF_BITMAP:
-       {
-            if (selection_data->type != GDK_SELECTION_TYPE_BITMAP) return;
-           
-           return;
-           
-           break;
-       }
-       
-       case wxDF_PRIVATE:
-       {
-            if (selection_data->type != GDK_SELECTION_TYPE_STRING) return;
-           
-           wxPrivateDataObject *private_object = (wxPrivateDataObject *) data_object;
-           
-           private_object->SetData( (const char*) selection_data->data, (size_t) selection_data->length );
-           
-           break;
-       }
-       
-       default:
-       {
-           return;
-       }
-    }
-    
-    wxTheClipboard->m_formatSupported = TRUE;
+    if ( !clipboard )
+        return;
+
+    wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
+
+    if ( !selection_data || selection_data->length <= 0 )
+        return;
+
+    clipboard->GTKOnSelectionReceived(*selection_data);
+}
 }
 
 //-----------------------------------------------------------------------------
 // "selection_clear"
 //-----------------------------------------------------------------------------
 
+extern "C" {
 static gint
-selection_clear( GtkWidget *WXUNUSED(widget), GdkEventSelection *WXUNUSED(event) )
+selection_clear_clip( GtkWidget *WXUNUSED(widget), GdkEventSelection *event )
 {
-    if (!wxTheClipboard) return TRUE;
-    
-    // the clipboard is no longer in our hands. we have to delete the
-    // clipboard data.
-    
-    wxTheClipboard->m_dataObjects.Clear();
-  
+    wxClipboard * const clipboard = wxTheClipboard;
+    if ( !clipboard )
+        return TRUE;
+
+    // notice the use of OnDoneIfInProgress() here instead of just OnDone():
+    // it's perfectly possible that we're receiving this notification from GTK+
+    // even though we hadn't cleared the clipboard ourselves but because
+    // another application (or even another window in the same program)
+    // acquired it
+    wxON_BLOCK_EXIT1(wxClipboardSync::OnDoneIfInProgress, clipboard);
+
+    wxClipboard::Kind kind;
+    if (event->selection == GDK_SELECTION_PRIMARY)
+    {
+        wxLogTrace(TRACE_CLIPBOARD, wxT("Lost primary selection" ));
+
+        kind = wxClipboard::Primary;
+    }
+    else if (event->selection == g_clipboardAtom)
+    {
+        wxLogTrace(TRACE_CLIPBOARD, wxT("Lost clipboard" ));
+
+        kind = wxClipboard::Clipboard;
+    }
+    else // some other selection, we're not concerned
+    {
+        return FALSE;
+    }
+
+    // the clipboard is no longer in our hands, we don't need data any more
+    clipboard->GTKClearData(kind);
+
     return TRUE;
 }
+}
 
 //-----------------------------------------------------------------------------
 // selection handler for supplying data
 //-----------------------------------------------------------------------------
 
+extern "C" {
 static void
-selection_handler( GtkWidget *WXUNUSED(widget), GtkSelectionData *selection_data, gpointer WXUNUSED(data) )
+selection_handler( GtkWidget *WXUNUSED(widget),
+                   GtkSelectionData *selection_data,
+                   guint WXUNUSED(info),
+                   guint WXUNUSED(time),
+                   gpointer signal_data )
 {
-    if (!wxTheClipboard) return;
-  
-    wxNode *node = wxTheClipboard->m_dataObjects.First();
-    
-    while (node)
+    wxClipboard * const clipboard = wxTheClipboard;
+    if ( !clipboard )
+        return;
+
+    wxDataObject * const data = clipboard->GTKGetDataObject();
+    if ( !data )
+        return;
+
+    // ICCCM says that TIMESTAMP is a required atom.
+    // In particular, it satisfies Klipper, which polls
+    // TIMESTAMP to see if the clipboards content has changed.
+    // It shall return the time which was used to set the data.
+    if (selection_data->target == g_timestampAtom)
     {
-        wxDataObject *data_object = (wxDataObject *)node->Data();
-    
-       if (data_object->m_formatAtom != selection_data->target)
-       {
-           node = node->Next();
-           break;
-       }
-       
-       switch (data_object->GetFormat())
-       {
-           case wxDF_TEXT:
-           {
-               wxTextDataObject *text_object = (wxTextDataObject*) data_object;
-           
-               wxString text = text_object->GetText();
-           
-               char *s = WXSTRINGCAST text;
-               int len = (int) text.Length();
-               
-                gtk_selection_data_set( 
-                    selection_data, 
-                   GDK_SELECTION_TYPE_STRING, 
-                   8*sizeof(gchar),
-                   (unsigned char*) s, 
-                   len ); 
-                   
-               break;
-           }
-           
-           case wxDF_BITMAP:
-           {
-               // wxBitmapDataObject *private_object = (wxBitmapDataObject*) data_object;
-           
-               // how do we do that ?
-               
-               break;
-           }
-           
-           case wxDF_PRIVATE:
-            {
-               wxPrivateDataObject *private_object = (wxPrivateDataObject*) data_object;
-           
-               if (private_object->GetDataSize() == 0) return;
-           
-                gtk_selection_data_set( 
-                    selection_data, 
-                   GDK_SELECTION_TYPE_STRING, 
-                   8*sizeof(gchar), 
-                   (unsigned char*) private_object->GetData(), 
-                   (int) private_object->GetDataSize() );
-           }
-           
-           default:
-             break;
-        }
-       
-       node = node->Next();
+        guint timestamp = GPOINTER_TO_UINT (signal_data);
+        gtk_selection_data_set(selection_data,
+                               GDK_SELECTION_TYPE_INTEGER,
+                               32,
+                               (guchar*)&(timestamp),
+                               sizeof(timestamp));
+        wxLogTrace(TRACE_CLIPBOARD,
+                   _T("Clipboard TIMESTAMP requested, returning timestamp=%u"),
+                   timestamp);
+        return;
     }
+
+    wxDataFormat format( selection_data->target );
+
+#ifdef __WXDEBUG__
+    wxLogTrace(TRACE_CLIPBOARD,
+               _T("clipboard data in format %s, GtkSelectionData is target=%s type=%s selection=%s timestamp=%u"),
+               format.GetId().c_str(),
+               wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->target))).c_str(),
+               wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->type))).c_str(),
+               wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->selection))).c_str(),
+               GPOINTER_TO_UINT( signal_data )
+               );
+#endif
+
+    if (!data->IsSupportedFormat( format )) return;
+
+    int size = data->GetDataSize( format );
+
+    if (size == 0) return;
+
+    void *d = malloc(size);
+    wxON_BLOCK_EXIT1(free, d);
+
+    // Text data will be in UTF8 in Unicode mode.
+    data->GetDataHere( selection_data->target, d );
+
+    // NB: GTK+ requires special treatment of UTF8_STRING data, the text
+    //     would show as UTF-8 data interpreted as latin1 (?) in other
+    //     GTK+ apps if we used gtk_selection_data_set()
+    if (format == wxDataFormat(wxDF_UNICODETEXT))
+    {
+        gtk_selection_data_set_text(
+            selection_data,
+            (const gchar*)d,
+            size );
+    }
+    else
+    {
+        gtk_selection_data_set(
+            selection_data,
+            GDK_SELECTION_TYPE_STRING,
+            8*sizeof(gchar),
+            (unsigned char*) d,
+            size );
+    }
+}
 }
 
-//-----------------------------------------------------------------------------
-// wxClipboard
-//-----------------------------------------------------------------------------
+void wxClipboard::GTKOnSelectionReceived(const GtkSelectionData& sel)
+{
+    wxCHECK_RET( m_receivedData, _T("should be inside GetData()") );
+
+    const wxDataFormat format(sel.target);
+    wxLogTrace(TRACE_CLIPBOARD, _T("Received selection %s"),
+               format.GetId().c_str());
+
+    if ( !m_receivedData->IsSupportedFormat(format) )
+        return;
+
+    m_receivedData->SetData(format, sel.length, sel.data);
+    m_formatSupported = true;
+}
+
+// ============================================================================
+// wxClipboard implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wxClipboard ctor/dtor
+// ----------------------------------------------------------------------------
 
 IMPLEMENT_DYNAMIC_CLASS(wxClipboard,wxObject)
 
 wxClipboard::wxClipboard()
 {
-    m_open = FALSE;
+    m_open = false;
+
+    m_dataPrimary =
+    m_dataClipboard =
+    m_receivedData = NULL;
+
+    m_formatSupported = false;
+    m_targetRequested = 0;
+
+    // we use m_targetsWidget to query what formats are available
+    m_targetsWidget = gtk_window_new( GTK_WINDOW_POPUP );
+    gtk_widget_realize( m_targetsWidget );
 
-    m_dataObjects.DeleteContents( TRUE );
-  
-    m_receivedData = (wxDataObject*) NULL;
+    g_signal_connect (m_targetsWidget, "selection_received",
+                      G_CALLBACK (targets_selection_received), this);
 
+    // we use m_clipboardWidget to get and to offer data
     m_clipboardWidget = gtk_window_new( GTK_WINDOW_POPUP );
     gtk_widget_realize( m_clipboardWidget );
 
-    gtk_signal_connect( GTK_OBJECT(m_clipboardWidget), 
-                        "selection_clear_event",
-                       GTK_SIGNAL_FUNC( selection_clear ), 
-                       (gpointer) NULL );
-                     
-    if (!g_clipboardAtom) g_clipboardAtom = gdk_atom_intern( "CLIPBOARD", FALSE );
-    if (!g_textAtom) g_textAtom = gdk_atom_intern( "TEXT", FALSE );
-    if (!g_targetsAtom) g_targetsAtom = gdk_atom_intern ("TARGETS", FALSE);
-  
-    m_formatSupported = FALSE;
-    m_targetRequested = 0;
+    g_signal_connect (m_clipboardWidget, "selection_received",
+                      G_CALLBACK (selection_received), this);
+
+    g_signal_connect (m_clipboardWidget, "selection_clear_event",
+                      G_CALLBACK (selection_clear_clip), NULL);
+
+    // initialize atoms we use if not done yet
+    if ( !g_clipboardAtom )
+        g_clipboardAtom = gdk_atom_intern( "CLIPBOARD", FALSE );
+    if ( !g_targetsAtom )
+        g_targetsAtom = gdk_atom_intern ("TARGETS", FALSE);
+    if ( !g_timestampAtom )
+        g_timestampAtom = gdk_atom_intern ("TIMESTAMP", FALSE);
 }
 
 wxClipboard::~wxClipboard()
 {
-    Clear();  
-  
-    if (m_clipboardWidget) gtk_widget_destroy( m_clipboardWidget );
+    Clear();
+
+    gtk_widget_destroy( m_clipboardWidget );
+    gtk_widget_destroy( m_targetsWidget );
 }
 
-void wxClipboard::Clear()
+// ----------------------------------------------------------------------------
+// wxClipboard helper functions
+// ----------------------------------------------------------------------------
+
+GdkAtom wxClipboard::GTKGetClipboardAtom() const
 {
-    if (m_dataObjects.GetCount())
-    { 
-        /*  As we have data we also own the clipboard. Once we no longer own
-            it, clear_selection is called which will set m_data to zero */
-     
-        if (gdk_selection_owner_get( g_clipboardAtom) == m_clipboardWidget->window)
-        {
-            gtk_selection_owner_set( (GtkWidget*) NULL, g_clipboardAtom, GDK_CURRENT_TIME );
-        }
-    
-        m_dataObjects.Clear();
-    }
-  
-    m_targetRequested = 0;
-  
-    m_formatSupported = FALSE;
+    return m_usePrimary ? (GdkAtom)GDK_SELECTION_PRIMARY
+                        : g_clipboardAtom;
 }
 
-bool wxClipboard::Open()
+void wxClipboard::GTKClearData(Kind kind)
 {
-    wxCHECK_MSG( !m_open, FALSE, "clipboard already open" );
-  
-    m_open = TRUE;
-  
-    return TRUE;
+    wxDataObject *&data = Data(kind);
+    if ( data )
+    {
+        delete data;
+        data = NULL;
+    }
 }
 
-bool wxClipboard::SetData( wxDataObject *data )
+bool wxClipboard::SetSelectionOwner(bool set)
 {
-    wxCHECK_MSG( data, FALSE, "data is invalid" );
-  
-    wxNode *node = m_dataObjects.First();
-    
-    while (node)
+    bool rc = gtk_selection_owner_set
+              (
+                set ? m_clipboardWidget : NULL,
+                GTKGetClipboardAtom(),
+                (guint32)GDK_CURRENT_TIME
+              );
+
+    if ( !rc )
     {
-        wxDataObject *d = (wxDataObject*)node->Data();
-       
-       if (d->GetFormat() == data->GetFormat())
-       {
-           m_dataObjects.DeleteNode( node );
-           
-           break;
-       }
-       
-        node = node->Next();
+        wxLogTrace(TRACE_CLIPBOARD, _T("Failed to %sset selection owner"),
+                   set ? _T("") : _T("un"));
     }
-    
-    m_dataObjects.Append( data );
-  
-    wxCHECK_MSG( m_open, FALSE, "clipboard not open" );
-  
-    if (data->GetFormat() == wxDF_PRIVATE)
+
+    return rc;
+}
+
+void wxClipboard::AddSupportedTarget(GdkAtom atom)
+{
+    gtk_selection_add_target
+    (
+        m_clipboardWidget,
+        GTKGetClipboardAtom(),
+        atom,
+        0 // info (same as client data) unused
+    );
+}
+
+bool wxClipboard::DoIsSupported(const wxDataFormat& format)
+{
+    wxCHECK_MSG( format, false, wxT("invalid clipboard format") );
+
+    wxLogTrace(TRACE_CLIPBOARD, wxT("Checking if format %s is available"),
+               format.GetId().c_str());
+
+    // these variables will be used by our GTKOnTargetReceived()
+    m_targetRequested = format;
+    m_formatSupported = false;
+
+    // block until m_formatSupported is set from targets_selection_received
+    // callback
     {
-        wxPrivateDataObject* pd = (wxPrivateDataObject*) data;
-       
-        wxCHECK_MSG( !pd->GetId().IsEmpty(), FALSE, "private clipboard format requires ID string" );
-       
-        data->m_formatAtom = GetTargetAtom( data->GetFormat(), pd->GetId() );
+        wxClipboardSync sync(*this);
+
+        gtk_selection_convert( m_targetsWidget,
+                               GTKGetClipboardAtom(),
+                               g_targetsAtom,
+                               (guint32) GDK_CURRENT_TIME );
     }
-    else
+
+    return m_formatSupported;
+}
+
+// ----------------------------------------------------------------------------
+// wxClipboard public API implementation
+// ----------------------------------------------------------------------------
+
+void wxClipboard::Clear()
+{
+    if ( gdk_selection_owner_get(GTKGetClipboardAtom()) ==
+            m_clipboardWidget->window )
     {
-        data->m_formatAtom = GetTargetAtom( data->GetFormat() );
+        wxClipboardSync sync(*this);
+
+        // this will result in selection_clear_clip callback being called and
+        // it will free our data
+        SetSelectionOwner(false);
     }
-      
-    // Add handlers if someone requests data
-  
-    gtk_selection_add_handler( m_clipboardWidget, 
-                               g_clipboardAtom,
-                              data->m_formatAtom,
-                              selection_handler,
-                              NULL );
-                              
-    // Tell the world we offer clipboard data
-  
-    if (!gtk_selection_owner_set( m_clipboardWidget, 
-                                  g_clipboardAtom,
-                                 GDK_CURRENT_TIME ))
+
+    m_targetRequested = 0;
+    m_formatSupported = false;
+}
+
+bool wxClipboard::Open()
+{
+    wxCHECK_MSG( !m_open, false, wxT("clipboard already open") );
+
+    m_open = true;
+
+    return true;
+}
+
+bool wxClipboard::SetData( wxDataObject *data )
+{
+    wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
+
+    wxCHECK_MSG( data, false, wxT("data is invalid") );
+
+    Clear();
+
+    return AddData( data );
+}
+
+bool wxClipboard::AddData( wxDataObject *data )
+{
+    wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
+
+    wxCHECK_MSG( data, false, wxT("data is invalid") );
+
+    // we can only store one wxDataObject so clear the old one
+    Clear();
+
+    Data() = data;
+
+    // get formats from wxDataObjects
+    const size_t count = data->GetFormatCount();
+    wxDataFormatArray formats(new wxDataFormat[count]);
+    data->GetAllFormats(formats.get());
+
+    // always provide TIMESTAMP as a target, see comments in selection_handler
+    // for explanation
+    AddSupportedTarget(g_timestampAtom);
+
+    for ( size_t i = 0; i < count; i++ )
     {
-        return FALSE;
+        const wxDataFormat format(formats[i]);
+
+        wxLogTrace(TRACE_CLIPBOARD, wxT("Adding support for %s"),
+                   format.GetId().c_str());
+
+        AddSupportedTarget(format);
     }
-                            
-    return TRUE;
+
+    g_signal_connect (m_clipboardWidget, "selection_get",
+                      G_CALLBACK (selection_handler),
+                      GUINT_TO_POINTER (gtk_get_current_event_time()) );
+
+    // tell the world we offer clipboard data
+    return SetSelectionOwner();
 }
 
 void wxClipboard::Close()
 {
-    wxCHECK_RET( m_open, "clipboard not open" );
-    
-    m_open = FALSE;
+    wxCHECK_RET( m_open, wxT("clipboard not open") );
+
+    m_open = false;
 }
 
-bool wxClipboard::IsSupportedFormat( wxDataFormat format, const wxString &id )
+bool wxClipboard::IsOpened() const
 {
-    m_targetRequested = GetTargetAtom( format, id );
-  
-    if (m_targetRequested == 0) return FALSE;
-    
-    // add handler for target (= format) query
-
-    gtk_signal_connect( GTK_OBJECT(m_clipboardWidget), 
-                        "selection_received",
-                       GTK_SIGNAL_FUNC( targets_selection_received ), 
-                       (gpointer) this );
-  
-    m_formatSupported = FALSE;
-  
-    // perform query. this will set m_formatSupported to 
-    // TRUE if m_targetRequested is supported
-    
-    gtk_selection_convert( m_clipboardWidget,
-                          g_clipboardAtom, 
-                          g_targetsAtom,
-                          GDK_CURRENT_TIME );
-
-    gtk_signal_disconnect_by_func( GTK_OBJECT(m_clipboardWidget), 
-                                  GTK_SIGNAL_FUNC( targets_selection_received ),
-                                  (gpointer) this );
-  
-    if (!m_formatSupported) return FALSE;
-  
-    return TRUE;
+    return m_open;
 }
 
-bool wxClipboard::GetData( wxDataObject *data )
+bool wxClipboard::IsSupported( const wxDataFormat& format )
 {
-    wxCHECK_MSG( m_open, FALSE, "clipboard not open" );
-    
-    m_receivedData = data;
-    
-    wxCHECK_MSG( m_receivedData, FALSE, "invalid data object" );
-    
-    if (m_receivedData->GetFormat() == wxDF_PRIVATE)
-    {
-        wxPrivateDataObject* pd = (wxPrivateDataObject*) m_receivedData;
-       
-        wxCHECK_MSG( !pd->GetId().IsEmpty(), FALSE, "private clipboard format requires ID string" );
-       
-        m_targetRequested = GetTargetAtom( m_receivedData->GetFormat(), pd->GetId() );
-    }
-    else
+    if ( DoIsSupported(format) )
+        return true;
+
+#if wxUSE_UNICODE
+    if ( format == wxDF_UNICODETEXT )
     {
-        m_targetRequested = GetTargetAtom( m_receivedData->GetFormat() );
+        // also with plain STRING format
+        return DoIsSupported(g_altTextAtom);
     }
-    
-    data->m_formatAtom = m_targetRequested;
-  
-    wxCHECK_MSG( m_targetRequested, FALSE, "unsupported clipboard format" );
-  
-    m_formatSupported = FALSE;
-  
-    gtk_signal_connect( GTK_OBJECT(m_clipboardWidget), 
-                        "selection_received",
-                       GTK_SIGNAL_FUNC( selection_received ), 
-                       (gpointer) this );
-
-    gtk_selection_convert( m_clipboardWidget,
-                          g_clipboardAtom, 
-                          m_targetRequested,
-                          GDK_CURRENT_TIME );
-  
-    gtk_signal_disconnect_by_func( GTK_OBJECT(m_clipboardWidget), 
-                                  GTK_SIGNAL_FUNC( selection_received ),
-                                  (gpointer) this );
-
-    wxCHECK_MSG( m_formatSupported, FALSE, "error retrieving data from clipboard" );
-  
-    return TRUE;
+#endif // wxUSE_UNICODE
+
+    return false;
 }
 
-GdkAtom wxClipboard::GetTargetAtom( wxDataFormat format, const wxString &id )
+bool wxClipboard::GetData( wxDataObject& data )
 {
-    // What is X representation of that format?
-  
-    switch (format)
+    wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
+
+    // get all supported formats from wxDataObjects
+    const size_t count = data.GetFormatCount();
+    wxDataFormatArray formats(new wxDataFormat[count]);
+    data.GetAllFormats(formats.get());
+
+    for ( size_t i = 0; i < count; i++ )
     {
-        case wxDF_TEXT:
-        {
-            return GDK_TARGET_STRING;
-                               // g_textAtom
-        }
-      
-        case wxDF_BITMAP:
+        const wxDataFormat format(formats[i]);
+
+        // is this format supported by clipboard ?
+        if ( !DoIsSupported(format) )
+            continue;
+
+        wxLogTrace(TRACE_CLIPBOARD, wxT("Requesting format %s"),
+                   format.GetId().c_str());
+
+        // these variables will be used by our GTKOnSelectionReceived()
+        m_receivedData = &data;
+        m_formatSupported = false;
+
         {
-            return GDK_TARGET_BITMAP;
-            break;
-        }
-      
-        case wxDF_PRIVATE:
+            wxClipboardSync sync(*this);
+
+            gtk_selection_convert(m_clipboardWidget,
+                                  GTKGetClipboardAtom(),
+                                  format,
+                                  (guint32) GDK_CURRENT_TIME );
+        } // wait until we get the results
+
+        /*
+           Normally this is a true error as we checked for the presence of such
+           data before, but there are applications that may return an empty
+           string (e.g. Gnumeric-1.6.1 on Linux if an empty cell is copied)
+           which would produce a false error message here, so we check for the
+           size of the string first. With ANSI, GetDataSize returns an extra
+           value (for the closing null?), with unicode, the exact number of
+           tokens is given (that is more than 1 for non-ASCII characters)
+           (tested with Gnumeric-1.6.1 and OpenOffice.org-2.0.2)
+         */
+#if wxUSE_UNICODE
+        if ( format != wxDF_UNICODETEXT || data.GetDataSize(format) > 0 )
+#else // !UNICODE
+        if ( format != wxDF_TEXT || data.GetDataSize(format) > 1 )
+#endif // UNICODE / !UNICODE
         {
-            // we create our own X representation
-    
-            return gdk_atom_intern( WXSTRINGCAST( id ), FALSE );
+            wxCHECK_MSG( m_formatSupported, false,
+                         wxT("error retrieving data from clipboard") );
         }
-       
-       default:
-       {
-           return (GdkAtom) 0;
-       }
-    }
-       
-    return (GdkAtom) 0;
-}
 
-//-----------------------------------------------------------------------------
-// wxClipboardModule
-//-----------------------------------------------------------------------------
+        return true;
+    }
 
-IMPLEMENT_DYNAMIC_CLASS(wxClipboardModule,wxModule)
+    wxLogTrace(TRACE_CLIPBOARD, wxT("GetData(): format not found"));
 
-bool wxClipboardModule::OnInit()
-{
-    wxTheClipboard = new wxClipboard();
-  
-    return TRUE;
+    return false;
 }
 
-void wxClipboardModule::OnExit()
-{
-    if (wxTheClipboard) delete wxTheClipboard;
-    wxTheClipboard = (wxClipboard*) NULL;
-}
+#endif // wxUSE_CLIPBOARD