src/gtk/clipbrd.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/gtk/clipbrd.cpp
   3 // Purpose:     wxClipboard implementation for wxGTK
   4 // Author:      Robert Roebling, Vadim Zeitlin
   5 // Id:          $Id$
   6 // Copyright:   (c) 1998 Robert Roebling
   7 //              (c) 2007 Vadim Zeitlin
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18
  19 // For compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #if wxUSE_CLIPBOARD
  23
  24 #include "wx/clipbrd.h"
  25
  26 #ifndef WX_PRECOMP
  27     #include "wx/log.h"
  28     #include "wx/utils.h"
  29     #include "wx/dataobj.h"
  30 #endif
  31
  32 #include "wx/ptr_scpd.h"
  33 #include "wx/scopeguard.h"
  34
  35 #include "wx/gtk/private.h"
  36
  37 wxDECLARE_SCOPED_ARRAY(wxDataFormat, wxDataFormatArray)
  38 wxDEFINE_SCOPED_ARRAY(wxDataFormat, wxDataFormatArray)
  39
  40 // ----------------------------------------------------------------------------
  41 // data
  42 // ----------------------------------------------------------------------------
  43
  44 static GdkAtom  g_clipboardAtom   = 0;
  45 static GdkAtom  g_targetsAtom     = 0;
  46 static GdkAtom  g_timestampAtom   = 0;
  47
  48 #if wxUSE_UNICODE
  49 extern GdkAtom g_altTextAtom;
  50 #endif
  51
  52 // the trace mask we use with wxLogTrace() - call
  53 // wxLog::AddTraceMask(TRACE_CLIPBOARD) to enable the trace messages from here
  54 // (there will be a *lot* of them!)
  55 #define TRACE_CLIPBOARD _T("clipboard")
  56
  57 // ----------------------------------------------------------------------------
  58 // wxClipboardSync: used to perform clipboard operations synchronously
  59 // ----------------------------------------------------------------------------
  60
  61 // constructing this object on stack will wait wait until the latest clipboard
  62 // operation is finished on block exit
  63 //
  64 // notice that there can be no more than one such object alive at any moment,
  65 // i.e. reentrancies are not allowed
  66 class wxClipboardSync
  67 {
  68 public:
  69     wxClipboardSync(wxClipboard& clipboard)
  70     {
  71         wxASSERT_MSG( !ms_clipboard, _T("reentrancy in clipboard code") );
  72         ms_clipboard = &clipboard;
  73     }
  74
  75     ~wxClipboardSync()
  76     {
  77         while ( ms_clipboard )
  78             gtk_main_iteration();
  79     }
  80
  81     // this method must be called by GTK+ callbacks to indicate that we got the
  82     // result for our clipboard operation
  83     static void OnDone(wxClipboard * WXUNUSED_UNLESS_DEBUG(clipboard))
  84     {
  85         wxASSERT_MSG( clipboard == ms_clipboard,
  86                         _T("got notification for alien clipboard") );
  87
  88         ms_clipboard = NULL;
  89     }
  90
  91     // this method should be called if it's possible that no async clipboard
  92     // operation is currently in progress (like it can be the case when the
  93     // clipboard is cleared but not because we asked about it), it should only
  94     // be called if such situation is expected -- otherwise call OnDone() which
  95     // would assert in this case
  96     static void OnDoneIfInProgress(wxClipboard *clipboard)
  97     {
  98         if ( ms_clipboard )
  99             OnDone(clipboard);
 100     }
 101
 102 private:
 103     static wxClipboard *ms_clipboard;
 104
 105     DECLARE_NO_COPY_CLASS(wxClipboardSync)
 106 };
 107
 108 wxClipboard *wxClipboardSync::ms_clipboard = NULL;
 109
 110 // ============================================================================
 111 // clipboard callbacks implementation
 112 // ============================================================================
 113
 114 //-----------------------------------------------------------------------------
 115 // "selection_received" for targets
 116 //-----------------------------------------------------------------------------
 117
 118 extern "C" {
 119 static void
 120 targets_selection_received( GtkWidget *WXUNUSED(widget),
 121                             GtkSelectionData *selection_data,
 122                             guint32 WXUNUSED(time),
 123                             wxClipboard *clipboard )
 124 {
 125     if ( !clipboard )
 126         return;
 127
 128     wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
 129
 130     if ( !selection_data || selection_data->length <= 0 )
 131         return;
 132
 133     // make sure we got the data in the correct form
 134     GdkAtom type = selection_data->type;
 135     if ( type != GDK_SELECTION_TYPE_ATOM )
 136     {
 137         if ( strcmp(wxGtkString(gdk_atom_name(type)), "TARGETS") != 0 )
 138         {
 139             wxLogTrace( TRACE_CLIPBOARD,
 140                         _T("got unsupported clipboard target") );
 141
 142             return;
 143         }
 144     }
 145
 146 #ifdef __WXDEBUG__
 147     // it's not really a format, of course, but we can reuse its GetId() method
 148     // to format this atom as string
 149     wxDataFormat clip(selection_data->selection);
 150     wxLogTrace( TRACE_CLIPBOARD,
 151                 wxT("Received available formats for clipboard %s"),
 152                 clip.GetId().c_str() );
 153 #endif // __WXDEBUG__
 154
 155     // the atoms we received, holding a list of targets (= formats)
 156     const GdkAtom * const atoms = (GdkAtom *)selection_data->data;
 157     for ( size_t i = 0; i < selection_data->length/sizeof(GdkAtom); i++ )
 158     {
 159         const wxDataFormat format(atoms[i]);
 160
 161         wxLogTrace(TRACE_CLIPBOARD, wxT("\t%s"), format.GetId().c_str());
 162
 163         if ( clipboard->GTKOnTargetReceived(format) )
 164             return;
 165     }
 166 }
 167 }
 168
 169 bool wxClipboard::GTKOnTargetReceived(const wxDataFormat& format)
 170 {
 171     if ( format != m_targetRequested )
 172         return false;
 173
 174     m_formatSupported = true;
 175     return true;
 176 }
 177
 178 //-----------------------------------------------------------------------------
 179 // "selection_received" for the actual data
 180 //-----------------------------------------------------------------------------
 181
 182 extern "C" {
 183 static void
 184 selection_received( GtkWidget *WXUNUSED(widget),
 185                     GtkSelectionData *selection_data,
 186                     guint32 WXUNUSED(time),
 187                     wxClipboard *clipboard )
 188 {
 189     if ( !clipboard )
 190         return;
 191
 192     wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
 193
 194     if ( !selection_data || selection_data->length <= 0 )
 195         return;
 196
 197     clipboard->GTKOnSelectionReceived(*selection_data);
 198 }
 199 }
 200
 201 //-----------------------------------------------------------------------------
 202 // "selection_clear"
 203 //-----------------------------------------------------------------------------
 204
 205 extern "C" {
 206 static gint
 207 selection_clear_clip( GtkWidget *WXUNUSED(widget), GdkEventSelection *event )
 208 {
 209     wxClipboard * const clipboard = wxTheClipboard;
 210     if ( !clipboard )
 211         return TRUE;
 212
 213     // notice the use of OnDoneIfInProgress() here instead of just OnDone():
 214     // it's perfectly possible that we're receiving this notification from GTK+
 215     // even though we hadn't cleared the clipboard ourselves but because
 216     // another application (or even another window in the same program)
 217     // acquired it
 218     wxON_BLOCK_EXIT1(wxClipboardSync::OnDoneIfInProgress, clipboard);
 219
 220     wxClipboard::Kind kind;
 221     if (event->selection == GDK_SELECTION_PRIMARY)
 222     {
 223         wxLogTrace(TRACE_CLIPBOARD, wxT("Lost primary selection" ));
 224
 225         kind = wxClipboard::Primary;
 226     }
 227     else if (event->selection == g_clipboardAtom)
 228     {
 229         wxLogTrace(TRACE_CLIPBOARD, wxT("Lost clipboard" ));
 230
 231         kind = wxClipboard::Clipboard;
 232     }
 233     else // some other selection, we're not concerned
 234     {
 235         return FALSE;
 236     }
 237
 238     // the clipboard is no longer in our hands, we don't need data any more
 239     clipboard->GTKClearData(kind);
 240
 241     return TRUE;
 242 }
 243 }
 244
 245 //-----------------------------------------------------------------------------
 246 // selection handler for supplying data
 247 //-----------------------------------------------------------------------------
 248
 249 extern "C" {
 250 static void
 251 selection_handler( GtkWidget *WXUNUSED(widget),
 252                    GtkSelectionData *selection_data,
 253                    guint WXUNUSED(info),
 254                    guint WXUNUSED(time),
 255                    gpointer signal_data )
 256 {
 257     wxClipboard * const clipboard = wxTheClipboard;
 258     if ( !clipboard )
 259         return;
 260
 261     wxDataObject * const data = clipboard->GTKGetDataObject();
 262     if ( !data )
 263         return;
 264
 265     // ICCCM says that TIMESTAMP is a required atom.
 266     // In particular, it satisfies Klipper, which polls
 267     // TIMESTAMP to see if the clipboards content has changed.
 268     // It shall return the time which was used to set the data.
 269     if (selection_data->target == g_timestampAtom)
 270     {
 271         guint timestamp = GPOINTER_TO_UINT (signal_data);
 272         gtk_selection_data_set(selection_data,
 273                                GDK_SELECTION_TYPE_INTEGER,
 274                                32,
 275                                (guchar*)&(timestamp),
 276                                sizeof(timestamp));
 277         wxLogTrace(TRACE_CLIPBOARD,
 278                    _T("Clipboard TIMESTAMP requested, returning timestamp=%u"),
 279                    timestamp);
 280         return;
 281     }
 282
 283     wxDataFormat format( selection_data->target );
 284
 285 #ifdef __WXDEBUG__
 286     wxLogTrace(TRACE_CLIPBOARD,
 287                _T("clipboard data in format %s, GtkSelectionData is target=%s type=%s selection=%s timestamp=%u"),
 288                format.GetId().c_str(),
 289                wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->target))).c_str(),
 290                wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->type))).c_str(),
 291                wxString::FromAscii(wxGtkString(gdk_atom_name(selection_data->selection))).c_str(),
 292                GPOINTER_TO_UINT( signal_data )
 293                );
 294 #endif // __WXDEBUG__
 295
 296     if ( !data->IsSupportedFormat( format ) )
 297         return;
 298
 299     int size = data->GetDataSize( format );
 300     if ( !size )
 301         return;
 302
 303     wxCharBuffer buf(size - 1); // it adds 1 internally (for NUL)
 304
 305     // text data must be returned in UTF8 if format is wxDF_UNICODETEXT
 306     if ( !data->GetDataHere(format, buf.data()) )
 307         return;
 308
 309     // use UTF8_STRING format if requested in Unicode build but just plain
 310     // STRING one in ANSI or if explicitly asked in Unicode
 311 #if wxUSE_UNICODE
 312     if (format == wxDataFormat(wxDF_UNICODETEXT))
 313     {
 314         gtk_selection_data_set_text(
 315             selection_data,
 316             (const gchar*)buf.data(),
 317             size );
 318     }
 319     else
 320 #endif // wxUSE_UNICODE
 321     {
 322         gtk_selection_data_set(
 323             selection_data,
 324             GDK_SELECTION_TYPE_STRING,
 325             8*sizeof(gchar),
 326             (const guchar*)buf.data(),
 327             size );
 328     }
 329 }
 330 }
 331
 332 void wxClipboard::GTKOnSelectionReceived(const GtkSelectionData& sel)
 333 {
 334     wxCHECK_RET( m_receivedData, _T("should be inside GetData()") );
 335
 336     const wxDataFormat format(sel.target);
 337     wxLogTrace(TRACE_CLIPBOARD, _T("Received selection %s"),
 338                format.GetId().c_str());
 339
 340     if ( !m_receivedData->IsSupportedFormat(format) )
 341         return;
 342
 343     m_receivedData->SetData(format, sel.length, sel.data);
 344     m_formatSupported = true;
 345 }
 346
 347 //-----------------------------------------------------------------------------
 348 // asynchronous "selection_received" for targets
 349 //-----------------------------------------------------------------------------
 350
 351 extern "C" {
 352 static void
 353 async_targets_selection_received( GtkWidget *WXUNUSED(widget),
 354                             GtkSelectionData *selection_data,
 355                             guint32 WXUNUSED(time),
 356                             wxClipboard *clipboard )
 357 {
 358     if ( !clipboard ) // Assert?
 359         return;
 360
 361     if (!clipboard->m_sink)
 362         return;
 363
 364     wxClipboardEvent *event = new wxClipboardEvent(wxEVT_CLIPBOARD_CHANGED);
 365
 366     if ( !selection_data || selection_data->length <= 0 )
 367     {
 368         clipboard->m_sink->QueueEvent( event );
 369         return;
 370     }
 371
 372     // make sure we got the data in the correct form
 373     GdkAtom type = selection_data->type;
 374     if ( type != GDK_SELECTION_TYPE_ATOM )
 375     {
 376         if ( strcmp(wxGtkString(gdk_atom_name(type)), "TARGETS") != 0 )
 377         {
 378             wxLogTrace( TRACE_CLIPBOARD,
 379                         _T("got unsupported clipboard target") );
 380
 381             clipboard->m_sink->QueueEvent( event );
 382             return;
 383         }
 384     }
 385
 386 #ifdef __WXDEBUG__
 387     // it's not really a format, of course, but we can reuse its GetId() method
 388     // to format this atom as string
 389     wxDataFormat clip(selection_data->selection);
 390     wxLogTrace( TRACE_CLIPBOARD,
 391                 wxT("Received available formats for clipboard %s"),
 392                 clip.GetId().c_str() );
 393 #endif // __WXDEBUG__
 394
 395     // the atoms we received, holding a list of targets (= formats)
 396     const GdkAtom * const atoms = (GdkAtom *)selection_data->data;
 397     for ( size_t i = 0; i < selection_data->length/sizeof(GdkAtom); i++ )
 398     {
 399         const wxDataFormat format(atoms[i]);
 400
 401         wxLogTrace(TRACE_CLIPBOARD, wxT("\t%s"), format.GetId().c_str());
 402
 403         event->AddFormat( format );
 404     }
 405
 406     clipboard->m_sink->QueueEvent( event );
 407 }
 408 }
 409
 410 // ============================================================================
 411 // wxClipboard implementation
 412 // ============================================================================
 413
 414 // ----------------------------------------------------------------------------
 415 // wxClipboard ctor/dtor
 416 // ----------------------------------------------------------------------------
 417
 418 IMPLEMENT_DYNAMIC_CLASS(wxClipboard,wxObject)
 419
 420 wxClipboard::wxClipboard()
 421 {
 422     m_open = false;
 423
 424     m_dataPrimary =
 425     m_dataClipboard =
 426     m_receivedData = NULL;
 427
 428     m_formatSupported = false;
 429     m_targetRequested = 0;
 430
 431     // we use m_targetsWidget to query what formats are available
 432     m_targetsWidget = gtk_window_new( GTK_WINDOW_POPUP );
 433     gtk_widget_realize( m_targetsWidget );
 434
 435     g_signal_connect (m_targetsWidget, "selection_received",
 436                       G_CALLBACK (targets_selection_received), this);
 437
 438     // we use m_targetsWidgetAsync to query what formats asynchronously
 439     m_targetsWidgetAsync = gtk_window_new( GTK_WINDOW_POPUP );
 440     gtk_widget_realize( m_targetsWidgetAsync );
 441
 442     g_signal_connect (m_targetsWidgetAsync, "selection_received",
 443                       G_CALLBACK (async_targets_selection_received), this);
 444
 445     // we use m_clipboardWidget to get and to offer data
 446     m_clipboardWidget = gtk_window_new( GTK_WINDOW_POPUP );
 447     gtk_widget_realize( m_clipboardWidget );
 448
 449     g_signal_connect (m_clipboardWidget, "selection_received",
 450                       G_CALLBACK (selection_received), this);
 451
 452     g_signal_connect (m_clipboardWidget, "selection_clear_event",
 453                       G_CALLBACK (selection_clear_clip), NULL);
 454
 455     // initialize atoms we use if not done yet
 456     if ( !g_clipboardAtom )
 457         g_clipboardAtom = gdk_atom_intern( "CLIPBOARD", FALSE );
 458     if ( !g_targetsAtom )
 459         g_targetsAtom = gdk_atom_intern ("TARGETS", FALSE);
 460     if ( !g_timestampAtom )
 461         g_timestampAtom = gdk_atom_intern ("TIMESTAMP", FALSE);
 462 }
 463
 464 wxClipboard::~wxClipboard()
 465 {
 466     Clear();
 467
 468     gtk_widget_destroy( m_clipboardWidget );
 469     gtk_widget_destroy( m_targetsWidget );
 470 }
 471
 472 // ----------------------------------------------------------------------------
 473 // wxClipboard helper functions
 474 // ----------------------------------------------------------------------------
 475
 476 GdkAtom wxClipboard::GTKGetClipboardAtom() const
 477 {
 478     return m_usePrimary ? (GdkAtom)GDK_SELECTION_PRIMARY
 479                         : g_clipboardAtom;
 480 }
 481
 482 void wxClipboard::GTKClearData(Kind kind)
 483 {
 484     wxDataObject *&data = Data(kind);
 485     if ( data )
 486     {
 487         delete data;
 488         data = NULL;
 489     }
 490 }
 491
 492 bool wxClipboard::SetSelectionOwner(bool set)
 493 {
 494     bool rc = gtk_selection_owner_set
 495               (
 496                 set ? m_clipboardWidget : NULL,
 497                 GTKGetClipboardAtom(),
 498                 (guint32)GDK_CURRENT_TIME
 499               );
 500
 501     if ( !rc )
 502     {
 503         wxLogTrace(TRACE_CLIPBOARD, _T("Failed to %sset selection owner"),
 504                    set ? _T("") : _T("un"));
 505     }
 506
 507     return rc;
 508 }
 509
 510 void wxClipboard::AddSupportedTarget(GdkAtom atom)
 511 {
 512     gtk_selection_add_target
 513     (
 514         m_clipboardWidget,
 515         GTKGetClipboardAtom(),
 516         atom,
 517         0 // info (same as client data) unused
 518     );
 519 }
 520
 521 bool wxClipboard::IsSupportedAsync(wxEvtHandler *sink)
 522 {
 523     m_sink = sink;
 524
 525     gtk_selection_convert( m_targetsWidgetAsync,
 526                            GTKGetClipboardAtom(),
 527                            g_targetsAtom,
 528                            (guint32) GDK_CURRENT_TIME );
 529
 530     return true;
 531 }
 532
 533 bool wxClipboard::DoIsSupported(const wxDataFormat& format)
 534 {
 535     wxCHECK_MSG( format, false, wxT("invalid clipboard format") );
 536
 537     wxLogTrace(TRACE_CLIPBOARD, wxT("Checking if format %s is available"),
 538                format.GetId().c_str());
 539
 540     // these variables will be used by our GTKOnTargetReceived()
 541     m_targetRequested = format;
 542     m_formatSupported = false;
 543
 544     // block until m_formatSupported is set from targets_selection_received
 545     // callback
 546     {
 547         wxClipboardSync sync(*this);
 548
 549         gtk_selection_convert( m_targetsWidget,
 550                                GTKGetClipboardAtom(),
 551                                g_targetsAtom,
 552                                (guint32) GDK_CURRENT_TIME );
 553     }
 554
 555     return m_formatSupported;
 556 }
 557
 558 // ----------------------------------------------------------------------------
 559 // wxClipboard public API implementation
 560 // ----------------------------------------------------------------------------
 561
 562 void wxClipboard::Clear()
 563 {
 564     if ( gdk_selection_owner_get(GTKGetClipboardAtom()) ==
 565             m_clipboardWidget->window )
 566     {
 567         wxClipboardSync sync(*this);
 568
 569         // this will result in selection_clear_clip callback being called and
 570         // it will free our data
 571         SetSelectionOwner(false);
 572     }
 573
 574     m_targetRequested = 0;
 575     m_formatSupported = false;
 576 }
 577
 578 bool wxClipboard::Open()
 579 {
 580     wxCHECK_MSG( !m_open, false, wxT("clipboard already open") );
 581
 582     m_open = true;
 583
 584     return true;
 585 }
 586
 587 bool wxClipboard::SetData( wxDataObject *data )
 588 {
 589     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 590
 591     wxCHECK_MSG( data, false, wxT("data is invalid") );
 592
 593     Clear();
 594
 595     return AddData( data );
 596 }
 597
 598 bool wxClipboard::AddData( wxDataObject *data )
 599 {
 600     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 601
 602     wxCHECK_MSG( data, false, wxT("data is invalid") );
 603
 604     // we can only store one wxDataObject so clear the old one
 605     Clear();
 606
 607     Data() = data;
 608
 609     // get formats from wxDataObjects
 610     const size_t count = data->GetFormatCount();
 611     wxDataFormatArray formats(new wxDataFormat[count]);
 612     data->GetAllFormats(formats.get());
 613
 614     // always provide TIMESTAMP as a target, see comments in selection_handler
 615     // for explanation
 616     AddSupportedTarget(g_timestampAtom);
 617
 618     for ( size_t i = 0; i < count; i++ )
 619     {
 620         const wxDataFormat format(formats[i]);
 621
 622         wxLogTrace(TRACE_CLIPBOARD, wxT("Adding support for %s"),
 623                    format.GetId().c_str());
 624
 625         AddSupportedTarget(format);
 626     }
 627
 628     g_signal_connect (m_clipboardWidget, "selection_get",
 629                       G_CALLBACK (selection_handler),
 630                       GUINT_TO_POINTER (gtk_get_current_event_time()) );
 631
 632     // tell the world we offer clipboard data
 633     return SetSelectionOwner();
 634 }
 635
 636 void wxClipboard::Close()
 637 {
 638     wxCHECK_RET( m_open, wxT("clipboard not open") );
 639
 640     m_open = false;
 641 }
 642
 643 bool wxClipboard::IsOpened() const
 644 {
 645     return m_open;
 646 }
 647
 648 bool wxClipboard::IsSupported( const wxDataFormat& format )
 649 {
 650     if ( DoIsSupported(format) )
 651         return true;
 652
 653 #if wxUSE_UNICODE
 654     if ( format == wxDF_UNICODETEXT )
 655     {
 656         // also with plain STRING format
 657         return DoIsSupported(g_altTextAtom);
 658     }
 659 #endif // wxUSE_UNICODE
 660
 661     return false;
 662 }
 663
 664 bool wxClipboard::GetData( wxDataObject& data )
 665 {
 666     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 667
 668     // get all supported formats from wxDataObjects
 669     const size_t count = data.GetFormatCount();
 670     wxDataFormatArray formats(new wxDataFormat[count]);
 671     data.GetAllFormats(formats.get());
 672
 673     for ( size_t i = 0; i < count; i++ )
 674     {
 675         const wxDataFormat format(formats[i]);
 676
 677         // is this format supported by clipboard ?
 678         if ( !DoIsSupported(format) )
 679             continue;
 680
 681         wxLogTrace(TRACE_CLIPBOARD, wxT("Requesting format %s"),
 682                    format.GetId().c_str());
 683
 684         // these variables will be used by our GTKOnSelectionReceived()
 685         m_receivedData = &data;
 686         m_formatSupported = false;
 687
 688         {
 689             wxClipboardSync sync(*this);
 690
 691             gtk_selection_convert(m_clipboardWidget,
 692                                   GTKGetClipboardAtom(),
 693                                   format,
 694                                   (guint32) GDK_CURRENT_TIME );
 695         } // wait until we get the results
 696
 697         /*
 698            Normally this is a true error as we checked for the presence of such
 699            data before, but there are applications that may return an empty
 700            string (e.g. Gnumeric-1.6.1 on Linux if an empty cell is copied)
 701            which would produce a false error message here, so we check for the
 702            size of the string first. With ANSI, GetDataSize returns an extra
 703            value (for the closing null?), with unicode, the exact number of
 704            tokens is given (that is more than 1 for non-ASCII characters)
 705            (tested with Gnumeric-1.6.1 and OpenOffice.org-2.0.2)
 706          */
 707 #if wxUSE_UNICODE
 708         if ( format != wxDF_UNICODETEXT || data.GetDataSize(format) > 0 )
 709 #else // !UNICODE
 710         if ( format != wxDF_TEXT || data.GetDataSize(format) > 1 )
 711 #endif // UNICODE / !UNICODE
 712         {
 713             wxCHECK_MSG( m_formatSupported, false,
 714                          wxT("error retrieving data from clipboard") );
 715         }
 716
 717         return true;
 718     }
 719
 720     wxLogTrace(TRACE_CLIPBOARD, wxT("GetData(): format not found"));
 721
 722     return false;
 723 }
 724
 725 #endif // wxUSE_CLIPBOARD