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/app.h"
  28     #include "wx/log.h"
  29     #include "wx/utils.h"
  30     #include "wx/dataobj.h"
  31 #endif
  32
  33 #include "wx/scopedarray.h"
  34 #include "wx/scopeguard.h"
  35 #include "wx/evtloop.h"
  36
  37 #include "wx/gtk/private.h"
  38
  39 typedef wxScopedArray<wxDataFormat> wxDataFormatArray;
  40
  41 // ----------------------------------------------------------------------------
  42 // data
  43 // ----------------------------------------------------------------------------
  44
  45 static GdkAtom  g_clipboardAtom   = 0;
  46 static GdkAtom  g_targetsAtom     = 0;
  47 static GdkAtom  g_timestampAtom   = 0;
  48
  49 #if wxUSE_UNICODE
  50 extern GdkAtom g_altTextAtom;
  51 #endif
  52
  53 // the trace mask we use with wxLogTrace() - call
  54 // wxLog::AddTraceMask(TRACE_CLIPBOARD) to enable the trace messages from here
  55 // (there will be a *lot* of them!)
  56 #define TRACE_CLIPBOARD wxT("clipboard")
  57
  58 // ----------------------------------------------------------------------------
  59 // wxClipboardSync: used to perform clipboard operations synchronously
  60 // ----------------------------------------------------------------------------
  61
  62 // constructing this object on stack will wait wait until the latest clipboard
  63 // operation is finished on block exit
  64 //
  65 // notice that there can be no more than one such object alive at any moment,
  66 // i.e. reentrancies are not allowed
  67 class wxClipboardSync
  68 {
  69 public:
  70     wxClipboardSync(wxClipboard& clipboard)
  71     {
  72         wxASSERT_MSG( !ms_clipboard, wxT("reentrancy in clipboard code") );
  73         ms_clipboard = &clipboard;
  74     }
  75
  76     ~wxClipboardSync()
  77     {
  78 #if wxUSE_CONSOLE_EVENTLOOP
  79         // ensure that there is a running event loop: this might not be the
  80         // case if we're called before the main event loop startup
  81         wxEventLoopGuarantor ensureEventLoop;
  82 #endif
  83         while (ms_clipboard)
  84             wxEventLoopBase::GetActive()->YieldFor(wxEVT_CATEGORY_CLIPBOARD);
  85     }
  86
  87     // this method must be called by GTK+ callbacks to indicate that we got the
  88     // result for our clipboard operation
  89     static void OnDone(wxClipboard * WXUNUSED_UNLESS_DEBUG(clipboard))
  90     {
  91         wxASSERT_MSG( clipboard == ms_clipboard,
  92                         wxT("got notification for alien clipboard") );
  93
  94         ms_clipboard = NULL;
  95     }
  96
  97     // this method should be called if it's possible that no async clipboard
  98     // operation is currently in progress (like it can be the case when the
  99     // clipboard is cleared but not because we asked about it), it should only
 100     // be called if such situation is expected -- otherwise call OnDone() which
 101     // would assert in this case
 102     static void OnDoneIfInProgress(wxClipboard *clipboard)
 103     {
 104         if ( ms_clipboard )
 105             OnDone(clipboard);
 106     }
 107
 108 private:
 109     static wxClipboard *ms_clipboard;
 110
 111     wxDECLARE_NO_COPY_CLASS(wxClipboardSync);
 112 };
 113
 114 wxClipboard *wxClipboardSync::ms_clipboard = NULL;
 115
 116 // ============================================================================
 117 // clipboard callbacks implementation
 118 // ============================================================================
 119
 120 //-----------------------------------------------------------------------------
 121 // "selection_received" for targets
 122 //-----------------------------------------------------------------------------
 123
 124 extern "C" {
 125 static void
 126 targets_selection_received( GtkWidget *WXUNUSED(widget),
 127                             GtkSelectionData *selection_data,
 128                             guint32 WXUNUSED(time),
 129                             wxClipboard *clipboard )
 130 {
 131     if ( !clipboard )
 132         return;
 133
 134     wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
 135
 136     if (!selection_data)
 137         return;
 138
 139     const int selection_data_length = gtk_selection_data_get_length(selection_data);
 140     if (selection_data_length <= 0)
 141         return;
 142
 143     // make sure we got the data in the correct form
 144     GdkAtom type = gtk_selection_data_get_data_type(selection_data);
 145     if ( type != GDK_SELECTION_TYPE_ATOM )
 146     {
 147         if ( strcmp(wxGtkString(gdk_atom_name(type)), "TARGETS") != 0 )
 148         {
 149             wxLogTrace( TRACE_CLIPBOARD,
 150                         wxT("got unsupported clipboard target") );
 151
 152             return;
 153         }
 154     }
 155
 156     // it's not really a format, of course, but we can reuse its GetId() method
 157     // to format this atom as string
 158     wxDataFormat clip(gtk_selection_data_get_selection(selection_data));
 159     wxLogTrace( TRACE_CLIPBOARD,
 160                 wxT("Received available formats for clipboard %s"),
 161                 clip.GetId().c_str() );
 162
 163     // the atoms we received, holding a list of targets (= formats)
 164     const GdkAtom* const atoms = (GdkAtom*)gtk_selection_data_get_data(selection_data);
 165     for (size_t i = 0; i < selection_data_length / sizeof(GdkAtom); i++)
 166     {
 167         const wxDataFormat format(atoms[i]);
 168
 169         wxLogTrace(TRACE_CLIPBOARD, wxT("\t%s"), format.GetId().c_str());
 170
 171         if ( clipboard->GTKOnTargetReceived(format) )
 172             return;
 173     }
 174 }
 175 }
 176
 177 bool wxClipboard::GTKOnTargetReceived(const wxDataFormat& format)
 178 {
 179     if ( format != m_targetRequested )
 180         return false;
 181
 182     m_formatSupported = true;
 183     return true;
 184 }
 185
 186 //-----------------------------------------------------------------------------
 187 // "selection_received" for the actual data
 188 //-----------------------------------------------------------------------------
 189
 190 extern "C" {
 191 static void
 192 selection_received( GtkWidget *WXUNUSED(widget),
 193                     GtkSelectionData *selection_data,
 194                     guint32 WXUNUSED(time),
 195                     wxClipboard *clipboard )
 196 {
 197     if ( !clipboard )
 198         return;
 199
 200     wxON_BLOCK_EXIT1(wxClipboardSync::OnDone, clipboard);
 201
 202     if (!selection_data || gtk_selection_data_get_length(selection_data) <= 0)
 203         return;
 204
 205     clipboard->GTKOnSelectionReceived(*selection_data);
 206 }
 207 }
 208
 209 //-----------------------------------------------------------------------------
 210 // "selection_clear"
 211 //-----------------------------------------------------------------------------
 212
 213 extern "C" {
 214 static gint
 215 selection_clear_clip( GtkWidget *WXUNUSED(widget), GdkEventSelection *event )
 216 {
 217     wxClipboard * const clipboard = wxTheClipboard;
 218     if ( !clipboard )
 219         return TRUE;
 220
 221     // notice the use of OnDoneIfInProgress() here instead of just OnDone():
 222     // it's perfectly possible that we're receiving this notification from GTK+
 223     // even though we hadn't cleared the clipboard ourselves but because
 224     // another application (or even another window in the same program)
 225     // acquired it
 226     wxON_BLOCK_EXIT1(wxClipboardSync::OnDoneIfInProgress, clipboard);
 227
 228     wxClipboard::Kind kind;
 229     if (event->selection == GDK_SELECTION_PRIMARY)
 230     {
 231         wxLogTrace(TRACE_CLIPBOARD, wxT("Lost primary selection" ));
 232
 233         kind = wxClipboard::Primary;
 234     }
 235     else if (event->selection == g_clipboardAtom)
 236     {
 237         wxLogTrace(TRACE_CLIPBOARD, wxT("Lost clipboard" ));
 238
 239         kind = wxClipboard::Clipboard;
 240     }
 241     else // some other selection, we're not concerned
 242     {
 243         return FALSE;
 244     }
 245
 246     // the clipboard is no longer in our hands, we don't need data any more
 247     clipboard->GTKClearData(kind);
 248
 249     return TRUE;
 250 }
 251 }
 252
 253 //-----------------------------------------------------------------------------
 254 // selection handler for supplying data
 255 //-----------------------------------------------------------------------------
 256
 257 extern "C" {
 258 static void
 259 selection_handler( GtkWidget *WXUNUSED(widget),
 260                    GtkSelectionData *selection_data,
 261                    guint WXUNUSED(info),
 262                    guint WXUNUSED(time),
 263                    gpointer signal_data )
 264 {
 265     wxClipboard * const clipboard = wxTheClipboard;
 266     if ( !clipboard )
 267         return;
 268
 269     wxDataObject * const data = clipboard->GTKGetDataObject(
 270         gtk_selection_data_get_selection(selection_data));
 271     if ( !data )
 272         return;
 273
 274     // ICCCM says that TIMESTAMP is a required atom.
 275     // In particular, it satisfies Klipper, which polls
 276     // TIMESTAMP to see if the clipboards content has changed.
 277     // It shall return the time which was used to set the data.
 278     if (gtk_selection_data_get_target(selection_data) == g_timestampAtom)
 279     {
 280         guint timestamp = GPOINTER_TO_UINT (signal_data);
 281         gtk_selection_data_set(selection_data,
 282                                GDK_SELECTION_TYPE_INTEGER,
 283                                32,
 284                                (guchar*)&(timestamp),
 285                                sizeof(timestamp));
 286         wxLogTrace(TRACE_CLIPBOARD,
 287                    wxT("Clipboard TIMESTAMP requested, returning timestamp=%u"),
 288                    timestamp);
 289         return;
 290     }
 291
 292     wxDataFormat format(gtk_selection_data_get_target(selection_data));
 293
 294     wxLogTrace(TRACE_CLIPBOARD,
 295                wxT("clipboard data in format %s, GtkSelectionData is target=%s type=%s selection=%s timestamp=%u"),
 296                format.GetId().c_str(),
 297                wxString::FromAscii(wxGtkString(gdk_atom_name(gtk_selection_data_get_target(selection_data)))).c_str(),
 298                wxString::FromAscii(wxGtkString(gdk_atom_name(gtk_selection_data_get_data_type(selection_data)))).c_str(),
 299                wxString::FromAscii(wxGtkString(gdk_atom_name(gtk_selection_data_get_selection(selection_data)))).c_str(),
 300                GPOINTER_TO_UINT( signal_data )
 301                );
 302
 303     if ( !data->IsSupportedFormat( format ) )
 304         return;
 305
 306     int size = data->GetDataSize( format );
 307     if ( !size )
 308         return;
 309
 310     wxCharBuffer buf(size - 1); // it adds 1 internally (for NUL)
 311
 312     // text data must be returned in UTF8 if format is wxDF_UNICODETEXT
 313     if ( !data->GetDataHere(format, buf.data()) )
 314         return;
 315
 316     // use UTF8_STRING format if requested in Unicode build but just plain
 317     // STRING one in ANSI or if explicitly asked in Unicode
 318 #if wxUSE_UNICODE
 319     if (format == wxDataFormat(wxDF_UNICODETEXT))
 320     {
 321         gtk_selection_data_set_text(
 322             selection_data,
 323             (const gchar*)buf.data(),
 324             size );
 325     }
 326     else
 327 #endif // wxUSE_UNICODE
 328     {
 329         gtk_selection_data_set(
 330             selection_data,
 331             GDK_SELECTION_TYPE_STRING,
 332             8*sizeof(gchar),
 333             (const guchar*)buf.data(),
 334             size );
 335     }
 336 }
 337 }
 338
 339 void wxClipboard::GTKOnSelectionReceived(const GtkSelectionData& sel)
 340 {
 341     wxCHECK_RET( m_receivedData, wxT("should be inside GetData()") );
 342
 343     const wxDataFormat format(gtk_selection_data_get_target(const_cast<GtkSelectionData*>(&sel)));
 344     wxLogTrace(TRACE_CLIPBOARD, wxT("Received selection %s"),
 345                format.GetId().c_str());
 346
 347     if ( !m_receivedData->IsSupportedFormat(format, wxDataObject::Set) )
 348         return;
 349
 350     m_receivedData->SetData(format,
 351         gtk_selection_data_get_length(const_cast<GtkSelectionData*>(&sel)),
 352         gtk_selection_data_get_data(const_cast<GtkSelectionData*>(&sel)));
 353     m_formatSupported = true;
 354 }
 355
 356 //-----------------------------------------------------------------------------
 357 // asynchronous "selection_received" for targets
 358 //-----------------------------------------------------------------------------
 359
 360 extern "C" {
 361 static void
 362 async_targets_selection_received( GtkWidget *WXUNUSED(widget),
 363                             GtkSelectionData *selection_data,
 364                             guint32 WXUNUSED(time),
 365                             wxClipboard *clipboard )
 366 {
 367     if ( !clipboard ) // Assert?
 368         return;
 369
 370     if (!clipboard->m_sink)
 371         return;
 372
 373     wxClipboardEvent *event = new wxClipboardEvent(wxEVT_CLIPBOARD_CHANGED);
 374     event->SetEventObject( clipboard );
 375
 376     int selection_data_length = 0;
 377     if (selection_data)
 378         selection_data_length = gtk_selection_data_get_length(selection_data);
 379
 380     if (selection_data_length <= 0)
 381     {
 382         clipboard->m_sink->QueueEvent( event );
 383         clipboard->m_sink.Release();
 384         return;
 385     }
 386
 387     // make sure we got the data in the correct form
 388     GdkAtom type = gtk_selection_data_get_data_type(selection_data);
 389     if ( type != GDK_SELECTION_TYPE_ATOM )
 390     {
 391         if ( strcmp(wxGtkString(gdk_atom_name(type)), "TARGETS") != 0 )
 392         {
 393             wxLogTrace( TRACE_CLIPBOARD,
 394                         wxT("got unsupported clipboard target") );
 395
 396             clipboard->m_sink->QueueEvent( event );
 397             clipboard->m_sink.Release();
 398             return;
 399         }
 400     }
 401
 402     // it's not really a format, of course, but we can reuse its GetId() method
 403     // to format this atom as string
 404     wxDataFormat clip(gtk_selection_data_get_selection(selection_data));
 405     wxLogTrace( TRACE_CLIPBOARD,
 406                 wxT("Received available formats for clipboard %s"),
 407                 clip.GetId().c_str() );
 408
 409     // the atoms we received, holding a list of targets (= formats)
 410     const GdkAtom* const atoms = (GdkAtom*)gtk_selection_data_get_data(selection_data);
 411     for (size_t i = 0; i < selection_data_length / sizeof(GdkAtom); i++)
 412     {
 413         const wxDataFormat format(atoms[i]);
 414
 415         wxLogTrace(TRACE_CLIPBOARD, wxT("\t%s"), format.GetId().c_str());
 416
 417         event->AddFormat( format );
 418     }
 419
 420     clipboard->m_sink->QueueEvent( event );
 421     clipboard->m_sink.Release();
 422 }
 423 }
 424
 425 // ============================================================================
 426 // wxClipboard implementation
 427 // ============================================================================
 428
 429 // ----------------------------------------------------------------------------
 430 // wxClipboard ctor/dtor
 431 // ----------------------------------------------------------------------------
 432
 433 IMPLEMENT_DYNAMIC_CLASS(wxClipboard,wxObject)
 434
 435 wxClipboard::wxClipboard()
 436 {
 437     m_open = false;
 438
 439     m_dataPrimary =
 440     m_dataClipboard =
 441     m_receivedData = NULL;
 442
 443     m_formatSupported = false;
 444     m_targetRequested = 0;
 445
 446     // we use m_targetsWidget to query what formats are available
 447     m_targetsWidget = gtk_window_new( GTK_WINDOW_POPUP );
 448     gtk_widget_realize( m_targetsWidget );
 449
 450     g_signal_connect (m_targetsWidget, "selection_received",
 451                       G_CALLBACK (targets_selection_received), this);
 452
 453     // we use m_targetsWidgetAsync to query what formats are available asynchronously
 454     m_targetsWidgetAsync = gtk_window_new( GTK_WINDOW_POPUP );
 455     gtk_widget_realize( m_targetsWidgetAsync );
 456
 457     g_signal_connect (m_targetsWidgetAsync, "selection_received",
 458                       G_CALLBACK (async_targets_selection_received), this);
 459
 460     // we use m_clipboardWidget to get and to offer data
 461     m_clipboardWidget = gtk_window_new( GTK_WINDOW_POPUP );
 462     gtk_widget_realize( m_clipboardWidget );
 463
 464     g_signal_connect (m_clipboardWidget, "selection_received",
 465                       G_CALLBACK (selection_received), this);
 466
 467     g_signal_connect (m_clipboardWidget, "selection_clear_event",
 468                       G_CALLBACK (selection_clear_clip), NULL);
 469
 470     // initialize atoms we use if not done yet
 471     if ( !g_clipboardAtom )
 472         g_clipboardAtom = gdk_atom_intern( "CLIPBOARD", FALSE );
 473     if ( !g_targetsAtom )
 474         g_targetsAtom = gdk_atom_intern ("TARGETS", FALSE);
 475     if ( !g_timestampAtom )
 476         g_timestampAtom = gdk_atom_intern ("TIMESTAMP", FALSE);
 477 }
 478
 479 wxClipboard::~wxClipboard()
 480 {
 481     Clear();
 482
 483     gtk_widget_destroy( m_clipboardWidget );
 484     gtk_widget_destroy( m_targetsWidget );
 485 }
 486
 487 // ----------------------------------------------------------------------------
 488 // wxClipboard helper functions
 489 // ----------------------------------------------------------------------------
 490
 491 GdkAtom wxClipboard::GTKGetClipboardAtom() const
 492 {
 493     return m_usePrimary ? (GdkAtom)GDK_SELECTION_PRIMARY
 494                         : g_clipboardAtom;
 495 }
 496
 497 void wxClipboard::GTKClearData(Kind kind)
 498 {
 499     wxDataObject *&data = Data(kind);
 500     wxDELETE(data);
 501 }
 502
 503 bool wxClipboard::SetSelectionOwner(bool set)
 504 {
 505     bool rc = gtk_selection_owner_set
 506               (
 507                 set ? m_clipboardWidget : NULL,
 508                 GTKGetClipboardAtom(),
 509                 (guint32)GDK_CURRENT_TIME
 510               ) != 0;
 511
 512     if ( !rc )
 513     {
 514         wxLogTrace(TRACE_CLIPBOARD, wxT("Failed to %sset selection owner"),
 515                    set ? wxT("") : wxT("un"));
 516     }
 517
 518     return rc;
 519 }
 520
 521 void wxClipboard::AddSupportedTarget(GdkAtom atom)
 522 {
 523     gtk_selection_add_target
 524     (
 525         m_clipboardWidget,
 526         GTKGetClipboardAtom(),
 527         atom,
 528         0 // info (same as client data) unused
 529     );
 530 }
 531
 532 bool wxClipboard::IsSupportedAsync(wxEvtHandler *sink)
 533 {
 534     if (m_sink.get())
 535         return false;  // currently busy, come back later
 536
 537     wxCHECK_MSG( sink, false, wxT("no sink given") );
 538
 539     m_sink = sink;
 540     gtk_selection_convert( m_targetsWidgetAsync,
 541                            GTKGetClipboardAtom(),
 542                            g_targetsAtom,
 543                            (guint32) GDK_CURRENT_TIME );
 544
 545     return true;
 546 }
 547
 548 bool wxClipboard::DoIsSupported(const wxDataFormat& format)
 549 {
 550     wxCHECK_MSG( format, false, wxT("invalid clipboard format") );
 551
 552     wxLogTrace(TRACE_CLIPBOARD, wxT("Checking if format %s is available"),
 553                format.GetId().c_str());
 554
 555     // these variables will be used by our GTKOnTargetReceived()
 556     m_targetRequested = format;
 557     m_formatSupported = false;
 558
 559     // block until m_formatSupported is set from targets_selection_received
 560     // callback
 561     {
 562         wxClipboardSync sync(*this);
 563
 564         gtk_selection_convert( m_targetsWidget,
 565                                GTKGetClipboardAtom(),
 566                                g_targetsAtom,
 567                                (guint32) GDK_CURRENT_TIME );
 568     }
 569
 570     return m_formatSupported;
 571 }
 572
 573 // ----------------------------------------------------------------------------
 574 // wxClipboard public API implementation
 575 // ----------------------------------------------------------------------------
 576
 577 void wxClipboard::Clear()
 578 {
 579     gtk_selection_clear_targets( m_clipboardWidget, GTKGetClipboardAtom() );
 580
 581     if ( gdk_selection_owner_get(GTKGetClipboardAtom()) ==
 582             gtk_widget_get_window(m_clipboardWidget) )
 583     {
 584         wxClipboardSync sync(*this);
 585
 586         // this will result in selection_clear_clip callback being called and
 587         // it will free our data
 588         SetSelectionOwner(false);
 589     }
 590
 591     m_targetRequested = 0;
 592     m_formatSupported = false;
 593 }
 594
 595 bool wxClipboard::Open()
 596 {
 597     wxCHECK_MSG( !m_open, false, wxT("clipboard already open") );
 598
 599     m_open = true;
 600
 601     return true;
 602 }
 603
 604 bool wxClipboard::SetData( wxDataObject *data )
 605 {
 606     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 607
 608     wxCHECK_MSG( data, false, wxT("data is invalid") );
 609
 610     Clear();
 611
 612     return AddData( data );
 613 }
 614
 615 bool wxClipboard::AddData( wxDataObject *data )
 616 {
 617     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 618
 619     wxCHECK_MSG( data, false, wxT("data is invalid") );
 620
 621     // we can only store one wxDataObject so clear the old one
 622     Clear();
 623
 624     Data() = data;
 625
 626     // get formats from wxDataObjects
 627     const size_t count = data->GetFormatCount();
 628     wxDataFormatArray formats(new wxDataFormat[count]);
 629     data->GetAllFormats(formats.get());
 630
 631     // always provide TIMESTAMP as a target, see comments in selection_handler
 632     // for explanation
 633     AddSupportedTarget(g_timestampAtom);
 634
 635     for ( size_t i = 0; i < count; i++ )
 636     {
 637         const wxDataFormat format(formats[i]);
 638
 639         wxLogTrace(TRACE_CLIPBOARD, wxT("Adding support for %s"),
 640                    format.GetId().c_str());
 641
 642         AddSupportedTarget(format);
 643     }
 644
 645     g_signal_connect (m_clipboardWidget, "selection_get",
 646                       G_CALLBACK (selection_handler),
 647                       GUINT_TO_POINTER (gtk_get_current_event_time()) );
 648
 649     // tell the world we offer clipboard data
 650     return SetSelectionOwner();
 651 }
 652
 653 void wxClipboard::Close()
 654 {
 655     wxCHECK_RET( m_open, wxT("clipboard not open") );
 656
 657     m_open = false;
 658 }
 659
 660 bool wxClipboard::IsOpened() const
 661 {
 662     return m_open;
 663 }
 664
 665 bool wxClipboard::IsSupported( const wxDataFormat& format )
 666 {
 667     if ( DoIsSupported(format) )
 668         return true;
 669
 670 #if wxUSE_UNICODE
 671     if ( format == wxDF_UNICODETEXT )
 672     {
 673         // also with plain STRING format
 674         return DoIsSupported(g_altTextAtom);
 675     }
 676 #endif // wxUSE_UNICODE
 677
 678     return false;
 679 }
 680
 681 bool wxClipboard::GetData( wxDataObject& data )
 682 {
 683     wxCHECK_MSG( m_open, false, wxT("clipboard not open") );
 684
 685     // get all supported formats from wxDataObjects: notice that we are setting
 686     // the object data, so we need them in "Set" direction
 687     const size_t count = data.GetFormatCount(wxDataObject::Set);
 688     wxDataFormatArray formats(new wxDataFormat[count]);
 689     data.GetAllFormats(formats.get(), wxDataObject::Set);
 690
 691     for ( size_t i = 0; i < count; i++ )
 692     {
 693         const wxDataFormat format(formats[i]);
 694
 695         // is this format supported by clipboard ?
 696         if ( !DoIsSupported(format) )
 697             continue;
 698
 699         wxLogTrace(TRACE_CLIPBOARD, wxT("Requesting format %s"),
 700                    format.GetId().c_str());
 701
 702         // these variables will be used by our GTKOnSelectionReceived()
 703         m_receivedData = &data;
 704         m_formatSupported = false;
 705
 706         {
 707             wxClipboardSync sync(*this);
 708
 709             gtk_selection_convert(m_clipboardWidget,
 710                                   GTKGetClipboardAtom(),
 711                                   format,
 712                                   (guint32) GDK_CURRENT_TIME );
 713         } // wait until we get the results
 714
 715         /*
 716            Normally this is a true error as we checked for the presence of such
 717            data before, but there are applications that may return an empty
 718            string (e.g. Gnumeric-1.6.1 on Linux if an empty cell is copied)
 719            which would produce a false error message here, so we check for the
 720            size of the string first. With ANSI, GetDataSize returns an extra
 721            value (for the closing null?), with unicode, the exact number of
 722            tokens is given (that is more than 1 for non-ASCII characters)
 723            (tested with Gnumeric-1.6.1 and OpenOffice.org-2.0.2)
 724          */
 725 #if wxUSE_UNICODE
 726         if ( format != wxDF_UNICODETEXT || data.GetDataSize(format) > 0 )
 727 #else // !UNICODE
 728         if ( format != wxDF_TEXT || data.GetDataSize(format) > 1 )
 729 #endif // UNICODE / !UNICODE
 730         {
 731             wxCHECK_MSG( m_formatSupported, false,
 732                          wxT("error retrieving data from clipboard") );
 733         }
 734
 735         return true;
 736     }
 737
 738     wxLogTrace(TRACE_CLIPBOARD, wxT("GetData(): format not found"));
 739
 740     return false;
 741 }
 742
 743 wxDataObject* wxClipboard::GTKGetDataObject( GdkAtom atom )
 744 {
 745     if ( atom == GDK_NONE )
 746         return Data();
 747
 748     if ( atom == GDK_SELECTION_PRIMARY )
 749     {
 750         wxLogTrace(TRACE_CLIPBOARD, wxT("Primary selection requested" ));
 751
 752         return Data( wxClipboard::Primary );
 753     }
 754     else if ( atom == g_clipboardAtom )
 755     {
 756         wxLogTrace(TRACE_CLIPBOARD, wxT("Clipboard data requested" ));
 757
 758         return Data( wxClipboard::Clipboard );
 759     }
 760     else // some other selection, we're not concerned
 761     {
 762         return (wxDataObject*)NULL;
 763     }
 764 }
 765
 766 #endif // wxUSE_CLIPBOARD