1 /////////////////////////////////////////////////////////////////////////////// 
   3 // Purpose:     wxDropTarget class 
   4 // Author:      Robert Roebling 
   6 // Copyright:   (c) 1998 Robert Roebling 
   7 // Licence:     wxWindows licence 
   8 /////////////////////////////////////////////////////////////////////////////// 
  10 // For compilers that support precompilation, includes "wx.h". 
  11 #include "wx/wxprec.h" 
  17 #if wxUSE_DRAG_AND_DROP 
  19 #include "wx/window.h" 
  21 #include "wx/gdicmn.h" 
  25 #include "wx/gtk/private.h" 
  27 #include <gdk/gdkprivate.h> 
  29 #include <gtk/gtkdnd.h> 
  30 #include <gtk/gtkselection.h> 
  32 //---------------------------------------------------------------------------- 
  34 //---------------------------------------------------------------------------- 
  36 extern bool g_blockEventsOnDrag
; 
  38 // the flags used for the last DoDragDrop() 
  39 static long gs_flagsForDrag 
= 0; 
  41 // the trace mask we use with wxLogTrace() - call 
  42 // wxLog::AddTraceMask(TRACE_DND) to enable the trace messages from here 
  43 // (there are quite a few of them, so don't enable this by default) 
  44 static const wxChar 
*TRACE_DND 
= _T("dnd"); 
  46 //---------------------------------------------------------------------------- 
  48 //---------------------------------------------------------------------------- 
  50 /* Copyright (c) Julian Smart */ 
  51 static const char * page_xpm
[] = { 
  52 /* columns rows colors chars-per-pixel */ 
 101 "       56477<<<<8<<9&:X         ", 
 102 "       59642%&*=-;<09&:5        ", 
 103 "       5q9642%&*=-<<<<<#        ", 
 104 "       5qqw777<<<<<88:>+        ", 
 105 "       erqq9642%&*=t;::+        ", 
 106 "       eyrqq9642%&*=t;:O        ", 
 107 "       eyywwww777<<<<t;O        ", 
 108 "       e0yyrqq9642%&*=to        ", 
 109 "       e00yyrqq9642%&*=o        ", 
 110 "       eu0wwwwwww777<&*X        ", 
 111 "       euu00yyrqq9642%&X        ", 
 112 "       eiuu00yyrqq9642%X        ", 
 113 "       eiiwwwwwwwwww742$        ", 
 114 "       eiiiuu00yyrqq964$        ", 
 115 "       eiiiiuu00yyrqq96$        ", 
 116 "       eiiiiiuu00yyrqq95        ", 
 117 "       eiiiiiiuu00yyrqq5        ", 
 118 "       eeeeeeeeeeeeee55e        ", 
 127 // ============================================================================ 
 129 // ============================================================================ 
 131 // ---------------------------------------------------------------------------- 
 132 // convert between GTK+ and wxWidgets DND constants 
 133 // ---------------------------------------------------------------------------- 
 135 static wxDragResult 
ConvertFromGTK(long action
) 
 139         case GDK_ACTION_COPY
: 
 142         case GDK_ACTION_LINK
: 
 145         case GDK_ACTION_MOVE
: 
 152 // ---------------------------------------------------------------------------- 
 154 // ---------------------------------------------------------------------------- 
 157 static void target_drag_leave( GtkWidget 
*WXUNUSED(widget
), 
 158                                GdkDragContext 
*context
, 
 159                                guint 
WXUNUSED(time
), 
 160                                wxDropTarget 
*drop_target 
) 
 162     if (g_isIdle
) wxapp_install_idle_handler(); 
 164     /* inform the wxDropTarget about the current GdkDragContext. 
 165        this is only valid for the duration of this call */ 
 166     drop_target
->SetDragContext( context 
); 
 168     /* we don't need return values. this event is just for 
 170     drop_target
->OnLeave(); 
 172     /* this has to be done because GDK has no "drag_enter" event */ 
 173     drop_target
->m_firstMotion 
= true; 
 175     /* after this, invalidate the drop_target's GdkDragContext */ 
 176     drop_target
->SetDragContext( (GdkDragContext
*) NULL 
); 
 180 // ---------------------------------------------------------------------------- 
 182 // ---------------------------------------------------------------------------- 
 185 static gboolean 
target_drag_motion( GtkWidget 
*WXUNUSED(widget
), 
 186                                     GdkDragContext 
*context
, 
 190                                     wxDropTarget 
*drop_target 
) 
 192     if (g_isIdle
) wxapp_install_idle_handler(); 
 194     /* Owen Taylor: "if the coordinates not in a drop zone, 
 195        return FALSE, otherwise call gtk_drag_status() and 
 198     /* inform the wxDropTarget about the current GdkDragContext. 
 199        this is only valid for the duration of this call */ 
 200     drop_target
->SetDragContext( context 
); 
 202     // GTK+ always supposes that we want to copy the data by default while we 
 203     // might want to move it, so examine not only suggested_action - which is 
 204     // only good if we don't have our own preferences - but also the actions 
 207     if (drop_target
->GetDefaultAction() == wxDragNone
) 
 209         // use default action set by wxDropSource::DoDragDrop() 
 210     if ( (gs_flagsForDrag 
& wxDrag_DefaultMove
) == wxDrag_DefaultMove 
&& 
 211             (context
->actions 
& GDK_ACTION_MOVE 
) ) 
 213         // move is requested by the program and allowed by GTK+ - do it, even 
 214         // though suggested_action may be currently wxDragCopy 
 217     else // use whatever GTK+ says we should 
 219         result 
= ConvertFromGTK(context
->suggested_action
); 
 221         if ( (result 
== wxDragMove
) && !(gs_flagsForDrag 
& wxDrag_AllowMove
) ) 
 223             // we're requested to move but we can't 
 228     else if (drop_target
->GetDefaultAction() == wxDragMove 
&& 
 229                 (context
->actions 
& GDK_ACTION_MOVE
)) 
 235         if (context
->actions 
& GDK_ACTION_COPY
) 
 237         else if (context
->actions 
& GDK_ACTION_MOVE
) 
 243     if (drop_target
->m_firstMotion
) 
 245         /* the first "drag_motion" event substitutes a "drag_enter" event */ 
 246         result 
= drop_target
->OnEnter( x
, y
, result 
); 
 250         /* give program a chance to react (i.e. to say no by returning FALSE) */ 
 251         result 
= drop_target
->OnDragOver( x
, y
, result 
); 
 254     bool ret 
= wxIsDragResultOk( result 
); 
 257         GdkDragAction action
; 
 258         if (result 
== wxDragCopy
) 
 259             action 
= GDK_ACTION_COPY
; 
 260         else if (result 
== wxDragLink
) 
 261             action 
= GDK_ACTION_LINK
; 
 263             action 
= GDK_ACTION_MOVE
; 
 265         gdk_drag_status( context
, action
, time 
); 
 268     /* after this, invalidate the drop_target's GdkDragContext */ 
 269     drop_target
->SetDragContext( (GdkDragContext
*) NULL 
); 
 271     /* this has to be done because GDK has no "drag_enter" event */ 
 272     drop_target
->m_firstMotion 
= false; 
 278 // ---------------------------------------------------------------------------- 
 280 // ---------------------------------------------------------------------------- 
 283 static gboolean 
target_drag_drop( GtkWidget 
*widget
, 
 284                                   GdkDragContext 
*context
, 
 288                                   wxDropTarget 
*drop_target 
) 
 290     if (g_isIdle
) wxapp_install_idle_handler(); 
 292     /* Owen Taylor: "if the drop is not in a drop zone, 
 293        return FALSE, otherwise, if you aren't accepting 
 294        the drop, call gtk_drag_finish() with success == FALSE 
 295        otherwise call gtk_drag_data_get()" */ 
 297 //    printf( "drop.\n" ); 
 299     /* this seems to make a difference between not accepting 
 300        due to wrong target area and due to wrong format. let 
 301        us hope that this is not required.. */ 
 303     /* inform the wxDropTarget about the current GdkDragContext. 
 304        this is only valid for the duration of this call */ 
 305     drop_target
->SetDragContext( context 
); 
 307     /* inform the wxDropTarget about the current drag widget. 
 308        this is only valid for the duration of this call */ 
 309     drop_target
->SetDragWidget( widget 
); 
 311     /* inform the wxDropTarget about the current drag time. 
 312        this is only valid for the duration of this call */ 
 313     drop_target
->SetDragTime( time 
); 
 316     wxDragResult result = wxDragMove; 
 317     if (context->suggested_action == GDK_ACTION_COPY) result = wxDragCopy; 
 320     /* reset the block here as someone might very well 
 321        show a dialog as a reaction to a drop and this 
 322        wouldn't work without events */ 
 323     g_blockEventsOnDrag 
= false; 
 325     bool ret 
= drop_target
->OnDrop( x
, y 
); 
 329         wxLogTrace(TRACE_DND
, wxT( "Drop target: OnDrop returned FALSE") ); 
 331         /* cancel the whole thing */ 
 332         gtk_drag_finish( context
, 
 333                           FALSE
,        /* no success */ 
 334                           FALSE
,        /* don't delete data on dropping side */ 
 339         wxLogTrace(TRACE_DND
, wxT( "Drop target: OnDrop returned TRUE") ); 
 342         /* disable GUI threads */ 
 345         GdkAtom format 
= drop_target
->GetMatchingPair(); 
 347         // this does happen somehow, see bug 555111 
 348         wxCHECK_MSG( format
, FALSE
, _T("no matching GdkAtom for format?") ); 
 351         GdkDragAction action = GDK_ACTION_MOVE; 
 352         if (result == wxDragCopy) action == GDK_ACTION_COPY; 
 353         context->action = action; 
 355         /* this should trigger an "drag_data_received" event */ 
 356         gtk_drag_get_data( widget
, 
 362         /* re-enable GUI threads */ 
 366     /* after this, invalidate the drop_target's GdkDragContext */ 
 367     drop_target
->SetDragContext( (GdkDragContext
*) NULL 
); 
 369     /* after this, invalidate the drop_target's drag widget */ 
 370     drop_target
->SetDragWidget( (GtkWidget
*) NULL 
); 
 372     /* this has to be done because GDK has no "drag_enter" event */ 
 373     drop_target
->m_firstMotion 
= true; 
 379 // ---------------------------------------------------------------------------- 
 380 // "drag_data_received" 
 381 // ---------------------------------------------------------------------------- 
 384 static void target_drag_data_received( GtkWidget 
*WXUNUSED(widget
), 
 385                                        GdkDragContext 
*context
, 
 388                                        GtkSelectionData 
*data
, 
 389                                        guint 
WXUNUSED(info
), 
 391                                        wxDropTarget 
*drop_target 
) 
 393     if (g_isIdle
) wxapp_install_idle_handler(); 
 395     /* Owen Taylor: "call gtk_drag_finish() with 
 398     if ((data
->length 
<= 0) || (data
->format 
!= 8)) 
 400         /* negative data length and non 8-bit data format 
 401            qualifies for junk */ 
 402         gtk_drag_finish (context
, FALSE
, FALSE
, time
); 
 407     wxLogTrace(TRACE_DND
, wxT( "Drop target: data received event") ); 
 409     /* inform the wxDropTarget about the current GtkSelectionData. 
 410        this is only valid for the duration of this call */ 
 411     drop_target
->SetDragData( data 
); 
 413     wxDragResult result 
= ConvertFromGTK(context
->action
); 
 415     if ( wxIsDragResultOk( drop_target
->OnData( x
, y
, result 
) ) ) 
 417         wxLogTrace(TRACE_DND
, wxT( "Drop target: OnData returned TRUE") ); 
 419         /* tell GTK that data transfer was successful */ 
 420         gtk_drag_finish( context
, TRUE
, FALSE
, time 
); 
 424         wxLogTrace(TRACE_DND
, wxT( "Drop target: OnData returned FALSE") ); 
 426         /* tell GTK that data transfer was not successful */ 
 427         gtk_drag_finish( context
, FALSE
, FALSE
, time 
); 
 430     /* after this, invalidate the drop_target's drag data */ 
 431     drop_target
->SetDragData( (GtkSelectionData
*) NULL 
); 
 435 //---------------------------------------------------------------------------- 
 437 //---------------------------------------------------------------------------- 
 439 wxDropTarget::wxDropTarget( wxDataObject 
*data 
) 
 440             : wxDropTargetBase( data 
) 
 442     m_firstMotion 
= true; 
 443     m_dragContext 
= (GdkDragContext
*) NULL
; 
 444     m_dragWidget 
= (GtkWidget
*) NULL
; 
 445     m_dragData 
= (GtkSelectionData
*) NULL
; 
 449 wxDragResult 
wxDropTarget::OnDragOver( wxCoord 
WXUNUSED(x
), 
 453     // GetMatchingPair() checks for m_dataObject too, no need to do it here 
 455     // disable the debug message from GetMatchingPair() - there are too many 
 461     return (GetMatchingPair() != (GdkAtom
) 0) ? def 
: wxDragNone
; 
 464 bool wxDropTarget::OnDrop( wxCoord 
WXUNUSED(x
), wxCoord 
WXUNUSED(y
) ) 
 469     return (GetMatchingPair() != (GdkAtom
) 0); 
 472 wxDragResult 
wxDropTarget::OnData( wxCoord 
WXUNUSED(x
), wxCoord 
WXUNUSED(y
), 
 478     if (GetMatchingPair() == (GdkAtom
) 0) 
 481     return GetData() ? def 
: wxDragNone
; 
 484 GdkAtom 
wxDropTarget::GetMatchingPair() 
 492     GList 
*child 
= m_dragContext
->targets
; 
 495         GdkAtom formatAtom 
= (GdkAtom
)(child
->data
); 
 496         wxDataFormat 
format( formatAtom 
); 
 499         wxLogTrace(TRACE_DND
, wxT("Drop target: drag has format: %s"), 
 500                    format
.GetId().c_str()); 
 503         if (m_dataObject
->IsSupportedFormat( format 
)) 
 512 bool wxDropTarget::GetData() 
 520     wxDataFormat 
dragFormat( m_dragData
->target 
); 
 522     if (!m_dataObject
->IsSupportedFormat( dragFormat 
)) 
 525     m_dataObject
->SetData( dragFormat
, (size_t)m_dragData
->length
, (const void*)m_dragData
->data 
); 
 530 void wxDropTarget::UnregisterWidget( GtkWidget 
*widget 
) 
 532     wxCHECK_RET( widget 
!= NULL
, wxT("unregister widget is NULL") ); 
 534     gtk_drag_dest_unset( widget 
); 
 536     g_signal_handlers_disconnect_by_func (widget
, 
 537                                           (gpointer
) target_drag_leave
, this); 
 538     g_signal_handlers_disconnect_by_func (widget
, 
 539                                           (gpointer
) target_drag_motion
, this); 
 540     g_signal_handlers_disconnect_by_func (widget
, 
 541                                           (gpointer
) target_drag_drop
, this); 
 542     g_signal_handlers_disconnect_by_func (widget
, 
 543                                           (gpointer
) target_drag_data_received
, this); 
 546 void wxDropTarget::RegisterWidget( GtkWidget 
*widget 
) 
 548     wxCHECK_RET( widget 
!= NULL
, wxT("register widget is NULL") ); 
 550     /* gtk_drag_dest_set() determines what default behaviour we'd like 
 551        GTK to supply. we don't want to specify out targets (=formats) 
 552        or actions in advance (i.e. not GTK_DEST_DEFAULT_MOTION and 
 553        not GTK_DEST_DEFAULT_DROP). instead we react individually to 
 554        "drag_motion" and "drag_drop" events. this makes it possible 
 555        to allow dropping on only a small area. we should set 
 556        GTK_DEST_DEFAULT_HIGHLIGHT as this will switch on the nice 
 557        highlighting if dragging over standard controls, but this 
 558        seems to be broken without the other two. */ 
 560     gtk_drag_dest_set( widget
, 
 561                        (GtkDestDefaults
) 0,         /* no default behaviour */ 
 562                        (GtkTargetEntry
*) NULL
,      /* we don't supply any formats here */ 
 563                        0,                           /* number of targets = 0 */ 
 564                        (GdkDragAction
) 0 );         /* we don't supply any actions here */ 
 566     g_signal_connect (widget
, "drag_leave", 
 567                       G_CALLBACK (target_drag_leave
), this); 
 569     g_signal_connect (widget
, "drag_motion", 
 570                       G_CALLBACK (target_drag_motion
), this); 
 572     g_signal_connect (widget
, "drag_drop", 
 573                       G_CALLBACK (target_drag_drop
), this); 
 575     g_signal_connect (widget
, "drag_data_received", 
 576                       G_CALLBACK (target_drag_data_received
), this); 
 579 //---------------------------------------------------------------------------- 
 581 //---------------------------------------------------------------------------- 
 585 source_drag_data_get  (GtkWidget          
*WXUNUSED(widget
), 
 586                        GdkDragContext     
*WXUNUSED(context
), 
 587                        GtkSelectionData   
*selection_data
, 
 588                        guint               
WXUNUSED(info
), 
 589                        guint               
WXUNUSED(time
), 
 590                        wxDropSource       
*drop_source 
) 
 592     if (g_isIdle
) wxapp_install_idle_handler(); 
 594     wxDataFormat 
format( selection_data
->target 
); 
 596     wxLogTrace(TRACE_DND
, wxT("Drop source: format requested: %s"), 
 597                format
.GetId().c_str()); 
 599     drop_source
->m_retValue 
= wxDragCancel
; 
 601     wxDataObject 
*data 
= drop_source
->GetDataObject(); 
 605         wxLogTrace(TRACE_DND
, wxT("Drop source: no data object") ); 
 609     if (!data
->IsSupportedFormat(format
)) 
 611         wxLogTrace(TRACE_DND
, wxT("Drop source: unsupported format") ); 
 615     if (data
->GetDataSize(format
) == 0) 
 617         wxLogTrace(TRACE_DND
, wxT("Drop source: empty data") ); 
 621     size_t size 
= data
->GetDataSize(format
); 
 623 //  printf( "data size: %d.\n", (int)data_size ); 
 625     guchar 
*d 
= new guchar
[size
]; 
 627     if (!data
->GetDataHere( format
, (void*)d 
)) 
 634     /* disable GUI threads */ 
 637     gtk_selection_data_set( selection_data
, 
 638                             selection_data
->target
, 
 644     /* enable GUI threads */ 
 651 //---------------------------------------------------------------------------- 
 652 // "drag_data_delete" 
 653 //---------------------------------------------------------------------------- 
 656 static void source_drag_data_delete( GtkWidget 
*WXUNUSED(widget
), 
 657                                      GdkDragContext 
*context
, 
 658                                      wxDropSource 
*WXUNUSED(drop_source
) ) 
 661         wxapp_install_idle_handler(); 
 663     // printf( "Drag source: drag_data_delete\n" ); 
 667 //---------------------------------------------------------------------------- 
 669 //---------------------------------------------------------------------------- 
 672 static void source_drag_begin( GtkWidget          
*WXUNUSED(widget
), 
 673                                GdkDragContext     
*WXUNUSED(context
), 
 674                                wxDropSource       
*WXUNUSED(drop_source
) ) 
 677         wxapp_install_idle_handler(); 
 679     // printf( "Drag source: drag_begin.\n" ); 
 683 //---------------------------------------------------------------------------- 
 685 //---------------------------------------------------------------------------- 
 688 static void source_drag_end( GtkWidget          
*WXUNUSED(widget
), 
 689                              GdkDragContext     
*WXUNUSED(context
), 
 690                              wxDropSource       
*drop_source 
) 
 692     if (g_isIdle
) wxapp_install_idle_handler(); 
 694     // printf( "Drag source: drag_end.\n" ); 
 696     drop_source
->m_waiting 
= false; 
 700 //----------------------------------------------------------------------------- 
 701 // "configure_event" from m_iconWindow 
 702 //----------------------------------------------------------------------------- 
 706 gtk_dnd_window_configure_callback( GtkWidget 
*WXUNUSED(widget
), GdkEventConfigure 
*WXUNUSED(event
), wxDropSource 
*source 
) 
 709         wxapp_install_idle_handler(); 
 711     source
->GiveFeedback( ConvertFromGTK(source
->m_dragContext
->action
) ); 
 717 //--------------------------------------------------------------------------- 
 719 //--------------------------------------------------------------------------- 
 721 wxDropSource::wxDropSource(wxWindow 
*win
, 
 722                            const wxIcon 
&iconCopy
, 
 723                            const wxIcon 
&iconMove
, 
 724                            const wxIcon 
&iconNone
) 
 728     m_iconWindow 
= (GtkWidget
*) NULL
; 
 731     m_widget 
= win
->m_widget
; 
 732     if (win
->m_wxwindow
) m_widget 
= win
->m_wxwindow
; 
 734     m_retValue 
= wxDragCancel
; 
 736     SetIcons(iconCopy
, iconMove
, iconNone
); 
 739 wxDropSource::wxDropSource(wxDataObject
& data
, 
 741                            const wxIcon 
&iconCopy
, 
 742                            const wxIcon 
&iconMove
, 
 743                            const wxIcon 
&iconNone
) 
 749     m_iconWindow 
= (GtkWidget
*) NULL
; 
 752     m_widget 
= win
->m_widget
; 
 753     if (win
->m_wxwindow
) m_widget 
= win
->m_wxwindow
; 
 755     m_retValue 
= wxDragCancel
; 
 757     SetIcons(iconCopy
, iconMove
, iconNone
); 
 760 void wxDropSource::SetIcons(const wxIcon 
&iconCopy
, 
 761                             const wxIcon 
&iconMove
, 
 762                             const wxIcon 
&iconNone
) 
 764     m_iconCopy 
= iconCopy
; 
 765     m_iconMove 
= iconMove
; 
 766     m_iconNone 
= iconNone
; 
 768     if ( !m_iconCopy
.Ok() ) 
 769         m_iconCopy 
= wxIcon(page_xpm
); 
 770     if ( !m_iconMove
.Ok() ) 
 771         m_iconMove 
= m_iconCopy
; 
 772     if ( !m_iconNone
.Ok() ) 
 773         m_iconNone 
= m_iconCopy
; 
 776 wxDropSource::~wxDropSource() 
 780 void wxDropSource::PrepareIcon( int action
, GdkDragContext 
*context 
) 
 782     // get the right icon to display 
 784     if ( action 
& GDK_ACTION_MOVE 
) 
 786     else if ( action 
& GDK_ACTION_COPY 
) 
 792     if ( icon
->GetMask() ) 
 793         mask 
= icon
->GetMask()->GetBitmap(); 
 795         mask 
= (GdkBitmap 
*)NULL
; 
 797     GdkPixmap 
*pixmap 
= icon
->GetPixmap(); 
 800     gdk_window_get_size (pixmap
, &width
, &height
); 
 802     GdkColormap 
*colormap 
= gtk_widget_get_colormap( m_widget 
); 
 803     gtk_widget_push_colormap (colormap
); 
 805     m_iconWindow 
= gtk_window_new (GTK_WINDOW_POPUP
); 
 806     gtk_widget_set_events (m_iconWindow
, GDK_BUTTON_PRESS_MASK 
| GDK_BUTTON_RELEASE_MASK
); 
 807     gtk_widget_set_app_paintable (GTK_WIDGET (m_iconWindow
), TRUE
); 
 809     gtk_widget_pop_colormap (); 
 811     gtk_widget_set_size_request (m_iconWindow
, width
, height
); 
 812     gtk_widget_realize (m_iconWindow
); 
 814     g_signal_connect (m_iconWindow
, "configure_event", 
 815                       G_CALLBACK (gtk_dnd_window_configure_callback
), this); 
 817     gdk_window_set_back_pixmap (m_iconWindow
->window
, pixmap
, FALSE
); 
 820         gtk_widget_shape_combine_mask (m_iconWindow
, mask
, 0, 0); 
 822     gtk_drag_set_icon_widget( context
, m_iconWindow
, 0, 0 ); 
 825 wxDragResult 
wxDropSource::DoDragDrop(int flags
) 
 827     wxCHECK_MSG( m_data 
&& m_data
->GetFormatCount(), wxDragNone
, 
 828                  wxT("Drop source: no data") ); 
 831     if (g_blockEventsOnDrag
) 
 835     g_blockEventsOnDrag 
= true; 
 841     GtkTargetList 
*target_list 
= gtk_target_list_new( (GtkTargetEntry
*) NULL
, 0 ); 
 843     wxDataFormat 
*array 
= new wxDataFormat
[ m_data
->GetFormatCount() ]; 
 844     m_data
->GetAllFormats( array 
); 
 845     size_t count 
= m_data
->GetFormatCount(); 
 846     for (size_t i 
= 0; i 
< count
; i
++) 
 848         GdkAtom atom 
= array
[i
]; 
 849         wxLogTrace(TRACE_DND
, wxT("Drop source: Supported atom %s"), gdk_atom_name( atom 
)); 
 850         gtk_target_list_add( target_list
, atom
, 0, 0 ); 
 854     GdkEventMotion event
; 
 855     event
.window 
= m_widget
->window
; 
 858     GdkModifierType state
; 
 859     gdk_window_get_pointer( event
.window
, &x
, &y
, &state 
); 
 863     event
.time 
= (guint32
)GDK_CURRENT_TIME
; 
 865     /* GTK wants to know which button was pressed which caused the dragging */ 
 866     int button_number 
= 0; 
 867     if (event
.state 
& GDK_BUTTON1_MASK
) button_number 
= 1; 
 868     else if (event
.state 
& GDK_BUTTON2_MASK
) button_number 
= 2; 
 869     else if (event
.state 
& GDK_BUTTON3_MASK
) button_number 
= 3; 
 872     /* disable GUI threads */ 
 875     /* don't start dragging if no button is down */ 
 878         int action 
= GDK_ACTION_COPY
; 
 879         if ( flags 
& wxDrag_AllowMove 
) 
 880             action 
|= GDK_ACTION_MOVE
; 
 882         // VZ: as we already use g_blockEventsOnDrag it shouldn't be that bad 
 883         //     to use a global to pass the flags to the drop target but I'd 
 884         //     surely prefer a better way to do it 
 885         gs_flagsForDrag 
= flags
; 
 887         GdkDragContext 
*context 
= gtk_drag_begin( m_widget
, 
 889                 (GdkDragAction
)action
, 
 890                 button_number
,  /* number of mouse button which started drag */ 
 891                 (GdkEvent
*) &event 
); 
 893         m_dragContext 
= context
; 
 895         PrepareIcon( action
, context 
); 
 898             gtk_main_iteration(); 
 900         m_retValue 
= ConvertFromGTK(context
->action
); 
 901         if ( m_retValue 
== wxDragNone 
) 
 902             m_retValue 
= wxDragCancel
; 
 906     /* re-enable GUI threads */ 
 909     g_blockEventsOnDrag 
= false; 
 916 void wxDropSource::RegisterWindow() 
 918     if (!m_widget
) return; 
 920     g_signal_connect (m_widget
, "drag_data_get", 
 921                       G_CALLBACK (source_drag_data_get
), this); 
 922     g_signal_connect (m_widget
, "drag_data_delete", 
 923                       G_CALLBACK (source_drag_data_delete
), this); 
 924     g_signal_connect (m_widget
, "drag_begin", 
 925                       G_CALLBACK (source_drag_begin
), this); 
 926     g_signal_connect (m_widget
, "drag_end", 
 927                       G_CALLBACK (source_drag_end
), this); 
 931 void wxDropSource::UnregisterWindow() 
 936     g_signal_handlers_disconnect_by_func (m_widget
, 
 937                                           (gpointer
) source_drag_data_get
, 
 939     g_signal_handlers_disconnect_by_func (m_widget
, 
 940                                           (gpointer
) source_drag_data_delete
, 
 942     g_signal_handlers_disconnect_by_func (m_widget
, 
 943                                           (gpointer
) source_drag_begin
, 
 945     g_signal_handlers_disconnect_by_func (m_widget
, 
 946                                           (gpointer
) source_drag_end
, 
 951       // wxUSE_DRAG_AND_DROP