src/gtk/listbox.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        listbox.cpp
   3 // Purpose:
   4 // Author:      Robert Roebling
   5 // Id:          $Id$
   6 // Copyright:   (c) 1998 Robert Roebling
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10
  11 #ifdef __GNUG__
  12 #pragma implementation "listbox.h"
  13 #endif
  14
  15 #include "wx/dynarray.h"
  16 #include "wx/listbox.h"
  17 #include "wx/utils.h"
  18 #include "wx/intl.h"
  19 #include "wx/checklst.h"
  20
  21 //-------------------------------------------------------------------------
  22 // conditional compilation
  23 //-------------------------------------------------------------------------
  24
  25 #if (GTK_MINOR_VERSION == 1)
  26 #if (GTK_MICRO_VERSION >= 5)
  27 #define NEW_GTK_SCROLL_CODE
  28 #endif
  29 #endif
  30
  31 //-----------------------------------------------------------------------------
  32 // data
  33 //-----------------------------------------------------------------------------
  34
  35 extern bool   g_blockEventsOnDrag;
  36 extern bool   g_blockEventsOnScroll;
  37
  38 //-----------------------------------------------------------------------------
  39 // "button_press_event"
  40 //-----------------------------------------------------------------------------
  41
  42 static gint
  43 gtk_listbox_button_press_callback( GtkWidget *widget, GdkEventButton *gdk_event, wxListBox *listbox )
  44 {
  45     if (g_blockEventsOnDrag) return FALSE;
  46     if (g_blockEventsOnScroll) return FALSE;
  47
  48     if (!listbox->HasVMT()) return FALSE;
  49
  50     int sel = listbox->GetIndex( widget );
  51
  52     if ((listbox->m_hasCheckBoxes) && (gdk_event->x < 15) && (gdk_event->type != GDK_2BUTTON_PRESS))
  53     {
  54         wxCheckListBox *clb = (wxCheckListBox *)listbox;
  55
  56         clb->Check( sel, !clb->IsChecked(sel) );
  57
  58         wxCommandEvent event( wxEVT_COMMAND_CHECKLISTBOX_TOGGLED, listbox->GetId() );
  59         event.SetEventObject( listbox );
  60         event.SetInt( sel );
  61         listbox->GetEventHandler()->ProcessEvent( event );
  62     }
  63
  64     if (gdk_event->type == GDK_2BUTTON_PRESS)
  65     {
  66         wxCommandEvent event( wxEVT_COMMAND_LISTBOX_DOUBLECLICKED, listbox->GetId() );
  67         event.SetEventObject( listbox );
  68         event.SetInt( sel );
  69         listbox->GetEventHandler()->ProcessEvent( event );
  70     }
  71
  72     return FALSE;
  73 }
  74
  75 //-----------------------------------------------------------------------------
  76 // "key_press_event"
  77 //-----------------------------------------------------------------------------
  78
  79 static gint
  80 gtk_listbox_key_press_callback( GtkWidget *widget, GdkEventKey *gdk_event, wxListBox *listbox )
  81 {
  82     if (g_blockEventsOnDrag) return FALSE;
  83
  84     if (!listbox->HasVMT()) return FALSE;
  85
  86     if (gdk_event->keyval != ' ') return FALSE;
  87
  88     int sel = listbox->GetIndex( widget );
  89
  90     wxCheckListBox *clb = (wxCheckListBox *)listbox;
  91
  92     clb->Check( sel, !clb->IsChecked(sel) );
  93
  94     wxCommandEvent event( wxEVT_COMMAND_CHECKLISTBOX_TOGGLED, listbox->GetId() );
  95     event.SetEventObject( listbox );
  96     event.SetInt( sel );
  97     listbox->GetEventHandler()->ProcessEvent( event );
  98
  99     return FALSE;
 100 }
 101
 102 //-----------------------------------------------------------------------------
 103 // "select" and "deselect"
 104 //-----------------------------------------------------------------------------
 105
 106 static void gtk_listitem_select_callback( GtkWidget *WXUNUSED(widget), wxListBox *listbox )
 107 {
 108     if (!listbox->HasVMT()) return;
 109     if (g_blockEventsOnDrag) return;
 110
 111     wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, listbox->GetId() );
 112
 113     wxArrayInt aSelections;
 114     int count = listbox->GetSelections(aSelections);
 115     if ( count > 0 )
 116     {
 117         event.m_commandInt = aSelections[0] ;
 118         event.m_clientData = listbox->GetClientData( event.m_commandInt );
 119         wxString str(listbox->GetString(event.m_commandInt));
 120         if (str != "") event.m_commandString = copystring((char *)(const char *)str);
 121     }
 122     else
 123     {
 124         event.m_commandInt = -1 ;
 125         event.m_commandString = copystring("") ;
 126     }
 127
 128     event.SetEventObject( listbox );
 129
 130     listbox->GetEventHandler()->ProcessEvent( event );
 131     if (event.m_commandString) delete[] event.m_commandString ;
 132 }
 133
 134 //-----------------------------------------------------------------------------
 135 // wxListBox
 136 //-----------------------------------------------------------------------------
 137
 138 IMPLEMENT_DYNAMIC_CLASS(wxListBox,wxControl)
 139
 140 wxListBox::wxListBox()
 141 {
 142     m_list = (GtkList *) NULL;
 143     m_hasCheckBoxes = FALSE;
 144 }
 145
 146 bool wxListBox::Create( wxWindow *parent, wxWindowID id,
 147                         const wxPoint &pos, const wxSize &size,
 148                         int n, const wxString choices[],
 149                         long style, const wxValidator& validator, const wxString &name )
 150 {
 151     m_needParent = TRUE;
 152     m_acceptsFocus = TRUE;
 153
 154     PreCreation( parent, id, pos, size, style, name );
 155
 156     SetValidator( validator );
 157
 158     m_widget = gtk_scrolled_window_new( (GtkAdjustment*) NULL, (GtkAdjustment*) NULL );
 159     gtk_scrolled_window_set_policy( GTK_SCROLLED_WINDOW(m_widget),
 160       GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC );
 161
 162     m_list = GTK_LIST( gtk_list_new() );
 163
 164     GtkSelectionMode mode = GTK_SELECTION_BROWSE;
 165     if (style & wxLB_MULTIPLE)
 166         mode = GTK_SELECTION_MULTIPLE;
 167     else if (style & wxLB_EXTENDED)
 168         mode = GTK_SELECTION_EXTENDED;
 169
 170     gtk_list_set_selection_mode( GTK_LIST(m_list), mode );
 171
 172 #ifdef NEW_GTK_SCROLL_CODE
 173     gtk_scrolled_window_add_with_viewport( GTK_SCROLLED_WINDOW(m_widget), GTK_WIDGET(m_list) );
 174 #else
 175     gtk_container_add( GTK_CONTAINER(m_widget), GTK_WIDGET(m_list) );
 176 #endif
 177
 178 #ifdef __WXDEBUG__
 179     debug_focus_in( m_widget, "wxListBox::m_widget", name );
 180
 181     debug_focus_in( GTK_WIDGET(m_list), "wxListBox::m_list", name );
 182
 183     GtkScrolledWindow *s_window = GTK_SCROLLED_WINDOW(m_widget);
 184
 185     debug_focus_in( s_window->hscrollbar, "wxWindow::hsrcollbar", name );
 186     debug_focus_in( s_window->vscrollbar, "wxWindow::vsrcollbar", name );
 187
 188 #ifdef NEW_GTK_SCROLL_CODE
 189     GtkViewport *viewport = GTK_VIEWPORT(s_window->child);
 190 #else
 191     GtkViewport *viewport = GTK_VIEWPORT(s_window->viewport);
 192 #endif
 193
 194     debug_focus_in( GTK_WIDGET(viewport), "wxWindow::viewport", name );
 195 #endif
 196
 197     gtk_widget_show( GTK_WIDGET(m_list) );
 198
 199     wxSize newSize = size;
 200     if (newSize.x == -1) newSize.x = 100;
 201     if (newSize.y == -1) newSize.y = 110;
 202     SetSize( newSize.x, newSize.y );
 203
 204     for (int i = 0; i < n; i++)
 205     {
 206         m_clientDataList.Append( (wxObject*) NULL );
 207         m_clientObjectList.Append( (wxObject*) NULL );
 208
 209         GtkWidget *list_item;
 210
 211         if (m_hasCheckBoxes)
 212         {
 213             wxString str = "[-] ";
 214             str += choices[i];
 215             list_item = gtk_list_item_new_with_label( str );
 216         }
 217         else
 218         {
 219             list_item = gtk_list_item_new_with_label( choices[i] );
 220         }
 221
 222 #ifdef __WXDEBUG__
 223         debug_focus_in( list_item, "wxListBox::list_item", name );
 224 #endif
 225
 226         gtk_container_add( GTK_CONTAINER(m_list), list_item );
 227
 228         gtk_signal_connect( GTK_OBJECT(list_item), "select",
 229           GTK_SIGNAL_FUNC(gtk_listitem_select_callback), (gpointer)this );
 230
 231         if (style & wxLB_MULTIPLE)
 232             gtk_signal_connect( GTK_OBJECT(list_item), "deselect",
 233               GTK_SIGNAL_FUNC(gtk_listitem_select_callback), (gpointer)this );
 234
 235         if (m_hasCheckBoxes)
 236         {
 237             gtk_signal_connect( GTK_OBJECT(list_item),
 238                                 "button_press_event",
 239                                 (GtkSignalFunc)gtk_listbox_button_press_callback,
 240                                 (gpointer) this );
 241         }
 242
 243         gtk_signal_connect( GTK_OBJECT(list_item),
 244                             "key_press_event",
 245                             (GtkSignalFunc)gtk_listbox_key_press_callback,
 246                             (gpointer)this );
 247
 248         ConnectWidget( list_item );
 249
 250         gtk_widget_show( list_item );
 251     }
 252
 253     m_parent->AddChild( this );
 254
 255     (m_parent->m_insertCallback)( m_parent, this );
 256
 257     PostCreation();
 258
 259     gtk_widget_realize( GTK_WIDGET(m_list) );
 260
 261     SetBackgroundColour( parent->GetBackgroundColour() );
 262     SetForegroundColour( parent->GetForegroundColour() );
 263
 264     Show( TRUE );
 265
 266     return TRUE;
 267 }
 268
 269 wxListBox::~wxListBox()
 270 {
 271     Clear();
 272 }
 273
 274 void wxListBox::AppendCommon( const wxString &item )
 275 {
 276     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 277
 278     GtkWidget *list_item;
 279
 280     if (m_hasCheckBoxes)
 281     {
 282         wxString str = "[-] ";
 283         str += item;
 284         list_item = gtk_list_item_new_with_label( str );
 285     }
 286     else
 287     {
 288         list_item = gtk_list_item_new_with_label( item );
 289     }
 290
 291     gtk_signal_connect( GTK_OBJECT(list_item), "select",
 292       GTK_SIGNAL_FUNC(gtk_listitem_select_callback), (gpointer)this );
 293
 294     if (GetWindowStyleFlag() & wxLB_MULTIPLE)
 295         gtk_signal_connect( GTK_OBJECT(list_item), "deselect",
 296           GTK_SIGNAL_FUNC(gtk_listitem_select_callback), (gpointer)this );
 297
 298     gtk_container_add( GTK_CONTAINER(m_list), list_item );
 299
 300     if (m_widgetStyle) ApplyWidgetStyle();
 301
 302     if (m_hasCheckBoxes)
 303     {
 304             gtk_signal_connect( GTK_OBJECT(list_item),
 305                                 "button_press_event",
 306                                 (GtkSignalFunc)gtk_listbox_button_press_callback,
 307                                 (gpointer) this );
 308     }
 309
 310     gtk_signal_connect( GTK_OBJECT(list_item),
 311                         "key_press_event",
 312                         (GtkSignalFunc)gtk_listbox_key_press_callback,
 313                         (gpointer)this );
 314
 315     gtk_widget_show( list_item );
 316
 317     ConnectWidget( list_item );
 318
 319 #ifndef NEW_GTK_DND_CODE
 320     if (m_dropTarget) m_dropTarget->RegisterWidget( list_item );
 321 #endif
 322 }
 323
 324 void wxListBox::Append( const wxString &item )
 325 {
 326     m_clientDataList.Append( (wxObject*) NULL );
 327     m_clientObjectList.Append( (wxObject*) NULL );
 328
 329     AppendCommon( item );
 330 }
 331
 332 void wxListBox::Append( const wxString &item, void *clientData )
 333 {
 334     m_clientDataList.Append( (wxObject*) clientData );
 335     m_clientObjectList.Append( (wxObject*) NULL );
 336
 337     AppendCommon( item );
 338 }
 339
 340 void wxListBox::Append( const wxString &item, wxClientData *clientData )
 341 {
 342     m_clientObjectList.Append( (wxObject*) clientData );
 343     m_clientDataList.Append( (wxObject*) NULL );
 344
 345     AppendCommon( item );
 346 }
 347
 348 void wxListBox::SetClientData( int n, void* clientData )
 349 {
 350     wxCHECK_RET( m_widget != NULL, "invalid combobox" );
 351
 352     wxNode *node = m_clientDataList.Nth( n );
 353     if (!node) return;
 354
 355     node->SetData( (wxObject*) clientData );
 356 }
 357
 358 void* wxListBox::GetClientData( int n )
 359 {
 360     wxCHECK_MSG( m_widget != NULL, NULL, "invalid combobox" );
 361
 362     wxNode *node = m_clientDataList.Nth( n );
 363     if (!node) return NULL;
 364
 365     return node->Data();
 366 }
 367
 368 void wxListBox::SetClientObject( int n, wxClientData* clientData )
 369 {
 370     wxCHECK_RET( m_widget != NULL, "invalid combobox" );
 371
 372     wxNode *node = m_clientObjectList.Nth( n );
 373     if (!node) return;
 374
 375     wxClientData *cd = (wxClientData*) node->Data();
 376     if (cd) delete cd;
 377
 378     node->SetData( (wxObject*) clientData );
 379 }
 380
 381 wxClientData* wxListBox::GetClientObject( int n )
 382 {
 383     wxCHECK_MSG( m_widget != NULL, (wxClientData*)NULL, "invalid combobox" );
 384
 385     wxNode *node = m_clientObjectList.Nth( n );
 386     if (!node) return (wxClientData*) NULL;
 387
 388     return (wxClientData*) node->Data();
 389 }
 390
 391 void wxListBox::Clear()
 392 {
 393     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 394
 395     gtk_list_clear_items( m_list, 0, Number() );
 396
 397     wxNode *node = m_clientObjectList.First();
 398     while (node)
 399     {
 400         wxClientData *cd = (wxClientData*)node->Data();
 401         if (cd) delete cd;
 402         node = node->Next();
 403     }
 404     m_clientObjectList.Clear();
 405
 406     m_clientDataList.Clear();
 407 }
 408
 409 void wxListBox::Delete( int n )
 410 {
 411     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 412
 413     GList *child = g_list_nth( m_list->children, n );
 414
 415     wxCHECK_RET( child, "wrong listbox index" );
 416
 417     GList *list = g_list_append( NULL, child->data );
 418     gtk_list_remove_items( m_list, list );
 419     g_list_free( list );
 420
 421     wxNode *node = m_clientObjectList.Nth( n );
 422     if (node)
 423     {
 424         wxClientData *cd = (wxClientData*)node->Data();
 425         if (cd) delete cd;
 426         m_clientObjectList.DeleteNode( node );
 427     }
 428
 429     node = m_clientDataList.Nth( n );
 430     if (node)
 431     {
 432         m_clientDataList.DeleteNode( node );
 433     }
 434 }
 435
 436 void wxListBox::Deselect( int n )
 437 {
 438     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 439
 440     gtk_list_unselect_item( m_list, n );
 441 }
 442
 443 int wxListBox::FindString( const wxString &item ) const
 444 {
 445     wxCHECK_MSG( m_list != NULL, -1, "invalid listbox" );
 446
 447     GList *child = m_list->children;
 448     int count = 0;
 449     while (child)
 450     {
 451         GtkBin *bin = GTK_BIN( child->data );
 452         GtkLabel *label = GTK_LABEL( bin->child );
 453
 454         wxString str = label->label;
 455         if (m_hasCheckBoxes) str.Remove( 0, 4 );
 456
 457         if (str == item) return count;
 458
 459         count++;
 460         child = child->next;
 461     }
 462
 463   // it's not an error if the string is not found -> no wxCHECK
 464
 465   return -1;
 466 }
 467
 468 int wxListBox::GetSelection() const
 469 {
 470     wxCHECK_MSG( m_list != NULL, -1, "invalid listbox" );
 471
 472     GList *child = m_list->children;
 473     int count = 0;
 474     while (child)
 475     {
 476         if (GTK_WIDGET(child->data)->state == GTK_STATE_SELECTED) return count;
 477         count++;
 478         child = child->next;
 479     }
 480     return -1;
 481 }
 482
 483 int wxListBox::GetSelections( wxArrayInt& aSelections ) const
 484 {
 485     wxCHECK_MSG( m_list != NULL, -1, "invalid listbox" );
 486
 487     // get the number of selected items first
 488     GList *child = m_list->children;
 489     int count = 0;
 490     for (child = m_list->children; child != NULL; child = child->next)
 491     {
 492         if (GTK_WIDGET(child->data)->state == GTK_STATE_SELECTED)
 493             count++;
 494     }
 495
 496     aSelections.Empty();
 497
 498     if (count > 0)
 499     {
 500         // now fill the list
 501         aSelections.Alloc(count); // optimization attempt
 502         int i = 0;
 503         for (child = m_list->children; child != NULL; child = child->next, i++)
 504         {
 505             if (GTK_WIDGET(child->data)->state == GTK_STATE_SELECTED)
 506                  aSelections.Add(i);
 507         }
 508     }
 509
 510     return count;
 511 }
 512
 513 wxString wxListBox::GetString( int n ) const
 514 {
 515     wxCHECK_MSG( m_list != NULL, "", "invalid listbox" );
 516
 517     GList *child = g_list_nth( m_list->children, n );
 518     if (child)
 519     {
 520         GtkBin *bin = GTK_BIN( child->data );
 521         GtkLabel *label = GTK_LABEL( bin->child );
 522
 523         wxString str = label->label;
 524         if (m_hasCheckBoxes) str.Remove( 0, 4 );
 525
 526         return str;
 527     }
 528     wxFAIL_MSG("wrong listbox index");
 529     return "";
 530 }
 531
 532 wxString wxListBox::GetStringSelection() const
 533 {
 534     wxCHECK_MSG( m_list != NULL, "", "invalid listbox" );
 535
 536     GList *selection = m_list->selection;
 537     if (selection)
 538     {
 539         GtkBin *bin = GTK_BIN( selection->data );
 540         GtkLabel *label = GTK_LABEL( bin->child );
 541
 542         wxString str = label->label;
 543         if (m_hasCheckBoxes) str.Remove( 0, 4 );
 544
 545         return str;
 546     }
 547
 548     wxFAIL_MSG("no listbox selection available");
 549     return "";
 550 }
 551
 552 int wxListBox::Number()
 553 {
 554     wxCHECK_MSG( m_list != NULL, -1, "invalid listbox" );
 555
 556     GList *child = m_list->children;
 557     int count = 0;
 558     while (child) { count++; child = child->next; }
 559     return count;
 560 }
 561
 562 bool wxListBox::Selected( int n )
 563 {
 564     wxCHECK_MSG( m_list != NULL, FALSE, "invalid listbox" );
 565
 566     GList *target = g_list_nth( m_list->children, n );
 567     if (target)
 568     {
 569         GList *child = m_list->selection;
 570         while (child)
 571         {
 572             if (child->data == target->data) return TRUE;
 573             child = child->next;
 574         }
 575     }
 576     wxFAIL_MSG("wrong listbox index");
 577     return FALSE;
 578 }
 579
 580 void wxListBox::Set( int WXUNUSED(n), const wxString *WXUNUSED(choices) )
 581 {
 582     wxFAIL_MSG("wxListBox::Set not implemented");
 583 }
 584
 585 void wxListBox::SetFirstItem( int WXUNUSED(n) )
 586 {
 587     wxFAIL_MSG("wxListBox::SetFirstItem not implemented");
 588 }
 589
 590 void wxListBox::SetFirstItem( const wxString &WXUNUSED(item) )
 591 {
 592     wxFAIL_MSG("wxListBox::SetFirstItem not implemented");
 593 }
 594
 595 void wxListBox::SetSelection( int n, bool select )
 596 {
 597     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 598
 599     if (select)
 600         gtk_list_select_item( m_list, n );
 601     else
 602         gtk_list_unselect_item( m_list, n );
 603 }
 604
 605 void wxListBox::SetString( int n, const wxString &string )
 606 {
 607     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 608
 609     GList *child = g_list_nth( m_list->children, n );
 610     if (child)
 611     {
 612         GtkBin *bin = GTK_BIN( child->data );
 613         GtkLabel *label = GTK_LABEL( bin->child );
 614
 615         wxString str;
 616         if (m_hasCheckBoxes) str += "[-] ";
 617         str += string;
 618
 619         gtk_label_set( label, str );
 620     }
 621     else
 622     {
 623         wxFAIL_MSG("wrong listbox index");
 624     }
 625 }
 626
 627 void wxListBox::SetStringSelection( const wxString &string, bool select )
 628 {
 629     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 630
 631     SetSelection( FindString(string), select );
 632 }
 633
 634 int wxListBox::GetIndex( GtkWidget *item ) const
 635 {
 636     if (item)
 637     {
 638         GList *child = m_list->children;
 639         int count = 0;
 640         while (child)
 641         {
 642             if (GTK_WIDGET(child->data) == item) return count;
 643             count++;
 644             child = child->next;
 645         }
 646     }
 647     return -1;
 648 }
 649
 650 void wxListBox::SetDropTarget( wxDropTarget *dropTarget )
 651 {
 652     wxCHECK_RET( m_list != NULL, "invalid listbox" );
 653
 654 #ifndef NEW_GTK_DND_CODE
 655     if (m_dropTarget)
 656     {
 657         GList *child = m_list->children;
 658         while (child)
 659         {
 660             m_dropTarget->UnregisterWidget( GTK_WIDGET( child->data ) );
 661             child = child->next;
 662         }
 663     }
 664 #endif
 665
 666     wxWindow::SetDropTarget( dropTarget );
 667
 668 #ifndef NEW_GTK_DND_CODE
 669     if (m_dropTarget)
 670     {
 671         GList *child = m_list->children;
 672         while (child)
 673         {
 674             m_dropTarget->RegisterWidget( GTK_WIDGET( child->data ) );
 675             child = child->next;
 676         }
 677     }
 678 #endif
 679 }
 680
 681 GtkWidget *wxListBox::GetConnectWidget()
 682 {
 683     return GTK_WIDGET(m_list);
 684 }
 685
 686 bool wxListBox::IsOwnGtkWindow( GdkWindow *window )
 687 {
 688     if (wxWindow::IsOwnGtkWindow( window )) return TRUE;
 689
 690     GList *child = m_list->children;
 691     while (child)
 692     {
 693         GtkWidget *bin = GTK_WIDGET( child->data );
 694         if (bin->window == window) return TRUE;
 695         child = child->next;
 696     }
 697
 698     return FALSE;
 699 }
 700
 701 void wxListBox::ApplyWidgetStyle()
 702 {
 703     SetWidgetStyle();
 704
 705     if (m_backgroundColour.Ok())
 706     {
 707         GdkWindow *window = GTK_WIDGET(m_list)->window;
 708         m_backgroundColour.CalcPixel( gdk_window_get_colormap( window ) );
 709         gdk_window_set_background( window, m_backgroundColour.GetColor() );
 710         gdk_window_clear( window );
 711     }
 712
 713     GList *child = m_list->children;
 714     while (child)
 715     {
 716         gtk_widget_set_style( GTK_WIDGET(child->data), m_widgetStyle );
 717
 718         GtkBin *bin = GTK_BIN( child->data );
 719         GtkWidget *label = GTK_WIDGET( bin->child );
 720         gtk_widget_set_style( label, m_widgetStyle );
 721
 722         child = child->next;
 723     }
 724 }