src/msw/combobox.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/combobox.cpp
   3 // Purpose:     wxComboBox class
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_COMBOBOX
  28
  29 #include "wx/combobox.h"
  30
  31 #ifndef WX_PRECOMP
  32     #include "wx/msw/wrapcctl.h" // include <commctrl.h> "properly"
  33     #include "wx/settings.h"
  34     #include "wx/log.h"
  35     // for wxEVT_COMMAND_TEXT_ENTER
  36     #include "wx/textctrl.h"
  37     #include "wx/app.h"
  38     #include "wx/brush.h"
  39 #endif
  40
  41 #include "wx/clipbrd.h"
  42 #include "wx/msw/private.h"
  43
  44 #if wxUSE_TOOLTIPS
  45     #include "wx/tooltip.h"
  46 #endif // wxUSE_TOOLTIPS
  47
  48 // ----------------------------------------------------------------------------
  49 // wxWin macros
  50 // ----------------------------------------------------------------------------
  51
  52 #if wxUSE_EXTENDED_RTTI
  53 WX_DEFINE_FLAGS( wxComboBoxStyle )
  54
  55 wxBEGIN_FLAGS( wxComboBoxStyle )
  56     // new style border flags, we put them first to
  57     // use them for streaming out
  58     wxFLAGS_MEMBER(wxBORDER_SIMPLE)
  59     wxFLAGS_MEMBER(wxBORDER_SUNKEN)
  60     wxFLAGS_MEMBER(wxBORDER_DOUBLE)
  61     wxFLAGS_MEMBER(wxBORDER_RAISED)
  62     wxFLAGS_MEMBER(wxBORDER_STATIC)
  63     wxFLAGS_MEMBER(wxBORDER_NONE)
  64
  65     // old style border flags
  66     wxFLAGS_MEMBER(wxSIMPLE_BORDER)
  67     wxFLAGS_MEMBER(wxSUNKEN_BORDER)
  68     wxFLAGS_MEMBER(wxDOUBLE_BORDER)
  69     wxFLAGS_MEMBER(wxRAISED_BORDER)
  70     wxFLAGS_MEMBER(wxSTATIC_BORDER)
  71     wxFLAGS_MEMBER(wxBORDER)
  72
  73     // standard window styles
  74     wxFLAGS_MEMBER(wxTAB_TRAVERSAL)
  75     wxFLAGS_MEMBER(wxCLIP_CHILDREN)
  76     wxFLAGS_MEMBER(wxTRANSPARENT_WINDOW)
  77     wxFLAGS_MEMBER(wxWANTS_CHARS)
  78     wxFLAGS_MEMBER(wxFULL_REPAINT_ON_RESIZE)
  79     wxFLAGS_MEMBER(wxALWAYS_SHOW_SB )
  80     wxFLAGS_MEMBER(wxVSCROLL)
  81     wxFLAGS_MEMBER(wxHSCROLL)
  82
  83     wxFLAGS_MEMBER(wxCB_SIMPLE)
  84     wxFLAGS_MEMBER(wxCB_SORT)
  85     wxFLAGS_MEMBER(wxCB_READONLY)
  86     wxFLAGS_MEMBER(wxCB_DROPDOWN)
  87
  88 wxEND_FLAGS( wxComboBoxStyle )
  89
  90 IMPLEMENT_DYNAMIC_CLASS_XTI(wxComboBox, wxChoice,"wx/combobox.h")
  91
  92 wxBEGIN_PROPERTIES_TABLE(wxComboBox)
  93     wxEVENT_PROPERTY( Select , wxEVT_COMMAND_COMBOBOX_SELECTED , wxCommandEvent )
  94     wxEVENT_PROPERTY( TextEnter , wxEVT_COMMAND_TEXT_ENTER , wxCommandEvent )
  95
  96     // TODO DELEGATES
  97     wxPROPERTY( Font , wxFont , SetFont , GetFont  , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  98     wxPROPERTY_COLLECTION( Choices , wxArrayString , wxString , AppendString , GetStrings , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  99     wxPROPERTY( Value ,wxString, SetValue, GetValue, EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
 100     wxPROPERTY( Selection ,int, SetSelection, GetSelection, EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
 101     wxPROPERTY_FLAGS( WindowStyle , wxComboBoxStyle , long , SetWindowStyleFlag , GetWindowStyleFlag , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group")) // style
 102 wxEND_PROPERTIES_TABLE()
 103
 104 wxBEGIN_HANDLERS_TABLE(wxComboBox)
 105 wxEND_HANDLERS_TABLE()
 106
 107 wxCONSTRUCTOR_5( wxComboBox , wxWindow* , Parent , wxWindowID , Id , wxString , Value , wxPoint , Position , wxSize , Size )
 108
 109 #else
 110
 111 IMPLEMENT_DYNAMIC_CLASS(wxComboBox, wxChoice)
 112
 113 #endif
 114
 115 BEGIN_EVENT_TABLE(wxComboBox, wxControl)
 116     EVT_MENU(wxID_CUT, wxComboBox::OnCut)
 117     EVT_MENU(wxID_COPY, wxComboBox::OnCopy)
 118     EVT_MENU(wxID_PASTE, wxComboBox::OnPaste)
 119     EVT_MENU(wxID_UNDO, wxComboBox::OnUndo)
 120     EVT_MENU(wxID_REDO, wxComboBox::OnRedo)
 121     EVT_MENU(wxID_CLEAR, wxComboBox::OnDelete)
 122     EVT_MENU(wxID_SELECTALL, wxComboBox::OnSelectAll)
 123
 124     EVT_UPDATE_UI(wxID_CUT, wxComboBox::OnUpdateCut)
 125     EVT_UPDATE_UI(wxID_COPY, wxComboBox::OnUpdateCopy)
 126     EVT_UPDATE_UI(wxID_PASTE, wxComboBox::OnUpdatePaste)
 127     EVT_UPDATE_UI(wxID_UNDO, wxComboBox::OnUpdateUndo)
 128     EVT_UPDATE_UI(wxID_REDO, wxComboBox::OnUpdateRedo)
 129     EVT_UPDATE_UI(wxID_CLEAR, wxComboBox::OnUpdateDelete)
 130     EVT_UPDATE_UI(wxID_SELECTALL, wxComboBox::OnUpdateSelectAll)
 131 END_EVENT_TABLE()
 132
 133 // ----------------------------------------------------------------------------
 134 // function prototypes
 135 // ----------------------------------------------------------------------------
 136
 137 LRESULT APIENTRY _EXPORT wxComboEditWndProc(HWND hWnd,
 138                                             UINT message,
 139                                             WPARAM wParam,
 140                                             LPARAM lParam);
 141
 142 // ---------------------------------------------------------------------------
 143 // global vars
 144 // ---------------------------------------------------------------------------
 145
 146 // the pointer to standard radio button wnd proc
 147 static WNDPROC gs_wndprocEdit = (WNDPROC)NULL;
 148
 149 // ============================================================================
 150 // implementation
 151 // ============================================================================
 152
 153 // ----------------------------------------------------------------------------
 154 // wnd proc for subclassed edit control
 155 // ----------------------------------------------------------------------------
 156
 157 LRESULT APIENTRY _EXPORT wxComboEditWndProc(HWND hWnd,
 158                                             UINT message,
 159                                             WPARAM wParam,
 160                                             LPARAM lParam)
 161 {
 162     HWND hwndCombo = ::GetParent(hWnd);
 163     wxWindow *win = wxFindWinFromHandle((WXHWND)hwndCombo);
 164
 165     switch ( message )
 166     {
 167         // forward some messages to the combobox to generate the appropriate
 168         // wxEvents from them
 169         case WM_KEYUP:
 170         case WM_KEYDOWN:
 171         case WM_CHAR:
 172         case WM_SYSCHAR:
 173         case WM_SYSKEYDOWN:
 174         case WM_SYSKEYUP:
 175         case WM_SETFOCUS:
 176         case WM_KILLFOCUS:
 177             {
 178                 wxComboBox *combo = wxDynamicCast(win, wxComboBox);
 179                 if ( !combo )
 180                 {
 181                     // we can get WM_KILLFOCUS while our parent is already half
 182                     // destroyed and hence doesn't look like a combobx any
 183                     // longer, check for it to avoid bogus assert failures
 184                     if ( !win->IsBeingDeleted() )
 185                     {
 186                         wxFAIL_MSG( _T("should have combo as parent") );
 187                     }
 188                 }
 189                 else if ( combo->MSWProcessEditMsg(message, wParam, lParam) )
 190                 {
 191                     // handled by parent
 192                     return 0;
 193                 }
 194             }
 195             break;
 196
 197         case WM_GETDLGCODE:
 198             {
 199                 wxCHECK_MSG( win, 0, _T("should have a parent") );
 200
 201                 if ( win->GetWindowStyle() & wxTE_PROCESS_ENTER )
 202                 {
 203                     // need to return a custom dlg code or we'll never get it
 204                     return DLGC_WANTMESSAGE;
 205                 }
 206             }
 207             break;
 208     }
 209
 210     return ::CallWindowProc(CASTWNDPROC gs_wndprocEdit, hWnd, message, wParam, lParam);
 211 }
 212
 213 // ----------------------------------------------------------------------------
 214 // wxComboBox callbacks
 215 // ----------------------------------------------------------------------------
 216
 217 WXLRESULT wxComboBox::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
 218 {
 219     // TODO: handle WM_CTLCOLOR messages from our EDIT control to be able to
 220     //       set its colour correctly (to be the same as our own one)
 221
 222     switch ( nMsg )
 223     {
 224         case WM_SIZE:
 225         // wxStaticBox can generate this message, when modifying the control's style.
 226         // This causes the content of the combobox to be selected, for some reason.
 227         case WM_STYLECHANGED:
 228             {
 229                 // combobox selection sometimes spontaneously changes when its
 230                 // size changes, restore it to the old value if necessary
 231                 if ( !GetEditHWNDIfAvailable() )
 232                     break;
 233
 234                 long fromOld, toOld;
 235                 GetSelection(&fromOld, &toOld);
 236                 WXLRESULT result = wxChoice::MSWWindowProc(nMsg, wParam, lParam);
 237
 238                 long fromNew, toNew;
 239                 GetSelection(&fromNew, &toNew);
 240
 241                 if ( fromOld != fromNew || toOld != toNew )
 242                 {
 243                     SetSelection(fromOld, toOld);
 244                 }
 245
 246                 return result;
 247             }
 248     }
 249
 250     return wxChoice::MSWWindowProc(nMsg, wParam, lParam);
 251 }
 252
 253 bool wxComboBox::MSWProcessEditMsg(WXUINT msg, WXWPARAM wParam, WXLPARAM lParam)
 254 {
 255     switch ( msg )
 256     {
 257         case WM_CHAR:
 258             // for compatibility with wxTextCtrl, generate a special message
 259             // when Enter is pressed
 260             if ( wParam == VK_RETURN )
 261             {
 262                 if (SendMessage(GetHwnd(), CB_GETDROPPEDSTATE, 0, 0))
 263                     return false;
 264
 265                 wxCommandEvent event(wxEVT_COMMAND_TEXT_ENTER, m_windowId);
 266
 267                 const int sel = GetSelection();
 268                 event.SetInt(sel);
 269                 event.SetString(GetValue());
 270                 InitCommandEventWithItems(event, sel);
 271
 272                 if ( ProcessCommand(event) )
 273                 {
 274                     // don't let the event through to the native control
 275                     // because it doesn't need it and may generate an annoying
 276                     // beep if it gets it
 277                     return true;
 278                 }
 279             }
 280             // fall through
 281
 282         case WM_SYSCHAR:
 283             return HandleChar(wParam, lParam, true /* isASCII */);
 284
 285         case WM_SYSKEYDOWN:
 286         case WM_KEYDOWN:
 287             return HandleKeyDown(wParam, lParam);
 288
 289         case WM_SYSKEYUP:
 290         case WM_KEYUP:
 291             return HandleKeyUp(wParam, lParam);
 292
 293         case WM_SETFOCUS:
 294             return HandleSetFocus((WXHWND)wParam);
 295
 296         case WM_KILLFOCUS:
 297             return HandleKillFocus((WXHWND)wParam);
 298
 299         case WM_CUT:
 300         case WM_COPY:
 301         case WM_PASTE:
 302             return HandleClipboardEvent(msg);
 303     }
 304
 305     return false;
 306 }
 307
 308 bool wxComboBox::MSWCommand(WXUINT param, WXWORD id)
 309 {
 310     int sel = -1;
 311     wxString value;
 312
 313     switch ( param )
 314     {
 315         case CBN_SELENDOK:
 316 #ifndef __SMARTPHONE__
 317             // we need to reset this to prevent the selection from being undone
 318             // by wxChoice, see wxChoice::MSWCommand() and comments there
 319             m_lastAcceptedSelection = wxID_NONE;
 320 #endif
 321
 322             // set these variables so that they could be also fixed in
 323             // CBN_EDITCHANGE below
 324             sel = GetSelection();
 325             value = GetStringSelection();
 326
 327             // this string is going to become the new combobox value soon but
 328             // we need it to be done right now, otherwise the event handler
 329             // could get a wrong value when it calls our GetValue()
 330             ::SetWindowText(GetHwnd(), value.wx_str());
 331
 332             {
 333                 wxCommandEvent event(wxEVT_COMMAND_COMBOBOX_SELECTED, GetId());
 334                 event.SetInt(sel);
 335                 event.SetString(value);
 336                 InitCommandEventWithItems(event, sel);
 337
 338                 ProcessCommand(event);
 339             }
 340
 341             // fall through: for compability with wxGTK, also send the text
 342             // update event when the selection changes (this also seems more
 343             // logical as the text does change)
 344
 345         case CBN_EDITCHANGE:
 346             {
 347                 wxCommandEvent event(wxEVT_COMMAND_TEXT_UPDATED, GetId());
 348
 349                 // if sel != -1, value was already initialized above
 350                 if ( sel == -1 )
 351                 {
 352                     value = wxGetWindowText(GetHwnd());
 353                 }
 354
 355                 event.SetString(value);
 356                 InitCommandEventWithItems(event, sel);
 357
 358                 ProcessCommand(event);
 359             }
 360             break;
 361
 362         default:
 363             return wxChoice::MSWCommand(param, id);
 364     }
 365
 366     // skip wxChoice version as it would generate its own events for
 367     // CBN_SELENDOK
 368     return true;
 369 }
 370
 371 bool wxComboBox::MSWShouldPreProcessMessage(WXMSG *pMsg)
 372 {
 373     // prevent command accelerators from stealing editing
 374     // hotkeys when we have the focus
 375     if (wxIsCtrlDown())
 376     {
 377         WPARAM vkey = pMsg->wParam;
 378
 379         switch (vkey)
 380         {
 381             case 'C':
 382             case 'V':
 383             case 'X':
 384             case VK_INSERT:
 385             case VK_DELETE:
 386             case VK_HOME:
 387             case VK_END:
 388                 return false;
 389         }
 390     }
 391
 392     return wxChoice::MSWShouldPreProcessMessage(pMsg);
 393 }
 394
 395 WXHWND wxComboBox::GetEditHWNDIfAvailable() const
 396 {
 397     // notice that a slightly safer alternative could be to use FindWindowEx()
 398     // but it's not available under WinCE so just take the first child for now
 399     // to keep one version of the code for all platforms and fix it later if
 400     // problems are discovered
 401
 402     // we assume that the only child of the combobox is the edit window
 403     return (WXHWND)::GetWindow(GetHwnd(), GW_CHILD);
 404 }
 405
 406 WXHWND wxComboBox::GetEditHWND() const
 407 {
 408     // this function should not be called for wxCB_READONLY controls, it is
 409     // the callers responsibility to check this
 410     wxASSERT_MSG( !HasFlag(wxCB_READONLY),
 411                   _T("read-only combobox doesn't have any edit control") );
 412
 413     WXHWND hWndEdit = GetEditHWNDIfAvailable();
 414     wxASSERT_MSG( hWndEdit, _T("combobox without edit control?") );
 415
 416     return hWndEdit;
 417 }
 418
 419 // ----------------------------------------------------------------------------
 420 // wxComboBox creation
 421 // ----------------------------------------------------------------------------
 422
 423 bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
 424                         const wxString& value,
 425                         const wxPoint& pos,
 426                         const wxSize& size,
 427                         int n, const wxString choices[],
 428                         long style,
 429                         const wxValidator& validator,
 430                         const wxString& name)
 431 {
 432     // pretend that wxComboBox is hidden while it is positioned and resized and
 433     // show it only right before leaving this method because otherwise there is
 434     // some noticeable flicker while the control rearranges itself
 435     m_isShown = false;
 436
 437     if ( !CreateAndInit(parent, id, pos, size, n, choices, style,
 438                         validator, name) )
 439         return false;
 440
 441     // we shouldn't call SetValue() for an empty string because this would
 442     // (correctly) result in an assert with a read only combobox and is useless
 443     // for the other ones anyhow
 444     if ( !value.empty() )
 445         SetValue(value);
 446
 447     // a (not read only) combobox is, in fact, 2 controls: the combobox itself
 448     // and an edit control inside it and if we want to catch events from this
 449     // edit control, we must subclass it as well
 450     if ( !(style & wxCB_READONLY) )
 451     {
 452         gs_wndprocEdit = wxSetWindowProc((HWND)GetEditHWND(), wxComboEditWndProc);
 453     }
 454
 455     // and finally, show the control
 456     Show(true);
 457
 458     return true;
 459 }
 460
 461 bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
 462                         const wxString& value,
 463                         const wxPoint& pos,
 464                         const wxSize& size,
 465                         const wxArrayString& choices,
 466                         long style,
 467                         const wxValidator& validator,
 468                         const wxString& name)
 469 {
 470     wxCArrayString chs(choices);
 471     return Create(parent, id, value, pos, size, chs.GetCount(),
 472                   chs.GetStrings(), style, validator, name);
 473 }
 474
 475 WXDWORD wxComboBox::MSWGetStyle(long style, WXDWORD *exstyle) const
 476 {
 477     // we never have an external border
 478     WXDWORD msStyle = wxChoice::MSWGetStyle
 479                       (
 480                         (style & ~wxBORDER_MASK) | wxBORDER_NONE, exstyle
 481                       );
 482
 483     // usually WS_TABSTOP is added by wxControl::MSWGetStyle() but as we're
 484     // created hidden (see Create() above), it is not done for us but we still
 485     // want to have this style
 486     msStyle |= WS_TABSTOP;
 487
 488     // remove the style always added by wxChoice
 489     msStyle &= ~CBS_DROPDOWNLIST;
 490
 491     if ( style & wxCB_READONLY )
 492         msStyle |= CBS_DROPDOWNLIST;
 493 #ifndef __WXWINCE__
 494     else if ( style & wxCB_SIMPLE )
 495         msStyle |= CBS_SIMPLE; // A list (shown always) and edit control
 496 #endif
 497     else
 498         msStyle |= CBS_DROPDOWN;
 499
 500     // there is no reason to not always use CBS_AUTOHSCROLL, so do use it
 501     msStyle |= CBS_AUTOHSCROLL;
 502
 503     // NB: we used to also add CBS_NOINTEGRALHEIGHT here but why?
 504
 505     return msStyle;
 506 }
 507
 508 // ----------------------------------------------------------------------------
 509 // wxComboBox text control-like methods
 510 // ----------------------------------------------------------------------------
 511
 512 wxString wxComboBox::GetValue() const
 513 {
 514     return HasFlag(wxCB_READONLY) ? GetStringSelection()
 515                                   : wxTextEntry::GetValue();
 516 }
 517
 518 void wxComboBox::SetValue(const wxString& value)
 519 {
 520     if ( HasFlag(wxCB_READONLY) )
 521         SetStringSelection(value);
 522     else
 523         wxTextEntry::SetValue(value);
 524 }
 525
 526 void wxComboBox::Clear()
 527 {
 528     wxChoice::Clear();
 529     if ( !HasFlag(wxCB_READONLY) )
 530         wxTextEntry::Clear();
 531 }
 532
 533 void wxComboBox::GetSelection(long *from, long *to) const
 534 {
 535     if ( !HasFlag(wxCB_READONLY) )
 536     {
 537         wxTextEntry::GetSelection(from, to);
 538     }
 539     else // text selection doesn't make sense for read only comboboxes
 540     {
 541         if ( from )
 542             *from = -1;
 543         if ( to )
 544             *to = -1;
 545     }
 546 }
 547
 548 bool wxComboBox::IsEditable() const
 549 {
 550     return !HasFlag(wxCB_READONLY) && wxTextEntry::IsEditable();
 551 }
 552
 553 // ----------------------------------------------------------------------------
 554 // standard event handling
 555 // ----------------------------------------------------------------------------
 556
 557 void wxComboBox::OnCut(wxCommandEvent& WXUNUSED(event))
 558 {
 559     Cut();
 560 }
 561
 562 void wxComboBox::OnCopy(wxCommandEvent& WXUNUSED(event))
 563 {
 564     Copy();
 565 }
 566
 567 void wxComboBox::OnPaste(wxCommandEvent& WXUNUSED(event))
 568 {
 569     Paste();
 570 }
 571
 572 void wxComboBox::OnUndo(wxCommandEvent& WXUNUSED(event))
 573 {
 574     Undo();
 575 }
 576
 577 void wxComboBox::OnRedo(wxCommandEvent& WXUNUSED(event))
 578 {
 579     Redo();
 580 }
 581
 582 void wxComboBox::OnDelete(wxCommandEvent& WXUNUSED(event))
 583 {
 584     long from, to;
 585     GetSelection(& from, & to);
 586     if (from != -1 && to != -1)
 587         Remove(from, to);
 588 }
 589
 590 void wxComboBox::OnSelectAll(wxCommandEvent& WXUNUSED(event))
 591 {
 592     SetSelection(-1, -1);
 593 }
 594
 595 void wxComboBox::OnUpdateCut(wxUpdateUIEvent& event)
 596 {
 597     event.Enable( CanCut() );
 598 }
 599
 600 void wxComboBox::OnUpdateCopy(wxUpdateUIEvent& event)
 601 {
 602     event.Enable( CanCopy() );
 603 }
 604
 605 void wxComboBox::OnUpdatePaste(wxUpdateUIEvent& event)
 606 {
 607     event.Enable( CanPaste() );
 608 }
 609
 610 void wxComboBox::OnUpdateUndo(wxUpdateUIEvent& event)
 611 {
 612     event.Enable( IsEditable() && CanUndo() );
 613 }
 614
 615 void wxComboBox::OnUpdateRedo(wxUpdateUIEvent& event)
 616 {
 617     event.Enable( IsEditable() && CanRedo() );
 618 }
 619
 620 void wxComboBox::OnUpdateDelete(wxUpdateUIEvent& event)
 621 {
 622     event.Enable(IsEditable() && HasSelection());
 623 }
 624
 625 void wxComboBox::OnUpdateSelectAll(wxUpdateUIEvent& event)
 626 {
 627     event.Enable(IsEditable() && GetLastPosition() > 0);
 628 }
 629
 630 #if wxUSE_TOOLTIPS
 631
 632 void wxComboBox::DoSetToolTip(wxToolTip *tip)
 633 {
 634     wxChoice::DoSetToolTip(tip);
 635
 636     if ( tip && !HasFlag(wxCB_READONLY) )
 637         tip->Add(GetEditHWND());
 638 }
 639
 640 #endif // wxUSE_TOOLTIPS
 641
 642 #endif // wxUSE_COMBOBOX