src/msw/choice.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/choice.cpp
   3 // Purpose:     wxChoice
   4 // Author:      Julian Smart
   5 // Modified by: Vadim Zeitlin to derive from wxChoiceBase
   6 // Created:     04/01/98
   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_CHOICE && !(defined(__SMARTPHONE__) && defined(__WXWINCE__))
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/choice.h"
  31     #include "wx/utils.h"
  32     #include "wx/log.h"
  33     #include "wx/brush.h"
  34     #include "wx/settings.h"
  35 #endif
  36
  37 #include "wx/msw/private.h"
  38
  39 #if wxUSE_EXTENDED_RTTI
  40 WX_DEFINE_FLAGS( wxChoiceStyle )
  41
  42 wxBEGIN_FLAGS( wxChoiceStyle )
  43     // new style border flags, we put them first to
  44     // use them for streaming out
  45     wxFLAGS_MEMBER(wxBORDER_SIMPLE)
  46     wxFLAGS_MEMBER(wxBORDER_SUNKEN)
  47     wxFLAGS_MEMBER(wxBORDER_DOUBLE)
  48     wxFLAGS_MEMBER(wxBORDER_RAISED)
  49     wxFLAGS_MEMBER(wxBORDER_STATIC)
  50     wxFLAGS_MEMBER(wxBORDER_NONE)
  51
  52     // old style border flags
  53     wxFLAGS_MEMBER(wxSIMPLE_BORDER)
  54     wxFLAGS_MEMBER(wxSUNKEN_BORDER)
  55     wxFLAGS_MEMBER(wxDOUBLE_BORDER)
  56     wxFLAGS_MEMBER(wxRAISED_BORDER)
  57     wxFLAGS_MEMBER(wxSTATIC_BORDER)
  58     wxFLAGS_MEMBER(wxBORDER)
  59
  60     // standard window styles
  61     wxFLAGS_MEMBER(wxTAB_TRAVERSAL)
  62     wxFLAGS_MEMBER(wxCLIP_CHILDREN)
  63     wxFLAGS_MEMBER(wxTRANSPARENT_WINDOW)
  64     wxFLAGS_MEMBER(wxWANTS_CHARS)
  65     wxFLAGS_MEMBER(wxFULL_REPAINT_ON_RESIZE)
  66     wxFLAGS_MEMBER(wxALWAYS_SHOW_SB )
  67     wxFLAGS_MEMBER(wxVSCROLL)
  68     wxFLAGS_MEMBER(wxHSCROLL)
  69
  70 wxEND_FLAGS( wxChoiceStyle )
  71
  72 IMPLEMENT_DYNAMIC_CLASS_XTI(wxChoice, wxControl,"wx/choice.h")
  73
  74 wxBEGIN_PROPERTIES_TABLE(wxChoice)
  75     wxEVENT_PROPERTY( Select , wxEVT_COMMAND_CHOICE_SELECTED , wxCommandEvent )
  76
  77     wxPROPERTY( Font , wxFont , SetFont , GetFont  , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  78     wxPROPERTY_COLLECTION( Choices , wxArrayString , wxString , AppendString , GetStrings , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  79     wxPROPERTY( Selection ,int, SetSelection, GetSelection, EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  80     wxPROPERTY_FLAGS( WindowStyle , wxChoiceStyle , long , SetWindowStyleFlag , GetWindowStyleFlag , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group")) // style
  81 wxEND_PROPERTIES_TABLE()
  82
  83 wxBEGIN_HANDLERS_TABLE(wxChoice)
  84 wxEND_HANDLERS_TABLE()
  85
  86 wxCONSTRUCTOR_4( wxChoice , wxWindow* , Parent , wxWindowID , Id , wxPoint , Position , wxSize , Size )
  87 #else
  88 IMPLEMENT_DYNAMIC_CLASS(wxChoice, wxControl)
  89 #endif
  90 /*
  91     TODO PROPERTIES
  92         selection (long)
  93         content (list)
  94             item
  95 */
  96
  97 // ============================================================================
  98 // implementation
  99 // ============================================================================
 100
 101 // ----------------------------------------------------------------------------
 102 // creation
 103 // ----------------------------------------------------------------------------
 104
 105 bool wxChoice::Create(wxWindow *parent,
 106                       wxWindowID id,
 107                       const wxPoint& pos,
 108                       const wxSize& size,
 109                       int n, const wxString choices[],
 110                       long style,
 111                       const wxValidator& validator,
 112                       const wxString& name)
 113 {
 114     // Experience shows that wxChoice vs. wxComboBox distinction confuses
 115     // quite a few people - try to help them
 116     wxASSERT_MSG( !(style & wxCB_DROPDOWN) &&
 117                   !(style & wxCB_READONLY) &&
 118                   !(style & wxCB_SIMPLE),
 119                   _T("this style flag is ignored by wxChoice, you ")
 120                   _T("probably want to use a wxComboBox") );
 121
 122     return CreateAndInit(parent, id, pos, size, n, choices, style,
 123                          validator, name);
 124 }
 125
 126 bool wxChoice::CreateAndInit(wxWindow *parent,
 127                              wxWindowID id,
 128                              const wxPoint& pos,
 129                              const wxSize& size,
 130                              int n, const wxString choices[],
 131                              long style,
 132                              const wxValidator& validator,
 133                              const wxString& name)
 134 {
 135     // initialize wxControl
 136     if ( !CreateControl(parent, id, pos, size, style, validator, name) )
 137         return false;
 138
 139     // now create the real HWND
 140     if ( !MSWCreateControl(wxT("COMBOBOX"), wxEmptyString, pos, size) )
 141         return false;
 142
 143
 144     // choice/combobox normally has "white" (depends on colour scheme, of
 145     // course) background rather than inheriting the parent's background
 146     SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));
 147
 148     // initialize the controls contents
 149     for ( int i = 0; i < n; i++ )
 150     {
 151         Append(choices[i]);
 152     }
 153
 154     // and now we may finally size the control properly (if needed)
 155     SetBestSize(size);
 156
 157     return true;
 158 }
 159
 160 bool wxChoice::Create(wxWindow *parent,
 161                       wxWindowID id,
 162                       const wxPoint& pos,
 163                       const wxSize& size,
 164                       const wxArrayString& choices,
 165                       long style,
 166                       const wxValidator& validator,
 167                       const wxString& name)
 168 {
 169     wxCArrayString chs(choices);
 170     return Create(parent, id, pos, size, chs.GetCount(), chs.GetStrings(),
 171                   style, validator, name);
 172 }
 173
 174 bool wxChoice::MSWShouldPreProcessMessage(WXMSG *pMsg)
 175 {
 176     MSG *msg = (MSG *) pMsg;
 177
 178     // if the dropdown list is visible, don't preprocess certain keys
 179     if ( msg->message == WM_KEYDOWN
 180         && (msg->wParam == VK_ESCAPE || msg->wParam == VK_RETURN) )
 181     {
 182         if (::SendMessage(GetHwndOf(this), CB_GETDROPPEDSTATE, 0, 0))
 183         {
 184             return false;
 185         }
 186     }
 187
 188     return wxControl::MSWShouldPreProcessMessage(pMsg);
 189 }
 190
 191 WXDWORD wxChoice::MSWGetStyle(long style, WXDWORD *exstyle) const
 192 {
 193     // we never have an external border
 194     WXDWORD msStyle = wxControl::MSWGetStyle
 195                       (
 196                         (style & ~wxBORDER_MASK) | wxBORDER_NONE, exstyle
 197                       );
 198
 199     // WS_CLIPSIBLINGS is useful with wxChoice and doesn't seem to result in
 200     // any problems
 201     msStyle |= WS_CLIPSIBLINGS;
 202
 203     // wxChoice-specific styles
 204     msStyle |= CBS_DROPDOWNLIST | WS_HSCROLL | WS_VSCROLL;
 205     if ( style & wxCB_SORT )
 206         msStyle |= CBS_SORT;
 207
 208     return msStyle;
 209 }
 210
 211 wxChoice::~wxChoice()
 212 {
 213     Free();
 214 }
 215
 216 // ----------------------------------------------------------------------------
 217 // adding/deleting items to/from the list
 218 // ----------------------------------------------------------------------------
 219
 220 int wxChoice::DoAppend(const wxString& item)
 221 {
 222     int n = (int)SendMessage(GetHwnd(), CB_ADDSTRING, 0, (LPARAM)item.c_str());
 223     if ( n == CB_ERR )
 224     {
 225         wxLogLastError(wxT("SendMessage(CB_ADDSTRING)"));
 226     }
 227     else // ok
 228     {
 229         // we need to refresh our size in order to have enough space for the
 230         // newly added items
 231         if ( !IsFrozen() )
 232             UpdateVisibleHeight();
 233     }
 234
 235     InvalidateBestSize();
 236     return n;
 237 }
 238
 239 int wxChoice::DoInsert(const wxString& item, int pos)
 240 {
 241     wxCHECK_MSG(!(GetWindowStyle() & wxCB_SORT), -1, wxT("can't insert into sorted list"));
 242     wxCHECK_MSG(IsValidInsert(pos), -1, wxT("invalid index"));
 243
 244     int n = (int)SendMessage(GetHwnd(), CB_INSERTSTRING, pos, (LPARAM)item.c_str());
 245     if ( n == CB_ERR )
 246     {
 247         wxLogLastError(wxT("SendMessage(CB_INSERTSTRING)"));
 248     }
 249     else // ok
 250     {
 251         if ( !IsFrozen() )
 252             UpdateVisibleHeight();
 253     }
 254
 255     InvalidateBestSize();
 256     return n;
 257 }
 258
 259 void wxChoice::Delete(int n)
 260 {
 261     wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::Delete") );
 262
 263     if ( HasClientObjectData() )
 264     {
 265         delete GetClientObject(n);
 266     }
 267
 268     SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
 269
 270     if ( !IsFrozen() )
 271         UpdateVisibleHeight();
 272
 273     InvalidateBestSize();
 274 }
 275
 276 void wxChoice::Clear()
 277 {
 278     Free();
 279
 280     SendMessage(GetHwnd(), CB_RESETCONTENT, 0, 0);
 281
 282     if ( !IsFrozen() )
 283         UpdateVisibleHeight();
 284
 285     InvalidateBestSize();
 286 }
 287
 288 void wxChoice::Free()
 289 {
 290     if ( HasClientObjectData() )
 291     {
 292         size_t count = GetCount();
 293         for ( size_t n = 0; n < count; n++ )
 294         {
 295             delete GetClientObject(n);
 296         }
 297     }
 298 }
 299
 300 // ----------------------------------------------------------------------------
 301 // selection
 302 // ----------------------------------------------------------------------------
 303
 304 int wxChoice::GetSelection() const
 305 {
 306     // if m_lastAcceptedSelection is set, it means that the dropdown is
 307     // currently shown and that we want to use the last "permanent" selection
 308     // instead of whatever is under the mouse pointer currently
 309     //
 310     // otherwise, get the selection from the control
 311     return m_lastAcceptedSelection == wxID_NONE ? GetCurrentSelection()
 312                                                 : m_lastAcceptedSelection;
 313 }
 314
 315 int wxChoice::GetCurrentSelection() const
 316 {
 317     return (int)SendMessage(GetHwnd(), CB_GETCURSEL, 0, 0);
 318 }
 319
 320 void wxChoice::SetSelection(int n)
 321 {
 322     SendMessage(GetHwnd(), CB_SETCURSEL, n, 0);
 323 }
 324
 325 // ----------------------------------------------------------------------------
 326 // string list functions
 327 // ----------------------------------------------------------------------------
 328
 329 size_t wxChoice::GetCount() const
 330 {
 331     return (size_t)SendMessage(GetHwnd(), CB_GETCOUNT, 0, 0);
 332 }
 333
 334 int wxChoice::FindString(const wxString& s, bool bCase) const
 335 {
 336 #if defined(__WATCOMC__) && defined(__WIN386__)
 337     // For some reason, Watcom in WIN386 mode crashes in the CB_FINDSTRINGEXACT message.
 338     // wxChoice::Do it the long way instead.
 339     size_t count = GetCount();
 340     for ( size_t i = 0; i < count; i++ )
 341     {
 342         // as CB_FINDSTRINGEXACT is case insensitive, be case insensitive too
 343         if ( GetString(i).IsSameAs(s, bCase) )
 344             return i;
 345     }
 346
 347     return wxNOT_FOUND;
 348 #else // !Watcom
 349    //TODO:  Evidently some MSW versions (all?) don't like empty strings
 350    //passed to SendMessage, so we have to do it ourselves in that case
 351    if ( s.empty() )
 352    {
 353        size_t count = GetCount();
 354        for ( size_t i = 0; i < count; i++ )
 355        {
 356          if ( GetString(i).empty() )
 357              return i;
 358        }
 359
 360        return wxNOT_FOUND;
 361    }
 362    else if (bCase)
 363    {
 364        // back to base class search for not native search type
 365        return wxItemContainerImmutable::FindString( s, bCase );
 366    }
 367    else
 368    {
 369        int pos = (int)SendMessage(GetHwnd(), CB_FINDSTRINGEXACT,
 370                                   (WPARAM)-1, (LPARAM)s.c_str());
 371
 372        return pos == LB_ERR ? wxNOT_FOUND : pos;
 373    }
 374 #endif // Watcom/!Watcom
 375 }
 376
 377 void wxChoice::SetString(int n, const wxString& s)
 378 {
 379     wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );
 380
 381     // we have to delete and add back the string as there is no way to change a
 382     // string in place
 383
 384     // we need to preserve the client data
 385     void *data;
 386     if ( m_clientDataItemsType != wxClientData_None )
 387     {
 388         data = DoGetItemClientData(n);
 389     }
 390     else // no client data
 391     {
 392         data = NULL;
 393     }
 394
 395     ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
 396     ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, (LPARAM)s.c_str() );
 397
 398     if ( data )
 399     {
 400         DoSetItemClientData(n, data);
 401     }
 402     //else: it's already NULL by default
 403
 404     InvalidateBestSize();
 405 }
 406
 407 wxString wxChoice::GetString(int n) const
 408 {
 409     int len = (int)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);
 410
 411     wxString str;
 412     if ( len != CB_ERR && len > 0 )
 413     {
 414         if ( ::SendMessage
 415                (
 416                 GetHwnd(),
 417                 CB_GETLBTEXT,
 418                 n,
 419                 (LPARAM)(wxChar *)wxStringBuffer(str, len)
 420                ) == CB_ERR )
 421         {
 422             wxLogLastError(wxT("SendMessage(CB_GETLBTEXT)"));
 423         }
 424     }
 425
 426     return str;
 427 }
 428
 429 // ----------------------------------------------------------------------------
 430 // client data
 431 // ----------------------------------------------------------------------------
 432
 433 void wxChoice::DoSetItemClientData( int n, void* clientData )
 434 {
 435     if ( ::SendMessage(GetHwnd(), CB_SETITEMDATA,
 436                        n, (LPARAM)clientData) == CB_ERR )
 437     {
 438         wxLogLastError(wxT("CB_SETITEMDATA"));
 439     }
 440 }
 441
 442 void* wxChoice::DoGetItemClientData( int n ) const
 443 {
 444     LPARAM rc = SendMessage(GetHwnd(), CB_GETITEMDATA, n, 0);
 445     if ( rc == CB_ERR )
 446     {
 447         wxLogLastError(wxT("CB_GETITEMDATA"));
 448
 449         // unfortunately, there is no way to return an error code to the user
 450         rc = (LPARAM) NULL;
 451     }
 452
 453     return (void *)rc;
 454 }
 455
 456 void wxChoice::DoSetItemClientObject( int n, wxClientData* clientData )
 457 {
 458     DoSetItemClientData(n, clientData);
 459 }
 460
 461 wxClientData* wxChoice::DoGetItemClientObject( int n ) const
 462 {
 463     return (wxClientData *)DoGetItemClientData(n);
 464 }
 465
 466 // ----------------------------------------------------------------------------
 467 // wxMSW specific helpers
 468 // ----------------------------------------------------------------------------
 469
 470 void wxChoice::UpdateVisibleHeight()
 471 {
 472     // be careful to not change the width here
 473     DoSetSize(wxDefaultCoord, wxDefaultCoord, wxDefaultCoord, GetSize().y, wxSIZE_USE_EXISTING);
 474 }
 475
 476 void wxChoice::DoMoveWindow(int x, int y, int width, int height)
 477 {
 478     // here is why this is necessary: if the width is negative, the combobox
 479     // window proc makes the window of the size width*height instead of
 480     // interpreting height in the usual manner (meaning the height of the drop
 481     // down list - usually the height specified in the call to MoveWindow()
 482     // will not change the height of combo box per se)
 483     //
 484     // this behaviour is not documented anywhere, but this is just how it is
 485     // here (NT 4.4) and, anyhow, the check shouldn't hurt - however without
 486     // the check, constraints/sizers using combos may break the height
 487     // constraint will have not at all the same value as expected
 488     if ( width < 0 )
 489         return;
 490
 491     wxControl::DoMoveWindow(x, y, width, height);
 492 }
 493
 494 void wxChoice::DoGetSize(int *w, int *h) const
 495 {
 496     // this is weird: sometimes, the height returned by Windows is clearly the
 497     // total height of the control including the drop down list -- but only
 498     // sometimes, and normally it isn't... I have no idea about what to do with
 499     // this
 500     wxControl::DoGetSize(w, h);
 501 }
 502
 503 void wxChoice::DoSetSize(int x, int y,
 504                          int width, int height,
 505                          int sizeFlags)
 506 {
 507     int heightOrig = height;
 508
 509     // the height which we must pass to Windows should be the total height of
 510     // the control including the drop down list while the height given to us
 511     // is, of course, just the height of the permanently visible part of it
 512     if ( height != wxDefaultCoord )
 513     {
 514         // don't make the drop down list too tall, arbitrarily limit it to 40
 515         // items max and also don't leave it empty
 516         size_t nItems = GetCount();
 517         if ( !nItems )
 518             nItems = 9;
 519         else if ( nItems > 24 )
 520             nItems = 24;
 521
 522         // add space for the drop down list
 523         const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
 524         height += hItem*(nItems + 1);
 525     }
 526     else
 527     {
 528         // We cannot pass wxDefaultCoord as height to wxControl. wxControl uses
 529         // wxGetWindowRect() to determine the current height of the combobox,
 530         // and then again sets the combobox's height to that value. Unfortunately,
 531         // wxGetWindowRect doesn't include the dropdown list's height (at least
 532         // on Win2K), so this would result in a combobox with dropdown height of
 533         // 1 pixel. We have to determine the default height ourselves and call
 534         // wxControl with that value instead.
 535         int w, h;
 536         RECT r;
 537         DoGetSize(&w, &h);
 538         if (::SendMessage(GetHwnd(), CB_GETDROPPEDCONTROLRECT, 0, (LPARAM) &r) != 0)
 539         {
 540             height = h + r.bottom - r.top;
 541         }
 542     }
 543
 544     wxControl::DoSetSize(x, y, width, height, sizeFlags);
 545
 546     // I'm commenting this out since the code appears to make choices
 547     // and comboxes too high when they have associated sizers. I'm sure this
 548     // is not the end of the story, which is why I'm leaving it #if'ed out for
 549     // now. JACS.
 550 #if 0
 551     // if the height specified for the visible part of the control is
 552     // different from the current one, we need to change it separately
 553     // as it is not affected by normal WM_SETSIZE
 554     if ( height != wxDefaultCoord )
 555     {
 556         const int delta = heightOrig - GetSize().y;
 557         if ( delta )
 558         {
 559             int h = ::SendMessage(GetHwnd(), CB_GETITEMHEIGHT, (WPARAM)-1, 0);
 560             SendMessage(GetHwnd(), CB_SETITEMHEIGHT, (WPARAM)-1, h + delta);
 561         }
 562     }
 563 #else
 564     wxUnusedVar(heightOrig);
 565 #endif
 566 }
 567
 568 wxSize wxChoice::DoGetBestSize() const
 569 {
 570     // find the widest string
 571     int wChoice = 0;
 572     const size_t nItems = GetCount();
 573     for ( size_t i = 0; i < nItems; i++ )
 574     {
 575         int wLine;
 576         GetTextExtent(GetString(i), &wLine, NULL);
 577         if ( wLine > wChoice )
 578             wChoice = wLine;
 579     }
 580
 581     // give it some reasonable default value if there are no strings in the
 582     // list
 583     if ( wChoice == 0 )
 584         wChoice = 100;
 585
 586     // the combobox should be slightly larger than the widest string
 587     wChoice += 5*GetCharWidth();
 588
 589     wxSize best(wChoice, EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight()));
 590     CacheBestSize(best);
 591     return best;
 592 }
 593
 594 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
 595 {
 596     switch ( nMsg )
 597     {
 598         case WM_LBUTTONUP:
 599             {
 600                 int x = (int)LOWORD(lParam);
 601                 int y = (int)HIWORD(lParam);
 602
 603                 // Ok, this is truly weird, but if a panel with a wxChoice
 604                 // loses the focus, then you get a *fake* WM_LBUTTONUP message
 605                 // with x = 65535 and y = 65535. Filter out this nonsense.
 606                 //
 607                 // VZ: I'd like to know how to reproduce this please...
 608                 if ( x == 65535 && y == 65535 )
 609                     return 0;
 610             }
 611             break;
 612
 613             // we have to handle both: one for the normal case and the other
 614             // for readonly
 615         case WM_CTLCOLOREDIT:
 616         case WM_CTLCOLORLISTBOX:
 617         case WM_CTLCOLORSTATIC:
 618             {
 619                 WXHDC hdc;
 620                 WXHWND hwnd;
 621                 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
 622
 623                 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
 624                 if ( hbr )
 625                     return (WXLRESULT)hbr;
 626                 //else: fall through to default window proc
 627             }
 628     }
 629
 630     return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
 631 }
 632
 633 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 634 {
 635     /*
 636         The native control provides a great variety in the events it sends in
 637         the different selection scenarios (undoubtedly for greater amusement of
 638         the programmers using it). For the reference, here are the cases when
 639         the final selection is accepted (things are quite interesting when it
 640         is cancelled too):
 641
 642         A. Selecting with just the arrows without opening the dropdown:
 643             1. CBN_SELENDOK
 644             2. CBN_SELCHANGE
 645
 646         B. Opening dropdown with F4 and selecting with arrows:
 647             1. CBN_DROPDOWN
 648             2. many CBN_SELCHANGE while changing selection in the list
 649             3. CBN_SELENDOK
 650             4. CBN_CLOSEUP
 651
 652         C. Selecting with the mouse:
 653             1. CBN_DROPDOWN
 654             -- no intermediate CBN_SELCHANGEs --
 655             2. CBN_SELENDOK
 656             3. CBN_CLOSEUP
 657             4. CBN_SELCHANGE
 658
 659         Admire the different order of messages in all of those cases, it must
 660         surely have taken a lot of effort to Microsoft developers to achieve
 661         such originality.
 662      */
 663     switch ( param )
 664     {
 665         case CBN_DROPDOWN:
 666             // we use this value both because we don't want to track selection
 667             // using CB_GETCURSEL while the dropdown is opened and because we
 668             // need to reset the selection back to it if it's eventually
 669             // cancelled by user
 670             m_lastAcceptedSelection = GetCurrentSelection();
 671             break;
 672
 673         case CBN_CLOSEUP:
 674             // if the selection was accepted by the user, it should have been
 675             // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
 676             // cancelled and we must restore the old one
 677             if ( m_lastAcceptedSelection != wxID_NONE )
 678             {
 679                 SetSelection(m_lastAcceptedSelection);
 680                 m_lastAcceptedSelection = wxID_NONE;
 681             }
 682             break;
 683
 684         case CBN_SELENDOK:
 685             // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
 686             // ok to reset it now as GetCurrentSelection() will now return the
 687             // same thing anyhow)
 688             m_lastAcceptedSelection = wxID_NONE;
 689
 690             {
 691                 const int n = GetSelection();
 692
 693                 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
 694                 event.SetInt(n);
 695                 event.SetEventObject(this);
 696
 697                 if ( n > -1 )
 698                 {
 699                     event.SetString(GetStringSelection());
 700                     if ( HasClientObjectData() )
 701                         event.SetClientObject( GetClientObject(n) );
 702                     else if ( HasClientUntypedData() )
 703                         event.SetClientData( GetClientData(n) );
 704                 }
 705
 706                 ProcessCommand(event);
 707             }
 708             break;
 709
 710         // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
 711         // valid and the selection will be undone in CBN_CLOSEUP above
 712
 713         // don't handle CBN_SELCHANGE neither, we don't want to generate events
 714         // while the dropdown is opened -- but do add it if we ever need this
 715
 716         default:
 717             return false;
 718     }
 719
 720     return true;
 721 }
 722
 723 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
 724 {
 725     if ( !IsEnabled() )
 726         return MSWControlColorDisabled(hDC);
 727
 728     return wxChoiceBase::MSWControlColor(hDC, hWnd);
 729 }
 730
 731 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)