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, unsigned 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(unsigned 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         unsigned int count = GetCount();
 293         for ( unsigned int 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 unsigned int wxChoice::GetCount() const
 330 {
 331     return (unsigned int)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     unsigned int count = GetCount();
 340     for ( unsigned int 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        unsigned int count = GetCount();
 354        for ( unsigned int 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(unsigned 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(unsigned 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(unsigned 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(unsigned 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(unsigned int n, wxClientData* clientData)
 457 {
 458     DoSetItemClientData(n, clientData);
 459 }
 460
 461 wxClientData* wxChoice::DoGetItemClientObject(unsigned 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     int widthCurrent, heightCurrent;
 510     DoGetSize(&widthCurrent, &heightCurrent);
 511
 512     // the height which we must pass to Windows should be the total height of
 513     // the control including the drop down list while the height given to us
 514     // is, of course, just the height of the permanently visible part of it
 515     if ( height != wxDefaultCoord && height != heightCurrent )
 516     {
 517         // don't make the drop down list too tall, arbitrarily limit it to 40
 518         // items max and also don't leave it empty
 519         unsigned int nItems = GetCount();
 520         if ( !nItems )
 521             nItems = 9;
 522         else if ( nItems > 24 )
 523             nItems = 24;
 524
 525         // add space for the drop down list
 526         const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
 527         height += hItem*(nItems + 1);
 528     }
 529     else // keep the same height as now
 530     {
 531         // normally wxWindow::DoSetSize() checks if we set the same size as the
 532         // window already has and does nothing in this case, but for us the
 533         // check fails as the size we pass to it includes the dropdown while
 534         // the size returned by our GetSize() does not, so test if the size
 535         // didn't really change ourselves here
 536         if ( width == wxDefaultCoord || width == widthCurrent )
 537         {
 538             // size doesn't change, what about position?
 539             int xCurrent, yCurrent;
 540             DoGetPosition(&xCurrent, &yCurrent);
 541             const bool defMeansUnchanged = !(sizeFlags & wxSIZE_ALLOW_MINUS_ONE);
 542             if ( ((x == wxDefaultCoord && defMeansUnchanged) || x == xCurrent)
 543                     &&
 544                  ((y == wxDefaultCoord && defMeansUnchanged) || y == yCurrent) )
 545             {
 546                 // nothing changes, nothing to do
 547                 return;
 548             }
 549         }
 550
 551         // We cannot pass wxDefaultCoord as height to wxControl. wxControl uses
 552         // wxGetWindowRect() to determine the current height of the combobox,
 553         // and then again sets the combobox's height to that value. Unfortunately,
 554         // wxGetWindowRect doesn't include the dropdown list's height (at least
 555         // on Win2K), so this would result in a combobox with dropdown height of
 556         // 1 pixel. We have to determine the default height ourselves and call
 557         // wxControl with that value instead.
 558         //
 559         // Also notice that sometimes CB_GETDROPPEDCONTROLRECT seems to return
 560         // wildly incorrect values (~32000) which looks like a bug in it, just
 561         // ignore them in this case
 562         RECT r;
 563         if ( ::SendMessage(GetHwnd(), CB_GETDROPPEDCONTROLRECT, 0, (LPARAM) &r)
 564                     && r.bottom < 30000 )
 565         {
 566             height = heightCurrent + r.bottom - r.top;
 567         }
 568     }
 569
 570     wxControl::DoSetSize(x, y, width, height, sizeFlags);
 571
 572     // I'm commenting this out since the code appears to make choices
 573     // and comboxes too high when they have associated sizers. I'm sure this
 574     // is not the end of the story, which is why I'm leaving it #if'ed out for
 575     // now. JACS.
 576 #if 0
 577     // if the height specified for the visible part of the control is
 578     // different from the current one, we need to change it separately
 579     // as it is not affected by normal WM_SETSIZE
 580     if ( height != wxDefaultCoord )
 581     {
 582         const int delta = heightOrig - GetSize().y;
 583         if ( delta )
 584         {
 585             int h = ::SendMessage(GetHwnd(), CB_GETITEMHEIGHT, (WPARAM)-1, 0);
 586             SendMessage(GetHwnd(), CB_SETITEMHEIGHT, (WPARAM)-1, h + delta);
 587         }
 588     }
 589 #else
 590     wxUnusedVar(heightOrig);
 591 #endif
 592 }
 593
 594 wxSize wxChoice::DoGetBestSize() const
 595 {
 596     // find the widest string
 597     int wChoice = 0;
 598     const unsigned int nItems = GetCount();
 599     for ( unsigned int i = 0; i < nItems; i++ )
 600     {
 601         int wLine;
 602         GetTextExtent(GetString(i), &wLine, NULL);
 603         if ( wLine > wChoice )
 604             wChoice = wLine;
 605     }
 606
 607     // give it some reasonable default value if there are no strings in the
 608     // list
 609     if ( wChoice == 0 )
 610         wChoice = 100;
 611
 612     // the combobox should be slightly larger than the widest string
 613     wChoice += 5*GetCharWidth();
 614
 615     wxSize best(wChoice, EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight()));
 616     CacheBestSize(best);
 617     return best;
 618 }
 619
 620 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
 621 {
 622     switch ( nMsg )
 623     {
 624         case WM_LBUTTONUP:
 625             {
 626                 int x = (int)LOWORD(lParam);
 627                 int y = (int)HIWORD(lParam);
 628
 629                 // Ok, this is truly weird, but if a panel with a wxChoice
 630                 // loses the focus, then you get a *fake* WM_LBUTTONUP message
 631                 // with x = 65535 and y = 65535. Filter out this nonsense.
 632                 //
 633                 // VZ: I'd like to know how to reproduce this please...
 634                 if ( x == 65535 && y == 65535 )
 635                     return 0;
 636             }
 637             break;
 638
 639             // we have to handle both: one for the normal case and the other
 640             // for readonly
 641         case WM_CTLCOLOREDIT:
 642         case WM_CTLCOLORLISTBOX:
 643         case WM_CTLCOLORSTATIC:
 644             {
 645                 WXHDC hdc;
 646                 WXHWND hwnd;
 647                 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
 648
 649                 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
 650                 if ( hbr )
 651                     return (WXLRESULT)hbr;
 652                 //else: fall through to default window proc
 653             }
 654     }
 655
 656     return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
 657 }
 658
 659 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 660 {
 661     /*
 662         The native control provides a great variety in the events it sends in
 663         the different selection scenarios (undoubtedly for greater amusement of
 664         the programmers using it). For the reference, here are the cases when
 665         the final selection is accepted (things are quite interesting when it
 666         is cancelled too):
 667
 668         A. Selecting with just the arrows without opening the dropdown:
 669             1. CBN_SELENDOK
 670             2. CBN_SELCHANGE
 671
 672         B. Opening dropdown with F4 and selecting with arrows:
 673             1. CBN_DROPDOWN
 674             2. many CBN_SELCHANGE while changing selection in the list
 675             3. CBN_SELENDOK
 676             4. CBN_CLOSEUP
 677
 678         C. Selecting with the mouse:
 679             1. CBN_DROPDOWN
 680             -- no intermediate CBN_SELCHANGEs --
 681             2. CBN_SELENDOK
 682             3. CBN_CLOSEUP
 683             4. CBN_SELCHANGE
 684
 685         Admire the different order of messages in all of those cases, it must
 686         surely have taken a lot of effort to Microsoft developers to achieve
 687         such originality.
 688      */
 689     switch ( param )
 690     {
 691         case CBN_DROPDOWN:
 692             // we use this value both because we don't want to track selection
 693             // using CB_GETCURSEL while the dropdown is opened and because we
 694             // need to reset the selection back to it if it's eventually
 695             // cancelled by user
 696             m_lastAcceptedSelection = GetCurrentSelection();
 697             break;
 698
 699         case CBN_CLOSEUP:
 700             // if the selection was accepted by the user, it should have been
 701             // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
 702             // cancelled and we must restore the old one
 703             if ( m_lastAcceptedSelection != wxID_NONE )
 704             {
 705                 SetSelection(m_lastAcceptedSelection);
 706                 m_lastAcceptedSelection = wxID_NONE;
 707             }
 708             break;
 709
 710         case CBN_SELENDOK:
 711             // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
 712             // ok to reset it now as GetCurrentSelection() will now return the
 713             // same thing anyhow)
 714             m_lastAcceptedSelection = wxID_NONE;
 715
 716             {
 717                 const int n = GetSelection();
 718
 719                 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
 720                 event.SetInt(n);
 721                 event.SetEventObject(this);
 722
 723                 if ( n > -1 )
 724                 {
 725                     event.SetString(GetStringSelection());
 726                     if ( HasClientObjectData() )
 727                         event.SetClientObject( GetClientObject(n) );
 728                     else if ( HasClientUntypedData() )
 729                         event.SetClientData( GetClientData(n) );
 730                 }
 731
 732                 ProcessCommand(event);
 733             }
 734             break;
 735
 736         // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
 737         // valid and the selection will be undone in CBN_CLOSEUP above
 738
 739         // don't handle CBN_SELCHANGE neither, we don't want to generate events
 740         // while the dropdown is opened -- but do add it if we ever need this
 741
 742         default:
 743             return false;
 744     }
 745
 746     return true;
 747 }
 748
 749 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
 750 {
 751     if ( !IsEnabled() )
 752         return MSWControlColorDisabled(hDC);
 753
 754     return wxChoiceBase::MSWControlColor(hDC, hWnd);
 755 }
 756
 757 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)