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 #include "wx/choice.h"
  30
  31 #ifndef WX_PRECOMP
  32     #include "wx/utils.h"
  33     #include "wx/log.h"
  34     #include "wx/brush.h"
  35     #include "wx/settings.h"
  36 #endif
  37
  38 #include "wx/msw/private.h"
  39
  40 #if wxUSE_EXTENDED_RTTI
  41 WX_DEFINE_FLAGS( wxChoiceStyle )
  42
  43 wxBEGIN_FLAGS( wxChoiceStyle )
  44     // new style border flags, we put them first to
  45     // use them for streaming out
  46     wxFLAGS_MEMBER(wxBORDER_SIMPLE)
  47     wxFLAGS_MEMBER(wxBORDER_SUNKEN)
  48     wxFLAGS_MEMBER(wxBORDER_DOUBLE)
  49     wxFLAGS_MEMBER(wxBORDER_RAISED)
  50     wxFLAGS_MEMBER(wxBORDER_STATIC)
  51     wxFLAGS_MEMBER(wxBORDER_NONE)
  52
  53     // old style border flags
  54     wxFLAGS_MEMBER(wxSIMPLE_BORDER)
  55     wxFLAGS_MEMBER(wxSUNKEN_BORDER)
  56     wxFLAGS_MEMBER(wxDOUBLE_BORDER)
  57     wxFLAGS_MEMBER(wxRAISED_BORDER)
  58     wxFLAGS_MEMBER(wxSTATIC_BORDER)
  59     wxFLAGS_MEMBER(wxBORDER)
  60
  61     // standard window styles
  62     wxFLAGS_MEMBER(wxTAB_TRAVERSAL)
  63     wxFLAGS_MEMBER(wxCLIP_CHILDREN)
  64     wxFLAGS_MEMBER(wxTRANSPARENT_WINDOW)
  65     wxFLAGS_MEMBER(wxWANTS_CHARS)
  66     wxFLAGS_MEMBER(wxFULL_REPAINT_ON_RESIZE)
  67     wxFLAGS_MEMBER(wxALWAYS_SHOW_SB )
  68     wxFLAGS_MEMBER(wxVSCROLL)
  69     wxFLAGS_MEMBER(wxHSCROLL)
  70
  71 wxEND_FLAGS( wxChoiceStyle )
  72
  73 IMPLEMENT_DYNAMIC_CLASS_XTI(wxChoice, wxControlWithItems,"wx/choice.h")
  74
  75 wxBEGIN_PROPERTIES_TABLE(wxChoice)
  76     wxEVENT_PROPERTY( Select , wxEVT_COMMAND_CHOICE_SELECTED , wxCommandEvent )
  77
  78     wxPROPERTY( Font , wxFont , SetFont , GetFont  , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  79     wxPROPERTY_COLLECTION( Choices , wxArrayString , wxString , AppendString , GetStrings , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  80     wxPROPERTY( Selection ,int, SetSelection, GetSelection, EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  81     wxPROPERTY_FLAGS( WindowStyle , wxChoiceStyle , long , SetWindowStyleFlag , GetWindowStyleFlag , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group")) // style
  82 wxEND_PROPERTIES_TABLE()
  83
  84 wxBEGIN_HANDLERS_TABLE(wxChoice)
  85 wxEND_HANDLERS_TABLE()
  86
  87 wxCONSTRUCTOR_4( wxChoice , wxWindow* , Parent , wxWindowID , Id , wxPoint , Position , wxSize , Size )
  88 #else
  89 IMPLEMENT_DYNAMIC_CLASS(wxChoice, wxControlWithItems)
  90 #endif
  91 /*
  92     TODO PROPERTIES
  93         selection (long)
  94         content (list)
  95             item
  96 */
  97
  98 // ============================================================================
  99 // implementation
 100 // ============================================================================
 101
 102 // ----------------------------------------------------------------------------
 103 // creation
 104 // ----------------------------------------------------------------------------
 105
 106 bool wxChoice::Create(wxWindow *parent,
 107                       wxWindowID id,
 108                       const wxPoint& pos,
 109                       const wxSize& size,
 110                       int n, const wxString choices[],
 111                       long style,
 112                       const wxValidator& validator,
 113                       const wxString& name)
 114 {
 115     // Experience shows that wxChoice vs. wxComboBox distinction confuses
 116     // quite a few people - try to help them
 117     wxASSERT_MSG( !(style & wxCB_DROPDOWN) &&
 118                   !(style & wxCB_READONLY) &&
 119                   !(style & wxCB_SIMPLE),
 120                   _T("this style flag is ignored by wxChoice, you ")
 121                   _T("probably want to use a wxComboBox") );
 122
 123     return CreateAndInit(parent, id, pos, size, n, choices, style,
 124                          validator, name);
 125 }
 126
 127 bool wxChoice::CreateAndInit(wxWindow *parent,
 128                              wxWindowID id,
 129                              const wxPoint& pos,
 130                              const wxSize& size,
 131                              int n, const wxString choices[],
 132                              long style,
 133                              const wxValidator& validator,
 134                              const wxString& name)
 135 {
 136     // initialize wxControl
 137     if ( !CreateControl(parent, id, pos, size, style, validator, name) )
 138         return false;
 139
 140     // now create the real HWND
 141     if ( !MSWCreateControl(wxT("COMBOBOX"), wxEmptyString, pos, size) )
 142         return false;
 143
 144
 145     // choice/combobox normally has "white" (depends on colour scheme, of
 146     // course) background rather than inheriting the parent's background
 147     SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));
 148
 149     // initialize the controls contents
 150     for ( int i = 0; i < n; i++ )
 151     {
 152         Append(choices[i]);
 153     }
 154
 155     // and now we may finally size the control properly (if needed)
 156     SetInitialSize(size);
 157
 158     return true;
 159 }
 160
 161 void wxChoice::SetLabel(const wxString& label)
 162 {
 163     if ( FindString(label) == wxNOT_FOUND )
 164     {
 165         // unless we explicitly do this here, CB_GETCURSEL will continue to
 166         // return the index of the previously selected item which will result
 167         // in wrongly replacing the value being set now with the previously
 168         // value if the user simply opens and closes (without selecting
 169         // anything) the combobox popup
 170         SetSelection(-1);
 171     }
 172
 173     wxChoiceBase::SetLabel(label);
 174 }
 175
 176 bool wxChoice::Create(wxWindow *parent,
 177                       wxWindowID id,
 178                       const wxPoint& pos,
 179                       const wxSize& size,
 180                       const wxArrayString& choices,
 181                       long style,
 182                       const wxValidator& validator,
 183                       const wxString& name)
 184 {
 185     wxCArrayString chs(choices);
 186     return Create(parent, id, pos, size, chs.GetCount(), chs.GetStrings(),
 187                   style, validator, name);
 188 }
 189
 190 bool wxChoice::MSWShouldPreProcessMessage(WXMSG *pMsg)
 191 {
 192     MSG *msg = (MSG *) pMsg;
 193
 194     // if the dropdown list is visible, don't preprocess certain keys
 195     if ( msg->message == WM_KEYDOWN
 196         && (msg->wParam == VK_ESCAPE || msg->wParam == VK_RETURN) )
 197     {
 198         if (::SendMessage(GetHwndOf(this), CB_GETDROPPEDSTATE, 0, 0))
 199         {
 200             return false;
 201         }
 202     }
 203
 204     return wxControl::MSWShouldPreProcessMessage(pMsg);
 205 }
 206
 207 WXDWORD wxChoice::MSWGetStyle(long style, WXDWORD *exstyle) const
 208 {
 209     // we never have an external border
 210     WXDWORD msStyle = wxControl::MSWGetStyle
 211                       (
 212                         (style & ~wxBORDER_MASK) | wxBORDER_NONE, exstyle
 213                       );
 214
 215     // WS_CLIPSIBLINGS is useful with wxChoice and doesn't seem to result in
 216     // any problems
 217     msStyle |= WS_CLIPSIBLINGS;
 218
 219     // wxChoice-specific styles
 220     msStyle |= CBS_DROPDOWNLIST | WS_HSCROLL | WS_VSCROLL;
 221     if ( style & wxCB_SORT )
 222         msStyle |= CBS_SORT;
 223
 224     return msStyle;
 225 }
 226
 227 wxChoice::~wxChoice()
 228 {
 229     Clear();
 230 }
 231
 232 // ----------------------------------------------------------------------------
 233 // adding/deleting items to/from the list
 234 // ----------------------------------------------------------------------------
 235
 236 int wxChoice::DoInsertItems(const wxArrayStringsAdapter& items,
 237                             unsigned int pos,
 238                             void **clientData, wxClientDataType type)
 239 {
 240     MSWAllocStorage(items, CB_INITSTORAGE);
 241
 242     const bool append = pos == GetCount();
 243
 244     // use CB_ADDSTRING when appending at the end to make sure the control is
 245     // resorted if it has wxCB_SORT style
 246     const unsigned msg = append ? CB_ADDSTRING : CB_INSERTSTRING;
 247
 248     if ( append )
 249         pos = 0;
 250
 251     int n = wxNOT_FOUND;
 252     const unsigned numItems = items.GetCount();
 253     for ( unsigned i = 0; i < numItems; ++i )
 254     {
 255         n = MSWInsertOrAppendItem(pos, items[i], msg);
 256         if ( n == wxNOT_FOUND )
 257             return n;
 258
 259         if ( !append )
 260             pos++;
 261
 262         AssignNewItemClientData(n, clientData, i, type);
 263     }
 264
 265     // we need to refresh our size in order to have enough space for the
 266     // newly added items
 267     if ( !IsFrozen() )
 268         MSWUpdateDropDownHeight();
 269
 270     InvalidateBestSize();
 271
 272     return n;
 273 }
 274
 275 void wxChoice::DoDeleteOneItem(unsigned int n)
 276 {
 277     wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::Delete") );
 278
 279     SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
 280
 281     if ( !IsFrozen() )
 282         MSWUpdateDropDownHeight();
 283
 284     InvalidateBestSize();
 285 }
 286
 287 void wxChoice::DoClear()
 288 {
 289     SendMessage(GetHwnd(), CB_RESETCONTENT, 0, 0);
 290
 291     if ( !IsFrozen() )
 292         MSWUpdateDropDownHeight();
 293
 294     InvalidateBestSize();
 295 }
 296
 297 // ----------------------------------------------------------------------------
 298 // selection
 299 // ----------------------------------------------------------------------------
 300
 301 int wxChoice::GetSelection() const
 302 {
 303     // if m_lastAcceptedSelection is set, it means that the dropdown is
 304     // currently shown and that we want to use the last "permanent" selection
 305     // instead of whatever is under the mouse pointer currently
 306     //
 307     // otherwise, get the selection from the control
 308     return m_lastAcceptedSelection == wxID_NONE ? GetCurrentSelection()
 309                                                 : m_lastAcceptedSelection;
 310 }
 311
 312 int wxChoice::GetCurrentSelection() const
 313 {
 314     return (int)SendMessage(GetHwnd(), CB_GETCURSEL, 0, 0);
 315 }
 316
 317 void wxChoice::SetSelection(int n)
 318 {
 319     SendMessage(GetHwnd(), CB_SETCURSEL, n, 0);
 320 }
 321
 322 // ----------------------------------------------------------------------------
 323 // string list functions
 324 // ----------------------------------------------------------------------------
 325
 326 unsigned int wxChoice::GetCount() const
 327 {
 328     return (unsigned int)SendMessage(GetHwnd(), CB_GETCOUNT, 0, 0);
 329 }
 330
 331 int wxChoice::FindString(const wxString& s, bool bCase) const
 332 {
 333 #if defined(__WATCOMC__) && defined(__WIN386__)
 334     // For some reason, Watcom in WIN386 mode crashes in the CB_FINDSTRINGEXACT message.
 335     // wxChoice::Do it the long way instead.
 336     unsigned int count = GetCount();
 337     for ( unsigned int i = 0; i < count; i++ )
 338     {
 339         // as CB_FINDSTRINGEXACT is case insensitive, be case insensitive too
 340         if (GetString(i).IsSameAs(s, bCase))
 341             return i;
 342     }
 343
 344     return wxNOT_FOUND;
 345 #else // !Watcom
 346    //TODO:  Evidently some MSW versions (all?) don't like empty strings
 347    //passed to SendMessage, so we have to do it ourselves in that case
 348    if ( s.empty() )
 349    {
 350        unsigned int count = GetCount();
 351        for ( unsigned int i = 0; i < count; i++ )
 352        {
 353          if (GetString(i).empty())
 354              return i;
 355        }
 356
 357        return wxNOT_FOUND;
 358    }
 359    else if (bCase)
 360    {
 361        // back to base class search for not native search type
 362        return wxItemContainerImmutable::FindString( s, bCase );
 363    }
 364    else
 365    {
 366        int pos = (int)SendMessage(GetHwnd(), CB_FINDSTRINGEXACT,
 367                                   (WPARAM)-1, (LPARAM)s.wx_str());
 368
 369        return pos == LB_ERR ? wxNOT_FOUND : pos;
 370    }
 371 #endif // Watcom/!Watcom
 372 }
 373
 374 void wxChoice::SetString(unsigned int n, const wxString& s)
 375 {
 376     wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );
 377
 378     // we have to delete and add back the string as there is no way to change a
 379     // string in place
 380
 381     // we need to preserve the client data manually
 382     void *oldData = NULL;
 383     wxClientData *oldObjData = NULL;
 384     if ( HasClientUntypedData() )
 385         oldData = GetClientData(n);
 386     else if ( HasClientObjectData() )
 387         oldObjData = GetClientObject(n);
 388
 389     ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
 390     ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, (LPARAM)s.wx_str() );
 391
 392     // restore the client data
 393     if ( oldData )
 394         SetClientData(n, oldData);
 395     else if ( oldObjData )
 396         SetClientObject(n, oldObjData);
 397
 398     InvalidateBestSize();
 399 }
 400
 401 wxString wxChoice::GetString(unsigned int n) const
 402 {
 403     int len = (int)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);
 404
 405     wxString str;
 406     if ( len != CB_ERR && len > 0 )
 407     {
 408         if ( ::SendMessage
 409                (
 410                 GetHwnd(),
 411                 CB_GETLBTEXT,
 412                 n,
 413                 (LPARAM)(wxChar *)wxStringBuffer(str, len)
 414                ) == CB_ERR )
 415         {
 416             wxLogLastError(wxT("SendMessage(CB_GETLBTEXT)"));
 417         }
 418     }
 419
 420     return str;
 421 }
 422
 423 // ----------------------------------------------------------------------------
 424 // client data
 425 // ----------------------------------------------------------------------------
 426
 427 void wxChoice::DoSetItemClientData(unsigned int n, void* clientData)
 428 {
 429     if ( ::SendMessage(GetHwnd(), CB_SETITEMDATA,
 430                        n, (LPARAM)clientData) == CB_ERR )
 431     {
 432         wxLogLastError(wxT("CB_SETITEMDATA"));
 433     }
 434 }
 435
 436 void* wxChoice::DoGetItemClientData(unsigned int n) const
 437 {
 438     LPARAM rc = SendMessage(GetHwnd(), CB_GETITEMDATA, n, 0);
 439     if ( rc == CB_ERR )
 440     {
 441         wxLogLastError(wxT("CB_GETITEMDATA"));
 442
 443         // unfortunately, there is no way to return an error code to the user
 444         rc = (LPARAM) NULL;
 445     }
 446
 447     return (void *)rc;
 448 }
 449
 450 // ----------------------------------------------------------------------------
 451 // wxMSW-specific geometry management
 452 // ----------------------------------------------------------------------------
 453
 454 namespace
 455 {
 456
 457 // there is a difference between the height passed to CB_SETITEMHEIGHT and the
 458 // real height of the combobox; it is probably not constant for all Windows
 459 // versions/settings but right now I don't know how to find what it is so it is
 460 // temporarily hardcoded to its value under XP systems with normal fonts sizes
 461 const int COMBO_HEIGHT_ADJ = 6;
 462
 463 } // anonymous namespace
 464
 465 void wxChoice::MSWUpdateVisibleHeight()
 466 {
 467     if ( m_heightOwn != wxDefaultCoord )
 468     {
 469         ::SendMessage(GetHwnd(), CB_SETITEMHEIGHT,
 470                       (WPARAM)-1, m_heightOwn - COMBO_HEIGHT_ADJ);
 471     }
 472 }
 473
 474 #if wxUSE_DEFERRED_SIZING
 475 void wxChoice::MSWEndDeferWindowPos()
 476 {
 477     // we can only set the height of the choice itself now as it is reset to
 478     // default every time the control is resized
 479     MSWUpdateVisibleHeight();
 480
 481     wxChoiceBase::MSWEndDeferWindowPos();
 482 }
 483 #endif // wxUSE_DEFERRED_SIZING
 484
 485 void wxChoice::MSWUpdateDropDownHeight()
 486 {
 487     // be careful to not change the width here
 488     DoSetSize(wxDefaultCoord, wxDefaultCoord, wxDefaultCoord, GetSize().y,
 489               wxSIZE_USE_EXISTING);
 490 }
 491
 492 void wxChoice::DoMoveWindow(int x, int y, int width, int height)
 493 {
 494     // here is why this is necessary: if the width is negative, the combobox
 495     // window proc makes the window of the size width*height instead of
 496     // interpreting height in the usual manner (meaning the height of the drop
 497     // down list - usually the height specified in the call to MoveWindow()
 498     // will not change the height of combo box per se)
 499     //
 500     // this behaviour is not documented anywhere, but this is just how it is
 501     // here (NT 4.4) and, anyhow, the check shouldn't hurt - however without
 502     // the check, constraints/sizers using combos may break the height
 503     // constraint will have not at all the same value as expected
 504     if ( width < 0 )
 505         return;
 506
 507     wxControl::DoMoveWindow(x, y, width, height);
 508 }
 509
 510 void wxChoice::DoGetSize(int *w, int *h) const
 511 {
 512     wxControl::DoGetSize(w, h);
 513
 514     // this is weird: sometimes, the height returned by Windows is clearly the
 515     // total height of the control including the drop down list -- but only
 516     // sometimes, and sometimes it isn't so work around this here by using our
 517     // own stored value if we have it
 518     if ( h && m_heightOwn != wxDefaultCoord )
 519         *h = m_heightOwn;
 520 }
 521
 522 void wxChoice::DoSetSize(int x, int y,
 523                          int width, int height,
 524                          int sizeFlags)
 525 {
 526     // we need the real height below so get the current one if it's not given
 527     if ( height != wxDefaultCoord && height != GetBestSize().y )
 528     {
 529         // set our new own height but be careful not to make it too big: the
 530         // native control apparently stores it as a single byte and so setting
 531         // own height to 256 pixels results in default height being used (255
 532         // is still ok)
 533         m_heightOwn = height;
 534
 535         if ( m_heightOwn > UCHAR_MAX )
 536             m_heightOwn = UCHAR_MAX;
 537         // nor too small: see MSWUpdateVisibleHeight()
 538         else if ( m_heightOwn < COMBO_HEIGHT_ADJ )
 539             m_heightOwn = COMBO_HEIGHT_ADJ;
 540     }
 541     else // height not specified
 542     {
 543         DoGetSize(NULL, &height);
 544     }
 545
 546
 547     // the height which we must pass to Windows should be the total height of
 548     // the control including the drop down list while the height given to us
 549     // is, of course, just the height of the permanently visible part of it so
 550     // add the drop down height to it
 551
 552     // don't make the drop down list too tall, arbitrarily limit it to 30
 553     // items max and also don't make it too small if it's currently empty
 554     size_t nItems = GetCount();
 555     if ( !nItems )
 556         nItems = 9;
 557     else if ( nItems > 30 )
 558         nItems = 30;
 559
 560     const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
 561     const int heightWithItems = height + hItem*nItems;
 562
 563
 564     // do resize the native control
 565     wxControl::DoSetSize(x, y, width, heightWithItems, sizeFlags);
 566
 567
 568     // make the control itself of the requested height: notice that this
 569     // must be done after changing its size or it has no effect (apparently
 570     // the height is reset to default during the control layout) and that it's
 571     // useless to to do it when using the deferred sizing -- in this case it
 572     // will be done from MSWEndDeferWindowPos()
 573 #if wxUSE_DEFERRED_SIZING
 574     if ( m_pendingSize == wxDefaultSize )
 575     {
 576         // not using deferred sizing, update it immediately
 577         MSWUpdateVisibleHeight();
 578     }
 579     else // in the middle of deferred sizing
 580     {
 581         // we need to report the size of the visible part of the control back
 582         // in GetSize() and not height stored by DoSetSize() in m_pendingSize
 583         m_pendingSize = wxSize(width, height);
 584     }
 585 #else // !wxUSE_DEFERRED_SIZING
 586     // always update the visible height immediately
 587     MSWUpdateVisibleHeight();
 588 #endif // wxUSE_DEFERRED_SIZING
 589 }
 590
 591 wxSize wxChoice::DoGetBestSize() const
 592 {
 593     // find the widest string
 594     int wChoice = 0;
 595     const unsigned int nItems = GetCount();
 596     for ( unsigned int i = 0; i < nItems; i++ )
 597     {
 598         int wLine;
 599         GetTextExtent(GetString(i), &wLine, NULL);
 600         if ( wLine > wChoice )
 601             wChoice = wLine;
 602     }
 603
 604     // give it some reasonable default value if there are no strings in the
 605     // list
 606     if ( wChoice == 0 )
 607         wChoice = 100;
 608
 609     // the combobox should be slightly larger than the widest string
 610     wChoice += 5*GetCharWidth();
 611
 612     wxSize best(wChoice, EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight()));
 613     CacheBestSize(best);
 614     return best;
 615 }
 616
 617 // ----------------------------------------------------------------------------
 618 // MSW message handlers
 619 // ----------------------------------------------------------------------------
 620
 621 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
 622 {
 623     switch ( nMsg )
 624     {
 625         case WM_LBUTTONUP:
 626             {
 627                 int x = (int)LOWORD(lParam);
 628                 int y = (int)HIWORD(lParam);
 629
 630                 // Ok, this is truly weird, but if a panel with a wxChoice
 631                 // loses the focus, then you get a *fake* WM_LBUTTONUP message
 632                 // with x = 65535 and y = 65535. Filter out this nonsense.
 633                 //
 634                 // VZ: I'd like to know how to reproduce this please...
 635                 if ( x == 65535 && y == 65535 )
 636                     return 0;
 637             }
 638             break;
 639
 640             // we have to handle both: one for the normal case and the other
 641             // for readonly
 642         case WM_CTLCOLOREDIT:
 643         case WM_CTLCOLORLISTBOX:
 644         case WM_CTLCOLORSTATIC:
 645             {
 646                 WXHDC hdc;
 647                 WXHWND hwnd;
 648                 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
 649
 650                 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
 651                 if ( hbr )
 652                     return (WXLRESULT)hbr;
 653                 //else: fall through to default window proc
 654             }
 655     }
 656
 657     return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
 658 }
 659
 660 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 661 {
 662     /*
 663         The native control provides a great variety in the events it sends in
 664         the different selection scenarios (undoubtedly for greater amusement of
 665         the programmers using it). For the reference, here are the cases when
 666         the final selection is accepted (things are quite interesting when it
 667         is cancelled too):
 668
 669         A. Selecting with just the arrows without opening the dropdown:
 670             1. CBN_SELENDOK
 671             2. CBN_SELCHANGE
 672
 673         B. Opening dropdown with F4 and selecting with arrows:
 674             1. CBN_DROPDOWN
 675             2. many CBN_SELCHANGE while changing selection in the list
 676             3. CBN_SELENDOK
 677             4. CBN_CLOSEUP
 678
 679         C. Selecting with the mouse:
 680             1. CBN_DROPDOWN
 681             -- no intermediate CBN_SELCHANGEs --
 682             2. CBN_SELENDOK
 683             3. CBN_CLOSEUP
 684             4. CBN_SELCHANGE
 685
 686         Admire the different order of messages in all of those cases, it must
 687         surely have taken a lot of effort to Microsoft developers to achieve
 688         such originality.
 689      */
 690     switch ( param )
 691     {
 692         case CBN_DROPDOWN:
 693             // we use this value both because we don't want to track selection
 694             // using CB_GETCURSEL while the dropdown is opened and because we
 695             // need to reset the selection back to it if it's eventually
 696             // cancelled by user
 697             m_lastAcceptedSelection = GetCurrentSelection();
 698             break;
 699
 700         case CBN_CLOSEUP:
 701             // if the selection was accepted by the user, it should have been
 702             // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
 703             // cancelled and we must restore the old one
 704             if ( m_lastAcceptedSelection != wxID_NONE )
 705             {
 706                 SetSelection(m_lastAcceptedSelection);
 707                 m_lastAcceptedSelection = wxID_NONE;
 708             }
 709             break;
 710
 711         case CBN_SELENDOK:
 712             // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
 713             // ok to reset it now as GetCurrentSelection() will now return the
 714             // same thing anyhow)
 715             m_lastAcceptedSelection = wxID_NONE;
 716
 717             {
 718                 const int n = GetSelection();
 719
 720                 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
 721                 event.SetInt(n);
 722                 event.SetEventObject(this);
 723
 724                 if ( n > -1 )
 725                 {
 726                     event.SetString(GetStringSelection());
 727                     InitCommandEventWithItems(event, n);
 728                 }
 729
 730                 ProcessCommand(event);
 731             }
 732             break;
 733
 734         // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
 735         // valid and the selection will be undone in CBN_CLOSEUP above
 736
 737         // don't handle CBN_SELCHANGE neither, we don't want to generate events
 738         // while the dropdown is opened -- but do add it if we ever need this
 739
 740         default:
 741             return false;
 742     }
 743
 744     return true;
 745 }
 746
 747 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
 748 {
 749     if ( !IsEnabled() )
 750         return MSWControlColorDisabled(hDC);
 751
 752     return wxChoiceBase::MSWControlColor(hDC, hWnd);
 753 }
 754
 755 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)