No changes, just refactor wxMSW wxComboBox code calling GetComboBoxInfo().
[wxWidgets.git] / 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/app.h"
34 #include "wx/log.h"
35 #include "wx/brush.h"
36 #include "wx/settings.h"
37 #endif
38
39 #include "wx/dynlib.h"
40
41 #include "wx/msw/private.h"
42
43 // ============================================================================
44 // implementation
45 // ============================================================================
46
47 // ----------------------------------------------------------------------------
48 // creation
49 // ----------------------------------------------------------------------------
50
51 bool wxChoice::Create(wxWindow *parent,
52 wxWindowID id,
53 const wxPoint& pos,
54 const wxSize& size,
55 int n, const wxString choices[],
56 long style,
57 const wxValidator& validator,
58 const wxString& name)
59 {
60 // Experience shows that wxChoice vs. wxComboBox distinction confuses
61 // quite a few people - try to help them
62 wxASSERT_MSG( !(style & wxCB_DROPDOWN) &&
63 !(style & wxCB_READONLY) &&
64 !(style & wxCB_SIMPLE),
65 wxT("this style flag is ignored by wxChoice, you ")
66 wxT("probably want to use a wxComboBox") );
67
68 return CreateAndInit(parent, id, pos, size, n, choices, style,
69 validator, name);
70 }
71
72 bool wxChoice::CreateAndInit(wxWindow *parent,
73 wxWindowID id,
74 const wxPoint& pos,
75 const wxSize& size,
76 int n, const wxString choices[],
77 long style,
78 const wxValidator& validator,
79 const wxString& name)
80 {
81 // initialize wxControl
82 if ( !CreateControl(parent, id, pos, size, style, validator, name) )
83 return false;
84
85 // now create the real HWND
86 if ( !MSWCreateControl(wxT("COMBOBOX"), wxEmptyString, pos, size) )
87 return false;
88
89
90 // initialize the controls contents
91 Append(n, choices);
92
93 // and now we may finally size the control properly (if needed)
94 SetInitialSize(size);
95
96 return true;
97 }
98
99 void wxChoice::SetLabel(const wxString& label)
100 {
101 if ( FindString(label) == wxNOT_FOUND )
102 {
103 // unless we explicitly do this here, CB_GETCURSEL will continue to
104 // return the index of the previously selected item which will result
105 // in wrongly replacing the value being set now with the previously
106 // value if the user simply opens and closes (without selecting
107 // anything) the combobox popup
108 SetSelection(-1);
109 }
110
111 wxChoiceBase::SetLabel(label);
112 }
113
114 bool wxChoice::Create(wxWindow *parent,
115 wxWindowID id,
116 const wxPoint& pos,
117 const wxSize& size,
118 const wxArrayString& choices,
119 long style,
120 const wxValidator& validator,
121 const wxString& name)
122 {
123 wxCArrayString chs(choices);
124 return Create(parent, id, pos, size, chs.GetCount(), chs.GetStrings(),
125 style, validator, name);
126 }
127
128 bool wxChoice::MSWShouldPreProcessMessage(WXMSG *pMsg)
129 {
130 MSG *msg = (MSG *) pMsg;
131
132 // if the dropdown list is visible, don't preprocess certain keys
133 if ( msg->message == WM_KEYDOWN
134 && (msg->wParam == VK_ESCAPE || msg->wParam == VK_RETURN) )
135 {
136 if (::SendMessage(GetHwndOf(this), CB_GETDROPPEDSTATE, 0, 0))
137 {
138 return false;
139 }
140 }
141
142 return wxControl::MSWShouldPreProcessMessage(pMsg);
143 }
144
145 WXDWORD wxChoice::MSWGetStyle(long style, WXDWORD *exstyle) const
146 {
147 // we never have an external border
148 WXDWORD msStyle = wxControl::MSWGetStyle
149 (
150 (style & ~wxBORDER_MASK) | wxBORDER_NONE, exstyle
151 );
152
153 // WS_CLIPSIBLINGS is useful with wxChoice and doesn't seem to result in
154 // any problems
155 msStyle |= WS_CLIPSIBLINGS;
156
157 // wxChoice-specific styles
158 msStyle |= CBS_DROPDOWNLIST | WS_HSCROLL | WS_VSCROLL;
159 if ( style & wxCB_SORT )
160 msStyle |= CBS_SORT;
161
162 return msStyle;
163 }
164
165 #ifndef EP_EDITTEXT
166 #define EP_EDITTEXT 1
167 #define ETS_NORMAL 1
168 #endif
169
170 wxVisualAttributes
171 wxChoice::GetClassDefaultAttributes(wxWindowVariant WXUNUSED(variant))
172 {
173 // it is important to return valid values for all attributes from here,
174 // GetXXX() below rely on this
175 wxVisualAttributes attrs;
176
177 // FIXME: Use better dummy window?
178 wxWindow* wnd = wxTheApp->GetTopWindow();
179 if (!wnd)
180 return attrs;
181
182 attrs.font = wxSystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
183
184 // there doesn't seem to be any way to get the text colour using themes
185 // API: TMT_TEXTCOLOR doesn't work neither for EDIT nor COMBOBOX
186 attrs.colFg = wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT);
187
188 // NB: use EDIT, not COMBOBOX (the latter works in XP but not Vista)
189 attrs.colBg = wnd->MSWGetThemeColour(L"EDIT",
190 EP_EDITTEXT,
191 ETS_NORMAL,
192 ThemeColourBackground,
193 wxSYS_COLOUR_WINDOW);
194
195 return attrs;
196 }
197
198 wxChoice::~wxChoice()
199 {
200 Clear();
201 }
202
203 bool wxChoice::MSWGetComboBoxInfo(COMBOBOXINFO* info) const
204 {
205 // TODO-Win9x: Get rid of this once we officially drop support for Win9x
206 // and just call the function directly.
207 #if wxUSE_DYNLIB_CLASS
208 typedef BOOL (WINAPI *GetComboBoxInfo_t)(HWND, COMBOBOXINFO*);
209 static GetComboBoxInfo_t s_pfnGetComboBoxInfo = NULL;
210 static bool s_triedToLoad = false;
211 if ( !s_triedToLoad )
212 {
213 s_triedToLoad = true;
214 wxLoadedDLL dllUser32("user32.dll");
215 wxDL_INIT_FUNC(s_pfn, GetComboBoxInfo, dllUser32);
216 }
217
218 if ( s_pfnGetComboBoxInfo )
219 return (*s_pfnGetComboBoxInfo)(GetHwnd(), info) != 0;
220 #endif // wxUSE_DYNLIB_CLASS
221
222 return false;
223 }
224
225 // ----------------------------------------------------------------------------
226 // adding/deleting items to/from the list
227 // ----------------------------------------------------------------------------
228
229 int wxChoice::DoInsertItems(const wxArrayStringsAdapter& items,
230 unsigned int pos,
231 void **clientData, wxClientDataType type)
232 {
233 MSWAllocStorage(items, CB_INITSTORAGE);
234
235 const bool append = pos == GetCount();
236
237 // use CB_ADDSTRING when appending at the end to make sure the control is
238 // resorted if it has wxCB_SORT style
239 const unsigned msg = append ? CB_ADDSTRING : CB_INSERTSTRING;
240
241 if ( append )
242 pos = 0;
243
244 int n = wxNOT_FOUND;
245 const unsigned numItems = items.GetCount();
246 for ( unsigned i = 0; i < numItems; ++i )
247 {
248 n = MSWInsertOrAppendItem(pos, items[i], msg);
249 if ( n == wxNOT_FOUND )
250 return n;
251
252 if ( !append )
253 pos++;
254
255 AssignNewItemClientData(n, clientData, i, type);
256 }
257
258 // we need to refresh our size in order to have enough space for the
259 // newly added items
260 if ( !IsFrozen() )
261 MSWUpdateDropDownHeight();
262
263 InvalidateBestSize();
264
265 return n;
266 }
267
268 void wxChoice::DoDeleteOneItem(unsigned int n)
269 {
270 wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::Delete") );
271
272 SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
273
274 if ( !IsFrozen() )
275 MSWUpdateDropDownHeight();
276
277 InvalidateBestSize();
278 }
279
280 void wxChoice::DoClear()
281 {
282 SendMessage(GetHwnd(), CB_RESETCONTENT, 0, 0);
283
284 if ( !IsFrozen() )
285 MSWUpdateDropDownHeight();
286
287 InvalidateBestSize();
288 }
289
290 // ----------------------------------------------------------------------------
291 // selection
292 // ----------------------------------------------------------------------------
293
294 int wxChoice::GetSelection() const
295 {
296 // if m_lastAcceptedSelection is set, it means that the dropdown is
297 // currently shown and that we want to use the last "permanent" selection
298 // instead of whatever is under the mouse pointer currently
299 //
300 // otherwise, get the selection from the control
301 return m_lastAcceptedSelection == wxID_NONE ? GetCurrentSelection()
302 : m_lastAcceptedSelection;
303 }
304
305 int wxChoice::GetCurrentSelection() const
306 {
307 return (int)SendMessage(GetHwnd(), CB_GETCURSEL, 0, 0);
308 }
309
310 void wxChoice::SetSelection(int n)
311 {
312 SendMessage(GetHwnd(), CB_SETCURSEL, n, 0);
313 }
314
315 // ----------------------------------------------------------------------------
316 // string list functions
317 // ----------------------------------------------------------------------------
318
319 unsigned int wxChoice::GetCount() const
320 {
321 return (unsigned int)SendMessage(GetHwnd(), CB_GETCOUNT, 0, 0);
322 }
323
324 int wxChoice::FindString(const wxString& s, bool bCase) const
325 {
326 #if defined(__WATCOMC__) && defined(__WIN386__)
327 // For some reason, Watcom in WIN386 mode crashes in the CB_FINDSTRINGEXACT message.
328 // wxChoice::Do it the long way instead.
329 unsigned int count = GetCount();
330 for ( unsigned int i = 0; i < count; i++ )
331 {
332 // as CB_FINDSTRINGEXACT is case insensitive, be case insensitive too
333 if (GetString(i).IsSameAs(s, bCase))
334 return i;
335 }
336
337 return wxNOT_FOUND;
338 #else // !Watcom
339 //TODO: Evidently some MSW versions (all?) don't like empty strings
340 //passed to SendMessage, so we have to do it ourselves in that case
341 if ( s.empty() )
342 {
343 unsigned int count = GetCount();
344 for ( unsigned int i = 0; i < count; i++ )
345 {
346 if (GetString(i).empty())
347 return i;
348 }
349
350 return wxNOT_FOUND;
351 }
352 else if (bCase)
353 {
354 // back to base class search for not native search type
355 return wxItemContainerImmutable::FindString( s, bCase );
356 }
357 else
358 {
359 int pos = (int)SendMessage(GetHwnd(), CB_FINDSTRINGEXACT,
360 (WPARAM)-1, wxMSW_CONV_LPARAM(s));
361
362 return pos == LB_ERR ? wxNOT_FOUND : pos;
363 }
364 #endif // Watcom/!Watcom
365 }
366
367 void wxChoice::SetString(unsigned int n, const wxString& s)
368 {
369 wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );
370
371 // we have to delete and add back the string as there is no way to change a
372 // string in place
373
374 // we need to preserve the client data manually
375 void *oldData = NULL;
376 wxClientData *oldObjData = NULL;
377 if ( HasClientUntypedData() )
378 oldData = GetClientData(n);
379 else if ( HasClientObjectData() )
380 oldObjData = GetClientObject(n);
381
382 // and also the selection if we're going to delete the item that was
383 // selected
384 const bool wasSelected = static_cast<int>(n) == GetSelection();
385
386 ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
387 ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, wxMSW_CONV_LPARAM(s) );
388
389 // restore the client data
390 if ( oldData )
391 SetClientData(n, oldData);
392 else if ( oldObjData )
393 SetClientObject(n, oldObjData);
394
395 // and the selection
396 if ( wasSelected )
397 SetSelection(n);
398
399 // the width could have changed so the best size needs to be recomputed
400 InvalidateBestSize();
401 }
402
403 wxString wxChoice::GetString(unsigned int n) const
404 {
405 int len = (int)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);
406
407 wxString str;
408 if ( len != CB_ERR && len > 0 )
409 {
410 if ( ::SendMessage
411 (
412 GetHwnd(),
413 CB_GETLBTEXT,
414 n,
415 (LPARAM)(wxChar *)wxStringBuffer(str, len)
416 ) == CB_ERR )
417 {
418 wxLogLastError(wxT("SendMessage(CB_GETLBTEXT)"));
419 }
420 }
421
422 return str;
423 }
424
425 // ----------------------------------------------------------------------------
426 // client data
427 // ----------------------------------------------------------------------------
428
429 void wxChoice::DoSetItemClientData(unsigned int n, void* clientData)
430 {
431 if ( ::SendMessage(GetHwnd(), CB_SETITEMDATA,
432 n, (LPARAM)clientData) == CB_ERR )
433 {
434 wxLogLastError(wxT("CB_SETITEMDATA"));
435 }
436 }
437
438 void* wxChoice::DoGetItemClientData(unsigned int n) const
439 {
440 LPARAM rc = SendMessage(GetHwnd(), CB_GETITEMDATA, n, 0);
441 if ( rc == CB_ERR && GetLastError() != ERROR_SUCCESS )
442 {
443 wxLogLastError(wxT("CB_GETITEMDATA"));
444
445 // unfortunately, there is no way to return an error code to the user
446 rc = (LPARAM) NULL;
447 }
448
449 return (void *)rc;
450 }
451
452 // ----------------------------------------------------------------------------
453 // wxMSW-specific geometry management
454 // ----------------------------------------------------------------------------
455
456 namespace
457 {
458
459 // there is a difference between the height passed to CB_SETITEMHEIGHT and the
460 // real height of the combobox; it is probably not constant for all Windows
461 // versions/settings but right now I don't know how to find what it is so it is
462 // temporarily hardcoded to its value under XP systems with normal fonts sizes
463 const int COMBO_HEIGHT_ADJ = 6;
464
465 } // anonymous namespace
466
467 void wxChoice::MSWUpdateVisibleHeight()
468 {
469 if ( m_heightOwn != wxDefaultCoord )
470 {
471 ::SendMessage(GetHwnd(), CB_SETITEMHEIGHT,
472 (WPARAM)-1, m_heightOwn - COMBO_HEIGHT_ADJ);
473 }
474 }
475
476 #if wxUSE_DEFERRED_SIZING
477 void wxChoice::MSWEndDeferWindowPos()
478 {
479 // we can only set the height of the choice itself now as it is reset to
480 // default every time the control is resized
481 MSWUpdateVisibleHeight();
482
483 wxChoiceBase::MSWEndDeferWindowPos();
484 }
485 #endif // wxUSE_DEFERRED_SIZING
486
487 void wxChoice::MSWUpdateDropDownHeight()
488 {
489 // be careful to not change the width here
490 DoSetSize(wxDefaultCoord, wxDefaultCoord, wxDefaultCoord, GetSize().y,
491 wxSIZE_USE_EXISTING);
492 }
493
494 void wxChoice::DoMoveWindow(int x, int y, int width, int height)
495 {
496 // here is why this is necessary: if the width is negative, the combobox
497 // window proc makes the window of the size width*height instead of
498 // interpreting height in the usual manner (meaning the height of the drop
499 // down list - usually the height specified in the call to MoveWindow()
500 // will not change the height of combo box per se)
501 //
502 // this behaviour is not documented anywhere, but this is just how it is
503 // here (NT 4.4) and, anyhow, the check shouldn't hurt - however without
504 // the check, constraints/sizers using combos may break the height
505 // constraint will have not at all the same value as expected
506 if ( width < 0 )
507 return;
508
509 wxControl::DoMoveWindow(x, y, width, height);
510 }
511
512 void wxChoice::DoGetSize(int *w, int *h) const
513 {
514 wxControl::DoGetSize(w, h);
515
516 // this is weird: sometimes, the height returned by Windows is clearly the
517 // total height of the control including the drop down list -- but only
518 // sometimes, and sometimes it isn't so work around this here by using our
519 // own stored value if we have it
520 if ( h && m_heightOwn != wxDefaultCoord )
521 *h = m_heightOwn;
522 }
523
524 void wxChoice::DoSetSize(int x, int y,
525 int width, int height,
526 int sizeFlags)
527 {
528 const int heightBest = GetBestSize().y;
529
530 // we need the real height below so get the current one if it's not given
531 if ( height == wxDefaultCoord )
532 {
533 // height not specified, use the same as before
534 DoGetSize(NULL, &height);
535 }
536 else if ( height == heightBest )
537 {
538 // we don't need to manually manage our height, let the system use the
539 // default one
540 m_heightOwn = wxDefaultCoord;
541 }
542 else // non-default height specified
543 {
544 // set our new own height but be careful not to make it too big: the
545 // native control apparently stores it as a single byte and so setting
546 // own height to 256 pixels results in default height being used (255
547 // is still ok)
548 m_heightOwn = height;
549
550 if ( m_heightOwn > UCHAR_MAX )
551 m_heightOwn = UCHAR_MAX;
552 // nor too small: see MSWUpdateVisibleHeight()
553 else if ( m_heightOwn < COMBO_HEIGHT_ADJ )
554 m_heightOwn = COMBO_HEIGHT_ADJ;
555 }
556
557
558 // the height which we must pass to Windows should be the total height of
559 // the control including the drop down list while the height given to us
560 // is, of course, just the height of the permanently visible part of it so
561 // add the drop down height to it
562
563 // don't make the drop down list too tall, arbitrarily limit it to 30
564 // items max and also don't make it too small if it's currently empty
565 size_t nItems = GetCount();
566 if (!HasFlag(wxCB_SIMPLE))
567 {
568 if ( !nItems )
569 nItems = 9;
570 else if ( nItems > 30 )
571 nItems = 30;
572 }
573
574 const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
575 int heightWithItems = 0;
576 if (!HasFlag(wxCB_SIMPLE))
577 // The extra item (" + 1") is required to prevent a vertical
578 // scrollbar from appearing with comctl32.dll versions earlier
579 // than 6.0 (such as found in Win2k).
580 heightWithItems = height + hItem*(nItems + 1);
581 else
582 heightWithItems = SetHeightSimpleComboBox(nItems);
583
584
585 // do resize the native control
586 wxControl::DoSetSize(x, y, width, heightWithItems, sizeFlags);
587
588
589 // make the control itself of the requested height: notice that this
590 // must be done after changing its size or it has no effect (apparently
591 // the height is reset to default during the control layout) and that it's
592 // useless to do it when using the deferred sizing -- in this case it
593 // will be done from MSWEndDeferWindowPos()
594 #if wxUSE_DEFERRED_SIZING
595 if ( m_pendingSize == wxDefaultSize )
596 {
597 // not using deferred sizing, update it immediately
598 MSWUpdateVisibleHeight();
599 }
600 else // in the middle of deferred sizing
601 {
602 // we need to report the size of the visible part of the control back
603 // in GetSize() and not height stored by DoSetSize() in m_pendingSize
604 m_pendingSize = wxSize(width, height);
605 }
606 #else // !wxUSE_DEFERRED_SIZING
607 // always update the visible height immediately
608 MSWUpdateVisibleHeight();
609 #endif // wxUSE_DEFERRED_SIZING
610 }
611
612 wxSize wxChoice::DoGetBestSize() const
613 {
614 // The base version returns the size of the largest string
615 wxSize best( wxChoiceBase::DoGetBestSize() );
616
617 // We just need to adjust it to account for the arrow width.
618 best.x += 5*GetCharWidth();
619
620 // set height on our own
621 if( HasFlag( wxCB_SIMPLE ) )
622 best.y = SetHeightSimpleComboBox(GetCount());
623 else
624 best.y = EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight());
625
626 return best;
627 }
628
629 int wxChoice::SetHeightSimpleComboBox(int nItems) const
630 {
631 int cx, cy;
632 wxGetCharSize( GetHWND(), &cx, &cy, GetFont() );
633 int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, (WPARAM)-1, 0);
634 return EDIT_HEIGHT_FROM_CHAR_HEIGHT( cy ) * wxMin( wxMax( nItems, 3 ), 6 ) + hItem - 1;
635 }
636
637 // ----------------------------------------------------------------------------
638 // Popup operations
639 // ----------------------------------------------------------------------------
640
641 void wxChoice::MSWDoPopupOrDismiss(bool show)
642 {
643 wxASSERT_MSG( !HasFlag(wxCB_SIMPLE),
644 wxT("can't popup/dismiss the list for simple combo box") );
645
646 // we *must* set focus to the combobox before showing or hiding the drop
647 // down as without this we get WM_LBUTTONDOWN messages with invalid HWND
648 // when hiding it (whether programmatically or manually) resulting in a
649 // crash when we pass them to IsDialogMessage()
650 //
651 // this can be seen in the combo page of the widgets sample under Windows 7
652 SetFocus();
653
654 ::SendMessage(GetHwnd(), CB_SHOWDROPDOWN, show, 0);
655 }
656
657 bool wxChoice::Show(bool show)
658 {
659 if ( !wxChoiceBase::Show(show) )
660 return false;
661
662 // When hiding the combobox, we also need to hide its popup part as it
663 // doesn't happen automatically.
664 if ( !show && ::SendMessage(GetHwnd(), CB_GETDROPPEDSTATE, 0, 0) )
665 MSWDoPopupOrDismiss(false);
666
667 return true;
668 }
669
670 // ----------------------------------------------------------------------------
671 // MSW message handlers
672 // ----------------------------------------------------------------------------
673
674 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
675 {
676 switch ( nMsg )
677 {
678 case WM_LBUTTONUP:
679 {
680 int x = (int)LOWORD(lParam);
681 int y = (int)HIWORD(lParam);
682
683 // Ok, this is truly weird, but if a panel with a wxChoice
684 // loses the focus, then you get a *fake* WM_LBUTTONUP message
685 // with x = 65535 and y = 65535. Filter out this nonsense.
686 //
687 // VZ: I'd like to know how to reproduce this please...
688 if ( x == 65535 && y == 65535 )
689 return 0;
690 }
691 break;
692
693 // we have to handle both: one for the normal case and the other
694 // for readonly
695 case WM_CTLCOLOREDIT:
696 case WM_CTLCOLORLISTBOX:
697 case WM_CTLCOLORSTATIC:
698 {
699 WXHDC hdc;
700 WXHWND hwnd;
701 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
702
703 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
704 if ( hbr )
705 return (WXLRESULT)hbr;
706 //else: fall through to default window proc
707 }
708 }
709
710 return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
711 }
712
713 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
714 {
715 /*
716 The native control provides a great variety in the events it sends in
717 the different selection scenarios (undoubtedly for greater amusement of
718 the programmers using it). For the reference, here are the cases when
719 the final selection is accepted (things are quite interesting when it
720 is cancelled too):
721
722 A. Selecting with just the arrows without opening the dropdown:
723 1. CBN_SELENDOK
724 2. CBN_SELCHANGE
725
726 B. Opening dropdown with F4 and selecting with arrows:
727 1. CBN_DROPDOWN
728 2. many CBN_SELCHANGE while changing selection in the list
729 3. CBN_SELENDOK
730 4. CBN_CLOSEUP
731
732 C. Selecting with the mouse:
733 1. CBN_DROPDOWN
734 -- no intermediate CBN_SELCHANGEs --
735 2. CBN_SELENDOK
736 3. CBN_CLOSEUP
737 4. CBN_SELCHANGE
738
739 Admire the different order of messages in all of those cases, it must
740 surely have taken a lot of effort to Microsoft developers to achieve
741 such originality.
742 */
743 switch ( param )
744 {
745 case CBN_DROPDOWN:
746 // we use this value both because we don't want to track selection
747 // using CB_GETCURSEL while the dropdown is opened and because we
748 // need to reset the selection back to it if it's eventually
749 // cancelled by user
750 m_lastAcceptedSelection = GetCurrentSelection();
751 break;
752
753 case CBN_CLOSEUP:
754 // if the selection was accepted by the user, it should have been
755 // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
756 // cancelled and we must restore the old one
757 if ( m_lastAcceptedSelection != wxID_NONE )
758 {
759 SetSelection(m_lastAcceptedSelection);
760 m_lastAcceptedSelection = wxID_NONE;
761 }
762 break;
763
764 case CBN_SELENDOK:
765 // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
766 // ok to reset it now as GetCurrentSelection() will now return the
767 // same thing anyhow)
768 m_lastAcceptedSelection = wxID_NONE;
769
770 {
771 const int n = GetSelection();
772
773 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
774 event.SetInt(n);
775 event.SetEventObject(this);
776
777 if ( n > -1 )
778 {
779 event.SetString(GetStringSelection());
780 InitCommandEventWithItems(event, n);
781 }
782
783 ProcessCommand(event);
784 }
785 break;
786
787 // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
788 // valid and the selection will be undone in CBN_CLOSEUP above
789
790 // don't handle CBN_SELCHANGE neither, we don't want to generate events
791 // while the dropdown is opened -- but do add it if we ever need this
792
793 default:
794 return false;
795 }
796
797 return true;
798 }
799
800 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
801 {
802 if ( !IsThisEnabled() )
803 return MSWControlColorDisabled(hDC);
804
805 return wxChoiceBase::MSWControlColor(hDC, hWnd);
806 }
807
808 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)