don't lose the combobox text when it's opened and closed (patch 1684252, closes bug...
[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/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 bool wxChoice::Create(wxWindow *parent,
162 wxWindowID id,
163 const wxPoint& pos,
164 const wxSize& size,
165 const wxArrayString& choices,
166 long style,
167 const wxValidator& validator,
168 const wxString& name)
169 {
170 wxCArrayString chs(choices);
171 return Create(parent, id, pos, size, chs.GetCount(), chs.GetStrings(),
172 style, validator, name);
173 }
174
175 bool wxChoice::MSWShouldPreProcessMessage(WXMSG *pMsg)
176 {
177 MSG *msg = (MSG *) pMsg;
178
179 // if the dropdown list is visible, don't preprocess certain keys
180 if ( msg->message == WM_KEYDOWN
181 && (msg->wParam == VK_ESCAPE || msg->wParam == VK_RETURN) )
182 {
183 if (::SendMessage(GetHwndOf(this), CB_GETDROPPEDSTATE, 0, 0))
184 {
185 return false;
186 }
187 }
188
189 return wxControl::MSWShouldPreProcessMessage(pMsg);
190 }
191
192 WXDWORD wxChoice::MSWGetStyle(long style, WXDWORD *exstyle) const
193 {
194 // we never have an external border
195 WXDWORD msStyle = wxControl::MSWGetStyle
196 (
197 (style & ~wxBORDER_MASK) | wxBORDER_NONE, exstyle
198 );
199
200 // WS_CLIPSIBLINGS is useful with wxChoice and doesn't seem to result in
201 // any problems
202 msStyle |= WS_CLIPSIBLINGS;
203
204 // wxChoice-specific styles
205 msStyle |= CBS_DROPDOWNLIST | WS_HSCROLL | WS_VSCROLL;
206 if ( style & wxCB_SORT )
207 msStyle |= CBS_SORT;
208
209 return msStyle;
210 }
211
212 wxChoice::~wxChoice()
213 {
214 Free();
215 }
216
217 // ----------------------------------------------------------------------------
218 // adding/deleting items to/from the list
219 // ----------------------------------------------------------------------------
220
221 int wxChoice::DoAppend(const wxString& item)
222 {
223 int n = (int)SendMessage(GetHwnd(), CB_ADDSTRING, 0,
224 (LPARAM)item.wx_str());
225 if ( n == CB_ERR )
226 {
227 wxLogLastError(wxT("SendMessage(CB_ADDSTRING)"));
228 }
229 else // ok
230 {
231 // we need to refresh our size in order to have enough space for the
232 // newly added items
233 if ( !IsFrozen() )
234 UpdateVisibleHeight();
235 }
236
237 InvalidateBestSize();
238 return n;
239 }
240
241 int wxChoice::DoInsert(const wxString& item, unsigned int pos)
242 {
243 wxCHECK_MSG(!(GetWindowStyle() & wxCB_SORT), -1, wxT("can't insert into sorted list"));
244 wxCHECK_MSG(IsValidInsert(pos), -1, wxT("invalid index"));
245
246 int n = (int)SendMessage(GetHwnd(), CB_INSERTSTRING, pos,
247 (LPARAM)item.wx_str());
248 if ( n == CB_ERR )
249 {
250 wxLogLastError(wxT("SendMessage(CB_INSERTSTRING)"));
251 }
252 else // ok
253 {
254 if ( !IsFrozen() )
255 UpdateVisibleHeight();
256 }
257
258 InvalidateBestSize();
259 return n;
260 }
261
262 void wxChoice::Delete(unsigned int n)
263 {
264 wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::Delete") );
265
266 if ( HasClientObjectData() )
267 {
268 delete GetClientObject(n);
269 }
270
271 SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
272
273 if ( !IsFrozen() )
274 UpdateVisibleHeight();
275
276 InvalidateBestSize();
277 }
278
279 void wxChoice::Clear()
280 {
281 Free();
282
283 SendMessage(GetHwnd(), CB_RESETCONTENT, 0, 0);
284
285 if ( !IsFrozen() )
286 UpdateVisibleHeight();
287
288 InvalidateBestSize();
289 }
290
291 void wxChoice::Free()
292 {
293 if ( HasClientObjectData() )
294 {
295 unsigned int count = GetCount();
296 for ( unsigned int n = 0; n < count; n++ )
297 {
298 delete GetClientObject(n);
299 }
300 }
301 }
302
303 // ----------------------------------------------------------------------------
304 // selection
305 // ----------------------------------------------------------------------------
306
307 int wxChoice::GetSelection() const
308 {
309 // if m_lastAcceptedSelection is set, it means that the dropdown is
310 // currently shown and that we want to use the last "permanent" selection
311 // instead of whatever is under the mouse pointer currently
312 //
313 // otherwise, get the selection from the control
314 return m_lastAcceptedSelection == wxID_NONE ? GetCurrentSelection()
315 : m_lastAcceptedSelection;
316 }
317
318 int wxChoice::GetCurrentSelection() const
319 {
320 return (int)SendMessage(GetHwnd(), CB_GETCURSEL, 0, 0);
321 }
322
323 void wxChoice::SetSelection(int n)
324 {
325 SendMessage(GetHwnd(), CB_SETCURSEL, n, 0);
326 }
327
328 // ----------------------------------------------------------------------------
329 // string list functions
330 // ----------------------------------------------------------------------------
331
332 unsigned int wxChoice::GetCount() const
333 {
334 return (unsigned int)SendMessage(GetHwnd(), CB_GETCOUNT, 0, 0);
335 }
336
337 int wxChoice::FindString(const wxString& s, bool bCase) const
338 {
339 #if defined(__WATCOMC__) && defined(__WIN386__)
340 // For some reason, Watcom in WIN386 mode crashes in the CB_FINDSTRINGEXACT message.
341 // wxChoice::Do it the long way instead.
342 unsigned int count = GetCount();
343 for ( unsigned int i = 0; i < count; i++ )
344 {
345 // as CB_FINDSTRINGEXACT is case insensitive, be case insensitive too
346 if (GetString(i).IsSameAs(s, bCase))
347 return i;
348 }
349
350 return wxNOT_FOUND;
351 #else // !Watcom
352 //TODO: Evidently some MSW versions (all?) don't like empty strings
353 //passed to SendMessage, so we have to do it ourselves in that case
354 if ( s.empty() )
355 {
356 unsigned int count = GetCount();
357 for ( unsigned int i = 0; i < count; i++ )
358 {
359 if (GetString(i).empty())
360 return i;
361 }
362
363 return wxNOT_FOUND;
364 }
365 else if (bCase)
366 {
367 // back to base class search for not native search type
368 return wxItemContainerImmutable::FindString( s, bCase );
369 }
370 else
371 {
372 int pos = (int)SendMessage(GetHwnd(), CB_FINDSTRINGEXACT,
373 (WPARAM)-1, (LPARAM)s.wx_str());
374
375 return pos == LB_ERR ? wxNOT_FOUND : pos;
376 }
377 #endif // Watcom/!Watcom
378 }
379
380 void wxChoice::SetString(unsigned int n, const wxString& s)
381 {
382 wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );
383
384 // we have to delete and add back the string as there is no way to change a
385 // string in place
386
387 // we need to preserve the client data
388 void *data;
389 if ( m_clientDataItemsType != wxClientData_None )
390 {
391 data = DoGetItemClientData(n);
392 }
393 else // no client data
394 {
395 data = NULL;
396 }
397
398 ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
399 ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, (LPARAM)s.wx_str() );
400
401 if ( data )
402 {
403 DoSetItemClientData(n, data);
404 }
405 //else: it's already NULL by default
406
407 InvalidateBestSize();
408 }
409
410 wxString wxChoice::GetString(unsigned int n) const
411 {
412 int len = (int)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);
413
414 wxString str;
415 if ( len != CB_ERR && len > 0 )
416 {
417 if ( ::SendMessage
418 (
419 GetHwnd(),
420 CB_GETLBTEXT,
421 n,
422 (LPARAM)(wxChar *)wxStringBuffer(str, len)
423 ) == CB_ERR )
424 {
425 wxLogLastError(wxT("SendMessage(CB_GETLBTEXT)"));
426 }
427 }
428
429 return str;
430 }
431
432 // ----------------------------------------------------------------------------
433 // client data
434 // ----------------------------------------------------------------------------
435
436 void wxChoice::DoSetItemClientData(unsigned int n, void* clientData)
437 {
438 if ( ::SendMessage(GetHwnd(), CB_SETITEMDATA,
439 n, (LPARAM)clientData) == CB_ERR )
440 {
441 wxLogLastError(wxT("CB_SETITEMDATA"));
442 }
443 }
444
445 void* wxChoice::DoGetItemClientData(unsigned int n) const
446 {
447 LPARAM rc = SendMessage(GetHwnd(), CB_GETITEMDATA, n, 0);
448 if ( rc == CB_ERR )
449 {
450 wxLogLastError(wxT("CB_GETITEMDATA"));
451
452 // unfortunately, there is no way to return an error code to the user
453 rc = (LPARAM) NULL;
454 }
455
456 return (void *)rc;
457 }
458
459 void wxChoice::DoSetItemClientObject(unsigned int n, wxClientData* clientData)
460 {
461 DoSetItemClientData(n, clientData);
462 }
463
464 wxClientData* wxChoice::DoGetItemClientObject(unsigned int n) const
465 {
466 return (wxClientData *)DoGetItemClientData(n);
467 }
468
469 // ----------------------------------------------------------------------------
470 // wxMSW specific helpers
471 // ----------------------------------------------------------------------------
472
473 void wxChoice::UpdateVisibleHeight()
474 {
475 // be careful to not change the width here
476 DoSetSize(wxDefaultCoord, wxDefaultCoord, wxDefaultCoord, GetSize().y, wxSIZE_USE_EXISTING);
477 }
478
479 void wxChoice::DoMoveWindow(int x, int y, int width, int height)
480 {
481 // here is why this is necessary: if the width is negative, the combobox
482 // window proc makes the window of the size width*height instead of
483 // interpreting height in the usual manner (meaning the height of the drop
484 // down list - usually the height specified in the call to MoveWindow()
485 // will not change the height of combo box per se)
486 //
487 // this behaviour is not documented anywhere, but this is just how it is
488 // here (NT 4.4) and, anyhow, the check shouldn't hurt - however without
489 // the check, constraints/sizers using combos may break the height
490 // constraint will have not at all the same value as expected
491 if ( width < 0 )
492 return;
493
494 wxControl::DoMoveWindow(x, y, width, height);
495 }
496
497 void wxChoice::DoGetSize(int *w, int *h) const
498 {
499 // this is weird: sometimes, the height returned by Windows is clearly the
500 // total height of the control including the drop down list -- but only
501 // sometimes, and normally it isn't... I have no idea about what to do with
502 // this
503 wxControl::DoGetSize(w, h);
504 }
505
506 void wxChoice::DoSetSize(int x, int y,
507 int width, int height,
508 int sizeFlags)
509 {
510 int heightOrig = height;
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 )
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 size_t 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
530 {
531 // We cannot pass wxDefaultCoord as height to wxControl. wxControl uses
532 // wxGetWindowRect() to determine the current height of the combobox,
533 // and then again sets the combobox's height to that value. Unfortunately,
534 // wxGetWindowRect doesn't include the dropdown list's height (at least
535 // on Win2K), so this would result in a combobox with dropdown height of
536 // 1 pixel. We have to determine the default height ourselves and call
537 // wxControl with that value instead.
538 int w, h;
539 RECT r;
540 DoGetSize(&w, &h);
541 if (::SendMessage(GetHwnd(), CB_GETDROPPEDCONTROLRECT, 0, (LPARAM) &r) != 0)
542 {
543 height = h + r.bottom - r.top;
544 }
545 }
546
547 wxControl::DoSetSize(x, y, width, height, sizeFlags);
548
549 // If we're storing a pending size, make sure we store
550 // the original size for reporting back to the app.
551 if (m_pendingSize != wxDefaultSize)
552 m_pendingSize = wxSize(width, heightOrig);
553
554 // This solution works on XP, but causes choice/combobox lists to be
555 // too short on W2K and earlier.
556 #if 0
557 int widthCurrent, heightCurrent;
558 DoGetSize(&widthCurrent, &heightCurrent);
559
560 // the height which we must pass to Windows should be the total height of
561 // the control including the drop down list while the height given to us
562 // is, of course, just the height of the permanently visible part of it
563 if ( height != wxDefaultCoord && height != heightCurrent )
564 {
565 // don't make the drop down list too tall, arbitrarily limit it to 40
566 // items max and also don't leave it empty
567 unsigned int nItems = GetCount();
568 if ( !nItems )
569 nItems = 9;
570 else if ( nItems > 24 )
571 nItems = 24;
572
573 // add space for the drop down list
574 const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
575 height += hItem*(nItems + 1);
576 }
577 else // keep the same height as now
578 {
579 // normally wxWindow::DoSetSize() checks if we set the same size as the
580 // window already has and does nothing in this case, but for us the
581 // check fails as the size we pass to it includes the dropdown while
582 // the size returned by our GetSize() does not, so test if the size
583 // didn't really change ourselves here
584 if ( width == wxDefaultCoord || width == widthCurrent )
585 {
586 // size doesn't change, what about position?
587 int xCurrent, yCurrent;
588 DoGetPosition(&xCurrent, &yCurrent);
589 const bool defMeansUnchanged = !(sizeFlags & wxSIZE_ALLOW_MINUS_ONE);
590 if ( ((x == wxDefaultCoord && defMeansUnchanged) || x == xCurrent)
591 &&
592 ((y == wxDefaultCoord && defMeansUnchanged) || y == yCurrent) )
593 {
594 // nothing changes, nothing to do
595 return;
596 }
597 }
598
599 // We cannot pass wxDefaultCoord as height to wxControl. wxControl uses
600 // wxGetWindowRect() to determine the current height of the combobox,
601 // and then again sets the combobox's height to that value. Unfortunately,
602 // wxGetWindowRect doesn't include the dropdown list's height (at least
603 // on Win2K), so this would result in a combobox with dropdown height of
604 // 1 pixel. We have to determine the default height ourselves and call
605 // wxControl with that value instead.
606 //
607 // Also notice that sometimes CB_GETDROPPEDCONTROLRECT seems to return
608 // wildly incorrect values (~32000) which looks like a bug in it, just
609 // ignore them in this case
610 RECT r;
611 if ( ::SendMessage(GetHwnd(), CB_GETDROPPEDCONTROLRECT, 0, (LPARAM) &r)
612 && r.bottom < 30000 )
613 {
614 height = heightCurrent + r.bottom - r.top;
615 }
616 }
617
618 wxControl::DoSetSize(x, y, width, height, sizeFlags);
619 #endif
620 }
621
622 wxSize wxChoice::DoGetBestSize() const
623 {
624 // find the widest string
625 int wChoice = 0;
626 const unsigned int nItems = GetCount();
627 for ( unsigned int i = 0; i < nItems; i++ )
628 {
629 int wLine;
630 GetTextExtent(GetString(i), &wLine, NULL);
631 if ( wLine > wChoice )
632 wChoice = wLine;
633 }
634
635 // give it some reasonable default value if there are no strings in the
636 // list
637 if ( wChoice == 0 )
638 wChoice = 100;
639
640 // the combobox should be slightly larger than the widest string
641 wChoice += 5*GetCharWidth();
642
643 wxSize best(wChoice, EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight()));
644 CacheBestSize(best);
645 return best;
646 }
647
648 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
649 {
650 switch ( nMsg )
651 {
652 case WM_LBUTTONUP:
653 {
654 int x = (int)LOWORD(lParam);
655 int y = (int)HIWORD(lParam);
656
657 // Ok, this is truly weird, but if a panel with a wxChoice
658 // loses the focus, then you get a *fake* WM_LBUTTONUP message
659 // with x = 65535 and y = 65535. Filter out this nonsense.
660 //
661 // VZ: I'd like to know how to reproduce this please...
662 if ( x == 65535 && y == 65535 )
663 return 0;
664 }
665 break;
666
667 // we have to handle both: one for the normal case and the other
668 // for readonly
669 case WM_CTLCOLOREDIT:
670 case WM_CTLCOLORLISTBOX:
671 case WM_CTLCOLORSTATIC:
672 {
673 WXHDC hdc;
674 WXHWND hwnd;
675 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
676
677 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
678 if ( hbr )
679 return (WXLRESULT)hbr;
680 //else: fall through to default window proc
681 }
682 }
683
684 return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
685 }
686
687 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
688 {
689 /*
690 The native control provides a great variety in the events it sends in
691 the different selection scenarios (undoubtedly for greater amusement of
692 the programmers using it). For the reference, here are the cases when
693 the final selection is accepted (things are quite interesting when it
694 is cancelled too):
695
696 A. Selecting with just the arrows without opening the dropdown:
697 1. CBN_SELENDOK
698 2. CBN_SELCHANGE
699
700 B. Opening dropdown with F4 and selecting with arrows:
701 1. CBN_DROPDOWN
702 2. many CBN_SELCHANGE while changing selection in the list
703 3. CBN_SELENDOK
704 4. CBN_CLOSEUP
705
706 C. Selecting with the mouse:
707 1. CBN_DROPDOWN
708 -- no intermediate CBN_SELCHANGEs --
709 2. CBN_SELENDOK
710 3. CBN_CLOSEUP
711 4. CBN_SELCHANGE
712
713 Admire the different order of messages in all of those cases, it must
714 surely have taken a lot of effort to Microsoft developers to achieve
715 such originality.
716 */
717 switch ( param )
718 {
719 case CBN_DROPDOWN:
720 // we use this value both because we don't want to track selection
721 // using CB_GETCURSEL while the dropdown is opened and because we
722 // need to reset the selection back to it if it's eventually
723 // cancelled by user
724 m_lastAcceptedSelection = GetCurrentSelection();
725 if ( m_lastAcceptedSelection == -1 )
726 {
727 // no current selection so no need to restore it later (this
728 // happens when opening a combobox containing text not from its
729 // list of items and we shouldn't erase this text)
730 m_lastAcceptedSelection = wxID_NONE;
731 }
732 break;
733
734 case CBN_CLOSEUP:
735 // if the selection was accepted by the user, it should have been
736 // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
737 // cancelled and we must restore the old one
738 if ( m_lastAcceptedSelection != wxID_NONE )
739 {
740 SetSelection(m_lastAcceptedSelection);
741 m_lastAcceptedSelection = wxID_NONE;
742 }
743 break;
744
745 case CBN_SELENDOK:
746 // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
747 // ok to reset it now as GetCurrentSelection() will now return the
748 // same thing anyhow)
749 m_lastAcceptedSelection = wxID_NONE;
750
751 {
752 const int n = GetSelection();
753
754 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
755 event.SetInt(n);
756 event.SetEventObject(this);
757
758 if ( n > -1 )
759 {
760 event.SetString(GetStringSelection());
761 InitCommandEventWithItems(event, n);
762 }
763
764 ProcessCommand(event);
765 }
766 break;
767
768 // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
769 // valid and the selection will be undone in CBN_CLOSEUP above
770
771 // don't handle CBN_SELCHANGE neither, we don't want to generate events
772 // while the dropdown is opened -- but do add it if we ever need this
773
774 default:
775 return false;
776 }
777
778 return true;
779 }
780
781 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
782 {
783 if ( !IsEnabled() )
784 return MSWControlColorDisabled(hDC);
785
786 return wxChoiceBase::MSWControlColor(hDC, hWnd);
787 }
788
789 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)