Applied #10025 (Patch to allow proper sizing of simple combo box)
[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 wxT("this style flag is ignored by wxChoice, you ")
121 wxT("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 (!HasFlag(wxCB_SIMPLE))
556 {
557 if ( !nItems )
558 nItems = 9;
559 else if ( nItems > 30 )
560 nItems = 30;
561 }
562
563 const int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, 0, 0);
564 int heightWithItems = 0;
565 if (!HasFlag(wxCB_SIMPLE))
566 heightWithItems = height + hItem*nItems;
567 else
568 heightWithItems = SetHeightSimpleComboBox(nItems);
569
570
571 // do resize the native control
572 wxControl::DoSetSize(x, y, width, heightWithItems, sizeFlags);
573
574
575 // make the control itself of the requested height: notice that this
576 // must be done after changing its size or it has no effect (apparently
577 // the height is reset to default during the control layout) and that it's
578 // useless to to do it when using the deferred sizing -- in this case it
579 // will be done from MSWEndDeferWindowPos()
580 #if wxUSE_DEFERRED_SIZING
581 if ( m_pendingSize == wxDefaultSize )
582 {
583 // not using deferred sizing, update it immediately
584 MSWUpdateVisibleHeight();
585 }
586 else // in the middle of deferred sizing
587 {
588 // we need to report the size of the visible part of the control back
589 // in GetSize() and not height stored by DoSetSize() in m_pendingSize
590 m_pendingSize = wxSize(width, height);
591 }
592 #else // !wxUSE_DEFERRED_SIZING
593 // always update the visible height immediately
594 MSWUpdateVisibleHeight();
595 #endif // wxUSE_DEFERRED_SIZING
596 }
597
598 wxSize wxChoice::DoGetBestSize() const
599 {
600 // find the widest string
601 int wChoice = 0;
602 int hChoice;
603 const unsigned int nItems = GetCount();
604 for ( unsigned int i = 0; i < nItems; i++ )
605 {
606 int wLine;
607 GetTextExtent(GetString(i), &wLine, NULL);
608 if ( wLine > wChoice )
609 wChoice = wLine;
610 }
611
612 // give it some reasonable default value if there are no strings in the
613 // list
614 if ( wChoice == 0 )
615 wChoice = 100;
616
617 // the combobox should be slightly larger than the widest string
618 wChoice += 5*GetCharWidth();
619 if( HasFlag( wxCB_SIMPLE ) )
620 {
621 hChoice = SetHeightSimpleComboBox( nItems );
622 }
623 else
624 hChoice = EDIT_HEIGHT_FROM_CHAR_HEIGHT(GetCharHeight());
625
626 wxSize best(wChoice, hChoice);
627 CacheBestSize(best);
628 return best;
629 }
630
631 int wxChoice::SetHeightSimpleComboBox(int nItems) const
632 {
633 int cx, cy;
634 wxGetCharSize( GetHWND(), &cx, &cy, GetFont() );
635 int hItem = SendMessage(GetHwnd(), CB_GETITEMHEIGHT, -1, 0);
636 return EDIT_HEIGHT_FROM_CHAR_HEIGHT( cy ) * wxMin( wxMax( nItems, 3 ), 6 ) + hItem - 1;
637 }
638
639 // ----------------------------------------------------------------------------
640 // MSW message handlers
641 // ----------------------------------------------------------------------------
642
643 WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
644 {
645 switch ( nMsg )
646 {
647 case WM_LBUTTONUP:
648 {
649 int x = (int)LOWORD(lParam);
650 int y = (int)HIWORD(lParam);
651
652 // Ok, this is truly weird, but if a panel with a wxChoice
653 // loses the focus, then you get a *fake* WM_LBUTTONUP message
654 // with x = 65535 and y = 65535. Filter out this nonsense.
655 //
656 // VZ: I'd like to know how to reproduce this please...
657 if ( x == 65535 && y == 65535 )
658 return 0;
659 }
660 break;
661
662 // we have to handle both: one for the normal case and the other
663 // for readonly
664 case WM_CTLCOLOREDIT:
665 case WM_CTLCOLORLISTBOX:
666 case WM_CTLCOLORSTATIC:
667 {
668 WXHDC hdc;
669 WXHWND hwnd;
670 UnpackCtlColor(wParam, lParam, &hdc, &hwnd);
671
672 WXHBRUSH hbr = MSWControlColor((WXHDC)hdc, hwnd);
673 if ( hbr )
674 return (WXLRESULT)hbr;
675 //else: fall through to default window proc
676 }
677 }
678
679 return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
680 }
681
682 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
683 {
684 /*
685 The native control provides a great variety in the events it sends in
686 the different selection scenarios (undoubtedly for greater amusement of
687 the programmers using it). For the reference, here are the cases when
688 the final selection is accepted (things are quite interesting when it
689 is cancelled too):
690
691 A. Selecting with just the arrows without opening the dropdown:
692 1. CBN_SELENDOK
693 2. CBN_SELCHANGE
694
695 B. Opening dropdown with F4 and selecting with arrows:
696 1. CBN_DROPDOWN
697 2. many CBN_SELCHANGE while changing selection in the list
698 3. CBN_SELENDOK
699 4. CBN_CLOSEUP
700
701 C. Selecting with the mouse:
702 1. CBN_DROPDOWN
703 -- no intermediate CBN_SELCHANGEs --
704 2. CBN_SELENDOK
705 3. CBN_CLOSEUP
706 4. CBN_SELCHANGE
707
708 Admire the different order of messages in all of those cases, it must
709 surely have taken a lot of effort to Microsoft developers to achieve
710 such originality.
711 */
712 switch ( param )
713 {
714 case CBN_DROPDOWN:
715 // we use this value both because we don't want to track selection
716 // using CB_GETCURSEL while the dropdown is opened and because we
717 // need to reset the selection back to it if it's eventually
718 // cancelled by user
719 m_lastAcceptedSelection = GetCurrentSelection();
720 break;
721
722 case CBN_CLOSEUP:
723 // if the selection was accepted by the user, it should have been
724 // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
725 // cancelled and we must restore the old one
726 if ( m_lastAcceptedSelection != wxID_NONE )
727 {
728 SetSelection(m_lastAcceptedSelection);
729 m_lastAcceptedSelection = wxID_NONE;
730 }
731 break;
732
733 case CBN_SELENDOK:
734 // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
735 // ok to reset it now as GetCurrentSelection() will now return the
736 // same thing anyhow)
737 m_lastAcceptedSelection = wxID_NONE;
738
739 {
740 const int n = GetSelection();
741
742 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
743 event.SetInt(n);
744 event.SetEventObject(this);
745
746 if ( n > -1 )
747 {
748 event.SetString(GetStringSelection());
749 InitCommandEventWithItems(event, n);
750 }
751
752 ProcessCommand(event);
753 }
754 break;
755
756 // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
757 // valid and the selection will be undone in CBN_CLOSEUP above
758
759 // don't handle CBN_SELCHANGE neither, we don't want to generate events
760 // while the dropdown is opened -- but do add it if we ever need this
761
762 default:
763 return false;
764 }
765
766 return true;
767 }
768
769 WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)
770 {
771 if ( !IsEnabled() )
772 return MSWControlColorDisabled(hDC);
773
774 return wxChoiceBase::MSWControlColor(hDC, hWnd);
775 }
776
777 #endif // wxUSE_CHOICE && !(__SMARTPHONE__ && __WXWINCE__)