]> git.saurik.com Git - wxWidgets.git/blob - src/msw/choice.cpp
Fix to prevent Assert when there is an empty string in a combobox/choice.
[wxWidgets.git] / src / msw / choice.cpp
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: 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 and Markus Holzem
9 // Licence: wxWindows license
10 /////////////////////////////////////////////////////////////////////////////
11
12 // ============================================================================
13 // declarations
14 // ============================================================================
15
16 // ----------------------------------------------------------------------------
17 // headers
18 // ----------------------------------------------------------------------------
19
20 #ifdef __GNUG__
21 #pragma implementation "choice.h"
22 #endif
23
24 // For compilers that support precompilation, includes "wx.h".
25 #include "wx/wxprec.h"
26
27 #ifdef __BORLANDC__
28 #pragma hdrstop
29 #endif
30
31 #ifndef WX_PRECOMP
32 #include "wx/choice.h"
33 #include "wx/utils.h"
34 #include "wx/log.h"
35 #endif
36
37 #include "wx/msw/private.h"
38
39 #if !USE_SHARED_LIBRARY
40 IMPLEMENT_DYNAMIC_CLASS(wxChoice, wxControl)
41 #endif
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 if ( !CreateControl(parent, id, pos, size, style, validator, name) )
61 return FALSE;
62
63 long msStyle = WS_CHILD | CBS_DROPDOWNLIST | WS_TABSTOP | WS_VISIBLE;
64 if ( style & wxCB_SORT )
65 msStyle |= CBS_SORT;
66
67 // the experience shows that wxChoice vs. wxComboBox distinction confuses
68 // quite a few people - try to help them
69 wxASSERT_MSG( !(style & wxCB_DROPDOWN) &&
70 !(style & wxCB_READONLY) &&
71 !(style & wxCB_SIMPLE),
72 _T("this style flag is ignored by wxChoice, you "
73 "probably want to use a wxComboBox") );
74
75 if ( !MSWCreateControl(_T("COMBOBOX"), msStyle) )
76 return FALSE;
77
78 for ( int i = 0; i < n; i++ )
79 {
80 Append(choices[i]);
81 }
82
83 SetSize(pos.x, pos.y, size.x, size.y);
84
85 return TRUE;
86 }
87
88 // ----------------------------------------------------------------------------
89 // adding/deleting items to/from the list
90 // ----------------------------------------------------------------------------
91
92 void wxChoice::DoAppend(const wxString& item)
93 {
94 SendMessage(GetHwnd(), CB_ADDSTRING, 0, (LONG)item.c_str());
95 }
96
97 void wxChoice::Delete(int n)
98 {
99 wxCHECK_RET( n < GetCount(), _T("invalid item index in wxChoice::Delete") );
100
101 SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);
102 }
103
104 void wxChoice::Clear()
105 {
106 SendMessage(GetHwnd(), CB_RESETCONTENT, 0, 0);
107 }
108
109 // ----------------------------------------------------------------------------
110 // selection
111 // ----------------------------------------------------------------------------
112
113 int wxChoice::GetSelection() const
114 {
115 return (int)SendMessage(GetHwnd(), CB_GETCURSEL, 0, 0);
116 }
117
118 void wxChoice::SetSelection(int n)
119 {
120 SendMessage(GetHwnd(), CB_SETCURSEL, n, 0);
121 }
122
123 // ----------------------------------------------------------------------------
124 // string list functions
125 // ----------------------------------------------------------------------------
126
127 int wxChoice::GetCount() const
128 {
129 return (int)SendMessage(GetHwnd(), CB_GETCOUNT, 0, 0);
130 }
131
132 int wxChoice::FindString(const wxString& s) const
133 {
134 #if defined(__WATCOMC__) && defined(__WIN386__)
135 // For some reason, Watcom in WIN386 mode crashes in the CB_FINDSTRINGEXACT message.
136 // wxChoice::Do it the long way instead.
137 int count = GetCount();
138 for ( int i = 0; i < count; i++ )
139 {
140 // as CB_FINDSTRINGEXACT is case insensitive, be case insensitive too
141 if ( GetString(i).IsSameAs(s, FALSE) )
142 return i;
143 }
144
145 return wxNOT_FOUND;
146 #else // !Watcom
147 int pos = (int)SendMessage(GetHwnd(), CB_FINDSTRINGEXACT,
148 (WPARAM)-1, (LPARAM)s.c_str());
149
150 return pos == LB_ERR ? wxNOT_FOUND : pos;
151 #endif // Watcom/!Watcom
152 }
153
154 wxString wxChoice::GetString(int n) const
155 {
156 size_t len = (size_t)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);
157 wxString str = "";
158 if (len) {
159 if ( ::SendMessage(GetHwnd(), CB_GETLBTEXT, n,
160 (LPARAM)str.GetWriteBuf(len)) == CB_ERR ) {
161 wxLogLastError("SendMessage(CB_GETLBTEXT)");
162 }
163 str.UngetWriteBuf();
164 }
165
166 return str;
167 }
168
169 // ----------------------------------------------------------------------------
170 // client data
171 // ----------------------------------------------------------------------------
172
173 void wxChoice::DoSetClientData( int n, void* clientData )
174 {
175 if ( SendMessage(GetHwnd(), CB_SETITEMDATA, n, (LPARAM)clientData) == CB_ERR )
176 {
177 wxLogLastError(_T("CB_SETITEMDATA"));
178 }
179 }
180
181 void* wxChoice::DoGetClientData( int n ) const
182 {
183 LPARAM rc = SendMessage(GetHwnd(), CB_GETITEMDATA, n, 0);
184 if ( rc == CB_ERR )
185 {
186 wxLogLastError(_T("CB_GETITEMDATA"));
187
188 // unfortunately, there is no way to return an error code to the user
189 rc = (LPARAM) NULL;
190 }
191
192 return (void *)rc;
193 }
194
195 void wxChoice::DoSetClientObject( int n, wxClientData* clientData )
196 {
197 DoSetClientData(n, clientData);
198 }
199
200 wxClientData* wxChoice::DoGetClientObject( int n ) const
201 {
202 return (wxClientData *)DoGetClientData(n);
203 }
204
205 // ----------------------------------------------------------------------------
206 // wxMSW specific helpers
207 // ----------------------------------------------------------------------------
208
209 void wxChoice::DoSetSize(int x, int y,
210 int width, int height,
211 int sizeFlags)
212 {
213 // Ignore height parameter because height doesn't mean 'initially
214 // displayed' height, it refers to the drop-down menu as well. The
215 // wxWindows interpretation is different; also, getting the size returns
216 // the _displayed_ size (NOT the drop down menu size) so
217 // setting-getting-setting size would not work.
218 wxControl::DoSetSize(x, y, width, -1, sizeFlags);
219 }
220
221 wxSize wxChoice::DoGetBestSize()
222 {
223 // find the widest string
224 int wLine;
225 int wChoice = 0;
226 int nItems = GetCount();
227 for ( int i = 0; i < nItems; i++ )
228 {
229 wxString str(GetString(i));
230 GetTextExtent(str, &wLine, NULL);
231 if ( wLine > wChoice )
232 wChoice = wLine;
233 }
234
235 // give it some reasonable default value if there are no strings in the
236 // list
237 if ( wChoice == 0 )
238 wChoice = 100;
239
240 // the combobox should be larger than the widest string
241 int cx, cy;
242 wxGetCharSize(GetHWND(), &cx, &cy, &GetFont());
243
244 wChoice += 5*cx;
245
246 // Choice drop-down list depends on number of items (limited to 10)
247 size_t nStrings = nItems == 0 ? 10 : wxMin(10, nItems) + 1;
248 int hChoice = EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy)*nStrings;
249
250 return wxSize(wChoice, hChoice);
251 }
252
253 long wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
254 {
255 if ( nMsg == WM_LBUTTONUP )
256 {
257 int x = (int)LOWORD(lParam);
258 int y = (int)HIWORD(lParam);
259
260 // Ok, this is truly weird, but if a panel with a wxChoice loses the
261 // focus, then you get a *fake* WM_LBUTTONUP message with x = 65535 and
262 // y = 65535. Filter out this nonsense.
263 //
264 // VZ: I'd like to know how to reproduce this please...
265 if ( x == 65535 && y == 65535 )
266 return 0;
267 }
268
269 return wxWindow::MSWWindowProc(nMsg, wParam, lParam);
270 }
271
272 bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
273 {
274 if ( param != CBN_SELCHANGE)
275 {
276 // "selection changed" is the only event we're after
277 return FALSE;
278 }
279
280 wxCommandEvent event(wxEVT_COMMAND_CHOICE_SELECTED, m_windowId);
281 event.SetInt(GetSelection());
282 event.SetEventObject(this);
283 event.SetString(GetStringSelection());
284 ProcessCommand(event);
285
286 return TRUE;
287 }
288