src/msw/listbox.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/listbox.cpp
   3 // Purpose:     wxListBox
   4 // Author:      Julian Smart
   5 // Modified by: Vadim Zeitlin (owner drawn stuff)
   6 // Created:
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16     #pragma hdrstop
  17 #endif
  18
  19 #if wxUSE_LISTBOX
  20
  21 #include "wx/listbox.h"
  22
  23 #ifndef WX_PRECOMP
  24     #include "wx/dynarray.h"
  25     #include "wx/settings.h"
  26     #include "wx/brush.h"
  27     #include "wx/font.h"
  28     #include "wx/dc.h"
  29     #include "wx/utils.h"
  30     #include "wx/log.h"
  31     #include "wx/window.h"
  32 #endif
  33
  34 #include "wx/msw/private.h"
  35
  36 #include <windowsx.h>
  37
  38 #if wxUSE_OWNER_DRAWN
  39     #include  "wx/ownerdrw.h"
  40 #endif
  41
  42 #if wxUSE_EXTENDED_RTTI
  43 WX_DEFINE_FLAGS( wxListBoxStyle )
  44
  45 wxBEGIN_FLAGS( wxListBoxStyle )
  46     // new style border flags, we put them first to
  47     // use them for streaming out
  48     wxFLAGS_MEMBER(wxBORDER_SIMPLE)
  49     wxFLAGS_MEMBER(wxBORDER_SUNKEN)
  50     wxFLAGS_MEMBER(wxBORDER_DOUBLE)
  51     wxFLAGS_MEMBER(wxBORDER_RAISED)
  52     wxFLAGS_MEMBER(wxBORDER_STATIC)
  53     wxFLAGS_MEMBER(wxBORDER_NONE)
  54
  55     // old style border flags
  56     wxFLAGS_MEMBER(wxSIMPLE_BORDER)
  57     wxFLAGS_MEMBER(wxSUNKEN_BORDER)
  58     wxFLAGS_MEMBER(wxDOUBLE_BORDER)
  59     wxFLAGS_MEMBER(wxRAISED_BORDER)
  60     wxFLAGS_MEMBER(wxSTATIC_BORDER)
  61     wxFLAGS_MEMBER(wxBORDER)
  62
  63     // standard window styles
  64     wxFLAGS_MEMBER(wxTAB_TRAVERSAL)
  65     wxFLAGS_MEMBER(wxCLIP_CHILDREN)
  66     wxFLAGS_MEMBER(wxTRANSPARENT_WINDOW)
  67     wxFLAGS_MEMBER(wxWANTS_CHARS)
  68     wxFLAGS_MEMBER(wxFULL_REPAINT_ON_RESIZE)
  69     wxFLAGS_MEMBER(wxALWAYS_SHOW_SB )
  70     wxFLAGS_MEMBER(wxVSCROLL)
  71     wxFLAGS_MEMBER(wxHSCROLL)
  72
  73     wxFLAGS_MEMBER(wxLB_SINGLE)
  74     wxFLAGS_MEMBER(wxLB_MULTIPLE)
  75     wxFLAGS_MEMBER(wxLB_EXTENDED)
  76     wxFLAGS_MEMBER(wxLB_HSCROLL)
  77     wxFLAGS_MEMBER(wxLB_ALWAYS_SB)
  78     wxFLAGS_MEMBER(wxLB_NEEDED_SB)
  79     wxFLAGS_MEMBER(wxLB_SORT)
  80
  81 wxEND_FLAGS( wxListBoxStyle )
  82
  83 IMPLEMENT_DYNAMIC_CLASS_XTI(wxListBox, wxControl,"wx/listbox.h")
  84
  85 wxBEGIN_PROPERTIES_TABLE(wxListBox)
  86     wxEVENT_PROPERTY( Select , wxEVT_COMMAND_LISTBOX_SELECTED , wxCommandEvent )
  87     wxEVENT_PROPERTY( DoubleClick , wxEVT_COMMAND_LISTBOX_DOUBLECLICKED , wxCommandEvent )
  88
  89     wxPROPERTY( Font , wxFont , SetFont , GetFont  , EMPTY_MACROVALUE, 0 /*flags*/ , wxT("Helpstring") , wxT("group"))
  90     wxPROPERTY_COLLECTION( Choices , wxArrayString , wxString , AppendString , GetStrings, 0 /*flags*/ , wxT("Helpstring") , wxT("group") )
  91     wxPROPERTY( Selection ,int, SetSelection, GetSelection, EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group") )
  92     wxPROPERTY_FLAGS( WindowStyle , wxListBoxStyle , long , SetWindowStyleFlag , GetWindowStyleFlag , EMPTY_MACROVALUE , 0 /*flags*/ , wxT("Helpstring") , wxT("group")) // style
  93 wxEND_PROPERTIES_TABLE()
  94
  95 wxBEGIN_HANDLERS_TABLE(wxListBox)
  96 wxEND_HANDLERS_TABLE()
  97
  98 wxCONSTRUCTOR_4( wxListBox , wxWindow* , Parent , wxWindowID , Id , wxPoint , Position , wxSize , Size )
  99 #else
 100 IMPLEMENT_DYNAMIC_CLASS(wxListBox, wxControl)
 101 #endif
 102
 103 /*
 104 TODO PROPERTIES
 105     selection
 106     content
 107         item
 108 */
 109
 110 // ============================================================================
 111 // list box item declaration and implementation
 112 // ============================================================================
 113
 114 #if wxUSE_OWNER_DRAWN
 115
 116 class wxListBoxItem : public wxOwnerDrawn
 117 {
 118 public:
 119     wxListBoxItem(const wxString& str = wxEmptyString);
 120 };
 121
 122 wxListBoxItem::wxListBoxItem(const wxString& str) : wxOwnerDrawn(str, false)
 123 {
 124     // no bitmaps/checkmarks
 125     SetMarginWidth(0);
 126 }
 127
 128 wxOwnerDrawn *wxListBox::CreateLboxItem(size_t WXUNUSED(n))
 129 {
 130     return new wxListBoxItem();
 131 }
 132
 133 #endif  //USE_OWNER_DRAWN
 134
 135 // ============================================================================
 136 // list box control implementation
 137 // ============================================================================
 138
 139 // ----------------------------------------------------------------------------
 140 // creation
 141 // ----------------------------------------------------------------------------
 142
 143 // Listbox item
 144 wxListBox::wxListBox()
 145 {
 146     m_noItems = 0;
 147     m_selected = 0;
 148 }
 149
 150 bool wxListBox::Create(wxWindow *parent,
 151                        wxWindowID id,
 152                        const wxPoint& pos,
 153                        const wxSize& size,
 154                        int n, const wxString choices[],
 155                        long style,
 156                        const wxValidator& validator,
 157                        const wxString& name)
 158 {
 159     m_noItems = 0;
 160     m_selected = 0;
 161
 162     // initialize base class fields
 163     if ( !CreateControl(parent, id, pos, size, style, validator, name) )
 164         return false;
 165
 166     // create the native control
 167     if ( !MSWCreateControl(_T("LISTBOX"), wxEmptyString, pos, size) )
 168     {
 169         // control creation failed
 170         return false;
 171     }
 172
 173     // initialize the contents
 174     for ( int i = 0; i < n; i++ )
 175     {
 176         Append(choices[i]);
 177     }
 178
 179     // now we can compute our best size correctly, so do it if necessary
 180     SetBestSize(size);
 181
 182     return true;
 183 }
 184
 185 bool wxListBox::Create(wxWindow *parent,
 186                        wxWindowID id,
 187                        const wxPoint& pos,
 188                        const wxSize& size,
 189                        const wxArrayString& choices,
 190                        long style,
 191                        const wxValidator& validator,
 192                        const wxString& name)
 193 {
 194     wxCArrayString chs(choices);
 195     return Create(parent, id, pos, size, chs.GetCount(), chs.GetStrings(),
 196                   style, validator, name);
 197 }
 198
 199 wxListBox::~wxListBox()
 200 {
 201     Free();
 202 }
 203
 204 WXDWORD wxListBox::MSWGetStyle(long style, WXDWORD *exstyle) const
 205 {
 206     WXDWORD msStyle = wxControl::MSWGetStyle(style, exstyle);
 207
 208     // always show the vertical scrollbar if necessary -- otherwise it is
 209     // impossible to use the control with the mouse
 210     msStyle |= WS_VSCROLL;
 211
 212     // we always want to get the notifications
 213     msStyle |= LBS_NOTIFY;
 214
 215     // without this style, you get unexpected heights, so e.g. constraint
 216     // layout doesn't work properly
 217     msStyle |= LBS_NOINTEGRALHEIGHT;
 218
 219     wxASSERT_MSG( !(style & wxLB_MULTIPLE) || !(style & wxLB_EXTENDED),
 220                   _T("only one of listbox selection modes can be specified") );
 221
 222     if ( style & wxLB_MULTIPLE )
 223         msStyle |= LBS_MULTIPLESEL;
 224     else if ( style & wxLB_EXTENDED )
 225         msStyle |= LBS_EXTENDEDSEL;
 226
 227     if ( m_windowStyle & wxLB_ALWAYS_SB )
 228         msStyle |= LBS_DISABLENOSCROLL;
 229     if ( m_windowStyle & wxLB_HSCROLL )
 230         msStyle |= WS_HSCROLL;
 231     if ( m_windowStyle & wxLB_SORT )
 232         msStyle |= LBS_SORT;
 233
 234 #if wxUSE_OWNER_DRAWN && !defined(__WXWINCE__)
 235     if ( m_windowStyle & wxLB_OWNERDRAW )
 236     {
 237         // we don't support LBS_OWNERDRAWVARIABLE yet and we also always put
 238         // the strings in the listbox for simplicity even though we could have
 239         // avoided it in this case
 240         msStyle |= LBS_OWNERDRAWFIXED | LBS_HASSTRINGS;
 241     }
 242 #endif // wxUSE_OWNER_DRAWN
 243
 244     return msStyle;
 245 }
 246
 247 // ----------------------------------------------------------------------------
 248 // implementation of wxListBoxBase methods
 249 // ----------------------------------------------------------------------------
 250
 251 void wxListBox::DoSetFirstItem(int N)
 252 {
 253     wxCHECK_RET( IsValid(N),
 254                  wxT("invalid index in wxListBox::SetFirstItem") );
 255
 256     SendMessage(GetHwnd(), LB_SETTOPINDEX, (WPARAM)N, (LPARAM)0);
 257 }
 258
 259 void wxListBox::Delete(unsigned int n)
 260 {
 261     wxCHECK_RET( IsValid(n),
 262                  wxT("invalid index in wxListBox::Delete") );
 263
 264     // for owner drawn objects, the data is used for storing wxOwnerDrawn
 265     // pointers and we shouldn't touch it
 266 #if !wxUSE_OWNER_DRAWN
 267     if ( !(m_windowStyle & wxLB_OWNERDRAW) )
 268 #endif // !wxUSE_OWNER_DRAWN
 269         if ( HasClientObjectData() )
 270         {
 271             delete GetClientObject(n);
 272         }
 273
 274     SendMessage(GetHwnd(), LB_DELETESTRING, n, 0);
 275     m_noItems--;
 276
 277     SetHorizontalExtent(wxEmptyString);
 278
 279     InvalidateBestSize();
 280 }
 281
 282 int wxListBox::DoAppend(const wxString& item)
 283 {
 284     int index = ListBox_AddString(GetHwnd(), item);
 285     m_noItems++;
 286
 287 #if wxUSE_OWNER_DRAWN
 288     if ( m_windowStyle & wxLB_OWNERDRAW ) {
 289         wxOwnerDrawn *pNewItem = CreateLboxItem(index); // dummy argument
 290         pNewItem->SetName(item);
 291         m_aItems.Insert(pNewItem, index);
 292         ListBox_SetItemData(GetHwnd(), index, pNewItem);
 293         pNewItem->SetFont(GetFont());
 294     }
 295 #endif // wxUSE_OWNER_DRAWN
 296
 297     SetHorizontalExtent(item);
 298
 299     InvalidateBestSize();
 300     return index;
 301 }
 302
 303 void wxListBox::DoSetItems(const wxArrayString& choices, void** clientData)
 304 {
 305     // avoid flicker - but don't need to do this for a hidden listbox
 306     bool hideAndShow = IsShown();
 307     if ( hideAndShow )
 308     {
 309         ShowWindow(GetHwnd(), SW_HIDE);
 310     }
 311
 312     ListBox_ResetContent(GetHwnd());
 313
 314     m_noItems = choices.GetCount();
 315     unsigned int i;
 316     for (i = 0; i < m_noItems; i++)
 317     {
 318         ListBox_AddString(GetHwnd(), choices[i]);
 319         if ( clientData )
 320         {
 321             SetClientData(i, clientData[i]);
 322         }
 323     }
 324
 325 #if wxUSE_OWNER_DRAWN
 326     if ( m_windowStyle & wxLB_OWNERDRAW ) {
 327         // first delete old items
 328         WX_CLEAR_ARRAY(m_aItems);
 329
 330         // then create new ones
 331         for ( unsigned int ui = 0; ui < m_noItems; ui++ ) {
 332             wxOwnerDrawn *pNewItem = CreateLboxItem(ui);
 333             pNewItem->SetName(choices[ui]);
 334             m_aItems.Add(pNewItem);
 335             ListBox_SetItemData(GetHwnd(), ui, pNewItem);
 336         }
 337     }
 338 #endif // wxUSE_OWNER_DRAWN
 339
 340     SetHorizontalExtent();
 341
 342     if ( hideAndShow )
 343     {
 344         // show the listbox back if we hid it
 345         ShowWindow(GetHwnd(), SW_SHOW);
 346     }
 347
 348     InvalidateBestSize();
 349 }
 350
 351 int wxListBox::FindString(const wxString& s, bool bCase) const
 352 {
 353     // back to base class search for not native search type
 354     if (bCase)
 355        return wxItemContainerImmutable::FindString( s, bCase );
 356
 357     int pos = ListBox_FindStringExact(GetHwnd(), -1, s);
 358     if (pos == LB_ERR)
 359         return wxNOT_FOUND;
 360     else
 361         return pos;
 362 }
 363
 364 void wxListBox::Clear()
 365 {
 366     Free();
 367
 368     ListBox_ResetContent(GetHwnd());
 369
 370     m_noItems = 0;
 371     SetHorizontalExtent();
 372
 373     InvalidateBestSize();
 374 }
 375
 376 void wxListBox::Free()
 377 {
 378 #if wxUSE_OWNER_DRAWN
 379     if ( m_windowStyle & wxLB_OWNERDRAW )
 380     {
 381         WX_CLEAR_ARRAY(m_aItems);
 382     }
 383     else
 384 #endif // wxUSE_OWNER_DRAWN
 385     if ( HasClientObjectData() )
 386     {
 387         for ( unsigned int n = 0; n < m_noItems; n++ )
 388         {
 389             delete GetClientObject(n);
 390         }
 391     }
 392 }
 393
 394 void wxListBox::DoSetSelection(int N, bool select)
 395 {
 396     wxCHECK_RET( N == wxNOT_FOUND || IsValid(N),
 397                  wxT("invalid index in wxListBox::SetSelection") );
 398
 399     if ( HasMultipleSelection() )
 400     {
 401         SendMessage(GetHwnd(), LB_SETSEL, select, N);
 402     }
 403     else
 404     {
 405         SendMessage(GetHwnd(), LB_SETCURSEL, select ? N : -1, 0);
 406     }
 407 }
 408
 409 bool wxListBox::IsSelected(int N) const
 410 {
 411     wxCHECK_MSG( IsValid(N), false,
 412                  wxT("invalid index in wxListBox::Selected") );
 413
 414     return SendMessage(GetHwnd(), LB_GETSEL, N, 0) == 0 ? false : true;
 415 }
 416
 417 wxClientData* wxListBox::DoGetItemClientObject(unsigned int n) const
 418 {
 419     return (wxClientData *)DoGetItemClientData(n);
 420 }
 421
 422 void *wxListBox::DoGetItemClientData(unsigned int n) const
 423 {
 424     wxCHECK_MSG( IsValid(n), NULL,
 425                  wxT("invalid index in wxListBox::GetClientData") );
 426
 427     return (void *)SendMessage(GetHwnd(), LB_GETITEMDATA, n, 0);
 428 }
 429
 430 void wxListBox::DoSetItemClientObject(unsigned int n, wxClientData* clientData)
 431 {
 432     DoSetItemClientData(n, clientData);
 433 }
 434
 435 void wxListBox::DoSetItemClientData(unsigned int n, void *clientData)
 436 {
 437     wxCHECK_RET( IsValid(n),
 438                  wxT("invalid index in wxListBox::SetClientData") );
 439
 440 #if wxUSE_OWNER_DRAWN
 441     if ( m_windowStyle & wxLB_OWNERDRAW )
 442     {
 443         // client data must be pointer to wxOwnerDrawn, otherwise we would crash
 444         // in OnMeasure/OnDraw.
 445         wxFAIL_MSG(wxT("Can't use client data with owner-drawn listboxes"));
 446     }
 447 #endif // wxUSE_OWNER_DRAWN
 448
 449     if ( ListBox_SetItemData(GetHwnd(), n, clientData) == LB_ERR )
 450         wxLogDebug(wxT("LB_SETITEMDATA failed"));
 451 }
 452
 453 // Return number of selections and an array of selected integers
 454 int wxListBox::GetSelections(wxArrayInt& aSelections) const
 455 {
 456     aSelections.Empty();
 457
 458     if ( HasMultipleSelection() )
 459     {
 460         int countSel = ListBox_GetSelCount(GetHwnd());
 461         if ( countSel == LB_ERR )
 462         {
 463             wxLogDebug(_T("ListBox_GetSelCount failed"));
 464         }
 465         else if ( countSel != 0 )
 466         {
 467             int *selections = new int[countSel];
 468
 469             if ( ListBox_GetSelItems(GetHwnd(),
 470                                      countSel, selections) == LB_ERR )
 471             {
 472                 wxLogDebug(wxT("ListBox_GetSelItems failed"));
 473                 countSel = -1;
 474             }
 475             else
 476             {
 477                 aSelections.Alloc(countSel);
 478                 for ( int n = 0; n < countSel; n++ )
 479                     aSelections.Add(selections[n]);
 480             }
 481
 482             delete [] selections;
 483         }
 484
 485         return countSel;
 486     }
 487     else  // single-selection listbox
 488     {
 489         if (ListBox_GetCurSel(GetHwnd()) > -1)
 490             aSelections.Add(ListBox_GetCurSel(GetHwnd()));
 491
 492         return aSelections.Count();
 493     }
 494 }
 495
 496 // Get single selection, for single choice list items
 497 int wxListBox::GetSelection() const
 498 {
 499     wxCHECK_MSG( !HasMultipleSelection(),
 500                  -1,
 501                  wxT("GetSelection() can't be used with multiple-selection listboxes, use GetSelections() instead.") );
 502
 503     return ListBox_GetCurSel(GetHwnd());
 504 }
 505
 506 // Find string for position
 507 wxString wxListBox::GetString(unsigned int n) const
 508 {
 509     wxCHECK_MSG( IsValid(n), wxEmptyString,
 510                  wxT("invalid index in wxListBox::GetString") );
 511
 512     int len = ListBox_GetTextLen(GetHwnd(), n);
 513
 514     // +1 for terminating NUL
 515     wxString result;
 516     ListBox_GetText(GetHwnd(), n, (wxChar*)wxStringBuffer(result, len + 1));
 517
 518     return result;
 519 }
 520
 521 void
 522 wxListBox::DoInsertItems(const wxArrayString& items, unsigned int pos)
 523 {
 524     wxCHECK_RET( IsValidInsert(pos),
 525                  wxT("invalid index in wxListBox::InsertItems") );
 526
 527     unsigned int nItems = items.GetCount();
 528     for ( unsigned int i = 0; i < nItems; i++ )
 529     {
 530         int idx = ListBox_InsertString(GetHwnd(), i + pos, items[i]);
 531
 532 #if wxUSE_OWNER_DRAWN
 533         if ( m_windowStyle & wxLB_OWNERDRAW )
 534         {
 535             wxOwnerDrawn *pNewItem = CreateLboxItem(idx);
 536             pNewItem->SetName(items[i]);
 537             pNewItem->SetFont(GetFont());
 538             m_aItems.Insert(pNewItem, idx);
 539
 540             ListBox_SetItemData(GetHwnd(), idx, pNewItem);
 541         }
 542 #else
 543         wxUnusedVar(idx);
 544 #endif // wxUSE_OWNER_DRAWN
 545     }
 546
 547     m_noItems += nItems;
 548
 549     SetHorizontalExtent();
 550
 551     InvalidateBestSize();
 552 }
 553
 554 int wxListBox::DoListHitTest(const wxPoint& point) const
 555 {
 556     LRESULT lRes =  ::SendMessage(GetHwnd(), LB_ITEMFROMPOINT,
 557                                   0L, MAKELONG(point.x, point.y));
 558
 559     // non zero high-order word means that this item is outside of the client
 560     // area, IOW the point is outside of the listbox
 561     return HIWORD(lRes) ? wxNOT_FOUND : lRes;
 562 }
 563
 564 void wxListBox::SetString(unsigned int n, const wxString& s)
 565 {
 566     wxCHECK_RET( IsValid(n),
 567                  wxT("invalid index in wxListBox::SetString") );
 568
 569     // remember the state of the item
 570     bool wasSelected = IsSelected(n);
 571
 572     void *oldData = NULL;
 573     wxClientData *oldObjData = NULL;
 574     if ( m_clientDataItemsType == wxClientData_Void )
 575         oldData = GetClientData(n);
 576     else if ( m_clientDataItemsType == wxClientData_Object )
 577         oldObjData = GetClientObject(n);
 578
 579     // delete and recreate it
 580     SendMessage(GetHwnd(), LB_DELETESTRING, n, 0);
 581
 582     int newN = n;
 583     if ( n == (m_noItems - 1) )
 584         newN = -1;
 585
 586     ListBox_InsertString(GetHwnd(), newN, s);
 587
 588     // restore the client data
 589     if ( oldData )
 590         SetClientData(n, oldData);
 591     else if ( oldObjData )
 592         SetClientObject(n, oldObjData);
 593
 594 #if wxUSE_OWNER_DRAWN
 595     if ( m_windowStyle & wxLB_OWNERDRAW )
 596     {
 597         // update item's text
 598         m_aItems[n]->SetName(s);
 599
 600         // reassign the item's data
 601         ListBox_SetItemData(GetHwnd(), n, m_aItems[n]);
 602     }
 603 #endif  //USE_OWNER_DRAWN
 604
 605     // we may have lost the selection
 606     if ( wasSelected )
 607         Select(n);
 608
 609     InvalidateBestSize();
 610 }
 611
 612 unsigned int wxListBox::GetCount() const
 613 {
 614     return m_noItems;
 615 }
 616
 617 // ----------------------------------------------------------------------------
 618 // helpers
 619 // ----------------------------------------------------------------------------
 620
 621 // Windows-specific code to set the horizontal extent of the listbox, if
 622 // necessary. If s is non-NULL, it's used to calculate the horizontal extent.
 623 // Otherwise, all strings are used.
 624 void wxListBox::SetHorizontalExtent(const wxString& s)
 625 {
 626     // Only necessary if we want a horizontal scrollbar
 627     if (!(m_windowStyle & wxHSCROLL))
 628         return;
 629     TEXTMETRIC lpTextMetric;
 630
 631     if ( !s.empty() )
 632     {
 633         int existingExtent = (int)SendMessage(GetHwnd(), LB_GETHORIZONTALEXTENT, 0, 0L);
 634         HDC dc = GetWindowDC(GetHwnd());
 635         HFONT oldFont = 0;
 636         if (GetFont().Ok() && GetFont().GetResourceHandle() != 0)
 637             oldFont = (HFONT) ::SelectObject(dc, (HFONT) GetFont().GetResourceHandle());
 638
 639         GetTextMetrics(dc, &lpTextMetric);
 640         SIZE extentXY;
 641         ::GetTextExtentPoint32(dc, (LPTSTR) (const wxChar *)s, s.length(), &extentXY);
 642         int extentX = (int)(extentXY.cx + lpTextMetric.tmAveCharWidth);
 643
 644         if (oldFont)
 645             ::SelectObject(dc, oldFont);
 646
 647         ReleaseDC(GetHwnd(), dc);
 648         if (extentX > existingExtent)
 649             SendMessage(GetHwnd(), LB_SETHORIZONTALEXTENT, LOWORD(extentX), 0L);
 650     }
 651     else
 652     {
 653         int largestExtent = 0;
 654         HDC dc = GetWindowDC(GetHwnd());
 655         HFONT oldFont = 0;
 656         if (GetFont().Ok() && GetFont().GetResourceHandle() != 0)
 657             oldFont = (HFONT) ::SelectObject(dc, (HFONT) GetFont().GetResourceHandle());
 658
 659         GetTextMetrics(dc, &lpTextMetric);
 660
 661         for (unsigned int i = 0; i < m_noItems; i++)
 662         {
 663             wxString str = GetString(i);
 664             SIZE extentXY;
 665             ::GetTextExtentPoint32(dc, str.c_str(), str.length(), &extentXY);
 666             int extentX = (int)(extentXY.cx + lpTextMetric.tmAveCharWidth);
 667             if (extentX > largestExtent)
 668                 largestExtent = extentX;
 669         }
 670         if (oldFont)
 671             ::SelectObject(dc, oldFont);
 672
 673         ReleaseDC(GetHwnd(), dc);
 674         SendMessage(GetHwnd(), LB_SETHORIZONTALEXTENT, LOWORD(largestExtent), 0L);
 675     }
 676 }
 677
 678 wxSize wxListBox::DoGetBestSize() const
 679 {
 680     // find the widest string
 681     int wLine;
 682     int wListbox = 0;
 683     for (unsigned int i = 0; i < m_noItems; i++)
 684     {
 685         wxString str(GetString(i));
 686         GetTextExtent(str, &wLine, NULL);
 687         if ( wLine > wListbox )
 688             wListbox = wLine;
 689     }
 690
 691     // give it some reasonable default value if there are no strings in the
 692     // list
 693     if ( wListbox == 0 )
 694         wListbox = 100;
 695
 696     // the listbox should be slightly larger than the widest string
 697     int cx, cy;
 698     wxGetCharSize(GetHWND(), &cx, &cy, GetFont());
 699
 700     wListbox += 3*cx;
 701
 702     // Add room for the scrollbar
 703     wListbox += wxSystemSettings::GetMetric(wxSYS_VSCROLL_X);
 704
 705     // don't make the listbox too tall (limit height to 10 items) but don't
 706     // make it too small neither
 707     int hListbox = EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy)*
 708                     wxMin(wxMax(m_noItems, 3), 10);
 709
 710     wxSize best(wListbox, hListbox);
 711     CacheBestSize(best);
 712     return best;
 713 }
 714
 715 // ----------------------------------------------------------------------------
 716 // callbacks
 717 // ----------------------------------------------------------------------------
 718
 719 bool wxListBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 720 {
 721     wxEventType evtType;
 722     if ( param == LBN_SELCHANGE )
 723     {
 724         evtType = wxEVT_COMMAND_LISTBOX_SELECTED;
 725     }
 726     else if ( param == LBN_DBLCLK )
 727     {
 728         evtType = wxEVT_COMMAND_LISTBOX_DOUBLECLICKED;
 729     }
 730     else
 731     {
 732         // some event we're not interested in
 733         return false;
 734     }
 735
 736     wxCommandEvent event(evtType, m_windowId);
 737     event.SetEventObject( this );
 738
 739     // retrieve the affected item
 740     int n = SendMessage(GetHwnd(), LB_GETCARETINDEX, 0, 0);
 741     if ( n != LB_ERR )
 742     {
 743         if ( HasClientObjectData() )
 744             event.SetClientObject( GetClientObject(n) );
 745         else if ( HasClientUntypedData() )
 746             event.SetClientData( GetClientData(n) );
 747
 748         event.SetString(GetString(n));
 749         event.SetExtraLong( HasMultipleSelection() ? IsSelected(n) : true );
 750     }
 751
 752     event.SetInt(n);
 753
 754     return GetEventHandler()->ProcessEvent(event);
 755 }
 756
 757 // ----------------------------------------------------------------------------
 758 // wxCheckListBox support
 759 // ----------------------------------------------------------------------------
 760
 761 #if wxUSE_OWNER_DRAWN
 762
 763 // drawing
 764 // -------
 765
 766 // space beneath/above each row in pixels
 767 // "standard" checklistbox use 1 here, some might prefer 2. 0 is ugly.
 768 #define OWNER_DRAWN_LISTBOX_EXTRA_SPACE    (1)
 769
 770 // the height is the same for all items
 771 // TODO should be changed for LBS_OWNERDRAWVARIABLE style listboxes
 772
 773 // NB: can't forward this to wxListBoxItem because LB_SETITEMDATA
 774 //     message is not yet sent when we get here!
 775 bool wxListBox::MSWOnMeasure(WXMEASUREITEMSTRUCT *item)
 776 {
 777     // only owner-drawn control should receive this message
 778     wxCHECK( ((m_windowStyle & wxLB_OWNERDRAW) == wxLB_OWNERDRAW), false );
 779
 780     MEASUREITEMSTRUCT *pStruct = (MEASUREITEMSTRUCT *)item;
 781
 782 #ifdef __WXWINCE__
 783     HDC hdc = GetDC(NULL);
 784 #else
 785     HDC hdc = CreateIC(wxT("DISPLAY"), NULL, NULL, 0);
 786 #endif
 787
 788     {
 789         wxDCTemp dc((WXHDC)hdc);
 790         dc.SetFont(GetFont());
 791
 792         pStruct->itemHeight = dc.GetCharHeight() + 2*OWNER_DRAWN_LISTBOX_EXTRA_SPACE;
 793         pStruct->itemWidth  = dc.GetCharWidth();
 794     }
 795
 796 #ifdef __WXWINCE__
 797     ReleaseDC(NULL, hdc);
 798 #else
 799     DeleteDC(hdc);
 800 #endif
 801
 802     return true;
 803 }
 804
 805 // forward the message to the appropriate item
 806 bool wxListBox::MSWOnDraw(WXDRAWITEMSTRUCT *item)
 807 {
 808     // only owner-drawn control should receive this message
 809     wxCHECK( ((m_windowStyle & wxLB_OWNERDRAW) == wxLB_OWNERDRAW), false );
 810
 811     DRAWITEMSTRUCT *pStruct = (DRAWITEMSTRUCT *)item;
 812     UINT itemID = pStruct->itemID;
 813
 814     // the item may be -1 for an empty listbox
 815     if ( itemID == (UINT)-1 )
 816         return false;
 817
 818     long data = ListBox_GetItemData(GetHwnd(), pStruct->itemID);
 819
 820     wxCHECK( data && (data != LB_ERR), false );
 821
 822     wxListBoxItem *pItem = (wxListBoxItem *)data;
 823
 824     wxDCTemp dc((WXHDC)pStruct->hDC);
 825     wxPoint pt1(pStruct->rcItem.left, pStruct->rcItem.top);
 826     wxPoint pt2(pStruct->rcItem.right, pStruct->rcItem.bottom);
 827     wxRect rect(pt1, pt2);
 828
 829     return pItem->OnDrawItem(dc, rect,
 830                              (wxOwnerDrawn::wxODAction)pStruct->itemAction,
 831                              (wxOwnerDrawn::wxODStatus)pStruct->itemState);
 832 }
 833
 834 #endif // wxUSE_OWNER_DRAWN
 835
 836 #endif // wxUSE_LISTBOX