Added chapter on collection and container classes to contents

[wxWidgets.git] / src / msw / combobox.cpp

diff --git a/src/msw/combobox.cpp b/src/msw/combobox.cpp
index 7f2f67ad41ff7a39f87475d33553db7c4fe302a5..cf839f4748e486aeb7e45c26f9710a6a8b9c6dd2 100644 (file)
--- a/src/msw/combobox.cpp
+++ b/src/msw/combobox.cpp
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        combobox.cpp
+// Name:        msw/combobox.cpp

 // Purpose:     wxComboBox class
 // Author:      Julian Smart
 // Modified by:
 // Purpose:     wxComboBox class
 // Author:      Julian Smart
 // Modified by:


@@ -9,6 +9,14 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 

+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+

 #ifdef __GNUG__
 #pragma implementation "combobox.h"
 #endif
 #ifdef __GNUG__
 #pragma implementation "combobox.h"
 #endif


@@ -20,137 +28,283 @@
 #pragma hdrstop
 #endif
 
 #pragma hdrstop
 #endif
 

+#if wxUSE_COMBOBOX
+

 #ifndef WX_PRECOMP
 #ifndef WX_PRECOMP

-#include "wx/setup.h"
+#include "wx/settings.h"

 #endif
 
 #endif
 

-#if wxUSE_COMBOBOX
-

 #include "wx/combobox.h"
 #include "wx/combobox.h"

+#include "wx/brush.h"

 #include "wx/clipbrd.h"
 #include "wx/msw/private.h"
 
 #include "wx/clipbrd.h"
 #include "wx/msw/private.h"
 

-#if !USE_SHARED_LIBRARY
+#if wxUSE_TOOLTIPS
+    #ifndef __GNUWIN32_OLD__
+        #include <commctrl.h>
+    #endif
+    #include "wx/tooltip.h"
+#endif // wxUSE_TOOLTIPS
+
+// ----------------------------------------------------------------------------
+// wxWin macros
+// ----------------------------------------------------------------------------
+

 IMPLEMENT_DYNAMIC_CLASS(wxComboBox, wxControl)
 IMPLEMENT_DYNAMIC_CLASS(wxComboBox, wxControl)

-#endif

 
 

-bool wxComboBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
+// ----------------------------------------------------------------------------
+// function prototypes
+// ----------------------------------------------------------------------------
+
+LRESULT APIENTRY _EXPORT wxComboEditWndProc(HWND hWnd,
+                                            UINT message,
+                                            WPARAM wParam,
+                                            LPARAM lParam);
+
+// ---------------------------------------------------------------------------
+// global vars
+// ---------------------------------------------------------------------------
+
+// the pointer to standard radio button wnd proc
+static WXFARPROC gs_wndprocEdit = (WXFARPROC)NULL;
+
+// ============================================================================
+// implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wnd proc for subclassed edit control
+// ----------------------------------------------------------------------------
+
+LRESULT APIENTRY _EXPORT wxComboEditWndProc(HWND hWnd,
+                                            UINT message,
+                                            WPARAM wParam,
+                                            LPARAM lParam)

 {
 {

-  if (param == CBN_SELCHANGE)
-  {
-    wxCommandEvent event(wxEVT_COMMAND_COMBOBOX_SELECTED, m_windowId);
-    event.SetInt(GetSelection());
-    event.SetEventObject(this);
-    event.SetString(GetStringSelection());
-    ProcessCommand(event);
+    HWND hwndCombo = ::GetParent(hWnd);
+    wxWindow *win = wxFindWinFromHandle((WXHWND)hwndCombo);

 
 

-    return TRUE;
-  }
-  else if (param == CBN_EDITCHANGE)
-  {
-    wxCommandEvent event(wxEVT_COMMAND_TEXT_UPDATED, m_windowId);
-    event.SetString(GetValue());
-    event.SetEventObject(this);
-    ProcessCommand(event);
+    switch ( message )
+    {
+        // forward some messages to the combobox
+        case WM_KEYUP:
+        case WM_KEYDOWN:
+        case WM_CHAR:
+            {
+                wxComboBox *combo = wxDynamicCast(win, wxComboBox);
+                wxCHECK_MSG( combo, 0, _T("should have combo as parent") );
+
+                if ( combo->MSWProcessEditMsg(message, wParam, lParam) )
+                    return 0;
+            }
+            break;
+
+#if 0
+        case WM_GETDLGCODE:
+            {
+                wxCHECK_MSG( win, 0, _T("should have a parent") );
+
+                if ( win->GetWindowStyle() & wxPROCESS_ENTER )
+                {
+                    // need to return a custom dlg code or we'll never get it
+                    return DLGC_WANTMESSAGE;
+                }
+            }
+            break;
+#endif // 0
+
+        // deal with tooltips here
+#if wxUSE_TOOLTIPS
+        case WM_NOTIFY:
+            {
+                wxCHECK_MSG( win, 0, _T("should have a parent") );
+
+                NMHDR* hdr = (NMHDR *)lParam;
+                if ( (int)hdr->code == TTN_NEEDTEXT )
+                {
+                    wxToolTip *tooltip = win->GetToolTip();
+                    if ( tooltip )
+                    {
+                        TOOLTIPTEXT *ttt = (TOOLTIPTEXT *)lParam;
+                        ttt->lpszText = (wxChar *)tooltip->GetTip().c_str();
+                    }
+
+                    // processed
+                    return 0;
+                }
+            }
+            break;
+#endif // wxUSE_TOOLTIPS
+    }

 
 

-    return TRUE;
-  }
-  else
-      return FALSE;
+    return ::CallWindowProc(CASTWNDPROC gs_wndprocEdit, hWnd, message, wParam, lParam);

 }
 
 }
 

-bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
-                        const wxString& value,
-                        const wxPoint& pos,
-                        const wxSize& size,
-                        int n, const wxString choices[],
-                        long style,
-                        const wxValidator& validator,
-                        const wxString& name)
+WXHBRUSH wxComboBox::OnCtlColor(WXHDC pDC, WXHWND pWnd, WXUINT nCtlColor,
+                               WXUINT message,
+                               WXWPARAM wParam,
+                               WXLPARAM lParam)

 {
 {

-  SetName(name);
-  SetValidator(validator);
-  if (parent) parent->AddChild(this);
-  SetBackgroundColour(parent->GetBackgroundColour()) ;
-  SetForegroundColour(parent->GetForegroundColour()) ;
-  m_noStrings = 0;
-
-  m_windowStyle = style;
+#if wxUSE_CTL3D
+    if ( m_useCtl3D )
+    {
+        HBRUSH hbrush = Ctl3dCtlColorEx(message, wParam, lParam);
+        return (WXHBRUSH) hbrush;
+    }
+#endif // wxUSE_CTL3D

 
 

-  if ( id == -1 )
-    m_windowId = (int)NewControlId();
-  else
-    m_windowId = id;
+    HDC hdc = (HDC)pDC;
+    if (GetParent()->GetTransparentBackground())
+        SetBkMode(hdc, TRANSPARENT);
+    else
+        SetBkMode(hdc, OPAQUE);

 
 

-  int x = pos.x;
-  int y = pos.y;
-  int width = size.x;
-  int height = size.y;
+    wxColour colBack = GetBackgroundColour();

 
 

-  long msStyle = WS_CHILD | WS_HSCROLL | WS_VSCROLL |
-                 WS_TABSTOP | WS_VISIBLE | CBS_NOINTEGRALHEIGHT;
+    if (!IsEnabled())
+        colBack = wxSystemSettings::GetSystemColour(wxSYS_COLOUR_3DFACE);

 
 

-  if (m_windowStyle & wxCB_READONLY)
-    msStyle |= CBS_DROPDOWNLIST;
-  else if (m_windowStyle & wxCB_SIMPLE)
-    msStyle |= CBS_SIMPLE; // A list (shown always) and edit control
-  else
-    msStyle |= CBS_DROPDOWN;
+    ::SetBkColor(hdc, wxColourToRGB(colBack));
+    ::SetTextColor(hdc, wxColourToRGB(GetForegroundColour()));

 
 

-  if (m_windowStyle & wxCB_SORT)
-    msStyle |= CBS_SORT;
+    wxBrush *brush = wxTheBrushList->FindOrCreateBrush(colBack, wxSOLID);

 
 

-  bool want3D;
-  WXDWORD exStyle = Determine3DEffects(WS_EX_CLIENTEDGE, &want3D) ;
+    return (WXHBRUSH)brush->GetResourceHandle();
+}

 
 

-  // Even with extended styles, need to combine with WS_BORDER
-  // for them to look right.
-  if ( want3D || wxStyleHasBorder(m_windowStyle) )
-    msStyle |= WS_BORDER;
+// ----------------------------------------------------------------------------
+// wxComboBox
+// ----------------------------------------------------------------------------

 
 

-  m_hWnd = (WXHWND)::CreateWindowEx(exStyle, "COMBOBOX", NULL,
-                   msStyle,
-                   0, 0, 0, 0, (HWND) parent->GetHWND(), (HMENU)m_windowId,
-                   wxGetInstance(), NULL);
+bool wxComboBox::MSWProcessEditMsg(WXUINT msg, WXWPARAM wParam, WXLPARAM lParam)
+{
+    switch ( msg )
+    {
+        case WM_CHAR:
+            return HandleChar(wParam, lParam, TRUE /* isASCII */);

 
 

-  wxCHECK_MSG( m_hWnd, FALSE, "Failed to create combobox" );
+        case WM_KEYDOWN:
+            return HandleKeyDown(wParam, lParam);

 
 

-/*
-#if wxUSE_CTL3D
-  if (want3D)
-  {
-    Ctl3dSubclassCtl(wx_combo);
-    m_useCtl3D = TRUE;
-  }
-#endif
-*/
+        case WM_KEYUP:
+            return HandleKeyUp(wParam, lParam);
+    }

 
 

-  // Subclass again for purposes of dialog editing mode
-  SubclassWin(m_hWnd);
+    return FALSE;
+}

 
 

-  SetFont(parent->GetFont());
-  int i;
-  for (i = 0; i < n; i++)
-  {
-    Append(choices[i]);
-  }
+bool wxComboBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
+{
+    switch ( param )
+    {
+        case CBN_SELCHANGE:
+            if (GetSelection() > -1)
+            {
+                wxCommandEvent event(wxEVT_COMMAND_COMBOBOX_SELECTED, GetId());
+                event.SetInt(GetSelection());
+                event.SetEventObject(this);
+                event.SetString(GetStringSelection());
+                ProcessCommand(event);
+            }
+            break;
+
+        case CBN_EDITCHANGE:
+            {
+                wxCommandEvent event(wxEVT_COMMAND_TEXT_UPDATED, GetId());
+                event.SetString(GetValue());
+                event.SetEventObject(this);
+                ProcessCommand(event);
+            }
+            break;
+    }

 
 

-  SetSelection(i);
+    // there is no return value for the CBN_ notifications, so always return
+    // FALSE from here to pass the message to DefWindowProc()
+    return FALSE;
+}

 
 

-  SetSize(x, y, width, height);
-  if ( !value.IsEmpty() )
-  {
-    SetValue(value);
-  }
+WXHWND wxComboBox::GetEditHWND() const
+{
+    // this function should not be called for wxCB_READONLY controls, it is
+    // the callers responsability to check this
+    wxASSERT_MSG( !(GetWindowStyle() & wxCB_READONLY),
+                  _T("read-only combobox doesn't have any edit control") );
+
+    POINT pt;
+    pt.x = pt.y = 4;
+    HWND hwndEdit = ::ChildWindowFromPoint(GetHwnd(), pt);
+    if ( !hwndEdit || hwndEdit == GetHwnd() )
+    {
+        wxFAIL_MSG(_T("not read only combobox without edit control?"));
+    }

 
 

-  return TRUE;
+    return (WXHWND)hwndEdit;

 }
 
 }
 

-wxString wxComboBox::GetValue() const
+bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
+                        const wxString& value,
+                        const wxPoint& pos,
+                        const wxSize& size,
+                        int n, const wxString choices[],
+                        long style,
+                        const wxValidator& validator,
+                        const wxString& name)

 {
 {

-  return wxGetWindowText(GetHWND());
+    // first create wxWin object
+    if ( !CreateControl(parent, id, pos, size, style, validator, name) )
+        return FALSE;
+
+    // get the right style
+    long msStyle = WS_TABSTOP | WS_VSCROLL | WS_HSCROLL |
+                   CBS_AUTOHSCROLL | CBS_NOINTEGRALHEIGHT /* | WS_CLIPSIBLINGS */;
+    if ( style & wxCB_READONLY )
+        msStyle |= CBS_DROPDOWNLIST;
+    else if ( style & wxCB_SIMPLE )
+        msStyle |= CBS_SIMPLE; // A list (shown always) and edit control
+    else
+        msStyle |= CBS_DROPDOWN;
+
+    if ( style & wxCB_SORT )
+        msStyle |= CBS_SORT;
+
+    // and now create the MSW control
+    if ( !MSWCreateControl(_T("COMBOBOX"), msStyle) )
+        return FALSE;
+
+    SetSize(pos.x, pos.y, size.x, size.y);
+
+    // A choice/combobox normally has a white background (or other, depending
+    // on global settings) rather than inheriting the parent's background colour.
+    SetBackgroundColour(wxSystemSettings::GetSystemColour(wxSYS_COLOUR_WINDOW));
+
+    for ( int i = 0; i < n; i++ )
+    {
+        Append(choices[i]);
+    }
+
+    if ( !value.IsEmpty() )
+    {
+        SetValue(value);
+    }
+
+    // a (not read only) combobox is, in fact, 2 controls: the combobox itself
+    // and an edit control inside it and if we want to catch events from this
+    // edit control, we must subclass it as well
+    if ( !(style & wxCB_READONLY) )
+    {
+        gs_wndprocEdit = (WXFARPROC)::SetWindowLong
+                                      (
+                                        (HWND)GetEditHWND(),
+                                        GWL_WNDPROC,
+                                        (LPARAM)wxComboEditWndProc
+                                      );
+    }
+
+    return TRUE;

 }
 
 }
 

+// TODO: update and clear all this horrible mess (VZ)
+

 void wxComboBox::SetValue(const wxString& value)
 {
   // If newlines are denoted by just 10, must stick 13 in front.
 void wxComboBox::SetValue(const wxString& value)
 {
   // If newlines are denoted by just 10, must stick 13 in front.


@@ -164,7 +318,7 @@ void wxComboBox::SetValue(const wxString& value)
   }
   if (singletons > 0)
   {
   }
   if (singletons > 0)
   {

-    char *tmp = new char[len + singletons + 1];
+    wxChar *tmp = new wxChar[len + singletons + 1];

     int j = 0;
     for (i = 0; i < len; i ++)
     {
     int j = 0;
     for (i = 0; i < len; i ++)
     {


@@ -177,98 +331,90 @@ void wxComboBox::SetValue(const wxString& value)
       j ++;
     }
     tmp[j] = 0;
       j ++;
     }
     tmp[j] = 0;

-    SetWindowText((HWND) GetHWND(), tmp);
+    SetWindowText(GetHwnd(), tmp);

     delete[] tmp;
   }
   else
     delete[] tmp;
   }
   else

-    SetWindowText((HWND) GetHWND(), (const char *)value);
+    SetWindowText(GetHwnd(), value);

 }
 
 // Clipboard operations
 void wxComboBox::Copy()
 {
 }
 
 // Clipboard operations
 void wxComboBox::Copy()
 {

-  HWND hWnd = (HWND) GetHWND();
+  HWND hWnd = GetHwnd();

   SendMessage(hWnd, WM_COPY, 0, 0L);
 }
 
 void wxComboBox::Cut()
 {
   SendMessage(hWnd, WM_COPY, 0, 0L);
 }
 
 void wxComboBox::Cut()
 {

-  HWND hWnd = (HWND) GetHWND();
+  HWND hWnd = GetHwnd();

   SendMessage(hWnd, WM_CUT, 0, 0L);
 }
 
 void wxComboBox::Paste()
 {
   SendMessage(hWnd, WM_CUT, 0, 0L);
 }
 
 void wxComboBox::Paste()
 {

-  HWND hWnd = (HWND) GetHWND();
+  HWND hWnd = GetHwnd();

   SendMessage(hWnd, WM_PASTE, 0, 0L);
 }
 
 void wxComboBox::SetEditable(bool editable)
 {
   // Can't implement in MSW?
   SendMessage(hWnd, WM_PASTE, 0, 0L);
 }
 
 void wxComboBox::SetEditable(bool editable)
 {
   // Can't implement in MSW?

-//  HWND hWnd = (HWND) GetHWND();
+//  HWND hWnd = GetHwnd();

 //  SendMessage(hWnd, EM_SETREADONLY, (WPARAM)!editable, (LPARAM)0L);
 }
 
 void wxComboBox::SetInsertionPoint(long pos)
 {
 //  SendMessage(hWnd, EM_SETREADONLY, (WPARAM)!editable, (LPARAM)0L);
 }
 
 void wxComboBox::SetInsertionPoint(long pos)
 {

-/*
-  HWND hWnd = (HWND) GetHWND();

 #ifdef __WIN32__
 #ifdef __WIN32__

-  SendMessage(hWnd, EM_SETSEL, pos, pos);
-  SendMessage(hWnd, EM_SCROLLCARET, (WPARAM)0, (LPARAM)0);
-#else
-  SendMessage(hWnd, EM_SETSEL, 0, MAKELPARAM(pos, pos));
+  HWND hWnd = GetHwnd();
+  SendMessage(hWnd, CB_SETEDITSEL, 0, MAKELPARAM(pos, pos));
+  HWND hEditWnd = (HWND) GetEditHWND() ;
+  if (hEditWnd)
+  {
+    // Scroll insertion point into view
+    SendMessage(hEditWnd, EM_SCROLLCARET, (WPARAM)0, (LPARAM)0);
+    // Why is this necessary? (Copied from wxTextCtrl::SetInsertionPoint)
+    static const wxChar *nothing = _T("");
+    SendMessage(hEditWnd, EM_REPLACESEL, 0, (LPARAM)nothing);
+  }

 #endif
 #endif

-  char *nothing = "";
-  SendMessage(hWnd, EM_REPLACESEL, 0, (LPARAM)nothing);
-*/

 }
 
 void wxComboBox::SetInsertionPointEnd()
 {
 }
 
 void wxComboBox::SetInsertionPointEnd()
 {

-/*

   long pos = GetLastPosition();
   SetInsertionPoint(pos);
   long pos = GetLastPosition();
   SetInsertionPoint(pos);

-*/

 }
 
 long wxComboBox::GetInsertionPoint() const
 {
 }
 
 long wxComboBox::GetInsertionPoint() const
 {

-/*
-  DWORD Pos=(DWORD)SendMessage((HWND) GetHWND(), EM_GETSEL, 0, 0L);
-  return Pos&0xFFFF;
-*/
-  return 0;
+#ifdef __WIN32__
+    DWORD Pos=(DWORD)SendMessage(GetHwnd(), CB_GETEDITSEL, 0, 0L);
+    return Pos&0xFFFF;
+#else
+    return 0;
+#endif

 }
 
 long wxComboBox::GetLastPosition() const
 {
 }
 
 long wxComboBox::GetLastPosition() const
 {

-/*
-    HWND hWnd = (HWND) GetHWND();
+    HWND hEditWnd = (HWND) GetEditHWND();

 
 

-    // Will always return a number > 0 (according to docs)
-    int noLines = (int)SendMessage(hWnd, EM_GETLINECOUNT, (WPARAM)0, (LPARAM)0L);
-
-    // This gets the char index for the _beginning_ of the last line
-    int charIndex = (int)SendMessage(hWnd, EM_LINEINDEX, (WPARAM)(noLines-1), (LPARAM)0L);
-    
-    // Get number of characters in the last line. We'll add this to the character
+    // Get number of characters in the last (only) line. We'll add this to the character

     // index for the last line, 1st position.
     // index for the last line, 1st position.

-    int lineLength = (int)SendMessage(hWnd, EM_LINELENGTH, (WPARAM)charIndex, (LPARAM)0L);
+    int lineLength = (int)SendMessage(hEditWnd, EM_LINELENGTH, (WPARAM) 0, (LPARAM)0L);

 
 

-    return (long)(charIndex + lineLength);
-*/
-  return 0;
+    return (long)(lineLength);

 }
 
 void wxComboBox::Replace(long from, long to, const wxString& value)
 {
 #if wxUSE_CLIPBOARD
 }
 
 void wxComboBox::Replace(long from, long to, const wxString& value)
 {
 #if wxUSE_CLIPBOARD

-    HWND hWnd = (HWND) GetHWND();
+    HWND hWnd = GetHwnd();

     long fromChar = from;
     long toChar = to;
     long fromChar = from;
     long toChar = to;

-    
+

     // Set selection and remove it
 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, fromChar, toChar);
     // Set selection and remove it
 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, fromChar, toChar);


@@ -278,7 +424,7 @@ void wxComboBox::Replace(long from, long to, const wxString& value)
     SendMessage(hWnd, WM_CUT, (WPARAM)0, (LPARAM)0);
 
     // Now replace with 'value', by pasting.
     SendMessage(hWnd, WM_CUT, (WPARAM)0, (LPARAM)0);
 
     // Now replace with 'value', by pasting.

-    wxSetClipboardData(wxDF_TEXT, (wxObject *)(const char *)value, 0, 0);
+    wxSetClipboardData(wxDF_TEXT, (wxObject *)(const wxChar *)value, 0, 0);

 
     // Paste into edit control
     SendMessage(hWnd, WM_PASTE, (WPARAM)0, (LPARAM)0L);
 
     // Paste into edit control
     SendMessage(hWnd, WM_PASTE, (WPARAM)0, (LPARAM)0L);


@@ -287,10 +433,10 @@ void wxComboBox::Replace(long from, long to, const wxString& value)
 
 void wxComboBox::Remove(long from, long to)
 {
 
 void wxComboBox::Remove(long from, long to)
 {

-    HWND hWnd = (HWND) GetHWND();
+    HWND hWnd = GetHwnd();

     long fromChar = from;
     long toChar = to;
     long fromChar = from;
     long toChar = to;

-    
+

     // Cut all selected text
 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, fromChar, toChar);
     // Cut all selected text
 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, fromChar, toChar);


@@ -302,7 +448,7 @@ void wxComboBox::Remove(long from, long to)
 
 void wxComboBox::SetSelection(long from, long to)
 {
 
 void wxComboBox::SetSelection(long from, long to)
 {

-    HWND hWnd = (HWND) GetHWND();
+    HWND hWnd = GetHwnd();

     long fromChar = from;
     long toChar = to;
     // if from and to are both -1, it means
     long fromChar = from;
     long toChar = to;
     // if from and to are both -1, it means


@@ -313,7 +459,7 @@ void wxComboBox::SetSelection(long from, long to)
       fromChar = 0;
       toChar = -1;
     }
       fromChar = 0;
       toChar = -1;
     }

-    
+

 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, (WPARAM)fromChar, (LPARAM)toChar);
 //    SendMessage(hWnd, EM_SCROLLCARET, (WPARAM)0, (LPARAM)0);
 #ifdef __WIN32__
     SendMessage(hWnd, CB_SETEDITSEL, (WPARAM)fromChar, (LPARAM)toChar);
 //    SendMessage(hWnd, EM_SCROLLCARET, (WPARAM)0, (LPARAM)0);


@@ -323,6 +469,49 @@ void wxComboBox::SetSelection(long from, long to)
 #endif
 }
 
 #endif
 }
 

+void wxComboBox::DoMoveWindow(int x, int y, int width, int height)
+{
+    // here is why this is necessary: if the width is negative, the combobox
+    // window proc makes the window of the size width*height instead of
+    // interpreting height in the usual manner (meaning the height of the drop
+    // down list - usually the height specified in the call to MoveWindow()
+    // will not change the height of combo box per se)
+    //
+    // this behaviour is not documented anywhere, but this is just how it is
+    // here (NT 4.4) and, anyhow, the check shouldn't hurt - however without
+    // the check, constraints/sizers using combos may break the height
+    // constraint will have not at all the same value as expected
+    if ( width < 0 )
+        return;
+
+    int cx, cy;
+    wxGetCharSize(GetHWND(), &cx, &cy, &GetFont());
+
+    // what should the height of the drop down list be? we choose 10 items by
+    // default and also 10 items max (if we always use n, the list will never
+    // have vertical scrollbar)
+    int n = GetCount();
+    if ( !n || (n > 10) )
+        n = 10;
+
+    height = (n + 1)* EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy);
+
+    wxControl::DoMoveWindow(x, y, width, height);
+}
+
+wxSize wxComboBox::DoGetBestSize() const
+{
+    // the choice calculates the horz size correctly, but not the vertical
+    // component: correct it
+    wxSize size = wxChoice::DoGetBestSize();
+
+    int cx, cy;
+    wxGetCharSize(GetHWND(), &cx, &cy, &GetFont());
+    size.y = EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy);
+
+    return size;
+}
+

 #endif
  // wxUSE_COMBOBOX
 
 #endif
  // wxUSE_COMBOBOX