🚀 go-pugleaf

Okay, here's a "working" example for the problem, i.e. it demonstrates
that something's wrong with the combo box.

class TForm1 : public TForm
{
__published:
  TButton *Button1;
  void __fastcall Button1Click(TObject *Sender);
private:
  HWND cb;
protected:
  virtual void __fastcall WndProc(Messages::TMessage &Message);
public:
  __fastcall TForm1(TComponent* Owner);
  __fastcall ~TForm1();
};

__fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner)
{
  int style = WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN;
  style |= CBS_DISABLENOSCROLL | CBS_DROPDOWNLIST | CBS_HASSTRINGS |
           CBS_OWNERDRAWFIXED | CBS_NOINTEGRALHEIGHT | WS_BORDER;
  style &= ~WS_TABSTOP;
  style &= ~WS_VISIBLE;
  cb = CreateWindow("COMBOBOX", "", style, 2, 2, 100, 25, Handle, 0, 0,
0);
}

__fastcall TForm1::~TForm1()
{
  DestroyWindow(cb);
}

void __fastcall TForm1::WndProc(Messages::TMessage &Message)
{
  switch (Message.Msg)
  {
    case WM_MEASUREITEM:
    {
      LPMEASUREITEMSTRUCT mis = (LPMEASUREITEMSTRUCT)Message.LParam;
      if (mis->CtlType == ODT_COMBOBOX)
      {
        mis->itemHeight = 17;
        Message.Result = 1;
      }
      break;
    }
    case WM_DRAWITEM:
    {
      LPDRAWITEMSTRUCT dis = (LPDRAWITEMSTRUCT)Message.LParam;
      if (dis->CtlType == ODT_COMBOBOX)
      {
        DWORD backColor = GetSysColor(COLOR_WINDOW);
        DWORD backColorH = GetSysColor(COLOR_HIGHLIGHT);
        DWORD textColor = GetSysColor(COLOR_WINDOWTEXT);
        DWORD textColorH = GetSysColor(COLOR_HIGHLIGHTTEXT);
        if (dis->itemState & ODS_COMBOBOXEDIT)
        {
          FillRect(dis->hDC, &dis->rcItem, (HBRUSH)(backColor + 1));
          TRect r(dis->rcItem);
          InflateRect(&r, -1, -1);
          COLORREF svTxtCol = SetTextColor(dis->hDC, RGB(255,0,127));
          int mode = SetBkMode(dis->hDC, OPAQUE);
          DrawText(dis->hDC, "myTest", -1, &r, DT_SINGLELINE |
DT_VCENTER);
          SetTextColor(dis->hDC, svTxtCol);
          SetBkMode(dis->hDC, mode);
        }
        else
        {
          DWORD bkCol = backColor;
          DWORD txtCol = textColor;
          if (dis->itemState & ODS_SELECTED)
          {
            bkCol = backColorH;
            txtCol = textColorH;
          }
          FillRect(dis->hDC, &dis->rcItem, (HBRUSH)(bkCol + 1));
          if (static_cast<int>(dis->itemID) >= 0)
          {
            TRect r(dis->rcItem);
            InflateRect(&r, -1, -1);
            SetTextColor(dis->hDC, txtCol);
            char buf[256] = {0};
            SendMessage(cb, CB_GETLBTEXT, dis->itemID, (LPARAM)buf);
            DrawText(dis->hDC, buf, -1, &r, DT_SINGLELINE | DT_VCENTER);
          }
        }
        Message.Result = 1;
      }
      break;
    }
  }
  TForm::WndProc(Message);
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  if (!IsWindowVisible(cb))
  {
    ShowWindow(cb, SW_SHOW);
    SendMessage(cb, CB_RESETCONTENT, 0, 0);
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 1");
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 2");
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 3");
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 4");
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 5");
    SendMessage(cb, CB_ADDSTRING, 0, (LPARAM)"Item 6");
  }
}

The text in the edit box is displayed just fine, but the list box isn't
(I don't even get a list box at all). The CB_ADDSTRING returns no error,
so the list box shouldn't be empty. But all I get in
DRAWITEMSTRUCT::itemID is 0xFFFFFFFF (-1). What am I doing wrong?

--
Martin