anchor.diff:      property    Items: TStringList read FItems;    {$Note Make this read/write }
       property    Options: TfpgComboOptions read FOptions write FOptions;
       property    Margin: integer read FMargin write SetMargin default 1;
  +    property    ReadOnly: Boolean read FReadOnly write SetReadOnly default False;
       property    OnChange: TNotifyEvent read FOnChange write FOnChange;
       property    OnCloseUp: TNotifyEvent read FOnCloseUp write FOnCloseUp;
       property    OnDropDown: TNotifyEvent read FOnDropDown write FOnDropDown;
  
positive.code:     FOnDropDown: TNotifyEvent;
      FOptions: TfpgComboOptions;
      FExtraHint: string;
      function    GetFontDesc: string;
      procedure   SetDropDownCount(const AValue: integer);
      procedure   SetFocusItem(const AValue: integer);
      procedure   SetFontDesc(const AValue: string);
      procedure   SetExtraHint(const AValue: string);
    protected
      FAutoSize: Boolean;
      FMargin: integer;
  
negative.code: var
    i: integer;
  begin
    if ReadOnly then
      Exit;
  
    if AValue = '' then
      SetFocusItem(-1)  // nothing selected
    else
  