设计模式、用Delphi实现---->Decorator 模式[7]

    procedure writeline(const line: string); virtual; abstract;

    property endoftext: boolean read getendoftext;

  end;

  ttextfilter = class (ttextstream)

  private

    fownsstream: boolean;

    ftextstream: ttextstream;

  protected

    function getendoftext: boolean; override;

    function gettextstream: ttextstream;

    procedure settextstream(value: ttextstream);

  public

    constructor create(atextstream: ttextstream; aownsstream: boolean);

    destructor destroy; override;

    function readline: string; override;

    procedure writeline(const line: string); override;

    property ownsstream: boolean read fownsstream write fownsstream;

    property textstream: ttextstream read gettextstream write settextstream;