shapes.pas

《Kylix程序设计》一书中附带的例程源代码

unit Shapes;

interface

uses
  SysUtils, Classes, Types, QGraphics;

type
  TGeoShape = class( TObject )
  public
    function Draw(): string;
  end;

  TGeoPoint = class( TGeoShape )
  protected
    FPoint: TPoint;
  public
    function Draw(): string; overload;
  end;

  TGeoLine = class( TGeoPoint )
  protected
    FToPoint: TPoint;
  public
    function Draw(): string; overload;
  end;

  TGeoRect = class( TGeoShape )
  protected
    FRect: TRect;
  public
    function Draw(): string; overload;
  end;
{
var
  Shape: TGeoShape;
  Point: TGeoPoint;
  Line: TGeoLine;
  Rect: TGeoRect;
}
implementation

{ TGeoShape }

function TGeoShape.Draw: string;
begin
  Result := 'TGeoShape.Draw called.';
end;

{ TGeoPoint }

function TGeoPoint.Draw: string;
begin
  Result := 'TGeoPoint.Draw called.';
end;

{ TGeoLine }

function TGeoLine.Draw: string;
begin
  Result := 'TGeoLine.Draw called.';
end;

{ TGeoRect }

function TGeoRect.Draw: string;
begin
  Result := 'TGeoLine.Draw called.';
end;

end.