sightingu.pas

source for card readers

unit SightingU;

interface

type

  TSighting = class(TObject)
  private
    FGrid: string;
    FNumber: integer;
    FSightType: string;
  public
    property Grid: string read FGrid;  // Immutable properties
    property Number: integer read FNumber;  // no of individuals
    property SightType: string read FSightType;
    constructor Create (AGrid: string; ANumber: integer);
  end; // end TSighting = class(TObject)

  TTreeSighting = class(TSighting)
  public
    constructor Create (AGrid: string; ANumber: integer;
                        ASightType: string);  // maintain immutability
  end; // end TTreeSighting = class(TSighting)

  TBirdSighting = class(TSighting)
  private
    FBreeding: boolean;
    FSightDate: string;
  public   
    property Breeding: boolean read FBreeding;
    property SightDate: string read FSightDate;
    constructor Create (AGrid: string;
                        ANumber: integer; ASightType: string;
                        ABreeding: boolean; ASightDate: string);
  end; // end TBirdSighting = class(TSighting)

implementation

{ TSighting }

constructor TSighting.Create(AGrid: string;
                             ANumber: integer);
begin
  FGrid := AGrid;
  FNumber := ANumber;
  FSightType := 'Unknown';
end; // end constructor TSighting.Create

{ TBirdSighting }

constructor TBirdSighting.Create(AGrid: string;
                        ANumber: integer; ASightType: string;
                        ABreeding: boolean; ASightDate: string);
begin
  inherited Create (AGrid, ANumber);
  FSightType := ASightType;  // Generalise up?
  FBreeding := ABreeding;
  FSightDate := ASightDate;
end; // end constructor TBirdSighting

{ TTreeSighting }

constructor TTreeSighting.Create(AGrid: string;
                                 ANumber: integer; ASightType: string);
begin 
  inherited Create (AGrid, ANumber);
  FSightType := ASightType;  // Generalise up?
end; // end constructor TTreeSighting

end. // end SightingU