datel.pas

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unit DateL;

interface

uses
  Classes, Dates;

type
  // inheritance based
  TDateListI = class (TList)
  protected
    procedure Put(Index: Integer; Item: TDate);
    function Get (Index: Integer): TDate;
  public
    procedure Add (Obj: TDate);
    property Items[Index: Integer]: TDate
      read Get write Put; default;
  end;

  // wrapper based
  TDateListW = class(TObject)
  private
    FList: TList;
    function Get(Index: Integer): TDate;
    procedure Put(Index: Integer; Item: TDate);
    function GetCount: Integer;
  public
    constructor Create;
    destructor Destroy; override;
    function Add(Item: TDate): Integer;
    function Equals(List: TDateListW): Boolean;
    property Count: Integer read GetCount;
    property Items[Index: Integer]: TDate
      read Get write Put; default;
  end;

implementation

// inherited version

procedure TDateListI.Add (Obj: TDate);
begin
  inherited Add (Obj)
end;

procedure TDateListI.Put(Index: Integer; Item: TDate);
begin
  inherited Put (Index, Item)
end;

function TDateListI.Get (Index: Integer): TDate;
begin
  Result := inherited Get (Index);
end;

// embedded version

constructor TDateListW.Create;
begin
  inherited Create;
  FList := TList.Create;
end;

destructor TDateListW.Destroy;
begin
  FList.Free;
  inherited Destroy;
end;

function TDateListW.Get(Index: Integer): TDate;
begin
  Result := FList[Index];
end;

procedure TDateListW.Put(Index: Integer; Item: TDate);
begin
  FList[Index] := Item;
end;

function TDateListW.GetCount: Integer;
begin
  Result := FList.Count;
end;

function TDateListW.Add(Item: TDate): Integer;
begin
  Result := FList.Add(Item);
end;

function TDateListW.Equals(List: TDateListW): Boolean;
var
  I: Integer;
begin
  Result := False;
  if List.Count <> FList.Count then Exit;
  for I := 0 to List.Count - 1 do
    if List[I] <> FList[I] then
      Exit;
  Result := True;
end;

end.