Undo-funktion

Kode 

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TCPoint=class
    X:byte;
    Y:byte;
    constructor create(aX,aY:Byte);
  end;
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
constructor TCPoint.create(aX,aY:Byte);
begin
  X:=aX;
  Y:=aY;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
 flist:TList;
 fPoint:TCPoint;
 i:integer;
begin
  {create list}
  flist:=TList.Create;
  {for each move add the position of the put piece}
  fPoint:=TCPoint.create(0,0);

  {for undo aquire last move}
  fPoint:=TCPoint(flist.Last);
  {undo the move.}

  {remove move from list}
  flist.Remove(flist.Last);
  {delete move}
  fPoint.Free;

  {when ending game clear list of all moves}
  for i:=flist.Count downto 0 do
  begin
    fPoint:=TCPoint(flist.Last);
    flist.Remove(flist.Last);
    fPoint.Free;
  end;

  {delete the list.}
  flist.Free;
end;
end.