Lazarus - ball

unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls,
  ExtCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Shape1: TShape;
    Timer1: TTimer;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private

  public

  end;

var
  Form1: TForm1;
  x,y: Integer;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.Button3Click(Sender: TObject);
begin
     Shape1.left := Shape1.Left - 10;
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
     Shape1.top := Shape1.top + 10;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  x := 5;
  y := 5;
  Timer1.Interval := 100;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
     if(Shape1.left+Shape1.Width>Form1.Width) then x:=-x;
     if(Shape1.Left<0) then x:=-x;

     if(Shape1.Top+Shape1.Height>Form1.Height) then y:=-y;
     if(Shape1.Top<0) then y:=-y;

     Shape1.left := Shape1.Left + x;
     Shape1.top := Shape1.top - y;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
     Shape1.left := Shape1.Left + 10;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
     Shape1.top := Shape1.top - 10;
end;

end.