TPanel/fi

unit Unit1;

{$mode objfpc}{$H+}

interface

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

type

  { TForm1 }

  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    aPanel:TPanel;
    procedure aButtonClick(Sender: TObject);
  public

  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.FormCreate(Sender: TObject);
var
  aButton:TButton;

  aShape1,aShape2:TShape;
begin
  Caption :='Panel demo';
  aButton:=TButton.Create(Self);
  aButton.Parent:=Self;
  aButton.Caption:= 'Show/Hide';
  aPanel:=TPanel.Create(Self);
  aPanel.Parent:=Self;
  aPanel.Caption:='';
  aShape1:=TShape.Create(aPanel);
  aShape1.Parent:=aPanel;
  aShape1.Shape:=stStar;
  aShape1.Top := 5;
  aShape2:=TShape.Create(aPanel);
  aShape2.Parent:=aPanel;
  aShape2.Shape:=stStar;
  aShape2.Top := 5;
  aShape2.Left:=aShape1.Width+10;
  aPanel.Height:=aShape1.Height+10;
  aButton.Top:=aPanel.Height+10;
  aButton.OnClick:=@aButtonClick;
  Height := aButton.Top+aButton.Height+10;
end;

procedure TForm1.aButtonClick(Sender: TObject);  //the event handler for the button
begin
  if (Sender is TButton)
    then begin
      if aPanel.Visible then aPanel.Visible := false else aPanel.Visible := true;
    end;
end;
end.