unit Unit1;

{$mode objfpc}{$H+}

interface

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

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    ColorDialog1: TColorDialog;
    Image1: TImage;
    Panel1: TPanel;
    SaveDialog1: TSaveDialog;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer
      );
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  ColorDialog1.Execute;
end;

procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if ssLeft in Shift then begin
    Image1.Picture.Bitmap.Canvas.Pen.Color := ColorDialog1.Color;
    Image1.Picture.Bitmap.Canvas.LineTo(x, y);
  end;
end;

procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbLeft then begin
    Image1.Picture.Bitmap.Canvas.MoveTo(x, y);
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if SaveDialog1.Execute then begin
    Image1.Picture.SaveToFile(SaveDialog1.FileName);
  end;
end;

end.