TÉMA:

unit Unit1;
 
{$mode objfpc}{$H+}
 
interface
 
uses
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs;
 
type
 
  { OwnGraph }
 
  OwnGraph = class (TGraphicControl)
  protected
    procedure Paint; override;
  public
    Constructor Create(AOwner: TComponent); override;
 
  end;
 
  { TForm1 }
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
 
  public
    Own3: OwnGraph;
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.lfm}
 
{ TForm1 }
 
constructor OwnGraph.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;
 
 
procedure OwnGraph.Paint;
begin
  inherited Paint;
  with Canvas do begin
    Pen.Width := 3;
    Line   (20, 20, 120, 20);
    LineTo (70, 100);
    LineTo (20, 20);
  end;
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  Own3 := OwnGraph.Create (Self);
  with Own3 do
  begin
    Top:= 10;
    Left:= 10;
    Width:=120;
    Height:=120;
    Hint := 'OWn3Hint';
    ShowHint := true;
    Parent:= self;
  end
end;
 
procedure TForm1.FormDestroy(Sender: TObject);
begin
  Own3.Free;
end;
 
end.

type
 
  OwnGraph = class (TGraphicControl)
    Constructor Create (AOwner: TComponent); override;
    Procedure DrawMe;
  public
    OwnerForm: TForm;
  end;
 
  { THForm }
 
  THForm = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormPaint(Sender: TObject);
  private
 
  public
    Own3: OwnGraph;
 
  end;
 
var
  HForm: THForm;
 
implementation
 
{$R *.lfm}
 
{ THForm }
 
procedure THForm.FormPaint(Sender: TObject);
begin
  Own3.DrawMe;
end;
 
procedure THForm.FormCreate(Sender: TObject);
begin
  Own3 := OwnGraph.Create (Self);
 
  Hint := 'FormHint';
  ShowHint := true;
end;
 
procedure THForm.FormDestroy(Sender: TObject);
begin
  Own3.Free;
end;
 
Constructor OwnGraph.Create (AOwner: TComponent);
begin
  inherited Create (AOwner);
 
  OwnerForm := TForm (AOwner);
 
  Hint := 'OwnGraphHint';
  ParentShowHint := true;
  {ShowHint := true;  // egyremegy }
end;
 
Procedure OwnGraph.DrawMe;
begin
  with {OwnerForm.}Canvas do begin
    Pen.Width := 3;
    Line   (20, 20, 120, 20);
    LineTo (70, 100);
    LineTo (20, 20);
  end;
end;