Criação de Componente: Propriedade Picture

unit Unit1;

interface

uses
  Classes, Graphics, ExtCtrls;

type
  TDrawStyle = (dsDefault, dsTiled, dsStreched);

  TPicturePanel = class(TPanel)
  private
    FPicture: TPicture;
    FStyle: TDrawStyle;
    procedure PictureChanged(Sender: TObject);
    procedure SetPicture(const Value: TPicture);
    procedure SetStyle(const Value: TDrawStyle);
  protected
    procedure Paint; override;
  public
    constructor Create(AOwner: TObject); override;
    destructor Destroy; override;
  published
    property Picture: TPicture read FPicture write SetPicture;
    property Style: TDrawStyle read FStyle write SetStyle;
  end;

implementation

{ TPicturePanel }

constructor TPicturePanel.Create(AOwner: TObject);
begin
  inherited;
  FPicture := TPicture.Create;
  FPicture.OnChange := PictureChanged;
end;

destructor TPicturePanel.Destroy;
begin
  FPicture.Free;
  inherited;
end;

procedure TPicturePanel.Paint;
begin
  if Picture.Graphic <> nil then
    case Style of
      dsDefault: Canvas.Draw(BorderWidth, BorderWidth, Picture.Graphic);
      dsTiled: TileImage(Canvas, BorderWidth, BorderWidth, Width - BorderWidth,
        Height - BorderWidth, Picture.Graphic);
      dsStreched: Canvas.StretchDraw(Rect(BorderWidth, BorderWidth, Width - BorderWidth,
        Height - BorderWidth), Picture.Graphic);
    end;
end;

procedure TPicturePanel.PictureChanged(Sender: TObject);
begin
  Invalidate;
end;

procedure TPicturePanel.SetPicture(const Value: TPicture);
begin
  FPicture.Assign(Value);
end;

procedure TPicturePanel.SetStyle(const Value: TDrawStyle);
begin
  if Style <> Value then
  begin
    FStyle := Value;
    Invalidate;
  end;
end;

end.