lazarus-ccr/applications/fpvviewer/fpvv_drawer.pas

unit fpvv_drawer;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Controls, Graphics, LCLType;

type

  { TFPVVDrawer }

  TFPVVDrawer = class(TCustomControl)
  public
    PosX, PosY: Integer;
    Drawing: TBitmap;
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure EraseBackground(DC: HDC); override;
    procedure Paint; override;
    procedure HandleKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Clear;
  end;

implementation

{ TFPVVDrawer }

constructor TFPVVDrawer.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  Drawing := TBitmap.Create;

  OnKeyDown := @HandleKeyDown;
end;

destructor TFPVVDrawer.Destroy;
begin
  Drawing.Free;
  inherited Destroy;
end;

procedure TFPVVDrawer.EraseBackground(DC: HDC);
begin

end;

procedure TFPVVDrawer.Paint;
begin
  Canvas.Draw(PosX, PosY, Drawing);
//  inherited Paint;
end;

procedure TFPVVDrawer.HandleKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  case Key of
  VK_UP: Inc(PosY, 5);
  VK_DOWN: Dec(PosY, 5);
  VK_LEFT: Inc(PosX, 5);
  VK_RIGHT: Dec(PosX, 5);
  else
    Exit;
  end;
  Invalidate();
end;

procedure TFPVVDrawer.Clear;
begin
  PosX := 0;
  PosY := 0;
end;

end.