Reference TScrollWindow

  TScrollWindow = class(TSurfaceCustomControl)
  protected
    { The control width less the border }
    function InternalWidth: Integer;
    { The control height less the border }
    function InternalHeight: Integer;
    { Returns true if a scroll bar is visible }
    function IsBarVisible(Kind: TScrollKind): Boolean;
    { Set the scroll position and scrollable size }
    procedure SetScrollData(const Value: TScrollData);
    { Return the scroll position and scrollable size }
    function GetScrollData: TScrollData;
    { Scroll to a position or until a rectangle is visible }
    procedure ScrollTo(X, Y: Integer); overload;
    procedure ScrollTo(const Rect: TRect); overload;
    { Invoked when the view scrolls by an amount }
    procedure SelectionScroll(DX, DY: Integer); virtual;
    { Call DoUpdate and refresh the scroll bars unless updates are suspended }
    procedure UpdateChanged;
    { Invoked when the scroll position changes }
    procedure DoScroll(X, Y: Integer); virtual;
    { Override to recalculate the scrollable size }
    procedure DoUpdate; virtual;
    { The horizontal amount scrolled by a scroll bar arrow }
    property LineWidth: Integer read FLineWidth write FLineWidth;
    { The vertical amount scrolled by a scroll bar arrow }
    property LineHeight: Integer read FLineHeight write FLineHeight;
    { OnScrollChange is invoked when the scroll position changes }
    property OnScrollChange: TScrollChangeEvent read FOnScrollChange write FOnScrollChange;
  public
    procedure SetBounds(ALeft, ATop, AWidth, AHeight: Integer); override;
    { Suspend updates until EndUpdate is called }
    procedure BeginUpdate;
    { Resume updates and apply changes }
    procedure EndUpdate;
    { CanUpdate is false while updates are suspended }
    property CanUpdate: Boolean read GetCanUpdate;
    property Anchors;
    property Canvas;
    property Color;
    { The width of the scrollable area }
    property ScrollWidth: Integer read GetScrollWidth;
    { The height of the scrollable area }
    property ScrollHeight: Integer read GetScrollHeight;
    { The horizontal scroll position }
    property ScrollLeft: Integer read GetScrollLeft;
    { The vertical scroll position }
    property ScrollTop: Integer read GetScrollTop;
    property OnResize;
  end;