Reference TCustomDrawList

  TCustomDrawList = class(TScrollList)
  protected
    { Invoke OnButtonCalc }
    procedure ButtonCalc(ItemIndex: Integer; const Rect: TRectI; out Buttons: TButtonRects);
    { Invoke OnButtonDraw }
    procedure ButtonDraw(Surface: ISurface; ItemIndex, Button: Integer; const Rect: TRectI; State: TDrawState);
    { Invoke OnButtonClick }
    procedure ButtonClick(ItemIndex, Button: Integer);
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseMove(Shift: TShiftState; X, Y: Integer); override;
    procedure DrawBackground(const Rect: TRectI); override;
    procedure DrawItem(Index: Integer; var Rect: TRectI; State: TDrawState); override;
    procedure Scroll(Delta: Integer); override;
    { When true scrolling moves the drawn content, otherwise the list repaints }
    property AutoScroll: Boolean read FAutoScroll write SetAutoScroll;
    { OnButtonCalc defines the buttons inside an item }
    property OnButtonCalc: TButtonCalcEvent read FOnButtonCalc write FOnButtonCalc;
    { OnButtonDraw draws a button inside an item }
    property OnButtonDraw: TButtonDrawEvent read FOnButtonDraw write FOnButtonDraw;
    { OnButtonClick is invoked when a button inside an item is clicked }
    property OnButtonClick: TButtonClickEvent read FOnButtonClick write FOnButtonClick;
    { OnDrawBackground draws the area behind the items }
    property OnDrawBackground: TDrawRectEvent read FOnDrawBackground write FOnDrawBackground;
    { OnDrawItem draws an item }
    property OnDrawItem: TDrawIndexEvent read FOnDrawItem write FOnDrawItem;
  public
    { Create a new draw list }
    constructor Create(AOwner: TComponent); override;
  end;