Reference TScrollList

  TScrollList = class(TSurfaceCustomControl)
  protected
    procedure CreateHandle; override;
    { Invoked when HeaderSize changes }
    procedure DoHeaderResize; virtual;
    { Invoked when the mouse moves while captured }
    procedure CaptureMove(X, Y: Integer); virtual;
    procedure KeyPress(var Key: Char); override;
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    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 MouseLeave; override;
    function DoMouseWheel(Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint): Boolean; override;
    { Invoke OnScrollLeft }
    procedure DoScrollLeft; virtual;
    procedure Resize; override;
    procedure Draw; override;
    { Draw the area behind the items }
    procedure DrawBackground(const Rect: TRectI); virtual;
    { Draw an item }
    procedure DrawItem(Index: Integer; var Rect: TRectI; State: TDrawState); virtual;
    { Update the scroll bars to match the item count and size }
    procedure UpdateScrollRange;
    { Scroll by a number of pixels }
    procedure Scroll(Delta: Integer); virtual;
    { Scroll while the mouse is dragged above or below the list }
    procedure ScrollMove(Distance: Integer; Direction: TScrollDir); virtual;
    { Invoked before the item index changes, set CanSelect to false to prevent
      it }
    procedure SelectItem(PriorIndex: Integer; NewIndex: Integer; var CanSelect: Boolean); virtual;
    { The item where the mouse was pressed }
    property DownIndex: Integer read FDownIndex;
    { The number of items }
    property Count: Integer read FCount write SetCount;
    { A hint window shown over the list }
    property HintWindow: TControlHintWindow read FHintWindow;
    { The item under the mouse or -1 }
    property HotIndex: Integer read FHotIndex;
    { When true the item under the mouse is highlighted }
    property HotTrack: Boolean read FHotTrack write SetHotTrack;
    { When true the list ignores the mouse }
    property MouseDisabled: Boolean read FMouseDisabled write SetMouseDisabled;
    { When true more than one item can be selected }
    property MultiSelect: Boolean read FMultiSelect write SetMultiSelect;
    { When true positions outside the client width do not match an item }
    property InsideRect: Boolean read FInsideRect write FInsideRect;
    { The height of each item }
    property ItemHeight: Integer read FItemHeight write SetItemHeight default 16;
    { The focused item or -1 }
    property ItemIndex: Integer read FItemIndex write SetItemIndex;
    { When true the mouse only matches the current item }
    property Locked: Boolean read FLocked write FLocked;
    { Scrolling is true while the mouse drags beyond the list }
    property Scrolling: Boolean read FScrolling write SetScrolling;
    { The selected state of an item when MultiSelect is true }
    property Selected[Index: Integer]: Boolean read GetSelected write SetSelected;
    { The number of selected items }
    property SelectCount: Integer read FSelectCount;
    { The first visible item }
    property TopIndex: Integer read FTopIndex write SetTopIndex;
    { OnSelectItem is invoked when an item is chosen }
    property OnSelectItem: TNotifyEvent read FOnSelectItem write FOnSelectItem;
    { OnScrollLeft is invoked when the horizontal scroll position changes }
    property OnScrollLeft: TNotifyEvent read FOnScrollLeft write FOnScrollLeft;
  public
    { Create a new scroll list }
    constructor Create(AOwner: TComponent); override;
    { Return the bounds of an item }
    function ItemRect(Item: Integer): TRectI;
    { Return the item at a point. When Existing is false points below the last
      item return the last item. }
    function ItemAtPos(const Pos: TPointI; Existing: Boolean = False): Integer;
    procedure ScrollBy(DeltaX, DeltaY: Integer); override;
    { Scroll so the item index is visible }
    procedure InsureItemVisible;
    { Repaint an item }
    procedure InvalidateItem(Item: Integer);
    { Returns true if an item is selected }
    function IsSelected(Index: Integer): Boolean;
    { Invoke OnSelectItem }
    procedure Select;
    { Scroll so the item index is visible }
    procedure ScrollToSelection;
    { Space reserved above the items for a header }
    property HeaderSize: Integer read FHeaderSize write SetHeaderSize;
    { The width of the horizontally scrollable area }
    property ScrollWidth: Integer read FScrollWidth write SetScrollWidth;
    { The horizontal scroll position }
    property ScrollLeft: Integer read FScrollLeft write SetScrollLeft;
  end;