Fl_Scrollbar(int X, int Y, int W, int H, const char *L=0);

function Create
       (X, Y, W, H : in Integer;
        Text       : in String)
    return Scrollbar;

void draw();

procedure Draw
       (This : in out Scrollbar);

int handle(int);

function Handle
       (This  : in out Scrollbar;
        Event : in     Event_Kind)
    return Event_Outcome;

int linesize() const;

function Get_Line_Size
       (This : in Scrollbar)
    return Natural;

void linesize(int i);

procedure Set_Line_Size
       (This : in out Scrollbar;
        To   : in     Natural);

int value() const;

function Get_Position
       (This : in Scrollbar)
    return Natural;

int value(int p);

procedure Set_Position
       (This : in out Scrollbar;
        To   : in     Natural);

int value(int pos, int windowSize, int first, int total);

procedure Set_All
       (This        : in out Scrollbar;
        Position    : in     Natural;
        Win_Size    : in     Natural;
        First_Line  : in     Natural;
        Total_Lines : in     Natural);