A Marquee.T displays a vertical marquee of lines of the form

name arg1 arg2 ... argN

where name and the arg's are texts. The lines are indented so that the spaces after name in each line are vertically aligned. The window has a fixed height and width.

INTERFACE Marquee;

IMPORT VBT, Font;

TYPE
  T <: Public;
  Public = Private OBJECT METHODS
    init(height := 8; nameWidth := 10; argWidth := 12; font := Font.BuiltIn): T;
    putName(nm: TEXT);
    putArg(nm: TEXT);
    remArg();
    erase();
    newline();
  END;
  Private <: VBT.T;

The call m.newline() ends the current line and advances to a new blank one.

The call m.putName(nm) requires that m be at the beginning of a line; it adds the name nm.

The call m.putArg(nm) adds the argument nm to the current line; it requires that the current line have a name.

The call m.remArg() removes the last added argument; it requires that this argument exist.

The arguments to init give the fixed height of the window, the width allowed for the name part, and the width allowed for the argument part. The units of the dimensions are the widths of a character in the specified font, which is assumed to be fixed-width.

It is required that height be at least two.

END Marquee.