import gui
$include "guih.icn"

class WindowApp : Dialog (label, direction)

  method rotate_left (msg)
    return msg[2:0] || msg[1]
  end

  method rotate_right (msg)
    return msg[-1:0] || msg[1:-1]
  end

  method reverse_direction ()
    direction := 1-direction
  end

  # this method gets called by the ticker, and updates the label
  method tick ()
    static msg := "Hello World! "
    if direction = 0
      then msg := rotate_left (msg)
      else msg := rotate_right (msg)
    label.set_label(msg)
  end

  method component_setup ()
    direction := 1 # start off rotating to the right
    label := Label("label=Hello World! ", "pos=0,0")
    # respond to a mouse click on the label
    label.connect (self, "reverse_direction", MOUSE_RELEASE_EVENT)
    add (label)

    connect (self, "dispose", CLOSE_BUTTON_EVENT)
    # tick every 100ms
    self.set_ticker (100)
  end
end

# create and show the window
procedure main ()
  w := WindowApp ()
  w.show_modal ()
end