class Picture
    export initialize, box_outline, box_fill

    var x_box_pos, y_box_pos, x_size, y_size, pic_colour : int

    proc initialize (x_box_pos_, y_box_pos_, x_size_, y_size_, pic_colour_ : int)
        x_box_pos := x_box_pos_
        y_box_pos := y_box_pos_
        x_size := x_size_
        y_size := y_size_
        pic_colour := pic_colour_
    end initialize

    proc box_outline
        drawbox (x_box_pos, y_box_pos, x_size, y_size, pic_colour)
    end box_outline

    proc box_fill
        drawfillbox (x_box_pos, y_box_pos, x_size, y_size, pic_colour)
    end box_fill

end Picture

var rect : ^Picture
new Picture, rect

class New_Mouse
    import Mouse, Picture, rect
    export mouse_where

    var x_mouse_pos, y_mouse_pos, mouse_click, start, finish : int

    proc mouse_where
        loop
            drawfillbox (0, 0, maxx, maxy, black)
            Mouse.Where (x_mouse_pos, y_mouse_pos, mouse_click)
            if (mouse_click = 0) then
                start := x_mouse_pos
                finish := y_mouse_pos
            end if
            Picture (rect).initialize (x_mouse_pos, y_mouse_pos, start, finish, red)
            Picture (rect).box_fill
            View.Update
        end loop
    end mouse_where

end New_Mouse

var loc : ^New_Mouse
new New_Mouse, loc

View.Set ("offscreenonly")
New_Mouse (loc).mouse_where