indexing description: "[ Border of an EM_WIDGET. ]" date: "$Date$" revision: "$Revision$" deferred class EM_BORDER feature -- Access top: INTEGER -- Top size of border left: INTEGER -- Left size of border right: INTEGER -- Right size of border bottom: INTEGER -- Bottom size of border feature -- Drawing draw_on (a_widget: EM_WIDGET) is -- Draw border on `a_widget'. require a_widget_not_void: a_widget /= Void deferred end invariant non_negative_size: top >= 0 and left >= 0 and right >= 0 and bottom >= 0 end