note
	description: "[
		Bulk implementation for {HELP_CONTEXT_I} making it easy to identify if help is available using Void-safe attached types.
	]"
	legal: "See notice at end of class."
	status: "See notice at end of class.";
	date: "$Date$";
	revision: "$Revision $"

deferred class
	HELP_CONTEXT

inherit
	HELP_CONTEXT_I
		redefine
			is_help_available
		end

feature -- Access

	frozen help_context_id: STRING_32
			-- <Precursor>
		do
			create Result.make_empty
			if attached help_context as l_result then
				Result.append (l_result)
			end
		end

	help_context_section: detachable HELP_CONTEXT_SECTION_I
			-- <Precursor>
		do
			--| Dummy implementation descendents can override to support a sub-section.
		end

feature {NONE} -- Access

	help_context: STRING_32
			-- A contextual identifier to link an associated help through.
		require
			is_interface_usable: is_interface_usable
		deferred
		ensure
			not_result_is_empty: Result /= Void implies not Result.is_empty
		end

feature -- Status report

	is_help_available: BOOLEAN
			-- <Precursor>
		do
			Result := Precursor {HELP_CONTEXT_I} and then help_context /= Void
		ensure then
			help_context_attached: Result implies help_context /= Void
		end

;note
	copyright: "Copyright (c) 1984-2012, Eiffel Software"
	license:   "GPL version 2 (see http://www.eiffel.com/licensing/gpl.txt)"
	licensing_options: "http://www.eiffel.com/licensing"
	copying: "[
			This file is part of Eiffel Software's Eiffel Development Environment.
			
			Eiffel Software's Eiffel Development Environment is free
			software; you can redistribute it and/or modify it under
			the terms of the GNU General Public License as published
			by the Free Software Foundation, version 2 of the License
			(available at the URL listed under "license" above).
			
			Eiffel Software's Eiffel Development Environment is
			distributed in the hope that it will be useful, but
			WITHOUT ANY WARRANTY; without even the implied warranty
			of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
			See the GNU General Public License for more details.
			
			You should have received a copy of the GNU General Public
			License along with Eiffel Software's Eiffel Development
			Environment; if not, write to the Free Software Foundation,
			Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
		]"
	source: "[
			Eiffel Software
			5949 Hollister Ave., Goleta, CA 93117 USA
			Telephone 805-685-1006, Fax 805-685-6869
			Website http://www.eiffel.com
			Customer support http://support.eiffel.com
		]"

end