indexing
	description: "Eiffel Vision menu item list. Implementation interface."
	legal: "See notice at end of class."
	status: "See notice at end of class."
	date: "$Date$"
	revision: "$Revision$"

deferred class interface
	EV_MENU_ITEM_LIST_I

feature -- Access

	cursor: EV_DYNAMIC_LIST_CURSOR [EV_MENU_ITEM]
			-- Current cursor position.
			-- (from EV_DYNAMIC_LIST_I)
		ensure -- from EV_DYNAMIC_LIST_I
			not_void: Result /= Void

	generating_type: STRING_8
			-- Name of current object's generating type
			-- (type of which it is a direct instance)
			-- (from ANY)

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)

	i_th (i: INTEGER_32): EV_MENU_ITEM
			-- Item at `i'-th position.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			i_within_bounds: i > 0 and then i <= count
		ensure -- from EV_DYNAMIC_LIST_I
			not_void: Result /= Void

	index: INTEGER_32
			-- Index of current position
			-- (from EV_DYNAMIC_LIST_I)

	index_of (v: like item; i: INTEGER_32): INTEGER_32
			-- Index of i_th item `v', if present.
			-- As dynamic list descendants are all sets,
			-- Result will be zero for all values of `i'
			-- that are not equal to one
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			positive_occurances: i > 0

	item: EV_MENU_ITEM
			-- Current item
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			readable: index > 0 and then index <= count
		ensure -- from EV_DYNAMIC_LIST_I
			not_void: Result /= Void

	item_by_data (data: ANY): like item
			-- First item with `data'.
			-- (from EV_ITEM_LIST_I)
		require -- from EV_ITEM_LIST_I
			data_not_void: data /= Void

	off: BOOLEAN
			-- Is there no current item?
			-- (from EV_DYNAMIC_LIST_I)

	retrieve_item_by_data (data: ANY; should_compare_objects: BOOLEAN): EV_MENU_ITEM
			-- `Result' is first item in `Current' with data
			-- matching `some_data'. Compare objects if
			-- `should_compare_objects' otherwise compare references.
			-- (from EV_DYNAMIC_LIST_I)

	retrieve_items_by_data (data: ANY; should_compare_objects: BOOLEAN): ARRAYED_LIST [EV_MENU_ITEM]
			-- `Result' is all items in `Current' with data
			-- matching `some_data'. Compare objects if
			-- `should_compare_objects' otherwise compare references.
			-- (from EV_DYNAMIC_LIST_I)
	
feature -- Measurement

	count: INTEGER_32
			-- Number of items.
			-- (from EV_DYNAMIC_LIST_I)
	
feature -- Comparison

	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void
			-- or attached to isomorphic object structures?
			-- (from ANY)
		ensure -- from ANY
			shallow_implies_deep: standard_equal (some, other) implies Result
			both_or_none_void: (some = Void) implies (Result = (other = Void))
			same_type: (Result and (some /= Void)) implies some.same_type (other)
			symmetric: Result implies deep_equal (other, some)

	frozen equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void or attached
			-- to objects considered equal?
			-- (from ANY)
		ensure -- from ANY
			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.is_equal (other))

	is_equal (other: like Current): BOOLEAN
			-- Is `other' attached to an object considered
			-- equal to current object?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			symmetric: Result implies other.is_equal (Current)
			consistent: standard_is_equal (other) implies Result

	frozen standard_equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void or attached to
			-- field-by-field identical objects of the same type?
			-- Always uses default object comparison criterion.
			-- (from ANY)
		ensure -- from ANY
			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.standard_is_equal (other))

	frozen standard_is_equal (other: like Current): BOOLEAN
			-- Is `other' attached to an object of the same type
			-- as current object, and field-by-field identical to it?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			same_type: Result implies same_type (other)
			symmetric: Result implies other.standard_is_equal (Current)
	
feature -- Status report

	conforms_to (other: ANY): BOOLEAN
			-- Does type of current object conform to type
			-- of `other' (as per Eiffel: The Language, chapter 13)?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void

	has (v: like item): BOOLEAN
			-- Does structure contain `v'?
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			v_not_void: v /= Void

	same_type (other: ANY): BOOLEAN
			-- Is type of current object identical to type of `other'?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			definition: Result = (conforms_to (other) and other.conforms_to (Current))

	valid_cursor (p: CURSOR): BOOLEAN
			-- Can the cursor be moved to position `p'?
			-- This is True if `p' conforms to EV_DYNAMIC_LIST_CURSOR and
			-- if it points to an item, `Current' must have it.
			-- (from EV_DYNAMIC_LIST_I)
	
feature -- Cursor movement

	back
			-- Move to previous item.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			not_before: index > 0

	forth
			-- Move cursor to next position.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			not_after: index <= count

	go_i_th (i: INTEGER_32)
			-- Move cursor to `i'-th position.
			-- (from EV_DYNAMIC_LIST_I)

	go_to (p: CURSOR)
			-- Move cursor to position `p'.
			-- (from EV_DYNAMIC_LIST_I)

	move (i: INTEGER_32)
			-- Move cursor `i' positions.
			-- (from EV_DYNAMIC_LIST_I)

	start
			-- Move cursor to first position.
			-- (from EV_DYNAMIC_LIST_I)
		ensure -- from EV_DYNAMIC_LIST_I
			index_on_first: index = 1
	
feature -- Element change

	append (s: SEQUENCE [EV_MENU_ITEM])
			-- Append a copy of `s'. Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			sequence_not_void: s /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			count_increased: old count + s.count = count

	extend (v: like item)
			-- Add `v' to end. Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)

	merge_left (other: like interface)
			-- Merge `other' into current structure before cursor
			-- position. Do not move cursor. Empty `other'.
			-- (from EV_DYNAMIC_LIST_I)

	merge_right (other: like interface)
			-- Merge `other' into current structure after cursor
			-- position. Do not move cursor. Empty `other'.
			-- (from EV_DYNAMIC_LIST_I)

	put_front (v: like item)
			-- Add `v' at beginning. Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)

	put_i_th (v: like item; i: INTEGER_32)
			-- Replace item at `i'-th position by `v'.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			valid_index: i > 0 and i <= count
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)

	put_left (v: like item)
			-- Add `v' to the left of cursor position. Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)

	put_right (v: like item)
			-- Add `v' to the right of cursor position. Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)

	replace (v: like item)
			-- Replace current item by `v'.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			writable: index > 0 and then index <= count
			v_not_void: v /= Void
		ensure -- from EV_DYNAMIC_LIST_I
			has_v: has (v)
	
feature -- Removal

	prune (v: like item)
			-- Remove `v' if present. Do not move cursor, except if
			-- cursor was on `v', move to right neighbor.
			-- (from EV_DYNAMIC_LIST_I)
		ensure -- from EV_DYNAMIC_LIST_I
			cursor_not_moved: not old has (v) implies old interface.index = interface.index
			cursor_not_moved: old has (v) and then old interface.index < old index_of (v, 1) implies index = old index
			cursor_not_moved: old has (v) and then old interface.index >= old index_of (v, 1) implies index = old index - 1
			not_has_v: not has (v)

	remove
			-- Remove current item. Move cursor to right neighbor
			-- (or `after' if no right neighbor).
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			writable: not off
		ensure -- from EV_DYNAMIC_LIST_I
			not_has_v: not has (old item)

	remove_left
			-- Remove item to the left of cursor position.
			-- Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			left_exists: index > 1
			not_before: not (index = 0)
		ensure then -- from EV_DYNAMIC_LIST_I
			left_neighbor_removed: not has (old i_th (index - 1))

	remove_right
			-- Remove item to the right of cursor position.
			-- Do not move cursor.
			-- (from EV_DYNAMIC_LIST_I)
		require -- from EV_DYNAMIC_LIST_I
			right_exists: index < count
		ensure then -- from EV_DYNAMIC_LIST_I
			right_neighbor_removed: not has (old i_th (index + 1))

	wipe_out
			-- Remove all items.
			-- (from EV_DYNAMIC_LIST_I)
	
feature -- Duplication

	copy (other: like Current)
			-- Update current object using fields of object attached
			-- to `other', so as to yield equal objects.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		ensure -- from ANY
			is_equal: is_equal (other)

	frozen deep_copy (other: like Current)
			-- Effect equivalent to that of:
			--		copy (`other' . deep_twin)
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			deep_equal: deep_equal (Current, other)

	frozen deep_twin: like Current
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		ensure -- from ANY
			deep_equal: deep_equal (Current, Result)

	frozen standard_copy (other: like Current)
			-- Copy every field of `other' onto corresponding field
			-- of current object.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		ensure -- from ANY
			is_standard_equal: standard_is_equal (other)

	frozen standard_twin: like Current
			-- New object field-by-field identical to `other'.
			-- Always uses default copying semantics.
			-- (from ANY)
		ensure -- from ANY
			standard_twin_not_void: Result /= Void
			equal: standard_equal (Result, Current)

	frozen twin: like Current
			-- New object equal to `Current'
			-- twin calls copy; to change copying/twining semantics, redefine copy.
			-- (from ANY)
		ensure -- from ANY
			twin_not_void: Result /= Void
			is_equal: Result.is_equal (Current)
	
feature -- Basic operations

	frozen default: like Current
			-- Default value of object's type
			-- (from ANY)

	frozen default_pointer: POINTER
			-- Default value of type `POINTER'
			-- (Avoid the need to write `p'.default for
			-- some `p' of type `POINTER'.)
			-- (from ANY)

	default_rescue
			-- Process exception for routines with no Rescue clause.
			-- (Default: do nothing.)
			-- (from ANY)

	frozen do_nothing
			-- Execute a null action.
			-- (from ANY)
	
feature -- Event handling

	item_select_actions: EV_MENU_ITEM_SELECT_ACTION_SEQUENCE
			-- Actions to be performed when a menu item is selected.
			-- (from EV_MENU_ITEM_LIST_ACTION_SEQUENCES_I)
		ensure -- from EV_MENU_ITEM_LIST_ACTION_SEQUENCES_I
			not_void: Result /= Void
	
feature -- Output

	io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)

	out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- Was declared in ANY as synonym of tagged_out.
			-- (from ANY)

	print (some: ANY)
			-- Write terse external representation of `some'
			-- on standard output.
			-- (from ANY)

	frozen tagged_out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- Was declared in ANY as synonym of out.
			-- (from ANY)
	
feature -- Platform

	operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
	
invariant
		-- from EV_DYNAMIC_LIST_I
	index_within_bounds: is_usable implies (index >= 0 and then index <= count + 1)

		-- from EV_ANY_I
	interface_coupled: is_usable implies interface /= Void and then interface.implementation = Current
	base_make_called: base_make_called

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

indexing
	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
	source: "[
		Eiffel Software
		356 Storke Road, Goleta, CA 93117 USA
		Telephone 805-685-1006, Fax 805-685-6869
		Website http://www.eiffel.com
		Customer support http://support.eiffel.com
	]"

end -- class EV_MENU_ITEM_LIST_I