indexing
	description: "Group of EV_FIGURE's. If a figure is added tothis group, it is removed from its previous group first."
	legal: "See notice at end of class."
	status: "See notice at end of class."
	keywords: "group, figure"
	date: "$Date: 2008-01-15 09:57:06 -0800 (Tue, 15 Jan 2008) $"
	revision: "$Revision: 71922 $"

class interface
	EV_FIGURE_GROUP


create 
	default_create
			-- Create without point.
		require -- from  ANY
			True

	make_with_point (a_point: EV_RELATIVE_POINT)
			-- Create on `a_point'.
			-- (from EV_SINGLE_POINTED_FIGURE)
		require -- from EV_SINGLE_POINTED_FIGURE
			a_point_not_void: a_point /= Void


create {EV_FIGURE_GROUP}
	make_filled (n: INTEGER_32)
			-- Allocate list with `n' items.
			-- (`n' may be zero for empty list.)
			-- This list will be full.
			-- (from ARRAYED_LIST)
		require -- from ARRAYED_LIST
			valid_number_of_items: n >= 0
		ensure -- from ARRAYED_LIST
			correct_position: before
			filled: full

feature -- Initialization

	list_make (n: INTEGER_32)
			-- Allocate list with `n' items.
			-- (`n' may be zero for empty list.)
			-- (from ARRAYED_LIST)
		require -- from ARRAYED_LIST
			valid_number_of_items: n >= 0
		ensure -- from ARRAYED_LIST
			correct_position: before
			is_empty: is_empty

	make_filled (n: INTEGER_32)
			-- Allocate list with `n' items.
			-- (`n' may be zero for empty list.)
			-- This list will be full.
			-- (from ARRAYED_LIST)
		require -- from ARRAYED_LIST
			valid_number_of_items: n >= 0
		ensure -- from ARRAYED_LIST
			correct_position: before
			filled: full
	
feature -- Access

	cursor: ARRAYED_LIST_CURSOR
			-- Current cursor position
			-- (from ARRAYED_LIST)
		ensure -- from CURSOR_STRUCTURE
			cursor_not_void: Result /= Void

	first: like item
			-- Item at first position
			-- (from ARRAYED_LIST)
		require -- from CHAIN
			not_empty: not is_empty

	generating_type: STRING_8
			-- Name of current object's generating type
			-- (type of which it is a direct instance)
			-- (from ANY)
		ensure -- from ANY
			generating_type_not_void: Result /= Void
			generating_type_not_empty: not Result.is_empty

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)
		ensure -- from ANY
			generator_not_void: Result /= Void
			generator_not_empty: not Result.is_empty

	group: EV_FIGURE_GROUP
			-- Parent of `Current'.
			-- (from EV_FIGURE)

	has (v: like item): BOOLEAN
			-- Does current include `v'?
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from ARRAYED_LIST)
		require -- from  CONTAINER
			True
		ensure -- from CONTAINER
			not_found_in_empty: Result implies not is_empty

	i_th alias "[]" (i: INTEGER_32): like item assign put_i_th
			-- Item at `i'-th position
			-- Was declared in ARRAYED_LIST as synonym of infix "@".
			-- (from ARRAYED_LIST)
		require -- from TABLE
			valid_key: valid_index (i)

	frozen id_object (an_id: INTEGER_32): ?IDENTIFIED
			-- Object associated with `an_id' (void if no such object)
			-- (from IDENTIFIED)
		ensure -- from IDENTIFIED
			consistent: Result = Void or else Result.object_id = an_id

	index: INTEGER_32
			-- Index of item, if valid.
			-- (from ARRAYED_LIST)

	index_of (v: like item; i: INTEGER_32): INTEGER_32
			-- Index of `i'-th occurrence of item identical to `v'.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- 0 if none.
			-- (from CHAIN)
		require -- from LINEAR
			positive_occurrences: i > 0
		ensure -- from LINEAR
			non_negative_result: Result >= 0

	item: EV_FIGURE
			-- Current item
			-- (from ARRAYED_LIST)
		require -- from TRAVERSABLE
			not_off: not off
		require -- from ACTIVE
			readable: readable
		require else -- from ARRAYED_LIST
			index_is_valid: valid_index (index)

	item_for_iteration: EV_FIGURE
			-- Item at current position
			-- (from LINEAR)
		require -- from LINEAR
			not_off: not off

	last: like first
			-- Item at last position
			-- (from ARRAYED_LIST)
		require -- from CHAIN
			not_empty: not is_empty

	frozen object_id: INTEGER_32
			-- Unique for current object in any given session
			-- (from IDENTIFIED)
		ensure -- from IDENTIFIED
			valid_id: Result > 0 implies id_object (Result) = Current

	sequential_occurrences (v: like item): INTEGER_32
			-- Number of times `v' appears.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from LINEAR)
		require -- from  BAG
			True
		ensure -- from BAG
			non_negative_occurrences: Result >= 0

	orientation: REAL_64
			-- Angle of first point of `Current'.
			-- (from EV_FIGURE)

	pebble: ANY
			-- Data to be transported by pick and drop mechanism.
			-- (from EV_FIGURE)

	pebble_function: FUNCTION [ANY, TUPLE, ANY]
			-- Returns data to be transported by pick and drop mechanism.
			-- When not `Void', pebble is ignored.
			-- (from EV_FIGURE)

	point: EV_RELATIVE_POINT
			-- First point of `Current'.
			-- (from EV_SINGLE_POINTED_FIGURE)

	point_array: ARRAY [EV_COORDINATE]
			-- points as absolute coordinates.
			-- (from EV_FIGURE)
		ensure -- from EV_FIGURE
			same_length: Result.count = points.count

	point_count: INTEGER_32
			-- `Current' has one point.
			-- (from EV_SINGLE_POINTED_FIGURE)
		require -- from  EV_FIGURE
			True

	pointer_style: EV_POINTER_STYLE
			-- Cursor displayed when pointer is over this figure.
			-- (from EV_FIGURE)

	target_data_function: FUNCTION [ANY, TUPLE [ANY], EV_PND_TARGET_DATA]
			-- Function for computing target meta data based on source pebble.
			-- Primarily used for Pick and Drop target menu.
			-- (from EV_ABSTRACT_PICK_AND_DROPABLE)

	target_name: STRING_GENERAL
			-- Optional textual name describing `Current' pick and drop hole.
			-- (from EV_ABSTRACT_PICK_AND_DROPABLE)

	world: EV_FIGURE_WORLD
			-- Top-level parent of `Current'.
			-- (from EV_FIGURE)

	infix "@" (i: INTEGER_32): like item assign put_i_th
			-- Item at `i'-th position
			-- Was declared in ARRAYED_LIST as synonym of i_th.
			-- (from ARRAYED_LIST)
		require -- from TABLE
			valid_key: valid_index (i)
	
feature -- Measurement

	capacity: INTEGER_32
			-- Number of available indices
			-- Was declared in ARRAY as synonym of count.
			-- (from ARRAY)
		require -- from  BOUNDED
			True
		ensure then -- from ARRAY
			consistent_with_bounds: Result = upper - lower + 1

	count: INTEGER_32
			-- Number of items.
			-- (from ARRAYED_LIST)

	index_set: INTEGER_INTERVAL
			-- Range of acceptable indexes
			-- (from CHAIN)
		require -- from  INDEXABLE
			True
		ensure -- from INDEXABLE
			not_void: Result /= Void
		ensure then -- from CHAIN
			count_definition: Result.count = count

	occurrences (v: like item): INTEGER_32
			-- Number of times `v' appears.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from CHAIN)
		require -- from  BAG
			True
		require -- from  LINEAR
			True
		ensure -- from BAG
			non_negative_occurrences: Result >= 0
	
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 (other /= Void and then 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))

	frozen is_deep_equal (other: EV_FIGURE_GROUP): BOOLEAN
			-- Are `Current' and `other' attached to isomorphic object structures?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			shallow_implies_deep: standard_is_equal (other) implies Result
			same_type: Result implies same_type (other)
			symmetric: Result implies other.is_deep_equal (Current)

	is_equal (other: EV_FIGURE_GROUP): 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
		ensure then -- from LIST
			indices_unchanged: index = old index and other.index = old other.index
			true_implies_same_size: Result implies count = other.count

	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: EV_FIGURE_GROUP): 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

	accept_cursor: EV_POINTER_STYLE
			-- Accept cursor set by user.
			-- To be displayed when the screen pointer is over a target that accepts
			-- pebble during pick and drop.
			-- (from EV_FIGURE)

	after: BOOLEAN
			-- Is there no valid cursor position to the right of cursor?
			-- (from LIST)
		require -- from  LINEAR
			True

	before: BOOLEAN
			-- Is there no valid cursor position to the left of cursor?
			-- (from LIST)
		require -- from  BILINEAR
			True

	bounding_box: EV_RECTANGLE
			-- Smallest orthogonal rectangular area `Current' fits in.
		ensure -- from EV_FIGURE
			not_void: Result /= Void

	changeable_comparison_criterion: BOOLEAN
			-- May object_comparison be changed?
			-- (Answer: yes by default.)
			-- (from CONTAINER)

	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

	deny_cursor: EV_POINTER_STYLE
			-- Deny cursor set by user.
			-- To be displayed when the screen pointer is not over a valid target.
			-- (from EV_FIGURE)

	exhausted: BOOLEAN
			-- Has structure been completely explored?
			-- (from LINEAR)
		ensure -- from LINEAR
			exhausted_when_off: off implies Result

	extendible: BOOLEAN is True
			-- May new items be added? (Answer: yes.)
			-- (from DYNAMIC_CHAIN)

	full: BOOLEAN
			-- Is structure filled to capacity?
			-- (from ARRAYED_LIST)
		require -- from  BOX
			True

	has_capture: BOOLEAN
			-- Are all events sent to `Current'?
			-- (from EV_FIGURE)

	invalid_rectangle: EV_RECTANGLE
			-- Rectangle that needs erasing.
			-- `Void' if no change is made.

	is_empty: BOOLEAN
			-- Is structure empty?
			-- (from FINITE)
		require -- from  CONTAINER
			True

	is_inserted (v: EV_FIGURE): BOOLEAN
			-- Has `v' been inserted at the end by the most recent put or
			-- extend?
			-- (from ARRAYED_LIST)

	is_sensitive: BOOLEAN
			-- Is object sensitive to user input?
			-- (from EV_FIGURE)

	is_show_requested: BOOLEAN
			-- Will `Current' be displayed when its parent is?
			-- (from EV_FIGURE)

	isfirst: BOOLEAN
			-- Is cursor at first position?
			-- (from CHAIN)
		ensure -- from CHAIN
			valid_position: Result implies not is_empty

	islast: BOOLEAN
			-- Is cursor at last position?
			-- (from CHAIN)
		ensure -- from CHAIN
			valid_position: Result implies not is_empty

	object_comparison: BOOLEAN
			-- Must search operations use equal rather than `='
			-- for comparing references? (Default: no, use `='.)
			-- (from CONTAINER)

	off: BOOLEAN
			-- Is there no current item?
			-- (from CHAIN)
		require -- from  TRAVERSABLE
			True

	prunable: BOOLEAN
			-- May items be removed? (Answer: yes.)
			-- (from ARRAYED_LIST)
		require -- from  COLLECTION
			True

	readable: BOOLEAN
			-- Is there a current item that may be read?
			-- (from SEQUENCE)
		require -- from  ACTIVE
			True

	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))

	update_rectangle: EV_RECTANGLE
			-- Rectangle that needs redrawing.
			-- `Void' if no change is made.

	valid_cursor (p: CURSOR): BOOLEAN
			-- Can the cursor be moved to position `p'?
			-- (from ARRAYED_LIST)

	valid_cursor_index (i: INTEGER_32): BOOLEAN
			-- Is `i' correctly bounded for cursor movement?
			-- (from CHAIN)
		ensure -- from CHAIN
			valid_cursor_index_definition: Result = ((i >= 0) and (i <= count + 1))

	valid_index (i: INTEGER_32): BOOLEAN
			-- Is `i' a valid index?
			-- (from ARRAYED_LIST)
		require -- from  TABLE
			True
		require -- from  TO_SPECIAL
			True
		ensure then -- from INDEXABLE
			only_if_in_index_set: Result implies ((i >= index_set.lower) and (i <= index_set.upper))
		ensure then -- from CHAIN
			valid_index_definition: Result = ((i >= 1) and (i <= count))

	writable: BOOLEAN
			-- Is there a current item that may be modified?
			-- (from SEQUENCE)
		require -- from  ACTIVE
			True
	
feature -- Status setting

	compare_objects
			-- Ensure that future search operations will use equal
			-- rather than `=' for comparing references.
			-- (from CONTAINER)
		require -- from CONTAINER
			changeable_comparison_criterion: changeable_comparison_criterion
		ensure -- from CONTAINER
			object_comparison

	compare_references
			-- Ensure that future search operations will use `='
			-- rather than equal for comparing references.
			-- (from CONTAINER)
		require -- from CONTAINER
			changeable_comparison_criterion: changeable_comparison_criterion
		ensure -- from CONTAINER
			reference_comparison: not object_comparison

	disable_capture
			-- Disable grab of all events on world.
			-- (from EV_FIGURE)
		require -- from EV_FIGURE
			in_world: world /= Void
		ensure -- from EV_FIGURE
			capture_released: not has_capture

	disable_sensitive
			-- Make object non-sensitive to user input.
			-- (from EV_FIGURE)
		ensure -- from EV_FIGURE
			insensitive_requested: not internal_is_sensitive

	enable_capture
			-- Grab all mouse events for world.
			-- (from EV_FIGURE)
		require -- from EV_FIGURE
			in_world: world /= Void
		ensure -- from EV_FIGURE
			capture_set: has_capture

	enable_sensitive
			-- Make object sensitive to user input.
			-- (from EV_FIGURE)
		ensure -- from EV_FIGURE
			sensitive_requested: internal_is_sensitive

	hide
			-- Request that `Current' not be displayed even when its group is.
			-- (from EV_FIGURE)
		ensure -- from EV_FIGURE
			not_is_show_requested: not is_show_requested

	intersects (r: EV_RECTANGLE): BOOLEAN
			-- Does `r' intersect `Current's bounding_box?
			-- (from EV_FIGURE)

	set_point (a_point: EV_RELATIVE_POINT)
			-- Assign `a_point' to point.
			-- (from EV_SINGLE_POINTED_FIGURE)
		require -- from EV_SINGLE_POINTED_FIGURE
			a_point_not_void: a_point /= Void
		ensure -- from EV_SINGLE_POINTED_FIGURE
			point_assigned: point = a_point

	set_target_data_function (a_function: FUNCTION [ANY, TUPLE [like pebble], EV_PND_TARGET_DATA])
			-- Set `a_function' to compute target meta data based on transport source.
			-- Overrides any target_name set with set_target_name.
			-- (from EV_ABSTRACT_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_function_not_void: a_function /= Void
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			target_data_function_assigned: target_data_function /= Void and then target_data_function.is_equal (a_function)

	set_target_name (a_name: STRING_GENERAL)
			-- Assign `a_name' to target_name.
			-- (from EV_ABSTRACT_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_name_not_void: a_name /= Void
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			target_name_assigned: a_name /= target_name and a_name.is_equal (target_name)

	show
			-- Request that `Current' be displayed when its group is.
			-- `True' by default.
			-- (from EV_FIGURE)
		ensure -- from EV_FIGURE
			is_show_requested: is_show_requested

	snap_to_grid
			-- Move all move handles to most nearby point on the grid.
		require
			world_not_void: world /= Void
			grid_enabled: world.grid_enabled
	
feature -- Cursor movement

	back
			-- Move cursor one position backward.
			-- (from ARRAYED_LIST)
		require -- from BILINEAR
			not_before: not before

	finish
			-- Move cursor to last position if any.
			-- (from ARRAYED_LIST)
		require -- from  LINEAR
			True
		ensure then -- from CHAIN
			at_last: not is_empty implies islast
		ensure then -- from ARRAYED_LIST
			before_when_empty: is_empty implies before

	forth
			-- Move cursor one position forward.
			-- (from ARRAYED_LIST)
		require -- from LINEAR
			not_after: not after
		ensure then -- from LIST
			moved_forth: index = old index + 1

	go_i_th (i: INTEGER_32)
			-- Move cursor to `i'-th position.
			-- (from ARRAYED_LIST)
		require -- from CHAIN
			valid_cursor_index: valid_cursor_index (i)
		ensure -- from CHAIN
			position_expected: index = i

	go_to (p: CURSOR)
			-- Move cursor to position `p'.
			-- (from ARRAYED_LIST)
		require -- from CURSOR_STRUCTURE
			cursor_position_valid: valid_cursor (p)

	move (i: INTEGER_32)
			-- Move cursor `i' positions.
			-- (from ARRAYED_LIST)
		ensure -- from CHAIN
			too_far_right: (old index + i > count) implies exhausted
			too_far_left: (old index + i < 1) implies exhausted
			expected_index: (not exhausted) implies (index = old index + i)

	search (v: like item)
			-- Move to first position (at or after current
			-- position) where item and `v' are equal.
			-- If structure does not include `v' ensure that
			-- exhausted will be true.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from ARRAYED_LIST)
		require -- from  LINEAR
			True
		ensure -- from LINEAR
			object_found: (not exhausted and object_comparison) implies equal (v, item)
			item_found: (not exhausted and not object_comparison) implies v = item

	start
			-- Move cursor to first position if any.
			-- (from ARRAYED_LIST)
		require -- from  TRAVERSABLE
			True
		ensure then -- from CHAIN
			at_first: not is_empty implies isfirst
		ensure then -- from ARRAYED_LIST
			after_when_empty: is_empty implies after
	
feature -- Element change

	extend (v: like item)
			-- Add `v' to end.
			-- Do not move cursor.
			-- Was declared in ARRAYED_LIST as synonym of force.
			-- (from ARRAYED_LIST)
		require -- from COLLECTION
			extendible: extendible
		ensure -- from COLLECTION
			item_inserted: is_inserted (v)
		ensure then -- from BAG
			one_more_occurrence: occurrences (v) = old (occurrences (v)) + 1

	fill (other: CONTAINER [EV_FIGURE])
			-- Fill with as many items of `other' as possible.
			-- The representations of `other' and current structure
			-- need not be the same.
			-- (from CHAIN)
		require -- from COLLECTION
			other_not_void: other /= Void
			extendible: extendible

	force (v: like item)
			-- Add `v' to end.
			-- Do not move cursor.
			-- Was declared in ARRAYED_LIST as synonym of extend.
			-- (from ARRAYED_LIST)
		require -- from SEQUENCE
			extendible: extendible
		ensure then -- from