indexing
	description: "[
				Displays a list of multi item rows from which the user can select.
		
				Note: The list start at the index 1, the titles are not count among
					the rows. The columns start also at the index 1.
	]"
	legal: "See notice at end of class."
	status: "See notice at end of class."
	keywords: "list, multi, column, row, table"
	date: "$Date: 2006-04-27 11:42:21 -0700 (Thu, 27 Apr 2006) $"
	revision: "$Revision: 58511 $"

class interface
	EV_MULTI_COLUMN_LIST

create 
	default_create
			-- Standard creation procedure.
			-- (from EV_ANY)
		require -- from  ANY
			True
		ensure then -- from EV_ANY
			is_coupled: implementation /= Void
			is_initialized: is_initialized
			default_create_called_set: default_create_called
			is_in_default_state: is_in_default_state

feature -- Access

	accept_cursor: EV_POINTER_STYLE
			-- `Result' is cursor displayed when the screen pointer is over a
			-- target that accepts pebble during pick and drop.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			result_not_void: Result /= Void
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.accept_cursor

	actual_drop_target_agent: FUNCTION [ANY, TUPLE [INTEGER_32, INTEGER_32], EV_ABSTRACT_PICK_AND_DROPABLE]
			-- Overrides default drop target on a certain position.
			-- If `Void', `Current' will use the default drop target.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.actual_drop_target_agent

	background_color: EV_COLOR
			-- Color displayed behind foreground features.
			-- (from EV_COLORIZABLE)
		require -- from EV_COLORIZABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_COLORIZABLE
			bridge_ok: Result.is_equal (implementation.background_color)

	column_count: INTEGER_32
			-- Column count.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.column_count

	cursor: EV_DYNAMIC_LIST_CURSOR [EV_MULTI_COLUMN_LIST_ROW]
			-- Current cursor position.
			-- (from EV_DYNAMIC_LIST)
		require -- from  CURSOR_STRUCTURE
			True
		ensure -- from CURSOR_STRUCTURE
			cursor_not_void: Result /= Void
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result.is_equal (implementation.cursor)

	data: ANY
			-- Arbitrary user data may be stored here.
			-- (from EV_ANY)

	default_key_processing_handler: PREDICATE [ANY, TUPLE [EV_KEY]] assign set_default_key_processing_handler
			-- Agent used to determine whether the default key processing should occur for Current.
			-- If agent returns True then default key processing continues as normal, False prevents
			-- default key processing from occurring.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.default_key_processing_handler

	deny_cursor: EV_POINTER_STYLE
			-- `Result' is cursor displayed when the screen pointer is over a
			-- target that does not accept pebble during pick and drop.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			result_not_void: Result /= Void
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.deny_cursor

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

	foreground_color: EV_COLOR
			-- Color of foreground features like text.
			-- (from EV_COLORIZABLE)
		require -- from EV_COLORIZABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_COLORIZABLE
			bridge_ok: Result.is_equal (implementation.foreground_color)

	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)

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

	help_context: FUNCTION [ANY, TUPLE, EV_HELP_CONTEXT]
			-- Agent that evaluates to help context sent to help engine when help is requested
			-- (from EV_HELP_CONTEXTABLE)
		require -- from EV_HELP_CONTEXTABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_HELP_CONTEXTABLE
			bridge_ok: Result = implementation.help_context

	i_th alias "[]" (i: INTEGER_32): like item
			-- Item at `i'-th position.
			-- (from EV_DYNAMIC_LIST)
		require -- from TABLE
			valid_key: valid_index (i)
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result.is_equal (implementation.i_th (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
			-- Current position.
			-- (from EV_DYNAMIC_LIST)
		require -- from  LINEAR
			True
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result = implementation.index

	index_of (v: like item; i: INTEGER_32): INTEGER_32
			-- Index of `i'th occurrence of `v'.
			-- (from EV_DYNAMIC_LIST)
		require -- from LINEAR
			positive_occurrences: i > 0
		ensure -- from LINEAR
			non_negative_result: Result >= 0
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result = implementation.index_of (v, i)

	item: EV_MULTI_COLUMN_LIST_ROW
			-- Item at current position.
			-- (from EV_DYNAMIC_LIST)
		require -- from TRAVERSABLE
			not_off: not off
		require -- from ACTIVE
			readable: readable
		ensure then -- from EV_DYNAMIC_LIST
			not_void: Result /= Void
			bridge_ok: Result.is_equal (implementation.item)

	last: like item
			-- Item at last position
			-- (from CHAIN)
		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: 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

	parent: EV_CONTAINER
			-- Contains `Current'.
			-- (from EV_WIDGET)
		require -- from EV_CONTAINABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_WIDGET
			bridge_ok: Result = implementation.parent

	pebble: ANY
			-- Data to be transported by pick and drop mechanism.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble

	pebble_function: FUNCTION [ANY, TUPLE, ANY]
			-- Returns data to be transported by pick and drop mechanism.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_function

	pebble_positioning_enabled: BOOLEAN
			-- If `True' then pick and drop start coordinates are
			-- pebble_x_position, pebble_y_position.
			-- If `False' then pick and drop start coordinates are
			-- the pointer coordinates.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_positioning_enabled

	pebble_x_position: INTEGER_32
			-- Initial x position for pick and drop relative to `Current'.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_x_position

	pebble_y_position: INTEGER_32
			-- Initial y position for pick and drop relative to `Current'.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_y_position

	pixmaps_height: INTEGER_32
			-- Height of displayed pixmaps in the list.
			-- (from EV_ITEM_PIXMAP_SCALER)
		require -- from EV_ITEM_PIXMAP_SCALER
			not_destroyed: not is_destroyed
		ensure -- from EV_ITEM_PIXMAP_SCALER
			bridge_ok: Result = implementation.pixmaps_height

	pixmaps_width: INTEGER_32
			-- Width of displayed pixmaps in the list.
			-- (from EV_ITEM_PIXMAP_SCALER)
		require -- from EV_ITEM_PIXMAP_SCALER
			not_destroyed: not is_destroyed
		ensure -- from EV_ITEM_PIXMAP_SCALER
			bridge_ok: Result = implementation.pixmaps_width

	pointer_position: EV_COORDINATE
			-- Position of the screen pointer relative to `Current'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			is_show_requested: is_show_requested

	pointer_style: EV_POINTER_STYLE
			-- Cursor displayed when pointer is over this widget.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	real_target: EV_DOCKABLE_TARGET
			-- `Result' is target used during a dockable transport if
			-- mouse pointer is above `Current'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.real_target

	retrieve_item_by_data (some_data: ANY; should_compare_objects: BOOLEAN): EV_MULTI_COLUMN_LIST_ROW
			-- `Result' is first item in `Current' with data
			-- matching `some_data'. Compare objects if
			-- `should_compare_objects' otherwise compare references.
			-- (from EV_DYNAMIC_LIST)
		ensure -- from EV_DYNAMIC_LIST
			not_found_in_empty: Result /= Void implies not is_empty
			index_not_changed: old index = index

	retrieve_items_by_data (some_data: ANY; should_compare_objects: BOOLEAN): ARRAYED_LIST [EV_MULTI_COLUMN_LIST_ROW]
			-- `Result' is all items in `Current' with data
			-- matching `some_data'. Compare objects if
			-- `should_compare_objects' otherwise compare references.
			-- (from EV_DYNAMIC_LIST)
		ensure -- from EV_DYNAMIC_LIST
			result_not_void: Result /= Void
			not_found_in_empty: not Result.is_empty implies not is_empty
			index_not_changed: old index = index

	row_height: INTEGER_32
			-- Height in pixels of each row.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.row_height

	selected_item: like item
			-- Currently selected item.
			-- Topmost selected item if multiple items are selected.
			-- (For multiple selections see selected_items).
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.selected_item

	selected_items: DYNAMIC_LIST [like item]
			-- Currently selected items.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: lists_equal (Result, implementation.selected_items)

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

	tooltip: STRING_32
			-- Tooltip displayed on `Current'.
			-- If `Result' is empty then no tooltip displayed.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_TOOLTIPABLE
			bridge_ok: equal (Result, implementation.tooltip)
			not_void: Result /= Void
			cloned: Result /= implementation.tooltip

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

	count: INTEGER_32
			-- Number of items.
			-- (from EV_DYNAMIC_LIST)
		require -- from  FINITE
			True
		require -- from  SET
			True
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result = implementation.count

	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

	screen_x: INTEGER_32
			-- Horizontal offset relative to left of screen in pixels.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.screen_x

	screen_y: INTEGER_32
			-- Vertical offset relative to top of screen in pixels.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.screen_y
	
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
			-- Does `other' contain the same elements?
			-- (from LIST)
		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: 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

	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

	column_alignment (a_column: INTEGER_32): EV_TEXT_ALIGNMENT
			-- `Result' is alignment of column `a_column'.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column >= 1 and a_column <= column_count
		ensure
			result_not_void: Result /= Void
			bridge_ok: Result.is_equal (implementation.column_alignment (a_column))

	column_title (a_column: INTEGER_32): STRING_32
			-- Title of `a_column'.
			-- Returns "" if no title given yet.
		require
			not_destroyed: not is_destroyed
			a_column_positive: a_column >= 1
		ensure
			bridge_ok: Result.is_equal (implementation.column_title (a_column))
			cloned: Result /= implementation.column_title (a_column)

	column_width (a_column: INTEGER_32): INTEGER_32
			-- Width of `a_column' in pixels.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column >= 1 and a_column <= column_count
		ensure
			bridge_ok: Result = implementation.column_width (a_column)

	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

	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 False
			-- Is structured filled to capacity? (Answer: no.)
			-- (from EV_DYNAMIC_LIST)

	has_capture: BOOLEAN
			-- Does widget have capture?
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.has_capture

	has_focus: BOOLEAN
			-- Does widget have the keyboard focus?
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.has_focus

	is_displayed: BOOLEAN
			-- Is `Current' visible on the screen?
			-- `True' when show requested and parent displayed.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.is_displayed

	is_dockable: BOOLEAN
			-- Is `Current' dockable?
			-- If `True', then `Current' may be dragged
			-- from its current parent. 
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			bridge_ok: Result = implementation.is_dockable

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

	is_external_docking_enabled: BOOLEAN
			-- Is `Current' able to be docked into an EV_DOCKABLE_DIALOG
			-- When there is no valid EV_DRAGABLE_TARGET upon completion
			-- of transport?
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			bridge_ok: Result = implementation.is_external_docking_enabled

	is_external_docking_relative: BOOLEAN
			-- Will dockable dialog displayed when `Current' is docked externally
			-- be displayed relative to parent window of `Current'?
			-- Otherwise displayed as a standard window.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			bridge_ok: Result = implementation.is_external_docking_relative

	is_inserted (v: EV_MULTI_COLUMN_LIST_ROW): BOOLEAN
			-- Has `v' been inserted by the most recent insertion?
			-- (By default, the value returned is equivalent to calling 
			-- `has (v)'. However, descendants might be able to provide more
			-- efficient implementations.)
			-- (from COLLECTION)

	is_sensitive: BOOLEAN
			-- Is object sensitive to user input.
			-- (from EV_SENSITIVE)
		require -- from EV_SENSITIVE
			not_destroyed: not is_destroyed
		ensure -- from EV_SENSITIVE
			bridge_ok: Result = implementation.user_is_sensitive

	is_show_requested: BOOLEAN
			-- Will `Current' be displayed when its parent is?
			-- See also is_displayed.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			bridge_ok: Result = implementation.is_show_requested

	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

	mode_is_drag_and_drop: BOOLEAN
			-- Is the user interface mode drag and drop?
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.mode_is_drag_and_drop

	mode_is_pick_and_drop: BOOLEAN
			-- Is the user interface mode pick and drop?
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.mode_is_pick_and_drop

	mode_is_target_menu: BOOLEAN
			-- Is the user interface mode a pop-up menu of targets?
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.mode_is_target_menu

	multiple_selection_enabled: BOOLEAN
			-- Can more than one item be selected?
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.multiple_selection_enabled

	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 DYNAMIC_CHAIN)
		require -- from  COLLECTION
			True

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

	real_source: EV_DOCKABLE_SOURCE
			-- `Result' is source to be dragged
			--  when a docking drag occurs on `Current'.
			-- If `Void', `Current' is dragged.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			bridge_ok: Result = implementation.real_source

	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))

	set_pixmaps_size (a_width: INTEGER_32; a_height: INTEGER_32)
			-- Set size of pixmaps disaplyed in `Current'.
			-- Note: Default value is 16x16
			-- (from EV_ITEM_PIXMAP_SCALER)
		require -- from EV_ITEM_PIXMAP_SCALER
			not_destroyed: not is_destroyed
			valid_width: a_width > 0
			valid_height: a_height > 0
		ensure -- from EV_ITEM_PIXMAP_SCALER
			width_set: pixmaps_width = a_width
			height_set: pixmaps_height = a_height

	title_shown: BOOLEAN
			-- Is a row displaying column titles shown?
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.title_shown

	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)
		require -- from  CURSOR_STRUCTURE
			True
		ensure then -- from EV_DYNAMIC_LIST
			bridge_ok: Result = implementation.valid_cursor (p)

	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' within allowable bounds?
			-- (from CHAIN)
		require -- from  TABLE
			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

	align_text_center (a_column: INTEGER_32)
			-- Display text of `a_column' centered.
			-- First column is always left aligned.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 1 and a_column <= column_count
		ensure
			center_aligned: column_alignment (a_column).is_center_aligned

	align_text_left (a_column: INTEGER_32)
			-- Display text of `a_column' left aligned.
			-- First column is always left aligned.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 1 and a_column <= column_count
		ensure
			left_aligned: column_alignment (a_column).is_left_aligned

	align_text_right (a_column: INTEGER_32)
			-- Display text of `a_column' right aligned.
			-- First column is always left aligned.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 1 and a_column <= column_count
		ensure
			right_aligned: column_alignment (a_column).is_right_aligned

	center_pointer
			-- Position screen pointer over center of `Current'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	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 user input events.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			not_has_capture: not has_capture

	disable_dockable
			-- Ensure `Current' is not dockable.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			not_is_dockable: not is_dockable

	disable_external_docking
			-- Assign `False' to is_external_docking_enabled.
			-- Forbid `Current' to be docked into an EV_DOCKABLE_DIALOG
			-- When there is no valid EV_DRAGABLE_TARGET upon completion
			-- of transport.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			is_dockable: is_dockable
		ensure -- from EV_DOCKABLE_SOURCE
			not_externally_dockable: not is_external_docking_enabled

	disable_external_docking_relative
			-- Assign `False' to is_external_docking_relative, ensuring that
			-- a dockable dialog displayed when `Current' is docked externally
			-- is displayed as a standard window.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			external_docking_enabled: is_external_docking_enabled
		ensure -- from EV_DOCKABLE_SOURCE
			external_docking_not_relative: not is_external_docking_relative

	disable_multiple_selection
			-- Allow only one item to be selected.
		require
			not_destroyed: not is_destroyed
		ensure
			not_multiple_selection_enabled: not multiple_selection_enabled

	disable_pebble_positioning
			-- Assign `False' to pebble_positioning_enabled.
			-- The pick and drop will start at the pointer position.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			pebble_positioning_updated: not pebble_positioning_enabled

	disable_sensitive
			-- Make object non-sensitive to user input.
			-- (from EV_SENSITIVE)
		require -- from EV_SENSITIVE
			not_destroyed: not is_destroyed
		ensure -- from EV_SENSITIVE
			is_unsensitive: not is_sensitive

	enable_capture
			-- Grab all user input events (mouse and keyboard).
			-- disable_capture must be called to resume normal input handling.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			is_displayed: is_displayed
		ensure -- from EV_WIDGET
			has_capture: has_capture

	enable_dockable
			-- Ensure `Current' is dockable.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			is_dockable: is_dockable

	enable_external_docking
			-- Assign `True' to is_external_docking_enabled.
			-- Allows `Current' to be docked into an EV_DOCKABLE_DIALOG
			-- When there is no valid EV_DRAGABLE_TARGET upon completion
			-- of transport.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			is_dockable: is_dockable
		ensure -- from EV_DOCKABLE_SOURCE
			is_externally_dockable: is_external_docking_enabled

	enable_external_docking_relative
			-- Assign `True' to is_external_docking_relative, ensuring that
			-- a dockable dialog displayed when `Current' is docked externally
			-- is displayed relative to the top level window.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			external_docking_enabled: is_external_docking_enabled
		ensure -- from EV_DOCKABLE_SOURCE
			external_docking_not_relative: is_external_docking_relative

	enable_multiple_selection
			-- Allow more than one item to be selected.
		require
			not_destroyed: not is_destroyed
		ensure
			multiple_selection_enabled: multiple_selection_enabled

	enable_pebble_positioning
			-- Assign `True' to pebble_positioning_enabled.
			-- Use pebble_x_position and pebble_y_position as the initial coordinates
			-- for the pick and drop in pixels relative to `Current'.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			pebble_positioning_updated: pebble_positioning_enabled

	enable_sensitive
			-- Make object sensitive to user input.
			-- (from EV_SENSITIVE)
		require -- from EV_SENSITIVE
			not_destroyed: not is_destroyed
		ensure -- from EV_SENSITIVE
			is_sensitive: (parent = Void or parent_is_sensitive) implies is_sensitive

	ensure_item_visible (an_item: EV_MULTI_COLUMN_LIST_ROW)
			-- Ensure `an_item' is visible in `Current'.
		require
			not_destroyed: not is_destroyed
			is_displayed: is_displayed
			an_item_contained: has (an_item)

	hide
			-- Request that `Current' not be displayed even when its parent is.
			-- If successful, make is_show_requested `False'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	hide_title_row
			-- Hide row displaying column titles.
		require
			not_destroyed: not is_destroyed
		ensure
			not_title_shown: not title_shown

	remove_default_key_processing_handler
			-- Ensure default_key_processing_handler is Void.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			default_key_processing_handler_removed: default_key_processing_handler = Void

	remove_pebble
			-- Make pebble `Void' and pebble_function `Void,
			-- Removing transport.
			-- (from EV_PICK_AND_DROPABLE)
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			pebble_removed: pebble = Void and pebble_function = Void

	remove_real_source
			-- Ensure real_source is `Void'.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
		ensure -- from EV_DOCKABLE_SOURCE
			real_source_void: real_source = Void

	remove_real_target
			-- Ensure real_target is `Void'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			real_target_void: real_target = Void

	remove_selection
			-- Ensure that selected_items is empty.
		require
			not_destroyed: not is_destroyed
		ensure
			selected_items_empty: selected_items.is_empty

	set_accept_cursor (a_cursor: like accept_cursor)
			-- Set `a_cursor' to be displayed when the screen pointer is over a
			-- target that accepts pebble during pick and drop.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_cursor_not_void: a_cursor /= Void
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			accept_cursor_assigned: accept_cursor.is_equal (a_cursor)

	set_actual_drop_target_agent (an_agent: like actual_drop_target_agent)
			-- Assign `an_agent' to actual_drop_target_agent.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			an_agent_not_void: an_agent /= Void
		ensure -- from EV_WIDGET
			assigned: actual_drop_target_agent = an_agent

	set_default_colors
			-- Set foreground and background color to their default values.
			-- (from EV_COLORIZABLE)
		require -- from EV_COLORIZABLE
			not_destroyed: not is_destroyed

	set_default_key_processing_handler (a_handler: like default_key_processing_handler)
			-- Assign default_key_processing_handler to `a_handler'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	set_deny_cursor (a_cursor: like deny_cursor)
			-- Set `a_cursor' to be displayed when the screen pointer is not
			-- over a valid target.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_cursor_not_void: a_cursor /= Void
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			deny_cursor_assigned: deny_cursor.is_equal (a_cursor)

	set_drag_and_drop_mode
			-- Set user interface mode to drag and drop.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			drag_and_drop_set: mode_is_drag_and_drop

	set_focus
			-- Grab keyboard focus.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			is_displayed: is_displayed
			is_sensitive: is_sensitive

	set_pebble (a_pebble: like pebble)
			-- Assign `a_pebble' to pebble.
			-- Overrides set_pebble_function.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_pebble_not_void: a_pebble /= Void
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			pebble_assigned: pebble = a_pebble

	set_pebble_function (a_function: FUNCTION [ANY, TUPLE, ANY])
			-- Set `a_function' to compute pebble.
			-- It will be called once each time a pick occurs, the result
			-- will be assigned to pebble for the duration of transport.
			-- When a pick occurs, the pick position in widget coordinates,
			-- <<x, y>> in pixels, is passed.
			-- To handle this data use `a_function' of type
			-- FUNCTION [ANY, TUPLE [INTEGER, INTEGER], ANY] and return the
			-- pebble as a function of x and y.
			-- Overrides set_pebble.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_ABSTRACT_PICK_AND_DROPABLE
			a_function_not_void: a_function /= Void
			a_function_takes_two_integer_open_operands: a_function.valid_operands ([1, 1])
		ensure -- from EV_ABSTRACT_PICK_AND_DROPABLE
			pebble_function_assigned: pebble_function = a_function

	set_pebble_position (a_x, a_y: INTEGER_32)
			-- Set the initial position for pick and drop
			-- Coordinates are in pixels and are relative to position of `Current'.
			-- Pebble_positioning_enabled must be `True' for the position to be used,
			-- use enable_pebble_positioning.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			pebble_position_assigned: pebble_x_position = a_x and pebble_y_position = a_y

	set_pick_and_drop_mode
			-- Set user interface mode to pick and drop.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			pick_and_drop_set: mode_is_pick_and_drop

	set_real_source (dockable_source: EV_DOCKABLE_SOURCE)
			-- Assign `dockable_source' to real_source.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			is_dockable: is_dockable
			dockable_source_not_void: dockable_source /= Void
			dockable_source_is_parent_recursive: source_has_current_recursive (dockable_source)
		ensure -- from EV_DOCKABLE_SOURCE
			real_source_assigned: real_source = dockable_source

	set_real_target (a_target: EV_DOCKABLE_TARGET)
			-- Assign `a_target' to real_target.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			target_not_void: a_target /= Void
		ensure -- from EV_WIDGET
			assigned: real_target = a_target

	set_target_menu_mode
			-- Set user interface mode to pop-up menu of targets.
			-- (from EV_PICK_AND_DROPABLE)
		require -- from EV_PICK_AND_DROPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_PICK_AND_DROPABLE
			target_menu_mode_set: mode_is_target_menu

	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 parent is.
			-- `True' by default.
			-- If successful, make is_show_requested `True'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	show_title_row
			-- Show row displaying column titles.
		require
			not_destroyed: not is_destroyed
		ensure
			title_shown: title_shown
	
feature -- Cursor movement

	back
			-- Move to previous position.
			-- (from EV_DYNAMIC_LIST)
		require -- from BILINEAR
			not_before: not before

	finish
			-- Move cursor to last position.
			-- (No effect if empty)
			-- (from CHAIN)
		require -- from  LINEAR
			True
		ensure then -- from CHAIN
			at_last: not is_empty implies islast

	forth
			-- Move cursor to next position.
			-- (from EV_DYNAMIC_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 EV_DYNAMIC_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 EV_DYNAMIC_LIST)
		require -- from CURSOR_STRUCTURE
			cursor_position_valid: valid_cursor (p)

	move (i: INTEGER_32)
			-- Move cursor `i' positions.
			-- (from EV_DYNAMIC_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 BILINEAR)
		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.
			-- (from EV_DYNAMIC_LIST)
		require -- from  TRAVERSABLE
			True
		ensure then -- from CHAIN
			at_first: not is_empty implies isfirst
		ensure then -- from EV_DYNAMIC_LIST
			empty_implies_after: is_empty implies after
	
feature -- Element change

	append (s: SEQUENCE [like item])
			-- Append a copy of `s'. Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			sequence_not_void: s /= Void
			sequence_not_current: s /= Current
			not_parented: not s.there_exists (agent (v: like item): BOOLEAN
			)
		ensure -- from EV_DYNAMIC_LIST
			count_increased: old count + s.count = count
			cursor_not_moved: (index = old index) or (after and old after)

	extend (v: like item)
			-- Add `v' to end. Do not move cursor.
			-- Was declared in EV_DYNAMIC_LIST as synonym of force.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			v_is_last: v = last
			count_increased: count = old count + 1
			cursor_not_moved: (index = old index) or (after and old after)

	fill (other: CONTAINER [EV_MULTI_COLUMN_LIST_ROW])
			-- 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 EV_DYNAMIC_LIST as synonym of extend.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			v_is_last: v = last
			count_increased: count = old count + 1
			cursor_not_moved: (index = old index) or (after and old after)

	dl_force (v: like item)
			-- Add `v' to end.
			-- (from SEQUENCE)
		require -- from SEQUENCE
			extendible: extendible
		ensure then -- from SEQUENCE
			new_count: count = old count + 1
			item_inserted: has (v)

	merge_left (other: like Current)
			-- Merge `other' into current structure before cursor
			-- position. Do not move cursor. Empty `other'.
			-- (from EV_DYNAMIC_LIST)
		require -- from DYNAMIC_CHAIN
			extendible: extendible
			not_before: not before
			other_exists: other /= Void
			not_current: other /= Current
		ensure -- from DYNAMIC_CHAIN
			new_count: count = old count + old other.count
			new_index: index = old index + old other.count
			other_is_empty: other.is_empty

	merge_right (other: like Current)
			-- Merge `other' into current structure after cursor
			-- position. Do not move cursor. Empty `other'.
			-- (from EV_DYNAMIC_LIST)
		require -- from DYNAMIC_CHAIN
			extendible: extendible
			not_after: not after
			other_exists: other /= Void
			not_current: other /= Current
		ensure -- from DYNAMIC_CHAIN
			new_count: count = old count + old other.count
			same_index: index = old index
			other_is_empty: other.is_empty

	put (v: like item)
			-- Replace current item by `v'.
			-- (Synonym for replace)
			-- (from CHAIN)
		require -- from COLLECTION
			extendible: extendible
		ensure -- from COLLECTION
			item_inserted: is_inserted (v)
		ensure then -- from SET
			in_set_already: old has (v) implies (count = old count)
			added_to_set: not old has (v) implies (count = old count + 1)
		ensure then -- from CHAIN
			same_count: count = old count

	put_front (v: like item)
			-- Add `v' at beginning. Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			v_is_first: v = first
			count_increased: count = old count + 1
			cursor_not_moved: (index = old index + 1) or (before and old before)

	put_i_th (v: like item; i: INTEGER_32)
			-- Replace item at `i'-th position by `v'.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			valid_index: i > 0 and i <= count
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			item_replaced: v = i_th (i)
			not_has_old_item: not has (old i_th (i))
			old_item_parent_void: (old i_th (i)).parent = Void
			count_same: count = old count
			cursor_not_moved: index = old index

	put_left (v: like item)
			-- Add `v' to the left of cursor position. Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			not_before: not before
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			v_at_index_plus_one: v = i_th (index - 1)
			count_increased: count = old count + 1
			cursor_not_moved: index = old index + 1

	put_right (v: like item)
			-- Add `v' to right of cursor position. Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			extendible: extendible
			not_after: not after
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			v_at_index_plus_one: v = i_th (index + 1)
			count_increased: count = old count + 1
			cursor_not_moved: index = old index

	remove_help_context
			-- Remove key press action associated with `EV_APPLICATION.help_key'.
			-- (from EV_HELP_CONTEXTABLE)
		require -- from EV_HELP_CONTEXTABLE
			not_destroyed: not is_destroyed
			help_context_not_void: help_context /= Void
		ensure -- from EV_HELP_CONTEXTABLE
			no_help_context: help_context = Void

	remove_tooltip
			-- Make tooltip empty.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_TOOLTIPABLE
			tooltip_removed: tooltip.is_empty

	replace (v: like item)
			-- Replace current item by `v'.
			-- (from EV_DYNAMIC_LIST)
		require -- from EV_DYNAMIC_LIST
			not_destroyed: not is_destroyed
			writable: writable
			v_not_void: v /= Void
			v_parent_void: v.parent = Void
			v_not_current: not same (v)
			v_not_parent_of_current: not is_parent_recursive (v)
		ensure -- from EV_DYNAMIC_LIST
			parent_is_current: v.parent = Current
			item_replaced: v = item
			not_has_old_item: not has (old item)
			old_item_parent_void: (old item).parent = Void
			count_same: count = old count
			cursor_not_moved: index = old index

	resize_column_to_content (a_column: INTEGER_32)
			-- Resize column `a_column' to width of its widest text.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 0 and a_column <= column_count

	set_background_color (a_color: like background_color)
			-- Assign `a_color' to background_color.
			-- (from EV_COLORIZABLE)
		require -- from EV_COLORIZABLE
			not_destroyed: not is_destroyed
			a_color_not_void: a_color /= Void
		ensure -- from EV_COLORIZABLE
			background_color_assigned: background_color.is_equal (a_color)

	set_column_alignment (an_alignment: EV_TEXT_ALIGNMENT; a_column: INTEGER_32)
			-- Align the text of column `a_column' to `an_alignment'
			-- The first column must stay as left aligned as MSDN
			-- states that the first column can only be set as left aligned
			-- for Win32.
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 1 and a_column <= column_count
			alignment_not_void: an_alignment /= Void
		ensure
			column_alignment_assigned: column_alignment (a_column).is_equal (an_alignment)

	set_column_alignments (alignments: LINKED_LIST [EV_TEXT_ALIGNMENT])
			-- Assign `alignments' to column text alignments in order.
			-- The first alignment element is ignored
			-- (see set_column_alignment).
		require
			not_destroyed: not is_destroyed
			alignments_not_void: alignments /= Void
		ensure
			column_alignments_assigned: column_alignments_assigned (alignments)

	set_column_title (a_title: STRING_GENERAL; a_column: INTEGER_32)
			-- Assign `a_title' to the column_title(`a_column').
		require
			not_destroyed: not is_destroyed
			a_column_positive: a_column > 0
			a_title_not_void: a_title /= Void
		ensure
			a_title_assigned: column_title (a_column).is_equal (a_title)
			column_count_valid: column_count >= a_column
			cloned: column_title (a_column) /= a_title

	set_column_titles (titles: ARRAY [STRING_GENERAL])
			-- Assign `titles' to titles of columns in order.
			-- `Current' will resize if the number of titles exceeds
			-- column_count.
		require
			not_destroyed: not is_destroyed
			titles_not_void: titles /= Void
		ensure
			column_count_valid: column_count >= titles.count
			column_titles_assigned: column_titles_assigned (titles)

	set_column_width (a_width: INTEGER_32; a_column: INTEGER_32)
			-- Assign `a_width' column_width(`a_column').
		require
			not_destroyed: not is_destroyed
			a_column_within_range: a_column > 0
			a_width_positive: a_width >= 0
		ensure
			column_count_valid: column_count >= a_column
			a_width_assigned: a_width = column_width (a_column)

	set_column_widths (widths: ARRAY [INTEGER_32])
			-- Assign `widths' to column widths in order.
		require
			not_destroyed: not is_destroyed
			widths_not_void: widths /= Void
		ensure
			column_count_valid: column_count >= widths.count
			column_widths_assigned: column_widths_assigned (widths)

	set_data (some_data: like data)
			-- Assign `some_data' to data.
			-- (from EV_ANY)
		require -- from EV_ANY
			not_destroyed: not is_destroyed
		ensure -- from EV_ANY
			data_assigned: data = some_data

	set_foreground_color (a_color: like foreground_color)
			-- Assign `a_color' to foreground_color.
			-- (from EV_COLORIZABLE)
		require -- from EV_COLORIZABLE
			not_destroyed: not is_destroyed
			a_color_not_void: a_color /= Void
		ensure -- from EV_COLORIZABLE
			foreground_color_assigned: foreground_color.is_equal (a_color)

	set_help_context (an_help_context: like help_context)
			-- Assign `an_help_context' to help_context.
			-- (from EV_HELP_CONTEXTABLE)
		require -- from EV_HELP_CONTEXTABLE
			not_destroyed: not is_destroyed
			an_help_context_not_void: an_help_context /= Void
		ensure -- from EV_HELP_CONTEXTABLE
			help_context_assigned: help_context.is_equal (an_help_context)

	set_minimum_height (a_minimum_height: INTEGER_32)
			-- Set `a_minimum_height' in pixels to minimum_height.
			-- If height is less than `a_minimum_height', resize.
			-- From now, minimum_height is fixed and will not be changed
			-- dynamically by the application anymore.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			a_minimum_height_positive: a_minimum_height >= 0
		ensure -- from EV_WIDGET
			minimum_height_assigned: minimum_height = a_minimum_height
			minimum_height_set_by_user_set: minimum_height_set_by_user

	set_minimum_size (a_minimum_width, a_minimum_height: INTEGER_32)
			-- Assign `a_minimum_height' to minimum_height
			-- and `a_minimum_width' to minimum_width in pixels.
			-- If width or height is less than minimum size, resize.
			-- From now, minimum size is fixed and will not be changed
			-- dynamically by the application anymore.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			a_minimum_width_positive: a_minimum_width >= 0
			a_minimum_height_positive: a_minimum_height >= 0
		ensure -- from EV_WIDGET
			minimum_width_assigned: minimum_width = a_minimum_width
			minimum_height_assigned: minimum_height = a_minimum_height
			minimum_height_set_by_user_set: minimum_height_set_by_user
			minimum_width_set_by_user_set: minimum_width_set_by_user

	set_minimum_width (a_minimum_width: INTEGER_32)
			-- Assign `a_minimum_width' in pixels to minimum_width.
			-- If width is less than `a_minimum_width', resize.
			-- From now, minimum_width is fixed and will not be changed
			-- dynamically by the application anymore.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			a_minimum_width_positive: a_minimum_width >= 0
		ensure -- from EV_WIDGET
			minimum_width_assigned: minimum_width = a_minimum_width
			minimum_width_set_by_user_set: minimum_width_set_by_user

	set_pointer_style (a_cursor: like pointer_style)
			-- Assign `a_cursor' to pointer_style.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
			a_cursor_not_void: a_cursor /= Void
		ensure -- from EV_WIDGET
			pointer_style_assigned: pointer_style.is_equal (a_cursor)

	set_tooltip (a_tooltip: STRING_GENERAL)
			-- Assign `a_tooltip' to tooltip.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
			tooltip: a_tooltip /= Void
		ensure -- from EV_TOOLTIPABLE
			tooltip_assigned: tooltip.is_equal (a_tooltip)
			cloned: tooltip /= a_tooltip

	swap (i: INTEGER_32)
			-- Exchange_item at `i'-th position with item
			-- at cursor position.
			-- (from EV_DYNAMIC_LIST)
		require -- from CHAIN
			not_off: not off
			valid_index: valid_index (i)
		ensure -- from CHAIN
			swapped_to_item: item = old i_th (i)
			swapped_from_item: i_th (i) = old item
	
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)
		require -- from COLLECTION
			prunable: prunable
		ensure then -- from SET
			removed_count_change: old has (v) implies (count = old count - 1)
			not_removed_no_count_change: not old has (v) implies (count = old count)
			item_deleted: not has (v)
		ensure then -- from EV_DYNAMIC_LIST
			not_has_v: not has (v)
			had_item_implies_parent_void: old has (v) implies v.parent = Void
			had_item_implies_count_decreased: old has (v) implies count = old count - 1
			had_item_and_was_after_implies_index_decreased: (old after and old has (v)) implies index = old index - 1

	prune_all (v: like item)
			-- Remove all occurrences of `v'.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- Leave structure exhausted.
			-- (from DYNAMIC_CHAIN)
		require -- from COLLECTION
			prunable: prunable
		ensure -- from COLLECTION
			no_more_occurrences: not has (v)
		ensure then -- from DYNAMIC_CHAIN
			is_exhausted: exhausted

	remove
			-- Remove current item. Move cursor to right neighbor.
			-- (or after if no right neighbor).
			-- (from EV_DYNAMIC_LIST)
		require -- from ACTIVE
			prunable: prunable
			writable: writable
		ensure then -- from DYNAMIC_LIST
			after_when_empty: is_empty implies after
		ensure then -- from EV_DYNAMIC_LIST
			v_removed: not has (old item)
			parent_void: (old item).parent = Void
			count_decreased: count = old count - 1
			index_same: index = old index

	remove_left
			-- Remove item to left of cursor position.
			-- Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from DYNAMIC_CHAIN
			left_exists: index > 1
		ensure -- from DYNAMIC_CHAIN
			new_count: count = old count - 1
			new_index: index = old index - 1
		ensure then -- from EV_DYNAMIC_LIST
			left_neighbor_removed: not has (old i_th (index - 1))
			parent_void: (old i_th (index - 1)).parent = Void
			index_decreased: index = old index - 1

	remove_right
			-- Remove item to right of cursor position.
			-- Do not move cursor.
			-- (from EV_DYNAMIC_LIST)
		require -- from DYNAMIC_CHAIN
			right_exists: index < count
		ensure -- from DYNAMIC_CHAIN
			new_count: count = old count - 1
			same_index: index = old index
		ensure then -- from EV_DYNAMIC_LIST
			right_neighbor_removed: not has (old i_th (index + 1))
			parent_void: (old i_th (index + 1)).parent = Void
			index_same: index = old index

	wipe_out
			-- Remove all items.
			-- (from EV_DYNAMIC_LIST)
		require -- from COLLECTION
			prunable: prunable
		ensure -- from COLLECTION
			wiped_out: is_empty
		ensure then -- from DYNAMIC_LIST
			is_before: before
	
feature -- Conversion

	linear_representation: LINEAR [EV_MULTI_COLUMN_LIST_ROW]
			-- Representation as a linear structure
			-- (from LINEAR)
		require -- from  CONTAINER
			True
	
feature -- Duplication

	copy (other: like Current)
			-- Update current object using fields of object attached
			-- to `other', so as to yield equal objects.
			-- (from EV_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)

	refresh_now
			-- Force an immediate redraw of `Current'.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
	
feature -- Implementation

	changeable_comparison_criterion: BOOLEAN is False
			-- May object_comparison be changed?
			-- (Answer: no by default.
			-- (from EV_ITEM_LIST)
	
feature -- Command

	destroy
			-- Destroy underlying native toolkit object.
			-- Render `Current' unusable.
			-- (from EV_ANY)
		ensure -- from EV_ANY
			is_destroyed: is_destroyed
	
feature -- Contract support

	is_parent_recursive (a_row: EV_MULTI_COLUMN_LIST_ROW): BOOLEAN
			-- Is `a_row' a parent of `Current'?
		require -- from EV_DYNAMIC_LIST
			a_list_not_void: a_row /= Void
			not_destroyed: not is_destroyed

	parent_of_source_allows_docking: BOOLEAN
			-- Does parent of source to be transported
			-- allow current to be dragged out? (See real_source)
			-- Not all Vision2 containers are currently supported by this
			-- mechanism, only descendents of EV_DOCKABLE_TARGET
			-- are supported.
			-- (from EV_DOCKABLE_SOURCE)

	same (other: EV_ANY): BOOLEAN
			-- Is `other' `Current'?
			-- (from EV_DYNAMIC_LIST)

	source_has_current_recursive (source: EV_DOCKABLE_SOURCE): BOOLEAN
			-- Does `source' recursively contain `Current'?
			-- As seen by parenting structure.
			-- (from EV_DOCKABLE_SOURCE)
		require -- from EV_DOCKABLE_SOURCE
			not_destroyed: not is_destroyed
			source_not_void: source /= Void
	
feature -- Event handling

	column_resized_actions: EV_COLUMN_ACTION_SEQUENCE
			-- Actions to be performed when a column has been resized.
			-- (from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES)
		ensure -- from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES
			not_void: Result /= Void

	column_title_click_actions: EV_COLUMN_ACTION_SEQUENCE
			-- Actions to be performed when a column title is clicked.
			-- (from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES)
		ensure -- from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES
			not_void: Result /= Void

	conforming_pick_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when a pebble that fits here is picked.
			-- (from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES
			not_void: Result /= Void

	deselect_actions: EV_MULTI_COLUMN_LIST_ROW_SELECT_ACTION_SEQUENCE
			-- Actions to be performed when a row is deselected.
			-- (from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES)
		ensure -- from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES
			not_void: Result /= Void

	dock_ended_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed after a dock completes from `Current'.
			-- Either to a dockable target or a dockable dialog.
			-- (from EV_DOCKABLE_SOURCE_ACTION_SEQUENCES)
		ensure -- from EV_DOCKABLE_SOURCE_ACTION_SEQUENCES
			not_void: Result /= Void

	dock_started_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when a dockable source is dragged.
			-- (from EV_DOCKABLE_SOURCE_ACTION_SEQUENCES)
		ensure -- from EV_DOCKABLE_SOURCE_ACTION_SEQUENCES
			not_void: Result /= Void

	drop_actions: EV_PND_ACTION_SEQUENCE
			-- Actions to be performed when a pebble is dropped here.
			-- (from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES
			not_void: Result /= Void

	focus_in_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when keyboard focus is gained.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	focus_out_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when keyboard focus is lost.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	key_press_actions: EV_KEY_ACTION_SEQUENCE
			-- Actions to be performed when a keyboard key is pressed.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	key_press_string_actions: EV_KEY_STRING_ACTION_SEQUENCE
			-- Actions to be performed when a keyboard press generates a displayable character.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	key_release_actions: EV_KEY_ACTION_SEQUENCE
			-- Actions to be performed when a keyboard key is released.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	mouse_wheel_actions: EV_INTEGER_ACTION_SEQUENCE
			-- Actions to be performed when mouse wheel is rotated.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pick_actions: EV_PND_START_ACTION_SEQUENCE
			-- Actions to be performed when pebble is picked up.
			-- (from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES
			not_void: Result /= Void

	pick_ended_actions: EV_PND_FINISHED_ACTION_SEQUENCE
			-- Actions to be performed when a transport from `Current' ends.
			-- If transport completed successfully, then event data
			-- is target. If cancelled, then event data is Void.
			-- (from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES)
		ensure -- from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_button_press_actions: EV_POINTER_BUTTON_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer button is pressed.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_button_release_actions: EV_POINTER_BUTTON_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer button is released.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_double_press_actions: EV_POINTER_BUTTON_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer is double clicked.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_enter_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer enters widget.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_leave_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer leaves widget.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	pointer_motion_actions: EV_POINTER_MOTION_ACTION_SEQUENCE
			-- Actions to be performed when screen pointer moves.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		require -- from  EV_ABSTRACT_PICK_AND_DROPABLE
			True
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	resize_actions: EV_GEOMETRY_ACTION_SEQUENCE
			-- Actions to be performed when size changes.
			-- (from EV_WIDGET_ACTION_SEQUENCES)
		ensure -- from EV_WIDGET_ACTION_SEQUENCES
			not_void: Result /= Void

	select_actions: EV_MULTI_COLUMN_LIST_ROW_SELECT_ACTION_SEQUENCE
			-- Actions to be performed when a row is selected.
			-- (from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES)
		ensure -- from EV_MULTI_COLUMN_LIST_ACTION_SEQUENCES
			not_void: Result /= Void
	
feature -- Iteration

	do_all (action: PROCEDURE [ANY, TUPLE [EV_MULTI_COLUMN_LIST_ROW]])
			-- Apply `action' to every item.
			-- Semantics not guaranteed if `action' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			action_exists: action /= Void

	do_if (action: PROCEDURE [ANY, TUPLE [EV_MULTI_COLUMN_LIST_ROW]]; test: FUNCTION [ANY, TUPLE [EV_MULTI_COLUMN_LIST_ROW], BOOLEAN])
			-- Apply `action' to every item that satisfies `test'.
			-- Semantics not guaranteed if `action' or `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			action_exists: action /= Void
			test_exits: test /= Void

	for_all (test: FUNCTION [ANY, TUPLE [EV_MULTI_COLUMN_LIST_ROW], BOOLEAN]): BOOLEAN
			-- Is `test' true for all items?
			-- Semantics not guaranteed if `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			test_exits: test /= Void
		ensure then -- from LINEAR
			empty: is_empty implies Result

	there_exists (test: FUNCTION [ANY, TUPLE [EV_MULTI_COLUMN_LIST_ROW], BOOLEAN]): BOOLEAN
			-- Is `test' true for at least one item?
			-- Semantics not guaranteed if `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			test_exits: test /= Void
	
feature -- Measurement 

	height: INTEGER_32
			-- Vertical size in pixels.
			-- Same as minimum_height when not displayed.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.height

	minimum_height: INTEGER_32
			-- Lower bound on height in pixels.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.minimum_height
			positive_or_zero: Result >= 0

	minimum_width: INTEGER_32
			-- Lower bound on width in pixels.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.minimum_width
			positive_or_zero: Result >= 0

	width: INTEGER_32
			-- Horizontal size in pixels.
			-- Same as minimum_width when not displayed.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.width

	x_position: INTEGER_32
			-- Horizontal offset relative to parent x_position in pixels.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.x_position

	y_position: INTEGER_32
			-- Vertical offset relative to parent y_position in pixels.
			-- (from EV_POSITIONED)
		require -- from EV_POSITIONED
			not_destroyed: not is_destroyed
		ensure -- from EV_POSITIONED
			bridge_ok: Result = implementation.y_position
	
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)
	
feature -- Status Report

	is_destroyed: BOOLEAN
			-- Is `Current' no longer usable?
			-- (from EV_ANY)
		ensure -- from EV_ANY
			bridge_ok: Result = implementation.is_destroyed
	
invariant
		-- from EV_WIDGET
	pointer_position_not_void: is_usable and is_show_requested implies pointer_position /= Void
	is_displayed_implies_show_requested: is_usable and then is_displayed implies is_show_requested
	parent_contains_current: is_usable and then parent /= Void implies parent.has (Current)

		-- from EV_PICK_AND_DROPABLE
	user_interface_modes_mutually_exclusive: mode_is_pick_and_drop.to_integer + mode_is_drag_and_drop.to_integer + mode_is_target_menu.to_integer = 1

		-- from EV_ANY
	is_initialized: is_initialized
	is_coupled: implementation /= Void and then implementation.interface = Current
	default_create_called: default_create_called

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

		-- from EV_DOCKABLE_SOURCE
	parent_permits_docking: is_dockable implies parent_of_source_allows_docking

		-- from EV_COLORIZABLE
	background_color_not_void: is_usable implies background_color /= Void
	foreground_color_not_void: is_usable implies foreground_color /= Void

		-- from EV_POSITIONED
	width_not_negative: is_usable implies width >= 0
	height_not_negative: is_usable implies height >= 0
	minimum_width_not_negative: is_usable implies minimum_width >= 0
	minimum_height_not_negative: is_usable implies minimum_height >= 0

		-- from EV_ITEM_LIST
	parent_of_items_is_current: is_usable and then not is_empty implies parent_of_items_is_current
	items_unique: is_usable and not is_empty implies items_unique

		-- from LIST
	before_definition: before = (index = 0)
	after_definition: after = (index = count + 1)

		-- from CHAIN
	non_negative_index: index >= 0
	index_small_enough: index <= count + 1
	off_definition: off = ((index = 0) or (index = count + 1))
	isfirst_definition: isfirst = ((not is_empty) and (index = 1))
	islast_definition: islast = ((not is_empty) and (index = count))
	item_corresponds_to_index: (not off) implies (item = i_th (index))
	index_set_has_same_count: index_set.count = count

		-- from ACTIVE
	writable_constraint: writable implies readable
	empty_constraint: is_empty implies (not readable) and (not writable)

		-- from INDEXABLE
	index_set_not_void: index_set /= Void

		-- from BILINEAR
	not_both: not (after and before)
	before_constraint: before implies off

		-- from LINEAR
	after_constraint: after implies off

		-- from TRAVERSABLE
	empty_constraint: is_empty implies off

		-- from FINITE
	empty_definition: is_empty = (count = 0)
	non_negative_count: count >= 0

		-- from DYNAMIC_CHAIN
	extendible: extendible

		-- from EV_ITEM_PIXMAP_SCALER
	pixmaps_size_positive: pixmaps_height > 0 and pixmaps_width > 0

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_MULTI_COLUMN_LIST