indexing
	description: "Top level window. Contains a single widget.`title' is not displayed."
	appearance: " _____________ |____________X||             ||   `item'    ||_____________|"
	status: "See notice at end of class"
	keywords: "toplevel, window, popup"
	date: "$Date$"
	revision: "$Revision$"

class interface
	EV_WINDOW

create 

	frozen default_create
			-- Standard creation procedure.
			-- (from EV_ANY)
		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

	make_with_title (a_title: STRING)
			-- Initialize with a_title.
		require
			a_title_not_void: a_title /= void

feature -- Initialization

	frozen default_create
			-- Standard creation procedure.
			-- (from EV_ANY)
		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_CURSOR
			-- Result is cursor displayed when the screen pointer is over a
			-- target that accepts pebble during pick and drop.
			-- (from EV_PICK_AND_DROPABLE)
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.accept_cursor

	actual_drop_target_agent: FUNCTION [ANY, TUPLE [INTEGER, INTEGER], 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)

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

	deny_cursor: EV_CURSOR
			-- 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)
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.deny_cursor

	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)

	has_recursive (an_item: like item): BOOLEAN
			-- Does structure include an_item or
			-- does any structure recursively included by structure,
			-- include an_item.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed

	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

	frozen id_object (an_id: INTEGER): 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

	is_parent_recursive (a_widget: EV_WIDGET): BOOLEAN
			-- Is a_widget parent, or recursively, parent of parent.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed

	item: EV_WIDGET
			-- Current item.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
			readable: readable
		ensure -- from EV_CONTAINER
			bridge_ok: Result = implementation.item

	lower_bar: EV_VERTICAL_BOX
			-- Room at bottom of window. (Example use: statusbar.)
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.lower_bar

	maximum_height: INTEGER
			-- Upper bound on height in pixels.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: (Result = implementation.internal_maximum_height) or (Result = implementation.minimum_height)

	maximum_width: INTEGER
			-- Upper bound on width in pixels.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: (Result = implementation.internal_maximum_width) or (Result = implementation.minimum_width)

	menu_bar: EV_MENU_BAR
			-- Horizontal bar at top of client area that contains menu's.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.menu_bar

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

	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)
		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)
		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
			-- Initial x position for pick and drop relative to Current.
			-- (from EV_PICK_AND_DROPABLE)
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_x_position

	pebble_y_position: INTEGER
			-- Initial y position for pick and drop relative to Current.
			-- (from EV_PICK_AND_DROPABLE)
		ensure then -- from EV_PICK_AND_DROPABLE
			bridge_ok: Result = implementation.pebble_y_position

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

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

	title: STRING
			-- A textual name used by the window manager.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: equal (Result, implementation.title)

	upper_bar: EV_VERTICAL_BOX
			-- Room at top of window. (Example use: toolbars.)
			-- Positioned below menu bar.
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.upper_bar
	
feature -- Measurement

	client_height: INTEGER
			-- Height of the area available to children in pixels.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
		ensure -- from EV_CONTAINER
			bridge_ok: Result = implementation.client_height

	client_width: INTEGER
			-- Width of the area available to children in pixels.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
		ensure -- from EV_CONTAINER
			bridge_ok: Result = implementation.client_width

	height: INTEGER
			-- 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
			-- 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
			-- 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

	screen_x: INTEGER
			-- 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
			-- 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

	width: INTEGER
			-- 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
			-- 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
			-- 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 -- Status report

	count: INTEGER
			-- Number of items in Current.
			-- (from EV_CELL)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
		ensure then -- from EV_CELL
			valid_result: Result = 0 or Result = 1

	extendible: BOOLEAN
			-- Is there no element?
			-- Was declared in EV_CELL as synonym of is_empty.
			-- (from EV_CELL)

	full: BOOLEAN
			-- Is structure filled to capacity?
			-- (from EV_CELL)

	has (v: EV_WIDGET): BOOLEAN
			-- Does structure include v?
		ensure -- from CONTAINER
			not_found_in_empty: Result implies not is_empty

	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_empty: BOOLEAN
			-- Is there no element?
			-- Was declared in EV_CELL as synonym of extendible.
			-- (from EV_CELL)

	is_inserted (v: EV_WIDGET): 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_modal: BOOLEAN
			-- Must the window be closed before application can
			-- receive user events again?
			--
			-- May be redefined in EV_DIALOG to return
			-- a different value
		require
			not_destroyed: not is_destroyed

	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

	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

	prunable: BOOLEAN
			-- May items be removed?
			-- (from EV_CELL)

	readable: BOOLEAN
			-- Is there a current item that may be accessed?
			-- (from EV_CELL)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed

	user_can_resize: BOOLEAN
			-- Can the user resize?
		require
			not_destroyed: not is_destroyed
		ensure
			bridge_ok: Result = implementation.user_can_resize

	writable: BOOLEAN
			-- Is there a current item that may be modified?
			-- (from EV_CELL)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
	
feature -- Status setting

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

	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_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

	disable_user_resize
			-- Prevent user from resizing.
		require
			not_destroyed: not is_destroyed
		ensure
			not_user_can_resize: not user_can_resize

	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_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

	enable_user_resize
			-- Allow user to resize.
		require
			not_destroyed: not is_destroyed
		ensure
			user_can_resize: user_can_resize

	hide
			-- Request that Current not be displayed even when its parent is.
			-- Make is_show_requested False.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			not_is_show_requested: not is_show_requested

	lock_update
			-- Lock drawing updates for this window on certain platforms until
			-- unlock_update is called.
			--
			-- Note: - Only one window can be locked at a time.
			--       - The window cannot be moved while update is locked.
		require
			not_destroyed: not is_destroyed
			no_locked_window: ((create {EV_ENVIRONMENT}).application.locked_window = void)
		ensure
			locked_window_is_current: (create {EV_ENVIRONMENT}).application.locked_window = Current

	merge_radio_button_groups (other: EV_CONTAINER)
			-- Merge Current radio button group with that of other.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
			other_not_void: other /= void

	remove_menu_bar
			-- Make menu_bar Void.
		require
			not_destroyed: not is_destroyed
		ensure
			void: menu_bar = 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_title
			-- Make title Void.
		require
			not_destroyed: not is_destroyed
		ensure
			a_title_removed: title = void

	set_accept_cursor (a_cursor: EV_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)
		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_deny_cursor (a_cursor: EV_CURSOR)
			-- Set a_cursor to be displayed when the screen pointer is not
			-- over a valid target.
			-- (from EV_PICK_AND_DROPABLE)
		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
		ensure -- from EV_WIDGET
			has_focus: has_focus

	set_height (a_height: INTEGER)
			-- Assign a_height to height in pixels.
			-- (from EV_POSITIONABLE)
		require -- from EV_POSITIONABLE
			a_height_positive_or_zero: a_height >= 0
		ensure -- from EV_POSITIONABLE
			height_assigned: height = minimum_height or else height = a_height

	set_maximum_height (a_maximum_height: INTEGER)
			-- Assign a_maximum_height to maximum_height in pixels.
		require
			not_destroyed: not is_destroyed
			a_maximum_height_non_negative: a_maximum_height >= 0
			a_maximum_height_not_less_than_minimum_height: a_maximum_height >= minimum_height
		ensure
			maximum_height_assigned: maximum_height = a_maximum_height

	set_maximum_size (a_maximum_width, a_maximum_height: INTEGER)
			-- Assign a_maximum_width to maximum_width
			-- and a_maximum_height to maximum_height in pixels.
		require
			not_destroyed: not is_destroyed
			a_maximum_width_not_less_than_minimum_width: a_maximum_width >= minimum_width
			a_maximum_height_not_less_than_minimum_height: a_maximum_height >= minimum_height
		ensure
			maximum_width_assigned: maximum_width = a_maximum_width
			maximum_height_assigned: maximum_height = a_maximum_height

	set_maximum_width (a_maximum_width: INTEGER)
			-- Assign a_maximum_width to maximum_width in pixels.
		require
			not_destroyed: not is_destroyed
			a_maximum_width_non_negative: a_maximum_width >= 0
			a_maximum_width_not_less_than_minimum_width: a_maximum_width >= minimum_width
		ensure
			maximum_width_assigned: maximum_width = a_maximum_width

	set_menu_bar (a_menu_bar: EV_MENU_BAR)
			-- Assign a_menu_bar to menu_bar.
		require
			not_destroyed: not is_destroyed
			no_menu_bar_assigned: menu_bar = void
			a_menu_bar_not_void: a_menu_bar /= void
		ensure
			assigned: menu_bar = a_menu_bar

	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)
			-- 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_position (a_x, a_y: INTEGER)
			-- Assign a_x to x_position and a_y to y_position in pixels.
			-- (from EV_POSITIONABLE)
		ensure -- from EV_POSITIONABLE
			x_position_assigned: x_position = a_x
			y_position_assigned: y_position = a_y

	set_size (a_width, a_height: INTEGER)
			-- Assign a_width to width and a_height to height in pixels.
			-- (from EV_POSITIONABLE)
		require -- from EV_POSITIONABLE
			a_width_positive_or_zero: a_width >= 0
			a_height_positive_or_zero: a_height >= 0
		ensure -- from EV_POSITIONABLE
			width_assigned: width = minimum_width or else width = a_width
			height_assigned: height = minimum_height or else height = a_height

	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)
			-- 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)

	set_title (a_title: STRING)
			-- Assign a_title to title.
		require
			not_destroyed: not is_destroyed
			a_title_not_void: a_title /= void
			a_title_not_empty: not a_title.is_empty
		ensure
			a_title_assigned: title.is_equal (a_title)

	set_width (a_width: INTEGER)
			-- Assign a_width to width in pixels.
			-- (from EV_POSITIONABLE)
		require -- from EV_POSITIONABLE
			a_width_positive_or_zero: a_width >= 0
		ensure -- from EV_POSITIONABLE
			width_assigned: width = minimum_width or else width = a_width

	set_x_position (a_x: INTEGER)
			-- Assign a_x to x_position in pixels.
			-- (from EV_POSITIONABLE)
		ensure -- from EV_POSITIONABLE
			x_position_assigned: x_position = a_x

	set_y_position (a_y: INTEGER)
			-- Assign a_y to y_position in pixels.
			-- (from EV_POSITIONABLE)
		ensure -- from EV_POSITIONABLE
			y_position_assigned: y_position = a_y

	show
			-- Request that Current be displayed when its parent is.
			-- True by default.
			-- Make is_show_requested True.
			-- (from EV_WIDGET)
		require -- from EV_WIDGET
			not_destroyed: not is_destroyed
		ensure -- from EV_WIDGET
			is_show_requested: is_show_requested

	unlock_update
			-- Unlock updates for this widget on certain platforms.
		require
			not_destroyed: not is_destroyed
			locked_window_is_current: (create {EV_ENVIRONMENT}).application.locked_window = Current
		ensure
			no_locked_window: ((create {EV_ENVIRONMENT}).application.locked_window = void)
	
feature -- Element change

	extend (v: like item)
			-- Ensure that structure includes v.
			-- Do not move cursor.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
			extendible: extendible
			v_not_void: v /= void
			v_parent_void: v.parent = void
			v_not_current: v /= Current
			v_not_parent_of_current: not is_parent_recursive (v)
			v_not_window: not v.conforms_to (create {EV_WINDOW})
		ensure -- from EV_CONTAINER
			has_v: has (v)

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

	put (v: like item)
			-- Replace item with v.
			-- Was declared in EV_CONTAINER as synonym of replace.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
			writable: writable
			v_not_void: v /= void
			v_parent_void: v.parent = void
			v_not_current: v /= Current
			v_not_parent_of_current: not is_parent_recursive (v)
			v_not_window: not v.conforms_to (create {EV_WINDOW})
		ensure -- from EV_CONTAINER
			has_v: has (v)

	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

	replace (v: like item)
			-- Replace item with v.
			-- Was declared in EV_CONTAINER as synonym of put.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
			writable: writable
			v_not_void: v /= void
			v_parent_void: v.parent = void
			v_not_current: v /= Current
			v_not_parent_of_current: not is_parent_recursive (v)
			v_not_window: not v.conforms_to (create {EV_WINDOW})
		ensure -- from EV_CONTAINER
			has_v: has (v)

	set_background_color (a_color: like background_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
			background_color_assigned: background_color.is_equal (a_color)

	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)
			-- Set a_minimum_height in pixels to minimum_height.
			-- If height is less than a_minimim_height, resize.
			-- This setting takes effect next time application is idle.
			-- 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

	set_minimum_size (a_minimum_width, a_minimum_height: INTEGER)
			-- 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.
			-- This setting takes effect next time application is idle.
			-- 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

	set_minimum_width (a_minimum_width: INTEGER)
			-- Assign a_minimum_width in pixels to minimum_width.
			-- If width is less than a_minimim_width, resize.
			-- This setting takes effect next time application is idle.
			-- 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

	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)
	
feature -- Removal

	prune (v: EV_WIDGET)
			-- Remove v if contained.
			-- (from EV_CELL)
		require -- from COLLECTION
			prunable: prunable
		ensure then -- from EV_CELL
			not has (v)

	prune_all (v: EV_WIDGET)
			-- Remove all occurrences of v.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from COLLECTION)
		require -- from COLLECTION
			prunable
		ensure -- from COLLECTION
			no_more_occurrences: not has (v)

	wipe_out
			-- Remove item.
			-- (from EV_CELL)
		require -- from COLLECTION
			prunable
		ensure -- from COLLECTION
			wiped_out: is_empty
	
feature -- Conversion

	linear_representation: LINEAR [like item]
			-- Representation as a linear structure
			-- (from EV_CELL)
	
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)
	
feature -- Basic operations

	propagate_background_color
			-- Propagate background_color to all children.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
		ensure -- from EV_CONTAINER
			background_color_propagated: background_color_propagated

	propagate_foreground_color
			-- Propagate foreground_color to all children.
			-- (from EV_CONTAINER)
		require -- from EV_CONTAINER
			not_destroyed: not is_destroyed
		ensure -- from EV_CONTAINER
			foreground_color_propagated: foreground_color_propagated
	
feature -- Command

	destroy
			-- Destroy underlying native toolkit object.
			-- Render Current unusable.
			-- (from EV_ANY)
		ensure -- from EV_ANY
			is_destroyed: is_destroyed
	
feature -- Event handling

	close_request_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed whan a request to close window
			-- has been received.
			-- (from EV_WINDOW_ACTION_SEQUENCES)
		ensure -- from EV_WINDOW_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)
		ensure -- from EV_PICK_AND_DROPABLE_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)
		ensure -- from EV_PICK_AND_DROPABLE_ACTION_SEQUENCES
			not_void: Result /= void

	focus_in_actions: EV_FOCUS_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_FOCUS_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

	move_actions: EV_GEOMETRY_ACTION_SEQUENCE
			-- Actions to be performed when window moves.
			-- (from EV_WINDOW_ACTION_SEQUENCES)
		ensure -- from EV_WINDOW_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)
		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)
		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

	show_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when window is shown.
			-- (from EV_WINDOW_ACTION_SEQUENCES)
		ensure -- from EV_WINDOW_ACTION_SEQUENCES
			not_void: Result /= void
	
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

	consistent_horizontal_bounds: maximum_width >= minimum_width
	consistent_vertical_bounds: maximum_height >= minimum_height
	upper_bar_not_void: is_usable implies upper_bar /= void
	lower_bar_not_void: is_usable implies lower_bar /= void
		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)
		-- from EV_CONTAINER
	client_width_within_bounds: is_usable implies client_width >= 0 and client_width <= width
	client_height_within_bounds: is_usable implies client_height >= 0 and client_height <= height
	all_radio_buttons_connected: is_usable implies all_radio_buttons_connected
	parent_of_items_is_current: is_usable implies parent_of_items_is_current
	items_unique: is_usable implies items_unique
		-- 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 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

end -- class EV_WINDOW