    indexing
    	description: "EiffelVision question dialog."
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	date: "$Date: 2006-01-22 18:25:44 -0800 (Sun, 22 Jan 2006) $"
    	revision: "$Revision: 56675 $"

    class interface
    	EV_QUESTION_DIALOG

    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

    	make_with_text (a_text: STRING_GENERAL)
    			-- Create `Current' and assign `a_text' to text.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			a_text_not_void: a_text /= Void

    	make_with_text_and_actions (a_text: STRING_GENERAL; actions: ARRAY [PROCEDURE [ANY, TUPLE]])
    			-- Create `Current', assign `a_text' to text and `actions' to `select_actions'
    			-- of buttons.
    			-- (`actions' are added to buttons in order.)
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			a_text_not_void: a_text /= Void
    			actions_not_void: actions /= Void
    			actions_not_empty: actions.count > 0

    feature -- Access

    	accelerators: EV_ACCELERATOR_LIST
    			-- Key combination shortcuts associated with this window.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			bridge_ok: Result = implementation.accelerator_list
    			not_void: Result /= Void

    	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
    			-- Background color of `Current'.
    			-- (from EV_MESSAGE_DIALOG)

    	background_pixmap: EV_PIXMAP
    			-- `Result' is pixmap displayed on background of `Current'.
    			-- It is tessellated and fills whole of `Current'.
    			-- (from EV_CONTAINER)
    		require -- from EV_PIXMAPABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_PIXMAPABLE
    			bridge_ok: (Result = Void and implementation.background_pixmap = Void) or Result.is_equal (implementation.background_pixmap)

    	blocking_window: EV_WINDOW
    			-- `Result' is window `Current' is shown to if
    			-- is_modal or is_relative.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DIALOG
    			bridge_ok: Result = implementation.blocking_window

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

    	default_cancel_button: EV_BUTTON
    			-- Default cancel button. This is the button that
    			-- is pushed if the user press the escape key or
    			-- close the window using the close icon.
    			-- If there is no default cancel button, the close
    			-- icon is disabled.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed

    	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

    	default_push_button: EV_BUTTON
    			-- Default pushed button. This is the button that
    			-- is pushed if the user press the enter key unless
    			-- a push button is currently focused.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed

    	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

    	foreground_color: EV_COLOR
    			-- Foreground color of `Current'.
    			-- (from EV_MESSAGE_DIALOG)

    	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_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

    	icon_name: STRING_32
    			-- Name displayed when `Current is minimized.
    			-- If is_empty then title is displayed.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			bridge_ok: equal (Result, implementation.icon_name)
    			result_not_void: Result /= Void
    			cloned: Result /= implementation.icon_name

    	icon_pixmap: EV_PIXMAP
    			-- Window icon.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			bridge_ok: Result.is_equal (implementation.icon_pixmap)

    	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

    	is_docking_enabled: BOOLEAN
    			-- May `Current' be docked to?
    			-- If True, `Current' will accept docking
    			-- from a compatible EV_DOCKABLE_SOURCE.
    			-- (from EV_DOCKABLE_TARGET)
    		require -- from EV_DOCKABLE_TARGET
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DOCKABLE_TARGET
    			bridge_ok: Result = implementation.is_docking_enabled

    	is_modal: BOOLEAN
    			-- Is `Current' shown modally to another window?
    			-- If `True' then `Current' must be closed before
    			-- application can receive user events again?
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed

    	is_relative: BOOLEAN
    			-- Is `Current' shown relative to another window?
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			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.)
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			bridge_ok: Result = implementation.lower_bar

    	maximum_dimension: INTEGER_32 is 32000
    			-- Maximum width/height that a window can be set to.
    			-- (from EV_WINDOW)

    	maximum_height: INTEGER_32
    			-- Upper bound on height in pixels.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			bridge_ok: (Result = implementation.internal_maximum_height) or (Result = implementation.minimum_height)

    	maximum_width: INTEGER_32
    			-- Upper bound on width in pixels.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			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.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			bridge_ok: Result = implementation.menu_bar

    	frozen object_id: INTEGER_32
    			-- 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)
    		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

    	pixmap: EV_PIXMAP
    			-- Icon displayed by `Current'.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed

    	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

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

    	text: STRING_32
    			-- Message displayed by `Current'.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    		ensure -- from EV_MESSAGE_DIALOG
    			not_void: Result /= Void

    	title: STRING_32
    			-- A textual name used by the window manager.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			bridge_ok: equal (Result, implementation.title)
    			not_void: Result /= Void
    			cloned: Result /= implementation.title

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

    	veto_dock_function: FUNCTION [ANY, TUPLE [EV_DOCKABLE_SOURCE], BOOLEAN]
    			-- Function to determine whether current dock is allowed.
    			-- If `Result' is `True', dock will be disallowed.
    			-- (from EV_DOCKABLE_TARGET)
    		require -- from EV_DOCKABLE_TARGET
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DOCKABLE_TARGET
    			bridge_ok: Result = implementation.veto_dock_function

    feature -- Measurement

    	client_height: INTEGER_32
    			-- 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_32
    			-- 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

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

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

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

    feature -- Status report

    	button (a_text: STRING_GENERAL): EV_BUTTON
    			-- Button that has `a_text'.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void
    			has_button_with_a_text: has_button (a_text)
    		ensure -- from EV_MESSAGE_DIALOG
    			not_void: Result /= Void

    	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

    	count: INTEGER_32
    			-- 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'?
    			-- (from EV_WINDOW)
    		require -- from  CONTAINER
    			True
    		ensure -- from CONTAINER
    			not_found_in_empty: Result implies not is_empty

    	has_button (a_text: STRING_GENERAL): BOOLEAN
    			-- Does `Current' contain a button with text `a_text'?
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void

    	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

    	frozen id_freed: BOOLEAN
    			-- Has `Current' been removed from the table?
    			-- (from IDENTIFIED)

    	is_border_enabled: BOOLEAN
    			-- Is a border displayed around `Current'?
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed

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

    	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_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_maximized: BOOLEAN
    			-- Is displayed at maximum size?
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			bridge_ok: Result = implementation.is_maximized

    	is_minimized: BOOLEAN
    			-- Is displayed iconified/minimised?
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			bridge_ok: Result = implementation.is_minimized

    	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

    	merged_radio_button_groups: ARRAYED_LIST [EV_CONTAINER]
    			-- `Result' is all other radio button groups
    			-- merged with `Current'. Void if no other containers
    			-- are merged.
    			-- (from EV_CONTAINER)
    		require -- from EV_CONTAINER
    			not_destroyed: not is_destroyed
    		ensure -- from EV_CONTAINER
    			not_is_empty: Result /= Void implies not Result.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

    	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

    	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))

    	selected_button: STRING_32
    			-- Label of last clicked button.
    			-- (from EV_MESSAGE_DIALOG)

    	user_can_resize: BOOLEAN
    			-- Can the user resize?
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			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_border
    			-- Ensure no border is displayed around `Current'.
    			-- Has no immediate effect if user_can_resize, although
    			-- is reflected at next call to disable_user_resize.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			border_disabled: not user_can_resize implies not is_border_enabled

    	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_docking
    			-- Ensure is_docking_enabled is False.
    			-- `Current' will not accept docking.
    			-- (from EV_DOCKABLE_TARGET)
    		require -- from EV_DOCKABLE_TARGET
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DOCKABLE_TARGET
    			not_dockable: not is_docking_enabled

    	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_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.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			not_user_can_resize: not user_can_resize

    	enable_border
    			-- Ensure a border is displayed around `Current'.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			is_border_enabled: is_border_enabled

    	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_docking
    			-- Ensure is_docking_enabled is True.
    			-- (from EV_DOCKABLE_TARGET)
    		require -- from EV_DOCKABLE_TARGET
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DOCKABLE_TARGET
    			is_dockable: is_docking_enabled

    	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_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.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			user_can_resize: user_can_resize

    	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

    	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.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    			no_locked_window: ((create {EV_ENVIRONMENT}).application.locked_window = Void)
    		ensure -- from EV_WINDOW
    			locked_window_is_current: (create {EV_ENVIRONMENT}).application.locked_window = Current

    	lower
    			-- Request that window be displayed below all other windows.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed

    	maximize
    			-- Display at maximum size.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    			shown: is_show_requested
    		ensure -- from EV_TITLED_WINDOW
    			is_maximized: is_maximized

    	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

    	minimize
    			-- Display iconified/minimised.
    			-- It is not possible to guarantee this on some
    			-- platform configurations.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    			shown: is_show_requested
    		ensure -- from EV_TITLED_WINDOW
    			not_displayed: not is_displayed

    	raise
    			-- Request that window be displayed above all other windows.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed

    	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_menu_bar
    			-- Make menu_bar `Void'.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			menu_bar_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_pixmap
    			-- Assign `Void' to pixmap.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    		ensure -- from EV_MESSAGE_DIALOG
    			pixmap_void: pixmap = 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_text
    			-- Make text empty.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    		ensure -- from EV_MESSAGE_DIALOG
    			text_not_void: text /= Void and text.is_empty

    	remove_title
    			-- Make title empty.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_WINDOW
    			title_empty: title.is_empty

    	restore
    			-- Restore to original position when minimized or maximized.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			minimize_restored: old is_minimized implies not is_minimized
    			maximize_restored: old is_maximized implies not is_maximized

    	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_background_color (a_color: EV_COLOR)
    			-- Assign `a_color' to background_color.
    			-- (from EV_MESSAGE_DIALOG)
    		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_buttons (button_labels: ARRAY [STRING_GENERAL])
    			-- Assign new buttons with `button_labels' to buttons.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			button_labels_not_void: button_labels /= Void
    			all_button_labels_items_not_void: button_labels.occurrences (Void) = 0

    	set_buttons_and_actions (button_labels: ARRAY [STRING_GENERAL]; actions: ARRAY [PROCEDURE [ANY, TUPLE]])
    			-- Assign new buttons with `button_labels' and `actions' to buttons.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			button_labels_not_void: button_labels /= Void
    			actions_not_void: actions /= Void
    			all_button_labels_items_not_void: button_labels.occurrences (Void) = 0
    			enough_actions_for_labels: actions.count >= button_labels.count

    	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_foreground_color (a_color: EV_COLOR)
    			-- Assign `a_color' to foreground_color.
    			-- (from EV_MESSAGE_DIALOG)
    		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_height (a_height: INTEGER_32)
    			-- Assign `a_height' to height in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    			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_32)
    			-- Assign `a_maximum_height' to maximum_height in pixels.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			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
    			a_maximum_height_not_greater_than_maximum_dimension: a_maximum_height <= maximum_dimension
    		ensure -- from EV_WINDOW
    			maximum_height_assigned: maximum_height = a_maximum_height

    	set_maximum_size (a_maximum_width, a_maximum_height: INTEGER_32)
    			-- Assign `a_maximum_width' to maximum_width
    			-- and `a_maximum_height' to maximum_height in pixels.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			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
    			a_maximum_width_not_greater_than_maximum_dimension: a_maximum_width <= maximum_dimension
    			a_maximum_height_not_greater_than_maximum_dimension: a_maximum_height <= maximum_dimension
    		ensure -- from EV_WINDOW
    			maximum_width_assigned: maximum_width = a_maximum_width
    			maximum_height_assigned: maximum_height = a_maximum_height

    	set_maximum_width (a_maximum_width: INTEGER_32)
    			-- Assign `a_maximum_width' to maximum_width in pixels.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			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
    			a_maximum_width_not_greater_than_maximum_dimension: a_maximum_width <= maximum_dimension
    		ensure -- from EV_WINDOW
    			maximum_width_assigned: maximum_width = a_maximum_width

    	set_menu_bar (a_menu_bar: EV_MENU_BAR)
    			-- Assign `a_menu_bar' to menu_bar.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    			no_menu_bar_assigned: menu_bar = Void
    			a_menu_bar_not_void: a_menu_bar /= Void
    			a_menu_bar_not_parented: a_menu_bar.parent = Void
    		ensure -- from EV_WINDOW
    			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_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_pixmap (a_pixmap: EV_PIXMAP)
    			-- Assign `a_pixmap' to pixmap.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			a_pixmap_not_void: a_pixmap /= Void
    		ensure -- from EV_MESSAGE_DIALOG
    			pixmap_assigned: pixmap.is_equal (a_pixmap)

    	set_position (a_x, a_y: INTEGER_32)
    			-- Assign `a_x' to x_position and `a_y' to y_position in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_POSITIONABLE
    			x_position_assigned: x_position = a_x
    			y_position_assigned: y_position = a_y

    	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_size (a_width, a_height: INTEGER_32)
    			-- Assign `a_width' to width and `a_height' to height in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    			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_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)

    	set_text (a_text: STRING_GENERAL)
    			-- Assign `a_text' to text.
    			-- (from EV_MESSAGE_DIALOG)
    		require -- from EV_MESSAGE_DIALOG
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void
    		ensure -- from EV_MESSAGE_DIALOG
    			assigned: text.is_equal (a_text)
    			cloned: text /= a_text

    	set_title (a_title: STRING_GENERAL)
    			-- Assign `a_title' to title.
    			-- (from EV_WINDOW)
    		require -- from EV_WINDOW
    			not_destroyed: not is_destroyed
    			a_title_not_void: a_title /= Void
    		ensure -- from EV_WINDOW
    			a_title_assigned: title.is_equal (a_title)
    			cloned: title /= a_title

    	set_veto_dock_function (a_function: FUNCTION [ANY, TUPLE [EV_DOCKABLE_SOURCE], BOOLEAN])
    			-- Assign `a_function' to veto_dock_function.
    			-- (from EV_DOCKABLE_TARGET)
    		require -- from EV_DOCKABLE_TARGET
    			not_destroyed: not is_destroyed
    			a_function_not_void: a_function /= Void
    		ensure -- from EV_DOCKABLE_TARGET
    			veto_function_set: veto_dock_function = a_function

    	set_width (a_width: INTEGER_32)
    			-- Assign `a_width' to width in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    			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_32)
    			-- Assign `a_x' to x_position in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_POSITIONABLE
    			x_position_assigned: x_position = a_x

    	set_y_position (a_y: INTEGER_32)
    			-- Assign `a_y' to y_position in pixels.
    			-- (from EV_POSITIONABLE)
    		require -- from EV_POSITIONABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_POSITIONABLE
    			y_position_assigned: y_position = a_y

    	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

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

    	unmerge_radio_button_groups (other: EV_CONTAINER)
    			-- Remove `other' from radio button group of `Current'.
    			-- If no radio button of `other' was checked before removal
    			-- then first radio button contained will be checked.
    			-- (from EV_CONTAINER)
    		require -- from EV_CONTAINER
    			not_destroyed: not is_destroyed
    			other_is_merged: merged_radio_button_groups.has (other)
    		ensure -- from EV_CONTAINER
    			other_not_merged: other.merged_radio_button_groups = Void
    			not_contained_in_this_group: merged_radio_button_groups /= Void implies not merged_radio_button_groups.has (other)
    			other_first_radio_button_now_selected: not old other.has_selected_radio_button and old other.has_radio_button implies other.first_radio_button_selected
    			original_radio_button_still_selected: old has_selected_radio_button implies has_selected_radio_button
    			other_first_radio_button_now_selected: not old has_selected_radio_button and old other.has_radio_button and old merged_radio_button_groups.count = 1 and has_radio_button implies first_radio_button_selected
    			other_original_radio_button_still_selected: old other.has_selected_radio_button implies other.has_selected_radio_button

    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_containable: may_contain (v)
    		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: 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_containable: may_contain (v)
    		ensure -- from EV_CONTAINER
    			has_v: has (v)
    			not_has_old_item: not has (old item)

    	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_icon_name
    			-- Make icon_name empty.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    		ensure -- from EV_TITLED_WINDOW
    			icon_name_removed: icon_name.is_empty

    	remove_background_pixmap
    			-- Remove image displayed on `Current'.
    			-- (from EV_PIXMAPABLE)
    		require -- from EV_PIXMAPABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_PIXMAPABLE
    			pixmap_removed: background_pixmap = 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_containable: may_contain (v)
    		ensure -- from EV_CONTAINER
    			has_v: has (v)
    			not_has_old_item: not has (old item)

    	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_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_icon_name (an_icon_name: STRING_GENERAL)
    			-- Assign `an_icon_name' to icon_name.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    			an_icon_name_not_void: an_icon_name /= Void
    		ensure -- from EV_TITLED_WINDOW
    			icon_name_assigned: icon_name.is_equal (an_icon_name)
    			cloned: icon_name /= an_icon_name

    	set_icon_pixmap (an_icon: EV_PIXMAP)
    			-- Assign `an_icon' to `icon'.
    			-- (from EV_TITLED_WINDOW)
    		require -- from EV_TITLED_WINDOW
    			not_destroyed: not is_destroyed
    			pixmap_not_void: an_icon /= Void
    		ensure -- from EV_TITLED_WINDOW
    			icon_pixmap_assigned: icon_pixmap.is_equal (an_icon)

    	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_background_pixmap (a_pixmap: EV_PIXMAP)
    			-- Display image of `a_pixmap' on `Current'.
    			-- Image of pixmap will be a copy of `a_pixmap'.
    			-- Image may be scaled in some descendents, i.e EV_TREE_ITEM
    			-- See EV_TREE.set_pixmaps_size.
    			-- (from EV_PIXMAPABLE)
    		require -- from EV_PIXMAPABLE
    			not_destroyed: not is_destroyed
    			pixmap_not_void: a_pixmap /= Void

    	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

    	frozen free_id
    			-- Free the entry associated with object_id if any
    			-- (from IDENTIFIED)
    		ensure -- from IDENTIFIED
    			object_freed: id_freed

    	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: prunable
    		ensure -- from COLLECTION
    			no_more_occurrences: not has (v)

    	wipe_out
    			-- Remove item.
    			-- (from EV_CELL)
    		require -- from COLLECTION
    			prunable: 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)

    	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)

    	dialog_key_press_action (a_key: EV_KEY)
    			-- The action performed to process default push and cancel
    			-- buttons. This is inserted in key_press_actions and
    			-- behaves as follows:
    			-- If escape is pressed at any time then
    			-- If there is a default_cancel_button then
    			-- If it is sensitive, call its `select_actions',
    			-- otherwise, close the dialog.
    			-- If there is no default_cancel_button, do nothing.
    			-- If enter is pressed at any time then
    			-- If a push button is currently focused then call its
    			-- `select_actions'. If no push button has the focus, then
    			-- call the `select_actions' of the default push button if
    			-- it is sensitive.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed

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

    	propagate_background_color
    			-- Propagate background_color recursively, 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 recursively, 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

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

    	show_modal_to_window (a_window: EV_WINDOW)
    			-- Show and wait until `Current' is closed.
    			-- `Current' is shown modal with respect to `a_window'.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    			dialog_modeless: not is_modal
    			a_window_not_void: a_window /= Void
    			a_window_not_current: a_window /= Current
    		ensure -- from EV_DIALOG
    			dialog_closed_so_no_blocking_window: not is_destroyed implies blocking_window = Void

    	show_relative_to_window (a_window: EV_WINDOW)
    			-- Show `Current' with respect to `a_window'.
    			-- (from EV_DIALOG)
    		require -- from EV_WINDOW
    			not_void: a_window /= Void
    			not_destroyed: not is_destroyed
    			parent_not_destroyed: not a_window.is_destroyed
    			a_window_not_current: a_window /= Current
    		ensure then -- from EV_DIALOG
    			is_relative_to_window: is_relative
    			blocking_window_set: blocking_window = a_window

    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_widget: EV_WIDGET): BOOLEAN
    			-- Is `a_widget' parent, or recursivly, parent of parent.
    			-- (from EV_CONTAINER)
    		require -- from EV_CONTAINER
    			not_destroyed: not is_destroyed

    	may_contain (v: EV_WIDGET): BOOLEAN
    			-- May `v' be inserted in `Current'.
    			-- Instances of EV_WINDOW may not be inserted
    			-- in a container even though they are widgets.
    			-- (from EV_CONTAINER)

    	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)

    	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

    	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

    	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

    	docked_actions: EV_DOCKABLE_SOURCE_ACTION_SEQUENCE
    			-- Actions to be performed when a dockable source completes a transport
    			-- Fired only if source has been moved, after parenting.
    			-- (from EV_DOCKABLE_TARGET_ACTION_SEQUENCES)
    		ensure -- from EV_DOCKABLE_TARGET_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

    	maximize_actions: EV_NOTIFY_ACTION_SEQUENCE
    			-- Actions to be performed when window is maximized.
    			-- (from EV_TITLED_WINDOW_ACTION_SEQUENCES)
    		ensure -- from EV_TITLED_WINDOW_ACTION_SEQUENCES
    			not_void: Result /= Void

    	minimize_actions: EV_NOTIFY_ACTION_SEQUENCE
    			-- Actions to be performed when window is minimized.
    			-- (from EV_TITLED_WINDOW_ACTION_SEQUENCES)
    		ensure -- from EV_TITLED_WINDOW_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

    	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)
    		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

    	restore_actions: EV_NOTIFY_ACTION_SEQUENCE
    			-- Actions to be performed when window leaves `maximized' or
    			-- `minimized' state.
    			-- (from EV_TITLED_WINDOW_ACTION_SEQUENCES)
    		ensure -- from EV_TITLED_WINDOW_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 -- 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

    feature -- Status Setting

    	remove_default_cancel_button
    			-- Remove default_cancel_button.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    			has_default_cancel_button: default_cancel_button /= Void
    		ensure -- from EV_DIALOG
    			not_has_default_cancel_button: default_cancel_button = Void

    	remove_default_push_button
    			-- Remove default_push_button.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    			has_default_push_button: default_push_button /= Void
    		ensure -- from EV_DIALOG
    			not_has_default_push_button: default_push_button = Void

    	set_default_cancel_button (a_button: EV_BUTTON)
    			-- Assign `a_button' to default_cancel_button.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    			a_button_not_void: a_button /= Void
    			has_button: has_recursive (a_button)
    		ensure -- from EV_DIALOG
    			default_cancel_button_set: default_cancel_button = a_button

    	set_default_push_button (a_button: EV_BUTTON)
    			-- Assign `a_button' to `default push button'.
    			-- (from EV_DIALOG)
    		require -- from EV_DIALOG
    			not_destroyed: not is_destroyed
    			a_button_not_void: a_button /= Void
    			has_button: has_recursive (a_button)
    		ensure -- from EV_DIALOG
    			default_push_button_set: default_push_button = a_button

    invariant
    		-- from EV_DIALOG
    	modal_or_relative: is_usable implies (is_modal implies not is_relative and is_relative implies not is_modal)
    	blocking_window_correct: is_usable implies (is_modal or is_relative implies blocking_window /= Void)
    	no_blocking_window_correct: is_usable implies (not is_modal and not is_relative implies blocking_window = Void)
    	no_blocking_window_when_hidden: is_usable implies (not is_show_requested implies blocking_window = Void)

    		-- from EV_TITLED_WINDOW
    	accelerators_not_void: is_usable implies accelerators /= Void

    		-- from EV_WINDOW
    	consistent_horizontal_bounds: is_usable implies maximum_width >= minimum_width
    	consistent_vertical_bounds: is_usable implies 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 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 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

    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_QUESTION_DIALOG