indexing
	description: "EiffelVision text area. To query multiple lines of text from the user."
	status: "See notice at end of class"
	date: "$Date$"
	revision: "$Revision$"

class interface
	EV_TEXT

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_text (txt: STRING)
			-- Create Current with txt assigned to text.
		require
			txt_not_void: txt /= 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)

	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

	line (i: INTEGER): STRING
			-- Result is content of ith line.
		require
			not_destroyed: not is_destroyed
			valid_line_index: valid_line_index (i) and then (i = line_count implies last_line_not_empty)
		ensure
			result_not_void: Result /= void

	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

	selected_text: STRING
			-- Currently selected text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result.is_equal (implementation.selected_text)

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

	text: STRING
			-- Text of Current.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: equal (Result, implementation.text)
			not_void_implies_cloned: Result /= void implies Result /= implementation.text

	text_length: INTEGER
			-- Number of characters making up text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.text_length

	tooltip: STRING
			-- Tooltip displayed on Current.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_TOOLTIPABLE
			bridge_ok: (Result = void and implementation.tooltip = void) or Result.is_equal (implementation.tooltip)
	
feature -- Measurement

	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

	caret_position: INTEGER
			-- Current position of caret.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.caret_position

	current_line_number: INTEGER
			-- Line currently containing cursor.
		require
			not_destroyed: not is_destroyed
		ensure
			valid_line_index: valid_line_index (Result)

	first_position_from_line_number (i: INTEGER): INTEGER
			-- Position of first character on i-th line.
		require
			not_destroyed: not is_destroyed
			valid_line: valid_line_index (i) and then (i = line_count implies last_line_not_empty)
		ensure
			valid_caret_position: valid_caret_position (i)

	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

	has_selection: BOOLEAN
			-- Does current have a selection?
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.has_selection

	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_editable: BOOLEAN
			-- Is text editable?
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.is_editable

	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

	last_position_from_line_number (i: INTEGER): INTEGER
			-- Position of last character on i-th line.
		require
			not_destroyed: not is_destroyed
			valid_line: valid_line_index (i) and then (i = line_count implies last_line_not_empty)
		ensure
			valid_caret_position: valid_caret_position (i)

	line_count: INTEGER
			-- Number of lines in Current.
		require
			not_destroyed: not is_destroyed
		ensure
			result_greater_zero: Result > 0

	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

	selection_end: INTEGER
			-- Index of last character selected
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			has_selection: has_selection
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.selection_end
			within_range: Result >= 1 and Result <= text_length
			consistent_with_selection_start: Result >= selection_start

	selection_start: INTEGER
			-- Index of first selected character.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			has_selection: has_selection
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.selection_start
			within_range: Result >= 1 and Result <= text_length
			consistent_with_selection_end: selection_end >= Result

	valid_caret_position (pos: INTEGER): BOOLEAN
			-- Is pos a valid caret position?
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			bridge_ok: Result = implementation.valid_caret_position (pos)
	
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_edit
			-- Make Current read-only.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			is_editable: not is_editable

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

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

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

	enable_edit
			-- Make Current editable.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			is_editable: is_editable

	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

	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

	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

	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_caret_position (a_caret_position: INTEGER)
			-- Assign a_caret_posiiton to caret_position.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			valid_caret_position: valid_caret_position (a_caret_position)
			is_editable: is_editable
		ensure -- from EV_TEXT_COMPONENT
			caret_position_assigned: caret_position = a_caret_position

	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_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_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)

	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
	
feature -- Element change

	append_text (a_text: STRING)
			-- Append a_text to text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			text_not_void: a_text /= void
			no_carriage_returns: not a_text.has ('%R')
		ensure -- from EV_TEXT_COMPONENT
			text_appended: check_text_modification (old text, a_text)
			caret_not_moved: old caret_position = caret_position

	insert_text (a_text: STRING)
			-- Insert a_text to right of caret_position.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			text_not_void: a_text /= void
			no_carriage_returns: not a_text.has ('%R')
		ensure -- from EV_TEXT_COMPONENT
			text_insert_correctly: text.is_equal ((old text).substring (1, (old caret_position - 1)) + a_text + (old text).substring ((old caret_position), (old text.count)))
			caret_not_moved: old caret_position = caret_position

	prepend_text (a_text: STRING)
			-- Prepend a_text to text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			text_not_void: a_text /= void
			no_carriage_returns: not a_text.has ('%R')
		ensure -- from EV_TEXT_COMPONENT
			text_prepended: text.is_equal (a_text + old text)
			caret_not_moved: old caret_position = caret_position

	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_text
			-- Make text Void.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			text_removed: text = void

	remove_tooltip
			-- Make tooltip Void.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
		ensure -- from EV_TOOLTIPABLE
			tooltip_removed: tooltip = void

	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)

	set_text (a_text: STRING)
			-- Assign a_text to text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			text_not_void: a_text /= void
			no_carriage_returns: not a_text.has ('%R')
			a_text_not_empty: not a_text.is_empty
		ensure -- from EV_TEXT_COMPONENT
			text_set: check_text_modification (void, a_text)

	set_tooltip (a_tooltip: STRING)
			-- Assign a_tooltip to tooltip.
			-- (from EV_TOOLTIPABLE)
		require -- from EV_TOOLTIPABLE
			not_destroyed: not is_destroyed
			tooltip: a_tooltip /= void
			a_tooltip_not_empty: not a_tooltip.is_empty
		ensure -- from EV_TOOLTIPABLE
			tooltip_assigned: a_tooltip.is_equal (tooltip) and tooltip /= a_tooltip
	
feature -- Resizing

	set_minimum_width_in_characters (nb: INTEGER)
			-- Make a minimum of nb of the widest character visible
			-- on one line.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			valid_nb: nb > 0
		ensure -- from EV_TEXT_COMPONENT
			minimum_width_in_characters_assigned: old minimum_width < minimum_width implies minimum_width >= maximum_character_width * nb
	
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 operation

	copy_selection
			-- Copy selected_text to clipboard.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			has_selection: has_selection
		ensure -- from EV_TEXT_COMPONENT
			selection_copied: clipboard_content.is_equal (selected_text)
			text_unchanged: text.is_equal (old text)
			caret_not_moved: caret_position = old caret_position

	cut_selection
			-- Move selected_text to clipboard.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			has_selection: has_selection
			is_editable: is_editable
		ensure -- from EV_TEXT_COMPONENT
			selection_in_clipboard: clipboard_content.is_equal (old selected_text)
			selection_cut: text.is_equal ((old text).substring (1, old selection_start - 1) + (old text).substring (old selection_end + 1, (old text).count))

	delete_selection
			-- Delete current selection.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			has_selection: has_selection
			is_editable: is_editable
		ensure -- from EV_TEXT_COMPONENT
			has_no_selection: not has_selection
			selection_deleted: text.is_equal ((old text).substring (1, old selection_start - 1) + (old text).substring (old selection_end + 1, (old text).count))

	deselect_all
			-- Unselect the current selection.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
		ensure -- from EV_TEXT_COMPONENT
			not_has_selection: not has_selection

	paste (a_position: INTEGER)
			-- Insert text from clipboard at a_position.
			-- No effect if clipboard is empty.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			a_position_within_range: a_position >= 1 and a_position <= text_length + 1
			is_editable: is_editable
		ensure -- from EV_TEXT_COMPONENT
			text_pasted_correctly: text.is_equal ((old text).substring (1, a_position - 1) + clipboard_content + ((old text).substring (a_position, ((old text).count))))
			caret_position_consistent: old caret_position <= a_position implies caret_position = old caret_position
			caret_position_consistent: old caret_position > a_position implies caret_position = old caret_position + clipboard_content.count

	put_new_line
			-- Insert return character at caret_position.
		require
			not_destroyed: not is_destroyed

	scroll_to_line (i: INTEGER)
			-- Ensure that line i is visible in Current.
		require
			not_destroyed: not is_destroyed
			valid_line_index: valid_line_index (i) and then (i = line_count implies last_line_not_empty)

	search (str: STRING; start: INTEGER): INTEGER
			-- Position of first occurrence of str at or after start;
			-- 0 if none.
		require
			not_destroyed: not is_destroyed
			valid_string: str /= void

	select_all
			-- Select all text.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			positive_length: text_length > 0
		ensure -- from EV_TEXT_COMPONENT
			has_selection: has_selection
			selection_start_set: selection_start = 1
			selection_end_set: selection_end = text_length

	select_lines (first_line, last_line: INTEGER)
			-- Select all lines from first_line to last_line.
		require
			not_destroyed: not is_destroyed
			valid_line_index: valid_line_index (first_line) and valid_line_index (last_line)
		ensure
			has_selection: has_selection

	select_region (start_pos, end_pos: INTEGER)
			-- Select text between start_pos and end_pos inclusive.
			-- (from EV_TEXT_COMPONENT)
		require -- from EV_TEXT_COMPONENT
			not_destroyed: not is_destroyed
			start_within_range: start_pos >= 1 and start_pos <= text_length
			end_within_range: end_pos >= 1 and end_pos <= text_length
		ensure -- from EV_TEXT_COMPONENT
			has_selection: (start_pos /= end_pos) implies has_selection
			selection_start_set: selection_start = start_pos
			selection_end_set: selection_end = end_pos
	
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

	last_line_not_empty: BOOLEAN
			-- Has last line at least one character?

	valid_line_index (i: INTEGER): BOOLEAN
			-- Is i a valid line index?
	
feature -- Event handling

	change_actions: EV_NOTIFY_ACTION_SEQUENCE
			-- Actions to be performed when text changes.
			-- (from EV_TEXT_COMPONENT_ACTION_SEQUENCES)
		ensure -- from EV_TEXT_COMPONENT_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

	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
	
feature -- Status Report

	is_destroyed: BOOLEAN
			-- Is Current no longer usable?
			-- (from EV_ANY)
		ensure -- from EV_ANY
			bridge_ok: Result = implementation.is_destroyed
	
invariant

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)
		-- from EV_TEXT_COMPONENT
	text_not_void_implies_text_not_empty: is_usable and text /= void implies text.count > 0
		-- 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_TEXT