    indexing
    	description: "Facilities for direct drawing on the screen."
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	keywords: "screen, root, window, visual, top"
    	date: "$Date: 2006-08-07 11:52:06 -0700 (Mon, 07 Aug 2006) $"
    	revision: "$Revision: 62292 $"

    class interface
    	EV_SCREEN

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

    feature -- Access

    	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)

    	clip_area: EV_RECTANGLE
    			-- Rectangular area to apply clipping on.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			bridge_ok: (Result = Void) = (implementation.clip_area = Void)

    	dashed_line_style: BOOLEAN
    			-- Are lines drawn dashed?
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			bridge_ok: Result = implementation.dashed_line_style

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

    	drawing_mode: INTEGER_32
    			-- Logical operation on pixels when drawing.
    			-- Default: drawing_mode_copy.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			bridge_ok: Result = implementation.drawing_mode

    	font: EV_FONT
    			-- Typeface appearance for `Current'.
    			-- (from EV_FONTABLE)
    		require -- from EV_FONTABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_FONTABLE
    			not_void: Result /= Void
    			bridge_ok: Result.is_equal (implementation.font)

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

    	generating_type: STRING_8
    			-- Name of current object's generating type
    			-- (type of which it is a direct instance)
    			-- (from ANY)

    	generator: STRING_8
    			-- Name of current object's generating class
    			-- (base class of the type of which it is a direct instance)
    			-- (from ANY)

    	line_width: INTEGER_32
    			-- Line thickness. Default: 1.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			bridge_ok: Result = implementation.line_width

    	tile: EV_PIXMAP
    			-- Pixmap that is used to draw filled primitives with
    			-- instead of foreground_color.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			bridge_ok: (Result = Void) = (implementation.tile = Void)

    feature -- Measurement

    	height: INTEGER_32
    			-- Vertical size in pixels.
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure then
    			bridge_ok: Result = implementation.height
    			positive: Result > 0

    	horizontal_resolution: INTEGER_32
    			-- Number of pixels per inch along screen width.
    		ensure
    			positive: Result > 0

    	vertical_resolution: INTEGER_32
    			-- Number of pixels per inch along screen height.
    		ensure
    			positive: Result > 0

    	width: INTEGER_32
    			-- Horizontal size in pixels.
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure then
    			bridge_ok: Result = implementation.width
    			positive: Result > 0

    feature -- Comparison

    	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void
    			-- or attached to isomorphic object structures?
    			-- (from ANY)
    		ensure -- from ANY
    			shallow_implies_deep: standard_equal (some, other) implies Result
    			both_or_none_void: (some = Void) implies (Result = (other = Void))
    			same_type: (Result and (some /= Void)) implies 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

    	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

    	pointer_position: EV_COORDINATE
    			-- Position of the screen pointer.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			result_not_void: Result /= Void

    	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))

    	widget_at_mouse_pointer: EV_WIDGET
    			-- Widget underneath mouse pointer if any.
    		require
    			not_destroyed: not is_destroyed

    	widget_at_position (x, y: INTEGER_32): EV_WIDGET
    			-- Widget at position (`x', `y') if any.
    		require
    			not_destroyed: not is_destroyed

    feature -- Status setting

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

    feature -- Element change

    	disable_dashed_line_style
    			-- Draw lines solid.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			dashed_line_style_disabled: not dashed_line_style

    	enable_dashed_line_style
    			-- Draw lines dashed.
    			-- See note at top.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			dashed_line_style_enabled: dashed_line_style

    	remove_clip_area
    			-- Do not apply any clipping.
    			-- Was declared in EV_DRAWABLE as synonym of remove_clipping.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			clip_area_void: clip_area = Void

    	remove_clipping
    			-- Do not apply any clipping.
    			-- Was declared in EV_DRAWABLE as synonym of remove_clip_area.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			clip_area_void: clip_area = Void

    	remove_tile
    			-- Do not apply a tile when filling.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			tile_void: tile = Void

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

    	set_clip_area (an_area: EV_RECTANGLE)
    			-- Set area which will be refreshed.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			an_area_not_void: an_area /= Void
    		ensure -- from EV_DRAWABLE
    			clip_area_assigned: clip_area.is_equal (an_area)

    	set_clip_region (a_region: EV_REGION)
    			-- Set region which will be refreshed.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_region_not_void: a_region /= Void

    	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_drawing_mode (a_mode: INTEGER_32)
    			-- Set drawing mode to `a_logical_mode'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_mode_valid: valid_drawing_mode (a_mode)
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = a_mode

    	set_font (a_font: EV_FONT)
    			-- Assign `a_font' to font.
    			-- (from EV_FONTABLE)
    		require -- from EV_FONTABLE
    			not_destroyed: not is_destroyed
    			a_font_not_void: a_font /= Void
    		ensure -- from EV_FONTABLE
    			font_assigned: font.is_equal (a_font) and font /= a_font

    	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_line_width (a_width: INTEGER_32)
    			-- Assign `a_width' to line_width.
    			-- See note at top.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_width_positive_or_zero: a_width >= 0
    		ensure -- from EV_DRAWABLE
    			line_width_assigned: line_width = a_width

    	set_tile (a_pixmap: EV_PIXMAP)
    			-- Set tile used to fill figures.
    			-- Set to Void to use background_color to fill.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_pixmap_not_void: a_pixmap /= Void
    		ensure -- from EV_DRAWABLE
    			tile_assigned: tile /= Void

    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)

    	sub_pixmap (area: EV_RECTANGLE): EV_PIXMAP
    			-- Return a pixmap region of `Current' represented by rectangle `area'
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			area_not_void: area /= Void
    		ensure -- from EV_DRAWABLE
    			result_not_void: Result /= Void

    	frozen twin: like Current
    			-- New object equal to `Current'
    			-- twin calls copy; to change copying/twining semantics, redefine copy.
    			-- (from ANY)
    		ensure -- from ANY
    			twin_not_void: Result /= Void
    			is_equal: Result.is_equal (Current)

    feature -- Basic operations

    	frozen default: like Current
    			-- Default value of object's type
    			-- (from ANY)

    	frozen default_pointer: POINTER
    			-- Default value of type `POINTER'
    			-- (Avoid the need to write `p'.default for
    			-- some `p' of type `POINTER'.)
    			-- (from ANY)

    	default_rescue
    			-- Process exception for routines with no Rescue clause.
    			-- (Default: do nothing.)
    			-- (from ANY)

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

    feature -- Basic operation

    	fake_key_click (a_key: EV_KEY)
    			-- Simulate the user clicking a `key'.
    		require
    			not_destroyed: not is_destroyed
    			key_not_void: a_key /= Void

    	fake_key_press (a_key: EV_KEY)
    			-- Simulate the user pressing a `key'.
    		require
    			not_destroyed: not is_destroyed
    			key_not_void: a_key /= Void

    	fake_key_release (a_key: EV_KEY)
    			-- Simulate the user releasing a `key'.
    		require
    			not_destroyed: not is_destroyed
    			key_not_void: a_key /= Void

    	fake_pointer_button_click (a_button: INTEGER_32)
    			-- Simulate the user clicking `a_button' on the pointing device.
    		require
    			not_destroyed: not is_destroyed

    	fake_pointer_button_press (a_button: INTEGER_32)
    			-- Simulate the user pressing a `a_button' on the pointing device.
    		require
    			not_destroyed: not is_destroyed

    	fake_pointer_button_release (a_button: INTEGER_32)
    			-- Simulate the user releasing a `a_button' on the pointing device.
    		require
    			not_destroyed: not is_destroyed

    	set_pointer_position (x, y: INTEGER_32)
    			-- Set pointer_position to (`x',`y`).
    		require
    			not_destroyed: not is_destroyed

    feature -- Clearing operations

    	clear
    			-- Erase `Current' with background_color.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed

    	clear_rectangle (x, y, a_width, a_height: INTEGER_32)
    			-- Draw rectangle with upper-left corner on (`x', `y')
    			-- with size `a_width' and `a_height' in background_color.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_width_positive_or_zero: a_width >= 0
    			a_height_positive_or_zero: a_height >= 0

    feature -- Command

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

    feature {ANY} -- Contract support

    	valid_drawing_mode (a_mode: INTEGER_32): BOOLEAN
    			-- Is `a_mode' a valid drawing mode?
    			-- (from EV_DRAWABLE_CONSTANTS)

    feature -- Drawing mode setting

    	set_and_mode
    			-- Set drawing_mode to bitwise AND.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = drawing_mode_and

    	set_copy_mode
    			-- Set drawing_mode to normal.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = drawing_mode_copy

    	set_invert_mode
    			-- Set drawing_mode to bitwise invert.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = drawing_mode_invert

    	set_or_mode
    			-- Set drawing_mode to bitwise OR.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = drawing_mode_or

    	set_xor_mode
    			-- Set drawing_mode to bitwise XOR.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    		ensure -- from EV_DRAWABLE
    			drawing_mode_assigned: drawing_mode = drawing_mode_xor

    feature -- Drawing operations

    	draw_arc (x, y, a_bounding_width, a_bounding_height: INTEGER_32; a_start_angle, an_aperture: REAL_32)
    			-- Draw part of an ellipse defined by a rectangular area with an
    			-- upper left corner at `x',`y', width `a_bounding_width' and height
    			-- `a_bounding_height'.
    			-- Start at `a_start_angle' and stop at `a_start_angle' + `an_aperture'.
    			-- Angles are measured in radians, and go
    			-- counterclockwise from the 3 o'clock angle.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_bounding_width_positive_or_zero: a_bounding_width >= 0
    			a_bounding_height_positive_or_zero: a_bounding_width >= 0

    	draw_ellipse (x, y, a_bounding_width, a_bounding_height: INTEGER_32)
    			-- Draw an ellipse defined by a rectangular area with an
    			-- upper left corner at `x',`y', width `a_bounding_width' and height
    			-- `a_bounding_height'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_bounding_width_positive_or_zero: a_bounding_width >= 0
    			a_bounding_height_positive_or_zero: a_bounding_height >= 0

    	draw_ellipsed_text (x, y: INTEGER_32; a_text: STRING_GENERAL; clipping_width: INTEGER_32)
    			-- Draw `a_text' with left of baseline at (`x', `y') using font.
    			-- Text is clipped to `clipping_width' in pixels and ellipses are displayed
    			-- to show truncated characters if any.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void
    			clipping_width_positive: clipping_width >= 0

    	draw_ellipsed_text_top_left (x, y: INTEGER_32; a_text: STRING_GENERAL; clipping_width: INTEGER_32)
    			-- Draw `a_text' with top left corner at (`x', `y') using font.
    			-- Text is clipped to `clipping_width' in pixels and ellipses are displayed
    			-- to show truncated characters if any.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void
    			clipping_width_positive: clipping_width >= 0

    	draw_pie_slice (x, y, a_bounding_width, a_bounding_height: INTEGER_32; a_start_angle, an_aperture: REAL_32)
    			-- Draw part of an ellipse defined by a rectangular area with an
    			-- upper left corner at `x',`y', width `a_bounding_width' and height
    			-- `a_bounding_height'.
    			-- Start at `a_start_angle' and stop at `a_start_angle' + `an_aperture'.
    			-- The arc is then closed by two segments through (`x', 'y').
    			-- Angles are measured in radians, start at the
    			-- 3 o'clock angle and grow counterclockwise.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_bounding_width_positive_or_zero: a_bounding_width >= 0
    			a_bounding_height_positive_or_zero: a_bounding_height >= 0

    	draw_pixmap (x, y: INTEGER_32; a_pixmap: EV_PIXMAP)
    			-- Draw `a_pixmap' with upper-left corner on (`x', `y').
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_pixmap_not_void: a_pixmap /= Void

    	draw_point (x, y: INTEGER_32)
    			-- Draw point at (`x', `y').
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed

    	draw_polyline (points: ARRAY [EV_COORDINATE]; is_closed: BOOLEAN)
    			-- Draw line segments between subsequent points in
    			-- `points'. If `is_closed' draw line segment between first
    			-- and last point in `points'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			points_not_void: points /= Void

    	draw_rectangle (x, y, a_width, a_height: INTEGER_32)
    			-- Draw rectangle with upper-left corner on (`x', `y')
    			-- with size `a_width' and `a_height'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_width_positive_or_zero: a_width >= 0
    			a_height_positive_or_zero: a_height >= 0

    	draw_segment (x1, y1, x2, y2: INTEGER_32)
    			-- Draw line segment from (`x1', `y1') to (`x2', `y2').
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed

    	draw_straight_line (x1, y1, x2, y2: INTEGER_32)
    			-- Draw infinite straight line through (`x1', `y1') and
    			-- (`x2', `y2').
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			points_not_equal: x1 /= x2 or y1 /= y2

    	draw_sub_pixmap (x, y: INTEGER_32; a_pixmap: EV_PIXMAP; area: EV_RECTANGLE)
    			-- Draw `area' of `a_pixmap' with upper-left corner on (`x', `y').
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_pixmap_not_void: a_pixmap /= Void
    			area_not_void: area /= Void

    	draw_text (x, y: INTEGER_32; a_text: STRING_GENERAL)
    			-- Draw `a_text' with left of baseline at (`x', `y') using font.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void

    	draw_text_top_left (x, y: INTEGER_32; a_text: STRING_GENERAL)
    			-- Draw `a_text' with top left corner at (`x', `y') using font.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_text_not_void: a_text /= Void

    feature -- Drawing operations (filled)

    	fill_ellipse (x, y, a_bounding_width, a_bounding_height: INTEGER_32)
    			-- Fill an ellipse defined by a rectangular area with an
    			-- upper left corner at `x',`y', width `a_bounding_width' and height
    			-- `a_bounding_height'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_bounding_width_positive_or_zero: a_bounding_width >= 0
    			a_bounding_height_positive_or_zero: a_bounding_height >= 0

    	fill_pie_slice (x, y, a_bounding_width, a_bounding_height: INTEGER_32; a_start_angle, an_aperture: REAL_32)
    			-- Fill part of an ellipse defined by a rectangular area with an
    			-- upper left corner at `x',`y', width `a_bounding_width' and height
    			-- `a_bounding_height'.
    			-- Start at `a_start_angle' and stop at `a_start_angle' + `an_aperture'.
    			-- The arc is then closed by two segments through (`x', `y').
    			-- Angles are measured in radians, start at the 3
    			-- o'clock angle and grow counterclockwise.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_bounding_width_positive_or_zero: a_bounding_width >= 0
    			a_bounding_height_positive_or_zero: a_bounding_height >= 0

    	fill_polygon (points: ARRAY [EV_COORDINATE])
    			-- Draw filled polygon between subsequent points in `points'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			points_not_void: points /= Void

    	fill_rectangle (x, y, a_width, a_height: INTEGER_32)
    			-- Draw filled rectangle with upper-left corner on (`x', `y')
    			-- with size `a_width' and `a_height'.
    			-- (from EV_DRAWABLE)
    		require -- from EV_DRAWABLE
    			not_destroyed: not is_destroyed
    			a_width_positive_or_zero: a_width >= 0
    			a_height_positive_or_zero: a_height >= 0

    feature -- Output

    	io: STD_FILES
    			-- Handle to standard file setup
    			-- (from ANY)

    	out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of tagged_out.
    			-- (from ANY)

    	print (some: ANY)
    			-- Write terse external representation of `some'
    			-- on standard output.
    			-- (from ANY)

    	frozen tagged_out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of out.
    			-- (from ANY)

    feature -- Platform

    	operating_environment: OPERATING_ENVIRONMENT
    			-- Objects available from the operating system
    			-- (from ANY)

    feature -- Status Report

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

    invariant
    		-- from EV_DRAWABLE
    	line_width_positive_or_zero: is_usable implies line_width >= 0
    	drawing_mode_valid: is_usable implies valid_drawing_mode (drawing_mode)

    		-- 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_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)

    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_SCREEN