    indexing
    	description: "[
    					Representation of a typeface.
    					Appearance is specified in terms of font family, height, shape and
    					weight. The local system font closest to the specification will be
    					displayed. A specific font name may optionally be specified. See `set_preferred_face'"

    					There are two available queries for a font height, height and height_in_points.
    					Changing one, changes the other accordingly. height is given in pixels while
    					height_in_points is in points or 1/72 of an inch. Using height_in_points ensures
    					that on different screen resolutions `Current' has the same physical size, although
    					the pixel height may differ to achieve this.
    	]"
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	keywords: "character, face, height, family, weight, shape, bold, italic"
    	date: "$Date: 2006-03-22 23:29:03 -0800 (Wed, 22 Mar 2006) $"
    	revision: "$Revision: 57641 $"

    class interface
    	EV_FONT

    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_values (a_family, a_weight, a_shape, a_height: INTEGER_32)
    			-- Create with `a_family', `a_weight', `a_shape' and `a_height'.
    		require
    			a_family_valid: valid_family (a_family)
    			a_weight_valid: valid_weight (a_weight)
    			a_shape_valid: valid_shape (a_shape)
    			a_height_bigger_than_zero: a_height > 0
    		ensure
    			a_family_set: family = a_family
    			a_weight_set: weight = a_weight
    			a_shape_set: shape = a_shape
    			a_height_set: height = a_height

    feature -- Access

    	char_set: INTEGER_32
    			-- Charset of the font.
    			-- Only meaningful on windows.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.char_set

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

    	family: INTEGER_32
    			-- Font category. Can be any of the Family_* constants
    			-- defined in EV_FONT_CONSTANTS.
    			-- Default: Family_sans
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.family

    	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)

    	height: INTEGER_32
    			-- Preferred font height in pixels.
    			-- Default: 8
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.height

    	height_in_points: INTEGER_32
    			-- Preferred font height in points.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.height_in_points

    	preferred_families: EV_ACTIVE_LIST [STRING_32]
    			-- Preferred familys. The first one in the list
    			-- will be tried first. If it does not exists on
    			-- the system, the second will be tried, etc.
    			--
    			-- Overrides family if found on current system.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.preferred_families
    			result_not_void: Result /= Void

    	shape: INTEGER_32
    			-- Preferred font slant. Can be any of the Shape_*
    			-- constants defined in EV_FONT_CONSTANTS.
    			-- Default: Shape_regular
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.shape

    	weight: INTEGER_32
    			-- Preferred font thickness. Can be any of the Weight_*
    			-- constants defined in EV_FONT_CONSTANTS.
    			-- Default: Weight_regular
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.weight

    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))

    	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

    	ascent: INTEGER_32
    			-- Vertical distance from the origin of the drawing
    			-- operation to the top of the drawn character.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.ascent

    	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

    	descent: INTEGER_32
    			-- Vertical distance from the origin of the drawing
    			-- operation to the bottom of the drawn character.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.descent

    	horizontal_resolution: INTEGER_32
    			-- Horizontal resolution of screen for which the font is designed.
    			-- Measured in dots per inch. If return value is zero, the
    			-- resolution is not known.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.horizontal_resolution

    	is_proportional: BOOLEAN
    			-- Can characters in the font have different widths?
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.is_proportional

    	maximum_width: INTEGER_32
    			-- Width of the biggest character in the font.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.maximum_width

    	minimum_width: INTEGER_32
    			-- Width of the smallest character in the font.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.minimum_width

    	name: STRING_32
    			-- Face name chosen by toolkit.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result.is_equal (implementation.name)

    	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))

    	string_size (a_string: STRING_GENERAL): TUPLE [INTEGER_32, INTEGER_32, INTEGER_32, INTEGER_32]
    			-- [width, height, left_offset, right_offset] in pixels of `a_string' in the current font,
    			-- taking into account line breaks ('%N').
    			-- width and height correspond to the rectange used to bound `a_string', and
    			-- should be used when placing strings next to each as part of a text.
    			-- On some fonts, characters may extend outside of the bounds given by width and height,
    			-- for example certain italic letters may overhang other letters. Use `left_offset' and
    			-- `right_offset' to determine if there is any overhang for `a_string'. a negative `left_offset'
    			-- indicates overhang to the left, while a positive `right_offset' indicates an overhang to the right.
    			-- To determine the complete bounding rectangle for `a_string' add negative `left_offset'
    			-- and positive `right_offset' to width.
    		require
    			not_destroyed: not is_destroyed
    			a_string_not_void: a_string /= Void
    		ensure
    			result_not_void: Result /= Void
    			bridge_ok: Result.item (1).is_equal (implementation.string_size (a_string).item (1)) and Result.item (2).is_equal (implementation.string_size (a_string).item (2))

    	string_width (a_string: STRING_GENERAL): INTEGER_32
    			-- Width in pixels of `a_string' in the current font.
    		require
    			not_destroyed: not is_destroyed
    			a_string_not_void: a_string /= Void
    		ensure
    			bridge_ok: Result = implementation.string_width (a_string)
    			positive: Result >= 0

    	vertical_resolution: INTEGER_32
    			-- Vertical resolution of screen for which the font is designed.
    			-- Measured in dots per inch. If return value is zero, the
    			-- resolution is not known.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.vertical_resolution

    	width: INTEGER_32
    			-- Character width of current fixed-width font.
    			-- If font is proportional, returns the average width.
    		require
    			not_destroyed: not is_destroyed
    		ensure
    			bridge_ok: Result = implementation.width

    feature -- Element change

    	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_family (a_family: INTEGER_32)
    			-- Assign  `a_family' to family.
    		require
    			not_destroyed: not is_destroyed
    			a_family_valid: valid_family (a_family)
    		ensure
    			family_assigned: family = a_family

    	set_height (a_height: INTEGER_32)
    			-- Set `a_height' to height.
    			-- height_in_points changes accordingly based on screen resolution.
    		require
    			not_destroyed: not is_destroyed
    			a_height_bigger_than_zero: a_height > 0
    		ensure
    			height_assigned: height = a_height

    	set_height_in_points (a_height: INTEGER_32)
    			-- Set height_in_points to `a_height'.
    			-- height changes accordingly based on screen resolution.
    		require
    			not_destroyed: not is_destroyed
    			a_height_bigger_than_zero: a_height > 0
    		ensure
    			height_assigned: height_in_points = a_height

    	set_shape (a_shape: INTEGER_32)
    			-- Set `a_shape' to shape.
    		require
    			not_destroyed: not is_destroyed
    			a_shape_valid: valid_shape (a_shape)
    		ensure
    			shape_assigned: shape = a_shape

    	set_weight (a_weight: INTEGER_32)
    			-- Set `a_weight' to weight.
    		require
    			not_destroyed: not is_destroyed
    			a_weight_valid: valid_weight (a_weight)
    		ensure
    			weight_assigned: weight = a_weight

    feature -- Duplication

    	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

    	copy (other: like Current)
    			-- Update `Current' with all attributes of `other'.
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_equal: is_equal (other)

    	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)

    	is_equal (other: like Current): BOOLEAN
    			-- Does `other' have same appearance?
    		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

    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_family (a_family: INTEGER_32): BOOLEAN
    			-- Is `a_family' a valid family value.
    			-- (from EV_FONT_CONSTANTS)

    	valid_shape (a_shape: INTEGER_32): BOOLEAN
    			-- Is `a_shape' a valid shape value.
    			-- (from EV_FONT_CONSTANTS)

    	valid_weight (a_weight: INTEGER_32): BOOLEAN
    			-- Is `a_weight' a valid weight value.
    			-- (from EV_FONT_CONSTANTS)

    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
    	family_valid: is_initialized implies valid_family (family)
    	weight_valid: is_initialized implies valid_weight (weight)
    	shape_valid: is_initialized implies valid_shape (shape)
    	height_positive: is_initialized implies height > 0
    	height_in_points_positive: is_initialized implies height_in_points > 0
    	ascent_not_negative: is_initialized implies ascent >= 0
    	descent_not_negative: is_initialized implies descent >= 0
    	width_of_empty_string_equals_zero: is_initialized implies string_width ("") = 0
    	horizontal_resolution_non_negative: is_initialized implies horizontal_resolution >= 0
    	vertical_resolution_non_negative: is_initialized implies vertical_resolution >= 0

    		-- 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_FONT