    indexing
    	description: "Defines the coordinates of the upper-left and lower-right corners of a rectangle."
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	date: "$Date: 2006-09-14 10:51:35 -0700 (Thu, 14 Sep 2006) $"
    	revision: "$Revision: 63567 $"

    class interface
    	WEL_RECT

    create
    	make (a_left, a_top, a_right, a_bottom: INTEGER_32)
    			-- Make a rectangle and set left, top,
    			-- right, bottom with `a_left', `a_top',
    			-- `a_right', `a_bottom'
    		ensure
    			left_set: left = a_left
    			top_set: top = a_top
    			right_set: right = a_right
    			bottom_set: bottom = a_bottom

    	make_by_pointer (a_pointer: POINTER)
    			-- Set item with `a_pointer'.
    			-- Since item is shared, it does not need
    			-- to be freed.
    			-- Caution: `a_pointer' must be a pointer
    			-- coming from Windows.
    			-- (from WEL_ANY)
    		ensure -- from WEL_ANY
    			item_set: item = a_pointer
    			shared: shared

    	make_client (window: WEL_WINDOW)
    			-- Make a client rectangle with `window'
    		require
    			window_not_void: window /= Void
    			window_exists: window.exists
    		ensure
    			left_equal_zero: left = 0
    			top_equal_zero: top = 0
    			client_rect_set: is_equal (window.client_rect)

    	make_window (window: WEL_WINDOW)
    			-- Make a window rectangle with `window'
    			-- (absolute position)
    		require
    			window_not_void: window /= Void
    			window_exists: window.exists
    		ensure
    			window_rect_set: is_equal (window.window_rect)

    feature -- Access

    	bottom: INTEGER_32
    			-- Position of the bottom border

    	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
    			-- Height of current rect

    	item: POINTER
    			-- Generic Windows handle or structure pointer.
    			-- Can be a HWND, HICON, RECT *, WNDCLASS *, etc...
    			-- (from WEL_ANY)

    	left: INTEGER_32
    			-- Position of the left border
    			-- Was declared in WEL_RECT as synonym of x.

    	right: INTEGER_32
    			-- Position of the right border

    	top: INTEGER_32
    			-- Position of the top border
    			-- Was declared in WEL_RECT as synonym of y.

    	width: INTEGER_32
    			-- Width of current rect

    	x: INTEGER_32
    			-- Position of the left border
    			-- Was declared in WEL_RECT as synonym of left.

    	y: INTEGER_32
    			-- Position of the top border
    			-- Was declared in WEL_RECT as synonym of top.

    feature -- Measurement

    	structure_size: INTEGER_32
    			-- Size to allocate (in bytes)
    		ensure -- from WEL_STRUCTURE
    			positive_result: 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 `Current' equal to `other'?
    		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

    	empty: BOOLEAN
    			-- Is it empty?
    			-- A rectangle is empty if the coordinate of the right
    			-- side is less than or equal to the coordinate
    			-- of the left side, or the coordinate of the bottom
    			-- side is less than or equal to the coordinate of
    			-- the top side.

    	exists: BOOLEAN
    			-- Does the item exist?
    			-- (from WEL_ANY)
    		ensure -- from WEL_ANY
    			Result = (item /= default_pointer)

    	point_in (point: WEL_POINT): BOOLEAN
    			-- Is `point' in the rectangle?
    		require
    			point_not_void: point /= 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))

    	shared: BOOLEAN
    			-- Is item shared by another object?
    			-- If False (by default), item will
    			-- be destroyed by destroy_item.
    			-- If True, item will not be destroyed.
    			-- (from WEL_ANY)

    feature -- Status setting

    	set_shared
    			-- Set shared to True.
    			-- (from WEL_ANY)
    		ensure -- from WEL_ANY
    			shared: shared

    	set_unshared
    			-- Set shared to False.
    			-- (from WEL_ANY)
    		ensure -- from WEL_ANY
    			unshared: not shared

    feature -- Element change

    	set_bottom (a_bottom: INTEGER_32)
    			-- Set bottom with `a_bottom'
    		ensure
    			bottom_set: bottom = a_bottom

    	set_item (an_item: POINTER)
    			-- Set item with `an_item'
    			-- (from WEL_ANY)
    		ensure -- from WEL_ANY
    			item_set: item = an_item

    	set_left (a_left: INTEGER_32)
    			-- Set left with `a_left'
    		ensure
    			left_set: left = a_left

    	set_rect (a_left, a_top, a_right, a_bottom: INTEGER_32)
    			-- Quick set of left, top, right, bottom
    			-- with `a_left', `a_top', `a_right', `a_bottom'
    			-- respectively.
    		ensure
    			left_set: left = a_left
    			top_set: top = a_top
    			right_set: right = a_right
    			bottom_set: bottom = a_bottom

    	set_right (a_right: INTEGER_32)
    			-- Set right with `a_right'
    		ensure
    			right_set: right = a_right

    	set_top (a_top: INTEGER_32)
    			-- Set top with `a_top'
    		ensure
    			top_set: top = a_top

    feature -- Removal

    	dispose
    			-- Destroy the inner structure of `Current'.
    			--
    			-- This function should be called by the GC when the
    			-- object is collected or by the user if `Current' is
    			-- no more usefull.
    			-- (from WEL_ANY)

    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

    	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)

    	inflate (a_x, a_y: INTEGER_32)
    			-- Inflate the rectangle by `a_x' and `a_y'.
    			-- Positive values increase the width and height,
    			-- and negative values decrease them.
    		ensure
    			left_set: left = old left - a_x
    			top_set: top = old top - a_x
    			right_set: right = old right + a_y
    			bottom_set: bottom = old bottom + a_y

    	initialize
    			-- Fill Current with zeros.
    			-- (from WEL_STRUCTURE)
    		require -- from WEL_STRUCTURE
    			exists: exists

    	initialize_with_character (a_character: CHARACTER_8)
    			-- Fill current with `a_character'.
    			-- (from WEL_STRUCTURE)
    		require -- from WEL_STRUCTURE
    			exists: exists

    	intersect (rect1, rect2: WEL_RECT)
    			-- Calculates the intersection of `rect1'
    			-- and `rect2'. If `rect1' and `rect2' do not
    			-- intersect then empty becomes True.
    		require
    			rect1_not_void: rect1 /= Void
    			rect2_not_void: rect2 /= Void

    	memory_copy (source_pointer: POINTER; length: INTEGER_32)
    			-- Copy `length' bytes from `source_pointer' to item.
    			-- (from WEL_STRUCTURE)
    		require -- from WEL_STRUCTURE
    			length_small_enough: length <= structure_size
    			length_large_enough: length > 0
    			exists: exists

    	offset (a_x, a_y: INTEGER_32)
    			-- Moves the rectangle by the specified
    			-- offsets `a_x' and `a_y'.
    		ensure
    			x_set: x = old x + a_x
    			y_set: y = old y + a_y
    			right_set: right = old right + a_x
    			bottom_set: bottom = old bottom + a_y

    	subtract (rect1, rect2: WEL_RECT)
    			-- Set the current rectangle by subtracting
    			-- `rect2' from `rect1'.
    		require
    			rect1_not_void: rect1 /= Void
    			rect2_not_void: rect2 /= Void

    	union (rect1, rect2: WEL_RECT)
    			-- Set the current rectangle by the smallest
    			-- rectangle that contains both source
    			-- rectangles `rect1' and `rect2'.
    		require
    			rect1_not_void: rect1 /= Void
    			rect2_not_void: rect2 /= Void

    feature {ANY} -- Basic operations

    	copy (other: like Current)
    			-- Update current object using fields of object attached
    			-- to `other', so as to yield equal objects.
    			-- (from WEL_STRUCTURE)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_equal: is_equal (other)

    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)

    invariant
    	positive_width: exists implies width >= 0
    	positive_height: exists implies height >= 0

    		-- 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 WEL_RECT