indexing
	description: "Specifies a range of characters in a rich edit control."
	status: "See notice at end of class."
	date: "$Date$"
	revision: "$Revision$"

class interface
	WEL_CHARACTER_RANGE

create 

	make (a_minimum, a_maximum: INTEGER)
			-- Make a char range structure and set maximum,
			-- minimum, with a_maximum, a_minimum
		require
			positive_minimum: a_minimum >= 0
			valid_maximum: a_minimum = 0 implies a_maximum >= - 1
			positive_maximum: a_minimum > 0 implies a_maximum >= 0
		ensure
			minimum_set: minimum = a_minimum
			maximum_set: maximum = a_maximum

	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_empty
			-- Make an empty character range structure.
		ensure
			minimum_set: minimum = 0
			maximum_set: maximum = 0

feature -- Access

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

	maximum: INTEGER
			-- Index of last intercharacter position

	minimum: INTEGER
			-- Index of first intercharacter position
	
feature -- Measurement

	structure_size: INTEGER
			-- Size to allocate (in bytes)
		ensure -- from WEL_STRUCTURE
			positive_result: Result > 0
	
feature -- Status report

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

	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_item (an_item: POINTER)
			-- Set item with an_item
			-- (from WEL_ANY)
		ensure -- from WEL_ANY
			item_set: item = an_item

	set_range (a_minimum, a_maximum: INTEGER)
			-- Set minimum with a_minimum and
			-- maximum with a_maximum
		require
			positive_minimum: a_minimum >= 0
			valid_maximum: a_minimum = 0 implies a_maximum >= - 1
			positive_maximum: a_minimum > 0 implies a_maximum >= 0
		ensure
			minimum_set: minimum = a_minimum
			maximum_set: maximum = a_maximum
	
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 -- Conversion

	to_integer: INTEGER
			-- Converts item to an integer.
			-- (from WEL_ANY)
		ensure -- from WEL_ANY
			Result = cwel_pointer_to_integer (item)
	
feature -- Basic operations

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

	initialize_with_character (a_character: CHARACTER)
			-- Fill current with a_character.
			-- (from WEL_STRUCTURE)
		require -- from WEL_STRUCTURE
			exists: exists

	memory_copy (source_pointer: POINTER; length: INTEGER)
			-- 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
	
invariant

	positive_minimum: minimum >= 0
	valid_minumum_maximum: maximum >= minimum
		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

end -- class WEL_CHARACTER_RANGE