indexing
	description: "Windows Bitmap, which can be loaded from a resource or created from an existing DIB."
	status: "See notice at end of class."
	date: "$Date$"
	revision: "$Revision$"

class interface
	WEL_BITMAP

create 

	make_by_id (id: INTEGER)
			-- Load the resource by an id
		require -- from WEL_RESOURCE
			valid_id: id > 0
		ensure -- from WEL_RESOURCE
			not_shared: not shared

	make_by_name (name: STRING)
			-- Load the resource by a name
		require -- from WEL_RESOURCE
			name_not_void: name /= void
			name_not_empty: not name.is_empty
		ensure -- from WEL_RESOURCE
			not_shared: not shared

	make_by_dib (a_dc: WEL_DC; dib: WEL_DIB; mode: INTEGER)
			-- Create a WEL_BITMAP from a dib in the a_dc
			-- using mode. See class WEL_DIB_COLORS_CONSTANTS
			-- for mode values.
		require
			a_dc_not_void: a_dc /= void
			a_dc_exists: a_dc.exists
			dib_not_void: dib /= void
			valid_mode: valid_dib_colors_constant (mode)
		ensure
			bitmap_created: item /= item.default

	make_compatible (a_dc: WEL_DC; a_width, a_height: INTEGER)
			-- Initialize current bitmap to be compatible
			-- with a_dc and with a_width as width,
			-- a_height as height.
		require
			a_dc_not_void: a_dc /= void
			a_dc_exists: a_dc.exists
			positive_width: a_width >= 0
			positive_height: a_height >= 0

	make_direct (a_width, a_height, a_planes, a_bits_per_pixel: INTEGER; a_data: STRING)
			-- Make a bitmap of dimension a_width x a_height that has a_planes number
			-- of color planes and a_bits_per_pixel (number of bits to identify color).
			-- a_data contains color data array.
		require
			positive_width: a_width >= 0
			positive_height: a_height >= 0
			positive_planes: a_planes >= 0
			positive_bits_per_pixel: a_bits_per_pixel >= 0
			data_not_void: a_data /= void
			data_count_big_enough: a_data.count >= 2 * (a_width * a_height * a_bits_per_pixel * a_planes) // 8

	make_indirect (a_log_bitmap: WEL_LOG_BITMAP)
			-- Make a bitmap using a_log_bitmap.
		require
			a_log_bitmap_not_void: a_log_bitmap /= void

	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_GDI_ANY)
		ensure -- from WEL_ANY
			item_set: item = a_pointer
			shared: shared

	make_by_bitmap (a_bitmap: WEL_BITMAP)
			-- Create a WEL_BITMAP from another WEL_BITMAP. The
			-- bitmap is copied by value

feature -- Access

	gdi_objects_count: INTEGER
			-- Number of GDI object currently allocated by the
			-- program.
			--
			-- Note: debug option "WEL_GDI_COUNT" should be enabled, otherwise
			-- this function will return zero.
			-- (from WEL_GDI_ANY)

	height: INTEGER
			-- Bitmap height
		require
			exists: exists
		ensure
			positive_result: Result >= 0

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

	log_bitmap: WEL_LOG_BITMAP
			-- Log bitmap structure associated to Current
		require
			exists: exists
		ensure
			result_not_void: Result /= void

	width: INTEGER
			-- Bitmap width
		require
			exists: exists
		ensure
			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 report

	valid_dib_colors_constant (c: INTEGER): BOOLEAN
			-- Is c a valid dib colors constant?
			-- (from WEL_DIB_COLORS_CONSTANTS)
	
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
	
feature -- Removal

	delete
			-- Destroy the inner structure of Current.
			--
			-- Call this function when Current is no more needed
			-- (from WEL_REFERENCE_TRACKABLE)
		require -- from WEL_REFERENCE_TRACKABLE
			reference_not_tracked: not reference_tracked
		ensure -- from WEL_REFERENCE_TRACKABLE
			destroyed: not shared implies not exists

	dispose
			-- Destroy the inner structure of Current.
			--
			-- This function is called by the GC when the
			-- object is collected, the developer should
			-- use delete.
			-- (from WEL_REFERENCE_TRACKABLE)
	
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

	set_di_bits (a_dc: WEL_DC; start_line, length: INTEGER; dib: WEL_DIB; mode: INTEGER)
			-- Set the bits of the current bitmap to the values
			-- given in dib, starting at line start_line
			-- during length lines, using mode.
			-- See class WEL_DIB_COLORS_CONSTANTS for mode values.
		require
			exists: exists
			a_dc_not_void: a_dc /= void
			a_dc_exists: a_dc.exists
			dib_not_void: dib /= void
			valid_mode: valid_dib_colors_constant (mode)
	
feature -- Status Report

	reference_tracked: BOOLEAN
			-- Are the number references of Current tracked?
			-- (from WEL_REFERENCE_TRACKABLE)

	references_count: INTEGER
			-- Number of object referring this object.
			-- (from WEL_REFERENCE_TRACKABLE)
	
feature -- Status Setting

	decrement_reference
			-- Decrement the number of references to this object.
			--
			-- When the number of references reach zero,
			-- delete is called if the object is not protected.
			-- (from WEL_REFERENCE_TRACKABLE)
		require -- from WEL_REFERENCE_TRACKABLE
			exists: exists
			tracking_references_started: reference_tracked

	enable_reference_tracking
			-- Set references_tracked to True.
			--
			-- (from WEL_REFERENCE_TRACKABLE)
		require -- from WEL_REFERENCE_TRACKABLE
			exists: exists
			tracking_reference_not_started: not reference_tracked

	increment_reference
			-- Increment the number of references to this object.
			-- (from WEL_REFERENCE_TRACKABLE)
		require -- from WEL_REFERENCE_TRACKABLE
			exists: exists
			tracking_references_started: reference_tracked

	object_id: INTEGER
			-- Runtime Id of Current.
			-- (from WEL_REFERENCE_TRACKABLE)
	
invariant

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

end -- class WEL_BITMAP