indexing
	description: "Memory device context compatible with a given device context."
	status: "See notice at end of class."
	date: "$Date$"
	revision: "$Revision$"

class interface
	WEL_COMPATIBLE_DC

create 

	make (a_dc: WEL_DC)
			-- Make a compatible dc with a_dc
		require
			a_dc_not: a_dc /= void
			a_dc_exists: a_dc.exists
		ensure
			exists: exists

feature -- Access

	bitmap: WEL_BITMAP
			-- Current bitmap selected.
			-- (from WEL_DC)

	brush: WEL_BRUSH
			-- Current brush selected.
			-- (from WEL_DC)

	font: WEL_FONT
			-- Current font selected.
			-- (from WEL_DC)

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

	palette: WEL_PALETTE
			-- Current palette selected.
			-- (from WEL_DC)

	pen: WEL_PEN
			-- Current pen selected.
			-- (from WEL_DC)

	region: WEL_REGION
			-- Current region selected.
			-- (from WEL_DC)
	
feature -- Status report

	background_color: WEL_COLOR_REF
			-- Current color of the background.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	bitmap_selected: BOOLEAN
			-- Is a bitmap selected?
			-- (from WEL_DC)

	brush_selected: BOOLEAN
			-- Is a brush selected?
			-- (from WEL_DC)

	device_caps (capability: INTEGER): INTEGER
			-- Give device-specific information about
			-- the current display device.
			-- See class WEL_CAPABILITIES_CONSTANTS for
			-- capability values and results.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

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

	font_selected: BOOLEAN
			-- Is a font selected?
			-- (from WEL_DC)

	height: INTEGER
			-- Height of screen (in raster lines).
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	is_opaque: BOOLEAN
			-- Is the background mode opaque?
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	is_transparent: BOOLEAN
			-- Is the background mode transparent?
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	map_mode: INTEGER
			-- Current mapping mode
			-- See class WEL_MM_CONSTANTS for values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			valid_map_mode: valid_map_mode_constant (Result)

	mask_blt_supported: BOOLEAN
			-- (from WEL_DC)

	palette_selected: BOOLEAN
			-- Is a palette selected?
			-- (from WEL_DC)

	pen_selected: BOOLEAN
			-- Is a pen selected?
			-- (from WEL_DC)

	pixel_color (x, y: INTEGER): WEL_COLOR_REF
			-- Color located at x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	polygon_fill_mode: INTEGER
			-- Current polygon fill mode
			-- See class WEL_POLYGON_FILL_MODE_CONSTANTS for values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			valid_polygon_fill_mode: valid_polygon_fill_mode_constant (Result)

	position: WEL_POINT
			-- Current position in logical coordinates.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_exists: Result /= void

	region_selected: BOOLEAN
			-- Is a region selected?
			-- (from WEL_DC)

	rop2: INTEGER
			-- Current drawing mode.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			valid_result: valid_rop2_constant (Result)

	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)

	stretch_blt_mode: INTEGER
			-- Current stretching mode. The stretching mode
			-- defines how color data is added to or removed from
			-- bitmaps that are stretched or compressed when
			-- stretch_blt is called.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			valid_stretch_mode: valid_stretch_mode_constant (Result)

	string_height (s: STRING): INTEGER
			-- Height of the string s using the selected font.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			s_exists: s /= void
		ensure -- from WEL_DC
			positive_result: Result >= 0

	string_size (s: STRING): WEL_SIZE
			-- Size of the string s using the selected font.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			s_exists: s /= void
		ensure -- from WEL_DC
			result_exists: Result /= void
			positive_width: Result.width >= 0
			positive_height: Result.height >= 0

	string_width (s: STRING): INTEGER
			-- Width of the string s using the selected font.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			s_exists: s /= void
		ensure -- from WEL_DC
			positive_result: Result >= 0

	tabbed_text_height (text: STRING): INTEGER
			-- Height of a tabbed text.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			text_not_void: text /= void
		ensure -- from WEL_DC
			positive_height: Result >= 0

	tabbed_text_size (text: STRING): WEL_SIZE
			-- Size of a tabbed text.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			text_not_void: text /= void
		ensure -- from WEL_DC
			result_not_void: Result /= void
			positive_width: Result.width >= 0
			positive_height: Result.height >= 0

	tabbed_text_size_with_tabulation (text: STRING; tabulations: ARRAY [INTEGER]): WEL_SIZE
			-- Size of a tabbed text, with tabulations as
			-- tabulation positions.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			text_not_void: text /= void
			tabulations_not_void: tabulations /= void
		ensure -- from WEL_DC
			result_not_void: Result /= void
			positive_width: Result.width >= 0
			positive_height: Result.height >= 0

	tabbed_text_width (text: STRING): INTEGER
			-- Width of a tabbed text.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			text_not_void: text /= void
		ensure -- from WEL_DC
			positive_width: Result >= 0

	text_alignment: INTEGER
			-- Current text alignment flags.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	text_color: WEL_COLOR_REF
			-- Current color of the text.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	text_face: STRING
			-- Typeface name of the font that is currently selected.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	valid_extent_map_mode (mode: INTEGER): BOOLEAN
			-- Is mode a valid window or viewport extent map mode?
			-- (from WEL_DC)
		require -- from WEL_DC
			valid_map_mode: valid_map_mode_constant (mode)

	viewport_extent: WEL_SIZE
			-- Retrieve the size of the current viewport for the dc.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	viewport_origin: WEL_POINT
			-- Viewport origin for the dc.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	width: INTEGER
			-- Width of the screen (in pixels).
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	window_extent: WEL_SIZE
			-- Window extent for the dc
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void

	window_origin: WEL_POINT
			-- Window origin for the dc.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			result_not_void: Result /= void
	
feature  -- Status report

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

	valid_htext_alignment_constant (c: INTEGER): BOOLEAN
			-- Is c a valid text alignment constant for horizontal positioning?
			-- (from WEL_TA_CONSTANTS)

	valid_map_mode_constant (c: INTEGER): BOOLEAN
			-- Is c a valid map mode constant?
			-- (from WEL_MM_CONSTANTS)

	valid_polygon_fill_mode_constant (c: INTEGER): BOOLEAN
			-- Is c a valid polygon fill mode constant?
			-- (from WEL_POLYGON_FILL_MODE_CONSTANTS)

	valid_rop2_constant (c: INTEGER): BOOLEAN
			-- Is c a valid rop2 constant?
			-- (from WEL_DRAWING_CONSTANTS)

	valid_stretch_mode_constant (c: INTEGER): BOOLEAN
			-- Is c a valid stretch mode constant?
			-- (from WEL_STRETCH_MODE_CONSTANTS)

	valid_text_alignment_constant (c: INTEGER): BOOLEAN
			-- Is c a valid text alignment constant?
			-- (from WEL_TA_CONSTANTS)

	valid_vtext_alignment_constant (c: INTEGER): BOOLEAN
			-- Is c a valid text alignment constant for vertical positioning?
			-- (from WEL_TA_CONSTANTS)
	
feature -- Status setting

	select_bitmap (a_bitmap: WEL_BITMAP)
			-- Select the a_bitmap as the current bitmap.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_bitmap_not_void: a_bitmap /= void
			a_bitmap_exists: a_bitmap.exists
		ensure -- from WEL_DC
			bitmap_set: bitmap = a_bitmap
			bitmap_selected: bitmap_selected

	select_brush (a_brush: WEL_BRUSH)
			-- Select the a_brush as the current brush.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_brush_not_void: a_brush /= void
			a_brush_exists: a_brush.exists
		ensure -- from WEL_DC
			brush_set: brush = a_brush
			brush_selected: brush_selected

	select_font (a_font: WEL_FONT)
			-- Select the a_font as the current font.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_font_not_void: a_font /= void
			a_font_exists: a_font.exists
		ensure -- from WEL_DC
			font_set: font = a_font
			font_selected: font_selected

	select_palette (a_palette: WEL_PALETTE)
			-- Select the a_palette as the current palette.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_palette_not_void: a_palette /= void
			a_palette_exists: a_palette.exists

	select_pen (a_pen: WEL_PEN)
			-- Select the a_pen as the current pen.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_pen_not_void: a_pen /= void
			a_pen_exists: a_pen.exists
		ensure -- from WEL_DC
			pen_set: pen = a_pen
			pen_selected: pen_selected

	select_region (a_region: WEL_REGION)
			-- Select the a_region as the current region.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_region_not_void: a_region /= void
			a_region_exists: a_region.exists
		ensure -- from WEL_DC
			region_set: region = a_region
			region_selected: region_selected

	set_background_color (color: WEL_COLOR_REF)
			-- Set the background_color to color.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			color_not_void: color /= void
		ensure -- from WEL_DC
			color_set: background_color.item = color.item

	set_background_opaque
			-- Set the background mode to opaque.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			is_opaque: is_opaque

	set_background_transparent
			-- Set the background mode to transparent.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			is_transparent: is_transparent

	set_hv_text_alignment (h, v: INTEGER)
			-- Set the text alignment using the horizontal and
			-- vertical components in h and v.
			-- See class WEL_TA_CONSTANTS for valid alignments.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_horizontal_alignment: valid_htext_alignment_constant (h)
			valid_vertical_alignment: valid_vtext_alignment_constant (v)
		ensure -- from WEL_DC
			text_alignments_set: flag_set (text_alignment, h) and flag_set (text_alignment, v)

	set_map_mode (mode: INTEGER)
			-- Set the mapping mode mode of the device context.
			-- See class WEL_MM_CONSTANTS for mode values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_map_mode: valid_map_mode_constant (mode)
		ensure -- from WEL_DC
			map_mode_set: map_mode = mode

	set_polygon_fill_mode (mode: INTEGER)
			-- Set the polygon fill mode polygon_fill_mode with
			-- mode.
			-- See class WEL_POLYGON_FILL_MODE_CONSTANTS for
			-- mode values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_polygon_fill_mode: valid_polygon_fill_mode_constant (mode)
		ensure -- from WEL_DC
			polygon_fill_mode_set: polygon_fill_mode = mode

	set_rop2 (a_rop2: INTEGER)
			-- Set the current foreground mix mode. GDI uses the
			-- foreground mix mode to combine pens and interiors of
			-- filled objects with the colors already on the screen.
			-- The foreground mix mode defines how colors from the
			-- brush or pen and the colors in the existing image
			-- are to be combined.
			-- For a_rop2 values, see class WEL_ROP2_CONSTANTS.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_rop2_constant: valid_rop2_constant (a_rop2)
		ensure -- from WEL_DC
			rop2_set: rop2 = a_rop2

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

	set_stretch_blt_mode (a_mode: INTEGER)
			-- Set the bitmap stretching mode with a_mode.
			-- See class WEL_STRETCH_MODE_CONSTANTS for a_mode
			-- values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_stretch_mode_constant: valid_stretch_mode_constant (a_mode)
		ensure -- from WEL_DC
			stretch_blt_mode_set: stretch_blt_mode = a_mode

	set_text_alignment (an_alignment: INTEGER)
			-- Set the text alignment with an_alignment.
			-- See class WEL_TA_CONSTANTS for an_alignment.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_alignment: valid_text_alignment_constant (an_alignment)
		ensure -- from WEL_DC
			text_alignment_set: flag_set (text_alignment, an_alignment)

	set_text_color (color: WEL_COLOR_REF)
			-- Set the text_color to color.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			color_not_void: color /= void
		ensure -- from WEL_DC
			color_set: text_color.item = color.item

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

	set_viewport_extent (x_extent, y_extent: INTEGER)
			-- Set the x_extent and y_extent of the viewport
			-- associated with the device context.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_current_map_mode: valid_extent_map_mode (map_mode)
		ensure -- from WEL_DC
			x_viewport_extent_set: map_mode /= mm_isotropic implies viewport_extent.width = x_extent
			y_viewport_extent_set: map_mode /= mm_isotropic implies viewport_extent.height = y_extent

	set_viewport_origin (x_origin, y_origin: INTEGER)
			-- Set the x_origin and y_origin of the viewport
			-- associated with the device context.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			x_viewport_origin_set: viewport_origin.x = x_origin
			y_viewport_origin_set: viewport_origin.y = y_origin

	set_window_extent (x_extent, y_extent: INTEGER)
			-- Set the x_extent and y_extent of the window
			-- associated with the device context.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_current_map_mode: valid_extent_map_mode (map_mode)
		ensure -- from WEL_DC
			x_window_extent_set: map_mode /= mm_isotropic implies window_extent.width = x_extent
			y_window_extent_set: map_mode /= mm_isotropic implies window_extent.height = y_extent

	set_window_origin (x_origin, y_origin: INTEGER)
			-- Set the x_origin and y_origin of the window
			-- associated with the device context
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			x_window_origin_set: window_origin.x = x_origin
			y_window_origin_set: window_origin.y = y_origin

	unselect_all
			-- Deselect all objects and restore the old ones.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
		ensure -- from WEL_DC
			pen_not_selected: not pen_selected
			brush_not_selected: not brush_selected
			region_not_selected: not region_selected
			palette_not_selected: not palette_selected
			font_not_selected: not font_selected
			bitmap_not_selected: not bitmap_selected

	unselect_bitmap
			-- Deselect the bitmap and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			bitmap_selected: bitmap_selected
		ensure -- from WEL_DC
			bitmap_not_selected: not bitmap_selected

	unselect_brush
			-- Deselect the brush and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			brush_selected: brush_selected
		ensure -- from WEL_DC
			brush_not_selected: not brush_selected

	unselect_font
			-- Deselect the font and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			font_selected: font_selected
		ensure -- from WEL_DC
			font_not_selected: not font_selected

	unselect_palette
			-- Deselect the palette and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			palette_selected: palette_selected
		ensure -- from WEL_DC
			palette_not_selected: not palette_selected

	unselect_pen
			-- Deselect the pen and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			pen_selected: pen_selected
		ensure -- from WEL_DC
			pen_not_selected: not pen_selected

	unselect_region
			-- Deselect the region and restore the old one.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			region_selected: region_selected
		ensure -- from WEL_DC
			region_not_selected: not region_selected
	
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

	arc (left, top, right, bottom, x_start_arc, y_start_arc, x_end_arc, y_end_arc: INTEGER)
			-- Draw an elliptical arc into a rectangle specified
			-- by left, top and right, bottom, starting
			-- at x_start_arc, y_start_arc and ending at
			-- x_end_arc, y_end_arc.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	bit_blt (x_destination, y_destination, a_width, a_height: INTEGER; dc_source: WEL_DC; x_source, y_source, raster_operation: INTEGER)
			-- Copy a bitmap from the dc_source to
			-- the current device context, from x_source,
			-- y_source to x_destination, y_destination,
			-- using a_width and a_height with raster_operation.
			-- See class WEL_RASTER_OPERATIONS_CONSTANTS for
			-- raster_operation values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			positive_width: a_width >= 0
			positive_height: a_height >= 0
			dc_source_not_void: dc_source /= void
			dc_source_exists: dc_source.exists

	chord (left, top, right, bottom, x_start_line, y_start_line, x_end_line, y_end_line: INTEGER)
			-- Draw a chord into a rectangle specified
			-- by left, top and right, bottom, starting
			-- at x_start_line, y_start_line and ending at
			-- x_end_line, y_end_line.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	copy_dc (dc_source: WEL_DC; rect: WEL_RECT)
			-- Copy the content of rect in dc_source
			-- to the current dc.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			rect_not_void: rect /= void
			dc_source_not_void: dc_source /= void
			dc_source_exists: dc_source.exists

	di_bits (a_bitmap: WEL_BITMAP; start_scan, scan_lines: INTEGER; bitmap_info: WEL_BITMAP_INFO; usage: INTEGER): ARRAY [CHARACTER]
			-- Device-independent bits of a_bitmap.
			-- start_scan specifies the first scan line to
			-- retrieve and scan_lines specifies the number of
			-- scan lines to retrieve. bitmap_info specifies the
			-- desired format for the dib data.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_bitmap_not_void: a_bitmap /= void
			a_bitmap_exists: a_bitmap.exists
			positive_start_scan: start_scan >= 0
			positive_scan_lines: scan_lines >= 0
			bitmap_info_not_void: bitmap_info /= void
			valid_usage: valid_dib_colors_constant (usage)
		ensure -- from WEL_DC
			result_not_void: Result /= void
			consistent_count: Result.count = bitmap_info.header.size_image

	draw_bitmap (a_bitmap: WEL_BITMAP; x, y, a_width, a_height: INTEGER)
			-- Draw bitmap at the x, y position
			-- using a_width and a_height.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_bitmap_not_void: a_bitmap /= void
			a_bitmap_exists: a_bitmap.exists

	draw_centered_text (string: STRING; rect: WEL_RECT)
			-- Draw the text string centered in rect.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
			rect_not_void: rect /= void

	draw_cursor (cursor: WEL_CURSOR; x, y: INTEGER)
			-- Draw cursor at the x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			cursor_not_void: cursor /= void
			cursor_exists: cursor.exists

	draw_disabled_text (string: STRING; rect: WEL_RECT; format: INTEGER)
			-- Draw the text string in disabled mode inside
			-- the rect using format
			-- See class WEL_DT_CONSTANTS for format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
			rect_not_void: rect /= void

	draw_edge (a_rect: WEL_RECT; edge_type: INTEGER; edge_border: INTEGER)
			-- Draw one or more edges depending on edge_type using the borders
			-- type edge_border in the bounding rectangle a_rect.
			--
			-- edge_type is a combination of the flags BDR_xxxx and EDGE_xxxx
			-- as found in WEL_DRAWING_CONSTANTS.
			--
			-- edge_type is a combination of the flags BF_xxxx and EDGE_xxxx
			-- as found in WEL_DRAWING_CONSTANTS.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_rect: a_rect /= void and then a_rect.exists

	draw_frame_control (a_rect: WEL_RECT; control_type: INTEGER; control_state: INTEGER)
			-- Draws a frame control of the type control_type with the style
			-- control_state.
			--
			-- control_type is a combination of the flags DFC_xxxx
			-- as found in WEL_DRAWING_CONSTANTS.
			--
			-- control_state is a combination of the flags DFCS_xxxx
			-- as found in WEL_DRAWING_CONSTANTS.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			valid_rect: a_rect /= void and then a_rect.exists

	draw_icon (icon: WEL_ICON; x, y: INTEGER)
			-- Draw icon at the x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			icon_not_void: icon /= void
			icon_exists: icon.exists

	draw_icon_ex (icon: WEL_ICON; x, y, icon_width, icon_height, frame_index: INTEGER; flicker_free_background: WEL_BRUSH; di_flags: INTEGER)
			-- Draw icon at the x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			icon_not_void: icon /= void
			icon_exists: icon.exists

	draw_state_bitmap (a_brush: WEL_BRUSH; a_bitmap: WEL_BITMAP; x, y: INTEGER; format: INTEGER)
			-- Draw the bitmap a_bitmap using format at the
			-- location (x,y) using the brush a_brush if format include Dss_mono.
			--
			-- See class DSS_xxx and DST_xxx constants in WEL_DRAWING_CONSTANTS for
			-- format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_bitmap_not_void: a_bitmap /= void

	draw_state_icon (a_brush: WEL_BRUSH; an_icon: WEL_GRAPHICAL_RESOURCE; x, y: INTEGER; format: INTEGER)
			-- Draw the icon/cursor an_icon using format at the
			-- location (x,y) using the brush a_brush if format include Dss_mono.
			--
			-- See class DSS_xxx and DST_xxx constants in WEL_DRAWING_CONSTANTS for
			-- format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			an_icon_not_void: an_icon /= void

	draw_state_text (a_brush: WEL_BRUSH; string: STRING; x, y: INTEGER; format: INTEGER)
			-- Draw the text string using format at the
			-- location (x,y) using the brush a_brush if format include Dss_mono.
			--
			-- See class DSS_xxx and DST_xxx constants in WEL_DRAWING_CONSTANTS for
			-- format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void

	draw_text (string: STRING; rect: WEL_RECT; format: INTEGER)
			-- Draw the text string inside
			-- the rect using format
			-- See class WEL_DT_CONSTANTS for format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
			rect_not_void: rect /= void

	draw_text_with_result (string: STRING; rect: WEL_RECT; format: INTEGER): INTEGER
			-- Draw the text string inside the rect using format.
			-- Return the height of the text drawn.
			-- See class WEL_DT_CONSTANTS for format value.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
			rect_not_void: rect /= void

	ellipse (left, top, right, bottom: INTEGER)
			-- Draw an ellipse into a rectangle specified by
			-- left, top and right, bottom.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	fill_rect (a_rect: WEL_RECT; a_brush: WEL_BRUSH)
			-- Fill a a_rect using a_brush.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_rect_not_void: a_rect /= void
			a_brush_not_void: a_brush /= void
			a_brush_exists: a_brush.exists

	fill_region (a_region: WEL_REGION; a_brush: WEL_BRUSH)
			-- Fill a_region using a_brush.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_region_not_void: a_region /= void
			a_brush_not_void: a_brush /= void
			a_brush_exists: a_brush.exists

	flood_fill_border (x, y: INTEGER; color: WEL_COLOR_REF)
			-- Fill an area which is bounded by color starting
			-- at x, y.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			color_not_void: color /= void

	flood_fill_surface (x, y: INTEGER; color: WEL_COLOR_REF)
			-- Fill an area which is defined by color starting
			-- at x, y. Filling continues outward in all
			-- directions as long as the color is encountered.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			color_not_void: color /= void

	get
			-- Get the device context

	invert_rect (a_rect: WEL_RECT)
			-- Invert a_rect in a window by performing a logical
			-- NOT operation on the color values for each pixel.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_rect_not_void: a_rect /= void

	invert_region (a_region: WEL_REGION)
			-- Invert the colors in a_region.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_region_not_void: a_region /= void
			a_region_exists: a_region.exists

	line (x1, y1, x2, y2: INTEGER)
			-- Draw a line from x1, y1 to x2, y2.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	line_to (x, y: INTEGER)
			-- Draw a line from the current position
			-- to x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	mask_blt (x_destination, y_destination, a_width, a_height: INTEGER; dc_source: WEL_DC; x_source, y_source: INTEGER; mask_bitmap: WEL_BITMAP; x_mask, y_mask, raster_operation: INTEGER)
			-- Combines the color data for the source and destination bitmaps using the specified mask and raster operation.
			-- See class WEL_RASTER_OPERATIONS_CONSTANTS for
			-- raster_operation values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			positive_width: a_width >= 0
			positive_height: a_height >= 0
			dc_source_not_void: dc_source /= void
			dc_source_exists: dc_source.exists
			mask_bitmap_not_void: mask_bitmap /= void
			function_is_supported: mask_blt_supported

	move_to (x, y: INTEGER)
			-- Set the current position to x, y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	pat_blt (x_destination, y_destination, a_width, a_height: INTEGER; raster_operation: INTEGER)
			-- Paint the rectangle specified by x_destination,
			-- y_destination, a_width, a_height using the brush
			-- that is currently selected into this device context.
			-- The brush color and the surface color or colors are
			-- combined by using the raster_operation.
			-- See class WEL_RASTER_OPERATIONS_CONSTANTS for
			-- raster_operation values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			positive_width: a_width >= 0
			positive_height: a_height >= 0

	pie (left, top, right, bottom, x_start_point, y_start_point, x_end_point, y_end_point: INTEGER)
			-- Draw a pie-shaped wedge by drawing an elliptical
			-- arc whose center and two endpoints are joined
			-- by lines. The pie is drawn into a rectangle
			-- specified by left, top and right, bottom,
			-- starting at x_start_point, y_start_point
			-- and ending at x_end_point, y_end_point.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	poly_bezier (points: ARRAY [INTEGER])
			-- Draw one or more Bezier curves by using the
			-- endpoints and control points specified by points.
			-- The first curve is drawn from the first point to the
			-- fourth point by using the second and third points as
			-- control points. Each subsequent curve in the sequence
			-- needs exactly three more points: the ending point of
			-- the previous curve is used as the starting point, the
			-- next two points in the sequence are control points,
			-- and the third is the ending point.
			-- The current position is neither used nor updated by
			-- this procedure.
			-- (from WEL_DC)
		require -- from WEL_DC
			points_not_void: points /= void
			points_count_ok: points.count \\ 2 = 0

	poly_bezier_to (points: ARRAY [INTEGER])
			-- Draw one or more Bezier curves by using the control
			-- points specified by points. The first curve is
			-- drawn from the current position to the third point
			-- by using the first two points as control points.
			-- For each subsequent curve, the procedure needs
			-- exactly three more points, and uses the ending point
			-- of the previous curve as the starting point for the
			-- next.
			-- This procedure moves the current position to the
			-- ending point of the last Bezier curve.
			-- (from WEL_DC)
		require -- from WEL_DC
			points_not_void: points /= void
			points_count_ok: points.count \\ 2 = 0

	polygon (points: ARRAY [INTEGER])
			-- Draw a polygon consisting of two or more points
			-- connected by lines.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			points_not_void: points /= void
			points_count: points.count \\ 2 = 0

	polyline (points: ARRAY [INTEGER])
			-- Draws a series of line segments by connecting the
			-- points specified in points.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			points_not_void: points /= void
			points_count: points.count \\ 2 = 0

	realize_palette
			-- Map palette entries from the current logical
			-- palette on the system palette.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			palette_selected: palette_selected

	rectangle (left, top, right, bottom: INTEGER)
			-- Draw a rectangle from left, top
			-- to right, bottom.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	release
			-- Release the device context

	remove_clip_region
			-- Remove the current clipping region.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	round_rect (left, top, right, bottom, ellipse_width, ellipse_height: INTEGER)
			-- Draw a rectangle from left, top to
			-- right, bottom with rounded corners.
			-- The rounded corners are specified by the
			-- ellipse_width and ellipse_height.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists

	save_bitmap (a_bitmap: WEL_BITMAP; file: FILE_NAME)
			-- Save a_bitmap in file.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_bitmap_not_void: a_bitmap /= void
			a_bitmap_exists: a_bitmap.exists
			file_not_void: file /= void
			file_is_valid: file.is_valid

	select_clip_region (a_region: WEL_REGION)
			-- Select a_region as the current clipping region.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			a_region_not_void: a_region /= void
			a_region_exists: a_region.exists

	set_pixel (x, y: INTEGER; color: WEL_COLOR_REF)
			-- Set the pixel at x, y position.
			-- with the color color.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			color_not_void: color /= void

	stretch_blt (x_destination, y_destination, width_destination, height_destination: INTEGER; dc_source: WEL_DC; x_source, y_source, width_source, height_source, raster_operation: INTEGER)
			-- Copy a bitmap from the dc_source to
			-- the current device context, from x_source,
			-- y_source to x_destination, y_destination,
			-- using width and height with raster_operation.
			-- See class WEL_RASTER_OPERATIONS_CONSTANTS for
			-- raster_operation values.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			positive_width_destination: width_destination >= 0
			positive_height_destination: height_destination >= 0
			positive_width_source: width_source >= 0
			positive_height_source: height_source >= 0
			dc_source_not_void: dc_source /= void
			dc_source_exists: dc_source.exists

	stretch_di_bits (x_destination, y_destination, a_width, a_height, x_source, y_source, dib_width, dib_height: INTEGER; dib: WEL_DIB; bitmap_info: WEL_BITMAP_INFO; rgb_mode, raster_operation: INTEGER)
			-- Copy a dib to the current device context, from
			-- x_source, y_source to x_destination,
			-- y_destination, using a_width and a_height
			-- with raster_operation and rgb_mode
			-- See class WEL_RASTER_OPERATIONS_CONSTANTS for
			-- raster_operation values
			-- See class WEL_DIB_COLORS_CONSTANTS for
			-- rgb_mode values
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			positive_width: a_width >= 0
			positive_height: a_height >= 0
			dib_not_void: dib /= void
			bitmap_not_void: bitmap_info /= void
			valid_rgb_mode: valid_dib_colors_constant (rgb_mode)

	tabbed_text_out (x, y: INTEGER; string: STRING; tabulations: ARRAY [INTEGER]; tabulations_origin: INTEGER)
			-- Write string on x and y position expanding
			-- tabs to the values specified in tabulations.
			-- tabulations_origin specifies the x-coordinate of
			-- the starting position from which tabs are expanded.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
			tabulations_not_void: tabulations /= void

	text_out (x, y: INTEGER; string: STRING)
			-- Write string on x and y position.
			-- (from WEL_DC)
		require -- from WEL_DC
			exists: exists
			string_not_void: string /= void
	
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)
		-- from WEL_DC
	valid_background_mode: exists implies is_opaque /= is_transparent

end -- class WEL_COMPATIBLE_DC