indexing
	description: "Pixel buffer used for storing RGBA values."
	legal: "See notice at end of class."
	status: "See notice at end of class."
	keywords: "drawable, primitives, figures, buffer, bitmap, picture"
	date: "$Date: 2007-10-09 11:12:13 -0700 (Tue, 09 Oct 2007) $"
	revision: "$Revision: 70540 $"

class interface
	EV_PIXEL_BUFFER


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: default_create_called
			is_in_default_state: is_in_default_state

	make_with_size (a_width, a_height: INTEGER_32)
			-- Create pixel buffer with width `a_width' and height `a_height'.
		require
			a_width_valid: a_width > 0
			a_height_valid: a_height > 0

	make_with_pixmap (a_pixmap: EV_PIXMAP)
			-- Create with `a_pixmap''s image data.
		require
			not_void: a_pixmap /= Void

convert
	make_with_pixmap ({EV_PIXMAP})

feature -- Access

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

	generating_type: STRING_8
			-- Name of current object's generating type
			-- (type of which it is a direct instance)
			-- (from ANY)
		ensure -- from ANY
			generating_type_not_void: Result /= Void
			generating_type_not_empty: not Result.is_empty

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)
		ensure -- from ANY
			generator_not_void: Result /= Void
			generator_not_empty: not Result.is_empty
	
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 (other /= Void and then 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 is_deep_equal (other: EV_PIXEL_BUFFER): BOOLEAN
			-- Are `Current' and `other' attached to isomorphic object structures?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			shallow_implies_deep: standard_is_equal (other) implies Result
			same_type: Result implies same_type (other)
			symmetric: Result implies other.is_deep_equal (Current)

	is_equal (other: EV_PIXEL_BUFFER): BOOLEAN
			-- Is `other' attached to an object considered
			-- equal to current object?
			-- (from ANY)
		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: EV_PIXEL_BUFFER): 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

	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))
	
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
	
feature -- Duplication

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

	frozen deep_copy (other: EV_PIXEL_BUFFER)
			-- 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: EV_PIXEL_BUFFER
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		ensure -- from ANY
			deep_twin_not_void: Result /= Void
			deep_equal: deep_equal (Current, Result)

	frozen standard_copy (other: EV_PIXEL_BUFFER)
			-- 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: EV_PIXEL_BUFFER
			-- 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: EV_PIXEL_BUFFER
			-- 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: ?EV_PIXEL_BUFFER
			-- 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)
	
feature -- Implementation

	implementation: EV_PIXEL_BUFFER_I
			-- Implementation interface
	
feature -- Command

	destroy
			-- Destroy underlying native toolkit object.
			-- Render `Current' unusable.
			-- (from EV_ANY)
		ensure -- from EV_ANY
			is_destroyed: is_destroyed

	draw_pixel_buffer_with_x_y (a_x, a_y: INTEGER_32; a_pixel_buffer: EV_PIXEL_BUFFER)
			-- Draw `a_pixel_buffer' at `a_x', `a_y'.
		require
			not_void: a_pixel_buffer /= Void
			vaild: a_x >= 0 and a_y >= 0 and a_x < width and a_y < height

	draw_text (a_text: STRING_GENERAL; a_font: EV_FONT; a_point: EV_COORDINATE)
			-- Draw `a_text' with `a_font' at `a_rect'.
		require
			not_void: a_text /= Void
			not_void: a_font /= Void
			not_void: a_point /= Void

	lock
			-- Lock pixel buffer for data access.
		require
			not_locked: not is_locked
		ensure
			is_locked: is_locked

	pixel_iterator: EV_PIXEL_BUFFER_ITERATOR
			-- Return a pixel buffer iterator covering.
		require
			is_locked: is_locked
		ensure
			result_not_void: Result /= Void

	save_to_named_file (a_file_name: STRING_8)
			-- Save pixel data to file `a_file_name'.
		require
			a_file_name_valid: a_file_name /= Void and then not a_file_name.is_empty
			not_locked: not is_locked

	set_with_named_file (a_file_name: STRING_8)
			-- Load pixel data from file `a_file_name'
		require
			a_file_name_valid: a_file_name /= Void and then not a_file_name.is_empty
			not_locked: not is_locked

	sub_pixel_buffer (a_rect: EV_RECTANGLE): EV_PIXEL_BUFFER
			-- Return a sub pixel buffer of `Current' represented by area `a_rect'.
		require
			not_void: a_rect /= Void
			not_locked: not is_locked
		ensure
			result_not_void: Result /= Void
			result_not_current: Result /= Current

	sub_pixmap (a_rect: EV_RECTANGLE): EV_PIXMAP
			-- Return a pixmap region of `Current' represented by area `a_rect'.
		require
			not_void: a_rect /= Void
			not_locked: not is_locked
		ensure
			result_not_void: Result /= Void

	to_pixmap: EV_PIXMAP
			-- Convert to EV_PIXMAP.

	unlock
			-- Unlock from data access with pixel_iterator.
		ensure
			not_locked: not is_locked
	
feature -- Output

	io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)
		ensure -- from ANY
			io_not_void: Result /= Void

	out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		ensure -- from ANY
			out_not_void: Result /= Void

	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
			-- (from ANY)
		ensure -- from ANY
			tagged_out_not_void: Result /= Void
	
feature -- Platform

	operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
		ensure -- from ANY
			operating_environment_not_void: Result /= Void
	
feature -- Query

	height: INTEGER_32
			-- Height of `Current' in pixels.
		ensure
			valid_height: Result >= 0

	is_locked: BOOLEAN
			-- Is buffer locked for data access.

	width: INTEGER_32
			-- Width of `Current' in pixels.
		ensure
			valid_width: Result >= 0
	
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
		-- 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_PIXEL_BUFFER