note
	description: "[
								Battery/power supply informations.
								You should never take a battery status as absolute truth. 
								Batteries (especially failing batteries) are delicate hardware, 
								and the values reported here are best estimates based on what that 
								hardware reports. It's not uncommon for older batteries to lose 
								stored power much faster than it reports, or completely drain when 
								reporting it has 20 percent left, etc.
		
								Battery status can change at any time; if you are concerned with power state,
								you should call this function frequently, and perhaps ignore changes until
								they seem to be stable for a few seconds.
	]"
	author: "Louis Marchand"
	date: "Thu, 28 Jan 2016 02:17:06 +0000"
	revision: "2.0"

class 
	GAME_BATTERY

create 
	default_create

feature {NONE} -- Initialization

	default_create
			-- Initialization of Current
		do
			create null
			update
		end
	
feature -- Access

	generating_type: TYPE [detachable GAME_BATTERY]
			-- Type of current object
			-- (type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generating_type_not_void: Result /= Void
		end

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generator_not_void: Result /= Void
			generator_not_empty: not Result.is_empty
		end

	has_error: BOOLEAN
			-- Is the library has generate an error
			-- (from GAME_ERROR_MANAGER)

	last_error: READABLE_STRING_GENERAL
			-- The last error generate by the library
			-- (from GAME_SDL_ANY)
		local
			l_string: C_STRING
		do
			if is_manual_error then
				Result := Precursor {GAME_ERROR_MANAGER}
			else
				create l_string.make_by_pointer ({GAME_SDL_EXTERNAL}.sdl_geterror)
				Result := l_string.string
			end
		end

	update
			-- Check the battery state and life to update the features of Current
		local
			l_seconds, l_percentage: INTEGER_32
		do
			state := {GAME_SDL_EXTERNAL}.sdl_getpowerinfo ($l_seconds.to_pointer, $l_percentage.to_pointer)
			seconds_left := l_seconds
			percentage_left := l_percentage
			if l_seconds < 0 or l_percentage < 0 then
				is_life_left_valid := False
			else
				is_life_left_valid := True
			end
		end
	
feature -- Comparison

	frozen deep_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void
			-- or attached to isomorphic object structures?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_deep_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			shallow_implies_deep: standard_equal (a, b) implies Result
			both_or_none_void: (a = Void) implies (Result = (b = Void))
			same_type: (Result and (a /= Void)) implies (b /= Void and then a.same_type (b))
			symmetric: Result implies deep_equal (b, a)
		end

	frozen equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached
			-- to objects considered equal?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.is_equal (b))
		end

	frozen is_deep_equal alias "≡≡≡" (other: GAME_BATTERY): BOOLEAN
			-- Are Current and other attached to isomorphic object structures?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		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)
		end

	is_equal (other: GAME_BATTERY): BOOLEAN
			-- Is other attached to an object considered
			-- equal to current object?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			symmetric: Result implies other ~ Current
			consistent: standard_is_equal (other) implies Result
		end

	frozen standard_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached to
			-- field-by-field identical objects of the same type?
			-- Always uses default object comparison criterion.
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.standard_is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.standard_is_equal (b))
		end

	frozen standard_is_equal alias "≜" (other: GAME_BATTERY): 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
		external
			"built_in"
		ensure -- from ANY
			same_type: Result implies same_type (other)
			symmetric: Result implies other.standard_is_equal (Current)
		end
	
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
		external
			"built_in"
		end

	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
		external
			"built_in"
		ensure -- from ANY
			definition: Result = (conforms_to (other) and other.conforms_to (Current))
		end
	
feature -- Duplication

	frozen clone (other: detachable ANY): like other
		obsolete "Use `twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- equal to other
			--
			-- For non-void other, clone calls copy;
			-- to change copying/cloning semantics, redefine copy.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.twin
			end
		ensure -- from ANY
			instance_free: class
			equal: Result ~ other
		end

	copy (other: GAME_BATTERY)
			-- Update current object using fields of object attached
			-- to other, so as to yield equal objects.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		external
			"built_in"
		ensure -- from ANY
			is_equal: Current ~ other
		end

	frozen deep_clone (other: detachable ANY): like other
		obsolete "Use `deep_twin' instead. [2017-05-31]"
			-- Void if other is void: otherwise, new object structure
			-- recursively duplicated from the one attached to other
			-- (from ANY)
		do
			if other /= Void then
				Result := other.deep_twin
			end
		ensure -- from ANY
			instance_free: class
			deep_equal: deep_equal (other, Result)
		end

	frozen deep_copy (other: GAME_BATTERY)
			-- Effect equivalent to that of:
			--		copy (other . deep_twin)
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		do
			copy (other.deep_twin)
		ensure -- from ANY
			deep_equal: deep_equal (Current, other)
		end

	frozen deep_twin: GAME_BATTERY
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			deep_twin_not_void: Result /= Void
			deep_equal: deep_equal (Current, Result)
		end

	frozen standard_clone (other: detachable ANY): like other
		obsolete "Use `standard_twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.standard_twin
			end
		ensure -- from ANY
			instance_free: class
			equal: standard_equal (Result, other)
		end

	frozen standard_copy (other: GAME_BATTERY)
			-- 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)
		external
			"built_in"
		ensure -- from ANY
			is_standard_equal: standard_is_equal (other)
		end

	frozen standard_twin: GAME_BATTERY
			-- New object field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			standard_twin_not_void: Result /= Void
			equal: standard_equal (Result, Current)
		end

	frozen twin: GAME_BATTERY
			-- New object equal to Current
			-- twin calls copy; to change copying/twinning semantics, redefine copy.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			twin_not_void: Result /= Void
			is_equal: Result ~ Current
		end
	
feature -- Basic operations

	frozen as_attached: attached GAME_BATTERY
		obsolete "Remove calls to this feature. [2017-05-31]"
			-- Attached version of Current.
			-- (Can be used during transitional period to convert
			-- non-void-safe classes to void-safe ones.)
			-- (from ANY)
		do
			Result := Current
		end

	frozen default: detachable GAME_BATTERY
			-- Default value of object's type
			-- (from ANY)
		do
		end

	frozen default_pointer: POINTER
			-- Default value of type POINTER
			-- (Avoid the need to write p.default for
			-- some p of type POINTER.)
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end

	default_rescue
			-- Process exception for routines with no Rescue clause.
			-- (Default: do nothing.)
			-- (from ANY)
		do
		end

	frozen do_nothing
			-- Execute a null action.
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end
	
feature {NONE} -- Implementation

	clear_error
			-- Remove error pending in Current
			-- (from GAME_SDL_ANY)
		require -- from  GAME_ERROR_MANAGER
			True
		do
			{GAME_SDL_EXTERNAL}.sdl_clearerror
			Precursor {GAME_ERROR_MANAGER}
			is_manual_error := False
		ensure -- from GAME_ERROR_MANAGER
			no_error: not has_error
		ensure then -- from GAME_SDL_ANY
			no_error: not is_manual_error
		end

	disable_print_on_error
			-- Desactive the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (False)
		end

	enable_print_on_error
			-- Active the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (True)
		end

	is_manual_error: BOOLEAN
			-- Is the current pending error is a manual error (using manual_error as message)
			-- (from GAME_SDL_ANY)

	manage_error_boolean (a_boolean: BOOLEAN; a_message: READABLE_STRING_GENERAL)
			-- Create an error if a_boolean is false.
			-- If there is an error, append a_message to the error message
			-- on the SDL2 library
			-- (from GAME_SDL_ANY)
		do
			if not a_boolean then
				if Print_on_error_internal.item then
					Io.Error.put_string (a_message.to_string_8 + "%N");
					Io.Error.put_string (last_error.to_string_8 + "%N")
				end
				has_error := True
			end
		ensure -- from GAME_SDL_ANY
				not a_boolean implies has_error
		end

	manage_error_code (a_error_code: INTEGER_32; a_message: READABLE_STRING_GENERAL)
			-- If needed create an error depending of the error code a_code.
			-- If there is an error, append a_message to the error message
			-- on the SDL2 library
			-- (from GAME_SDL_ANY)
		do
			if a_error_code < 0 then
				if Print_on_error_internal.item then
					Io.Error.put_string (a_message.to_string_8 + "%N");
					Io.Error.put_string (last_error.to_string_8 + "%N")
				end
				has_error := True
			end
		end

	manage_error_pointer (a_pointer: POINTER; a_message: READABLE_STRING_GENERAL)
			-- Create an error if a_pointer is not valid.
			-- If there is an error, append a_message to the error message
			-- on the SDL2 library
			-- (from GAME_SDL_ANY)
		do
			if a_pointer.is_default_pointer then
				if Print_on_error_internal.item then
					Io.Error.put_string (a_message.to_string_8 + "%N");
					Io.Error.put_string (last_error.to_string_8 + "%N")
				end
				has_error := True
			end
		ensure -- from GAME_SDL_ANY
				a_pointer.is_default_pointer implies has_error
		end

	manual_error: detachable READABLE_STRING_GENERAL
			-- The specific message for the last error
			-- (from GAME_ERROR_MANAGER)

	null: POINTER
			-- A default null pointer

	print_on_error: BOOLEAN
			-- When an error occured, the library will print
			-- informations about the error on the error console
			-- output (default is True).
			-- (from GAME_ERROR_MANAGER)
		do
			Result := Print_on_error_internal.item
		end

	Print_on_error_internal: CELL [BOOLEAN]
			-- True when an error occured,
			-- The library will print it right away.
			-- (from GAME_ERROR_MANAGER)
		once ("PROCESS")
			create Result.put (True)
		end

	put_manual_error (a_general_message, a_specific_error: READABLE_STRING_GENERAL)
			-- Create an error using a_general_error for the debug information
			-- and a_specific_error for the lasting information
			-- (from GAME_SDL_ANY)
		do
			is_manual_error := True
			Precursor {GAME_ERROR_MANAGER} (a_general_message, a_specific_error)
		ensure -- from GAME_ERROR_MANAGER
				has_error
		end

	set_print_on_error (a_value: BOOLEAN)
			-- Assign to print_on_error the value of a_value
			-- (from GAME_ERROR_MANAGER)
		do
			if a_value then
				enable_print_on_error
			else
				disable_print_on_error
			end
		ensure -- from GAME_ERROR_MANAGER
			is_assign: print_on_error ~ a_value
		end

	state: NATURAL_32
			-- The last state of Current  returned by update
	
feature -- Output

	Io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)
		once
			create Result;
			Result.set_output_default
		ensure -- from ANY
			instance_free: class
			io_not_void: Result /= Void
		end

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

	print (o: detachable ANY)
			-- Write terse external representation of o
			-- on standard output.
			-- (from ANY)
		local
			s: READABLE_STRING_8
		do
			if attached o then
				s := o.out
				if attached {READABLE_STRING_32} s as s32 then
					Io.put_string_32 (s32)
				elseif attached {READABLE_STRING_8} s as s8 then
					Io.put_string (s8)
				else
					Io.put_string_32 (s.as_string_32)
				end
			end
		ensure -- from ANY
			instance_free: class
		end

	frozen tagged_out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			tagged_out_not_void: Result /= Void
		end
	
feature -- Platform

	Operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
		once
			create Result
		ensure -- from ANY
			instance_free: class
			operating_environment_not_void: Result /= Void
		end
	
feature {NONE} -- Retrieval

	frozen internal_correct_mismatch
			-- Called from runtime to perform a proper dynamic dispatch on correct_mismatch
			-- from MISMATCH_CORRECTOR.
			-- (from ANY)
		local
			l_msg: STRING_32
			l_exc: EXCEPTIONS
		do
			if attached {MISMATCH_CORRECTOR} Current as l_corrector then
				l_corrector.correct_mismatch
			else
				create l_msg.make_from_string ("Mismatch: ".as_string_32)
				create l_exc;
				l_msg.append (generating_type.name_32);
				l_exc.raise_retrieval_exception (l_msg)
			end
		end
	
feature -- Status Report

	is_life_left_valid: BOOLEAN
			-- The last update did not return any valid value for seconds_left and percentage_left.
			-- You can wait for some time and retry. If it is always not valid, maybe the system does not
			-- support battery life information or the system is not running on battery.

	is_state_charged: BOOLEAN
			-- plugged in, battery charged
		do
			Result := state = {GAME_SDL_EXTERNAL}.sdl_powerstate_charged
		end

	is_state_charging: BOOLEAN
			-- plugged in, charging battery
		do
			Result := state = {GAME_SDL_EXTERNAL}.sdl_powerstate_charging
		end

	is_state_no_battery: BOOLEAN
			-- plugged in, no battery available
		do
			Result := state = {GAME_SDL_EXTERNAL}.sdl_powerstate_no_battery
		end

	is_state_on_battery: BOOLEAN
			-- not plugged in, running on the battery
		do
			Result := state = {GAME_SDL_EXTERNAL}.sdl_powerstate_on_battery
		end

	is_state_unknown: BOOLEAN
			-- Cannot identify the state of Current
			-- You can wait for some time and retry.
			-- If it is always unknown, maybe the system does not support battery.
		do
			Result := state = {GAME_SDL_EXTERNAL}.sdl_powerstate_unknown
		end

	percentage_left: INTEGER_32
			-- An approximation of the percentage of battery life left

	seconds_left: INTEGER_32
			-- An approximation of the seconds of battery life left
	
invariant
		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

end -- class GAME_BATTERY

Generated by ISE EiffelStudio