awesomewm/modules/backlight/util.lua

local backlight = {}

backlight.get = function(callback)
	awful.spawn.easy_async(
		"xbacklight -get",
		function(stdout, stderr, exitreason, exitcode)
			callback(tonumber(stdout))
		end
	)
end

backlight.set = function(value)
	awful.spawn("xbacklight -set " .. value, false)
end

backlight.watch = function(timeout, callback, widget)
	awful.widget.watch(
		"xbacklight -get",
		timeout,
		callback,
		widget
	)
end


backlight.backlight_up = function(value)
	awful.spawn.easy_async(
		"xbacklight -inc " .. value,
		function(stdout, stderr, exitreason, exitcode)
			awesome.emit_signal("module::backlight:update_read")
		end
	)
end

backlight.backlight_down = function(value)
	awful.spawn.easy_async(
		"xbacklight -dec " .. value,
		function(stdout, stderr, exitreason, exitcode)
			awesome.emit_signal("module::backlight:update_read")
		end
	)
end

awesome.connect_signal("module::backlight:update_read",
	function()
		backlight.get(
			function(value)
				awesome.emit_signal(
					"module::backlight:update",
					value
				)
			end
		)
	end
)


return backlight