awesomewm/modules/backlight/util.lua

local brightnessctl = {}
brightnessctl.parse = function(s)
	local batpec = string.match(s, ",%d?%d?%d%%,")
	batpec = batpec:sub(2, batpec:len() - 2)
	return tonumber(batpec)
end

brightnessctl.get = function(callback)
	awful.spawn.easy_async(
		"brightnessctl info -m",
		function(stdout, stderr, exitreason, exitcode)
			callback(brightnessctl.parse(stdout))
		end
	)
end

brightnessctl.set = function(value)
	awful.spawn.easy_async(
		"brightnessctl set " .. value .. "% -m",
		function(stdout, stderr, exitreason, exitcode)
			awesome.emit_signal(
				"module::backlight:update",
				brightnessctl.parse(stdout)
			)
		end
	)
end

brightnessctl.watch = function(timeout, callback, widget)
	awful.widget.watch(
		"brightnessctl get -m",
		timeout,
		function(stdout, stderr, exitreason, exitcode)
			callback(brightnessctl.parse(stdout))
		end,
		widget
	)
end

brightnessctl.backlight_up = function(value)
	awful.spawn.easy_async(
		"brightnessctl set " .. value .. "%+ -m",
		function(stdout, stderr, exitreason, exitcode)
			awesome.emit_signal(
				"module::backlight:update",
				brightnessctl.parse(stdout)
			)
		end
	)
end

brightnessctl.backlight_down = function(value)
	awful.spawn.easy_async(
		"brightnessctl set " .. value .. "%- -m",
		function(stdout, stderr, exitreason, exitcode)
			awesome.emit_signal(
				"module::backlight:update",
				brightnessctl.parse(stdout)
			)
		end
	)
end


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

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

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


xbacklight.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

xbacklight.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


local backlight = {}
if config.backlight.backend == "xbacklight" then
	backlight = xbacklight
elseif  config.backlight.backend == "brightnessctl" then
	backlight = brightnessctl
else
	backlight = xbacklight
end



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


return backlight