fix lost of frontlight intensity after exiting kobo

This should fix #243.

frontend/ui/device.lua

@@ -221,13 +221,12 @@ function Device:getFrontlight()
 	elseif self:hasFrontlight() then
 		local model = self:getModel()
 		if model == "KindlePaperWhite" or model == "KindlePaperWhite2" then
-			self.frontlight = KindleFrontLight
+			self.frontlight = KindleFrontLight:new()
 		elseif self:isKobo() then
-			self.frontlight = KoboFrontLight
+			self.frontlight = KoboFrontLight:new()
 		else -- emulated FrontLight
-			self.frontlight = BaseFrontLight
+			self.frontlight = BaseFrontLight:new()
 		end
-		self.frontlight:init()
 	end
 	return self.frontlight
 end

frontend/ui/device/basefrontlight.lua

@@ -3,6 +3,14 @@ local BaseFrontLight = {
 	intensity = nil,
 }
 
+function BaseFrontLight:new(o)
+	local o = o or {}
+	setmetatable(o, self)
+	self.__index = self
+	if o.init then o:init() end
+	return o
+end
+
 function BaseFrontLight:init() end
 function BaseFrontLight:toggle() end
 function BaseFrontLight:setIntensityHW() end

frontend/ui/device/kindlefrontlight.lua

@@ -1,7 +1,7 @@
 local BaseFrontLight = require("ui/device/basefrontlight")
 -- liblipclua, see require below
 
-local KindleFrontLight = {
+local KindleFrontLight = BaseFrontLight:new{
 	min = 0, max = 24,
 	-- FIXME: Check how to handle this on the PW2, initial reports on IRC suggest that this isn't possible anymore
 	kpw_fl = "/sys/devices/system/fl_tps6116x/fl_tps6116x0/fl_intensity",
@@ -28,8 +28,6 @@ function KindleFrontLight:toggle()
 	end
 end
 
-KindleFrontLight.setIntensity = BaseFrontLight.setIntensity
-
 function KindleFrontLight:setIntensityHW()
 	if self.lipc_handle ~= nil then
 		self.lipc_handle:set_int_property("com.lab126.powerd", "flIntensity", self.intensity)

frontend/ui/device/kobofrontlight.lua

@@ -1,6 +1,6 @@
 local BaseFrontLight = require("ui/device/basefrontlight")
 
-local KoboFrontLight = {
+local KoboFrontLight = BaseFrontLight:new{
 	min = 1, max = 100,
 	intensity = 20,
 	restore_settings = true,
@@ -17,8 +17,6 @@ function KoboFrontLight:toggle()
 	end
 end
 
-KoboFrontLight.setIntensity = BaseFrontLight.setIntensity
-
 function KoboFrontLight:setIntensityHW()
 	if self.fl ~= nil then
 		self.fl:setBrightness(self.intensity)