init.lua

local awful       = require("awful")
local beautiful   = require("beautiful")
local helpers     = require("lain.helpers")
local proxy       = require("dbus_proxy")
local wibox       = require("wibox")

local MediaPlayer = {}

function MediaPlayer:new(args)
	return setmetatable({}, {__index = self}):init(args)
end

function MediaPlayer:init(args)
	self.font  = args.font or beautiful.font
	self.icons = args.icons or {
		play  = args.play_icon  or beautiful.play,
		pause = args.pause_icon or beautiful.pause,
		stop  = args.stop_icon  or beautiful.stop
	}

	self.autohide = args.autohide == nil
	self.widget   = wibox.widget {
		{
			id = "icon",
			widget = wibox.widget.imagebox,
		},
		{
			id = 'current_song',
			widget = wibox.widget.textbox,
			font = self.font
		},
		layout = wibox.layout.fixed.horizontal,
		set_status = function(self, image)
			self.icon.image = image
		end,
		set_text = function(self, text)
			self.current_song.markup = text
		end,
	}

	self.dbus = proxy.monitored.new({
		bus       = proxy.Bus.SESSION,
		name      = "org.mpris.MediaPlayer2." .. args.name or "spotify",
		path      = "/org/mpris/MediaPlayer2",
		interface = "org.mpris.MediaPlayer2.Player"
	})

	-- Higher refresh_rate == less CPU requirements
	-- Lower refresh_rate == better Widget response time
	self:watch(args.refresh_rate or 3)
	self:signal()

	return self
end

function MediaPlayer:escape_xml(str)
	str = string.gsub(str, "&", "&")
	str = string.gsub(str, "<", "&lt;")
	str = string.gsub(str, ">", "&gt;")
	str = string.gsub(str, "'", "&apos;")
	str = string.gsub(str, '"', "&quot;")

	return str
end

function MediaPlayer:update_widget_icon(output)
	output = string.gsub(output, "\n", "")
	self.widget:set_status(
		(output == 'Playing') and self.icons.play or self.icons.pause
	)
end

function MediaPlayer:update_widget_text(output)
	self.widget:set_text(self:escape_xml(output))
	self.widget:set_visible(true)
end

function MediaPlayer:hide_widget()
	self.widget:set_text('Offline')
	self.widget:set_status(self.icons.stop)
	self.widget:set_visible(not self.autohide)
end

function MediaPlayer:info()
	if not self.dbus.is_connected then
		return {}
	end

	local metadata = self.dbus:Get(self.dbus.interface, "Metadata")
	local status   = self.dbus:Get(self.dbus.interface, "PlaybackStatus")

	local artists = metadata["xesam:artist"]
	if type(artists) == "table" then
		artists = table.concat(artists, ", ")
	end

	local info = {
		album = metadata["xesam:album"],
		title = metadata["xesam:title"],
		artists = artists,
		status = status
	}

	return info
end

function MediaPlayer:watch(refresh_rate)
	local update_widget = function()
		local info = self:info()
		-- Status unavailable? Media Player isn't active, hide the widget
		if not info["status"] then
			self:hide_widget()
		else
			if not (info.artists == nil or info.title == nil) then
				-- Change the artist and title fields in case they aren't nil
				self:update_widget_icon(info["status"])
				self:update_widget_text(
					string.format(
						"%s | %s",
						info.artists,
						info.title
					)
				)
			end
		end
	end

	helpers.newtimer("media-player", refresh_rate, update_widget)
end

function MediaPlayer:signal()
	local spawn_update = function()
		awful.spawn.easy_async(
			function() self:info() end,
			function(info)
				self:update_widget_icon(info["status"])
		end)
	end

	self.widget:buttons(
		awful.util.table.join(
			awful.button(
				{}, 1, -- button 1: left click  - play/pause
				function()
					awful.spawn.easy_async(self.dbus:PlayPause(), spawn_update)
				end
			),
			awful.button(
				{}, 4, -- button 4: scroll up   - next song
				function()
					awful.spawn.easy_async(self.dbus:Next(), spawn_update)
				end
			),
			awful.button(
				{}, 5, -- button 5: scroll down - previous song
				function()
					awful.spawn.easy_async(self.dbus:Previous(), spawn_update)
				end
			)
		)
	)
end

return setmetatable(MediaPlayer, { __call = MediaPlayer.new, })