Turn TimerManager into a Singleton

software/src/app.py

@@ -4,16 +4,17 @@
 from collections import namedtuple
 import os
 import time
+from utils import TimerManager
 
 
-Dependencies = namedtuple('PlayerAppDependencies', ('mp3player', 'timermanager', 'nfcreader', 'buttons'))
+Dependencies = namedtuple('Dependencies', ('mp3player', 'nfcreader', 'buttons'))
 
 
 class PlayerApp:
     def __init__(self, deps: Dependencies):
         self.current_tag = None
         self.current_tag_time = time.ticks_ms()
-        self.timer_manager = deps.timermanager(self)
+        self.timer_manager = TimerManager()
         self.player = deps.mp3player(self)
         self.nfc = deps.nfcreader(self)
         self.buttons = deps.buttons(self) if deps.buttons is not None else None

software/src/main.py

@@ -92,20 +92,17 @@ def run():
         player.set_volume(32)
         asyncio.create_task(player.task())
 
-        timer_manager = TimerManager(True)
-
         # Setup NFC
         reader = MFRC522(spi_id=1, sck=10, miso=12, mosi=11, cs=13, rst=9, tocard_retries=20)
 
         # Setup app
         deps = app.Dependencies(mp3player=lambda _: player,
-                                timermanager=lambda _: timer_manager,
                                 nfcreader=lambda the_app: Nfc(reader, the_app),
                                 buttons=lambda the_app: Buttons(the_app))
         the_app = app.PlayerApp(deps)
 
         # Start
-        asyncio.create_task(aiorepl.task({'player': player, 'timer_manager': timer_manager,
+        asyncio.create_task(aiorepl.task({'timer_manager': TimerManager(),
                                           'app': the_app}))
         asyncio.get_event_loop().run_forever()
 

software/src/utils/timer.py

@@ -5,13 +5,20 @@ import asyncio
 import heapq
 import time
 
+TIMER_DEBUG = True
 
-class TimerManager:
-    def __init__(self, timer_debug=False):
-        self.timers = []
-        self.timer_debug = timer_debug
-        self.task = asyncio.create_task(self._timer_worker())
-        self.worker_event = asyncio.Event()
+
+class TimerManager(object):
+    _instance = None
+
+    def __new__(cls):
+        if cls._instance is None:
+            cls._instance = super(TimerManager, cls).__new__(cls)
+            cls._instance.timers = []
+            cls._instance.timer_debug = TIMER_DEBUG
+            cls._instance.task = asyncio.create_task(cls._instance._timer_worker())
+            cls._instance.worker_event = asyncio.Event()
+        return cls._instance
 
     def schedule(self, when, what):
         cur_nearest = self.timers[0][0] if len(self.timers) > 0 else None