Lower CPU usage

Screen will not be always updated

mopidy_touchscreen/screens/base_screen.py

@@ -1,12 +1,16 @@
 class BaseScreen():
 
+    update_all = 0
+    update_partial = 1
+    no_update = 2
+
     def __init__(self, size, base_size, manager, fonts):
         self.size = size
         self.base_size = base_size
         self.manager = manager
         self.fonts = fonts
 
-    def update(self, surface):
+    def update(self, surface, update_type, rects):
         pass
 
     def event(self, event):
@@ -14,3 +18,6 @@ class BaseScreen():
 
     def change_screen(self, direction):
         return False
+
+    def should_update(self):
+        return BaseScreen.update_partial