Add event processing functionality to RemoteControl

Author: ddemidov

ev3dev.py

@@ -2296,44 +2296,86 @@ class RemoteControl(object):
             11: ['blue_up',  'blue_down']
             }
 
+    on_red_up    = None
+    on_red_down  = None
+    on_blue_up   = None
+    on_blue_down = None
+    on_beacon    = None
+    on_change    = None
+
     def __init__(self, sensor=None, channel=1):
         if sensor is None:
             self._sensor = InfraredSensor()
         else:
             self._sensor = sensor
 
         self._channel = max(1, min(4, channel)) - 1
+        self._state = set([])
 
         if self._sensor.connected:
             self._sensor.mode = 'IR-REMOTE'
 
     @property
     def buttons_pressed(self):
+        """
+        Returns list of currently pressed buttons.
+        """
         return RemoteControl._BUTTON_VALUES.get(self._sensor.value(self._channel), [])
 
     @property
     def any(self):
+        """
+        Checks if any button is pressed.
+        """
         return bool(self.buttons_pressed)
 
     def check_buttons(self, buttons=[]):
         return set(self.buttons_pressed) == set(buttons)
 
     @property
     def red_up(self):
+        """
+        Checks if `red_up` button is pressed
+        """
         return 'red_up' in self.buttons_pressed
 
     @property
     def red_down(self):
+        """
+        Checks if `red_down` button is pressed
+        """
         return 'red_down' in self.buttons_pressed
 
     @property
     def blue_up(self):
+        """
+        Checks if `blue_up` button is pressed
+        """
         return 'blue_up' in self.buttons_pressed
 
     @property
     def blue_down(self):
+        """
+        Checks if `blue_down` button is pressed
+        """
         return 'blue_down' in self.buttons_pressed
 
     @property
     def beacon(self):
+        """
+        Checks if `beacon` button is pressed
+        """
         return 'beacon' in self.buttons_pressed
+
+    def process(self):
+        new_state = set(self.buttons_pressed)
+        old_state = self._state
+        self._state = new_state
+
+        state_diff = new_state.symmetric_difference(old_state)
+        for button in state_diff:
+            handler = getattr(self, 'on_' + button)
+            if handler is not None: handler(button in new_state)
+
+        if self.on_change is not None and state_diff:
+            self.on_change([(button, button in new_state) for button in state_diff])