Add untested DirectoryMonitoringEventHandler implementation

lib/tfw/components/directory_monitor.py

@@ -3,6 +3,7 @@ from watchdog.events import FileSystemEventHandler
 
 from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
 from tfw.components.decorators import RateLimiter
+from tfw.event_handler_base import TriggerlessEventHandler
 
 from tfw.config.logs import logging
 log = logging.getLogger(__name__)
@@ -65,3 +66,47 @@ class DirectoryMonitor:
             self.directorymonitor.pause()
         def __exit__(self, exc_type, exc_val, exc_tb):
             self.directorymonitor.resume()
+
+
+class DirectoryMonitoringEventHandler(TriggerlessEventHandler):
+    def __init__(self, key, directory):
+        super().__init__(key)
+        self._directory = directory
+        self._monitor = None
+        self.reload_monitor()
+        self.commands = {'pause':  self.pause,
+                         'resume': self.resume,
+                         'ignore': self.ignore}
+
+    @property
+    def monitor(self):
+        return self._monitor
+
+    def reload_monitor(self):
+        if self._monitor:
+            try: self._monitor.stop()
+            except KeyError: logging.debug('Working directory was removed – ignoring...')
+        self._monitor = DirectoryMonitor(self._directory)
+        self._monitor.watch()   # This runs on a separate thread
+
+    def handle_event(self, key, message):
+        try:
+            message['data'] = self.commands[message['data']['command']](message['data'])
+            return message
+        except KeyError:
+            log.error('IGNORING MESSAGE: Invalid message received: {}'.format(message))
+
+    def pause(self, data):
+        self.monitor.pause()
+        return data
+
+    def resume(self, data):
+        self.monitor.resume()
+        return data
+
+    def ignore(self, data):
+        self.monitor.ignore += data['ignore']
+        return data
+
+    def cleanup(self):
+        self.monitor.stop()