Added eventloop.Event.

jonathanslenders · jonathanslenders · commit 892f98e0cb9e · 2018-06-19T23:42:28.000+02:00
diff --git a/prompt_toolkit/eventloop/__init__.py b/prompt_toolkit/eventloop/__init__.py
@@ -5,6 +5,7 @@
 from .async_generator import AsyncGeneratorItem, generator_to_async_generator, consume_async_generator
 from .defaults import create_event_loop, create_asyncio_event_loop, use_asyncio_event_loop, get_event_loop, set_event_loop, run_in_executor, call_from_executor, run_until_complete
 from .future import Future, InvalidStateError
+from .event import Event
 
 __all__ = [
     # Base.
@@ -34,4 +35,7 @@
     # Futures.
     'Future',
     'InvalidStateError',
+
+    # Event.
+    'Event',
 ]
diff --git a/prompt_toolkit/eventloop/event.py b/prompt_toolkit/eventloop/event.py
@@ -0,0 +1,42 @@
+"""
+Asyncronous event implementation.
+"""
+from __future__ import unicode_literals
+from .future import Future
+
+__all__ = [
+    'Event'
+]
+
+
+class Event(object):
+    """
+    Like `asyncio.event`.
+
+    The state is intially false.
+    """
+    def __init__(self):
+        self._state = False
+        self._waiting_futures = []
+
+    def is_set(self):
+        return self._state
+
+    def clear(self):
+        self._state = False
+
+    def set(self):
+        self._state = True
+        futures = self._waiting_futures
+        self._waiting_futures = []
+
+        for f in futures:
+            f.set_result(None)
+
+    def wait(self):
+        if self._state:
+            return Future.succeed(None)
+        else:
+            f = Future()
+            self._waiting_futures.append(f)
+            return f
