[input] Add per-PID UNIX socket for additional commands

Allow passing in commands / events via a unix socket. This should allow
for "emulating" input events.

see #547

bumblebee/input.py

@@ -1,9 +1,11 @@
 """Input classes"""
 
+import os
 import sys
 import json
 import uuid
 import time
+import socket
 import select
 import logging
 import threading
@@ -23,10 +25,28 @@ def is_terminated():
             return True
     return False
 
+class CommandSocket(object):
+    def __init__(self):
+        self._name = "/tmp/.bumblebee-status.{}".format(os.getpid())
+        self._socket = None
+
+    def __enter__(self):
+        self._socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        self._socket.bind(self._name)
+        self._socket.listen(5)
+        return self._socket
+
+    def __exit__(self, type, value, traceback):
+        self._socket.close()
+        os.unlink(self._name)
+
 def read_input(inp):
     """Read i3bar input and execute callbacks"""
+
+    with CommandSocket() as cmdsocket:
         poll = select.poll()
-    poll.register(sys.stdin.fileno(), select.POLLIN)
+        poll.register(sys.stdin, select.POLLIN)
+        poll.register(cmdsocket, select.POLLIN)
         log.debug("starting click event processing")
         while inp.running:
             if is_terminated():
@@ -37,6 +57,12 @@ def read_input(inp):
             except Exception:
                 continue
             for fileno, event in events:
+
+                if fileno == cmdsocket.fileno():
+                    tmp, _ = cmdsocket.accept()
+                    line = tmp.recv(4096).decode()
+                    tmp.close()
+                else:
                     line = "["
                     while line.startswith("["):
                         line = sys.stdin.readline().strip(",").strip()