Add DuckTrack as initial annotation tool; Initial multimodal test

annotation/ducktrack/keycomb.py

@@ -0,0 +1,33 @@
+from pynput.keyboard import Listener
+
+from .util import name_to_key
+
+
+class KeyCombinationListener:
+    """
+    Simple and bad key combination listener.
+    """
+    
+    def __init__(self):
+        self.current_keys = set()
+        self.callbacks = {}
+        self.listener = Listener(on_press=self.on_key_press, on_release=self.on_key_release)
+
+    def add_comb(self, keys, callback):
+        self.callbacks[tuple([name_to_key(key_name) for key_name in sorted(keys)])] = callback
+
+    def on_key_press(self, key):
+        self.current_keys.add(key)
+        for comb, callback in self.callbacks.items():
+            if all(k in self.current_keys for k in comb):
+                return callback()
+
+    def on_key_release(self, key):
+        if key in self.current_keys:
+            self.current_keys.remove(key)
+
+    def start(self):
+        self.listener.start()
+
+    def stop(self):
+        self.listener.stop()