add option for specific key filtering

src/__main__.py

@@ -20,14 +20,18 @@ def get_device_handle(keyboard_name: str) -> libevdev.Device:
     finally:
         fd.close()
 
-
+def parse_keys(keys_str):
+    """Parse a comma-separated list of keys into a list of integers."""
+    return [key.strip() for key in keys_str.split(',')]
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument('-k', '--keyboard', type=str, default=str(),
                         help=f"Name of your chattering keyboard device as listed in {INPUT_DEVICES_PATH}. "
                              f"If left unset, will be attempted to be retrieved automatically.")
     parser.add_argument('-t', '--threshold', type=int, default=30, help="Filter time threshold in milliseconds. "
                                                                         "Default=30ms.")
+    parser.add_argument('--keys', type=parse_keys, default=[], help="Comma-separated list of keys to filter. Default All. e.g KEY_A,KEY_B")
     parser.add_argument('-v', '--verbosity', type=int, default=1, choices=[0, 1, 2])
     args = parser.parse_args()
 
@@ -46,5 +50,8 @@ def get_device_handle(keyboard_name: str) -> libevdev.Device:
         datefmt="%H:%M:%S"
     )
 
+    # Convert them to libevdev.EventCode
+    keys = [libevdev.evbit(key) for key in args.keys]
+
     with get_device_handle(args.keyboard or retrieve_keyboard_name()) as device:
-        filter_chattering(device, args.threshold)
+        filter_chattering(device, args.threshold, keys)

src/filtering.py

@@ -5,7 +5,7 @@
 import libevdev
 
 
-def filter_chattering(evdev: libevdev.Device, threshold: int) -> NoReturn:
+def filter_chattering(evdev: libevdev.Device, threshold: int, keys:libevdev.EventCode) -> NoReturn:
     # grab the device - now only we see the events it emits
     evdev.grab()
     # create a copy of the device that we can write to - this will emit the filtered events to anyone who listens
@@ -16,18 +16,22 @@ def filter_chattering(evdev: libevdev.Device, threshold: int) -> NoReturn:
     while True:
         # since the descriptor is blocking, this blocks until there are events available
         for e in evdev.events():
-            if _from_keystroke(e, threshold):
+            if _from_keystroke(e, threshold, keys):
                 ui_dev.send_events([e, libevdev.InputEvent(libevdev.EV_SYN.SYN_REPORT, 0)])
 
 
-def _from_keystroke(event: libevdev.InputEvent, threshold: int) -> bool:
+def _from_keystroke(event: libevdev.InputEvent, threshold: int, keys:libevdev.EventCode) -> bool:
     # no need to relay those - we are going to emit our own
     if event.matches(libevdev.EV_SYN) or event.matches(libevdev.EV_MSC):
         return False
 
     # some events we don't want to filter, like EV_LED for toggling NumLock and the like, and also key hold events
     if not event.matches(libevdev.EV_KEY) or event.value > 1:
         logging.debug(f'FORWARDING {event.code}')
+
+    # If the event is not in the list of keys to filter, return True
+    if event.code not in keys:
+        logging.debug(f'Skipping {event.code} since it is not requested by user')
         return True
 
     # the values are 0 for up, 1 for down and 2 for hold