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input-remapper/inputremapper/gui/reader.py

253 lines
8.8 KiB
Python

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# input-remapper - GUI for device specific keyboard mappings
# Copyright (C) 2022 sezanzeb <proxima@sezanzeb.de>
#
# This file is part of input-remapper.
#
# input-remapper is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# input-remapper is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with input-remapper. If not, see <https://www.gnu.org/licenses/>.
"""Talking to the GUI helper that has root permissions.
see gui.helper.helper
"""
from typing import Optional
from evdev.ecodes import EV_REL
from inputremapper.input_event import InputEvent
from inputremapper.logger import logger
from inputremapper.event_combination import EventCombination
from inputremapper.groups import groups, GAMEPAD
from inputremapper.ipc.pipe import Pipe
from inputremapper.gui.helper import (
MSG_EVENT,
MSG_GROUPS,
CMD_TERMINATE,
CMD_REFRESH_GROUPS,
)
from inputremapper import utils
from inputremapper.gui.active_preset import active_preset
from inputremapper.user import USER
DEBOUNCE_TICKS = 3
def will_report_up(ev_type):
"""Check if this event will ever report a key up (wheels)."""
return ev_type != EV_REL
class Reader:
"""Processes events from the helper for the GUI to use.
Does not serve any purpose for the injection service.
When a button was pressed, the newest keycode can be obtained from this
object. GTK has get_key for keyboard keys, but Reader also
has knowledge of buttons like the middle-mouse button.
"""
def __init__(self):
self.previous_event = None
self.previous_result = None
self._unreleased = {}
self._debounce_remove = {}
self._groups_updated = False
self._cleared_at = 0
self.group = None
self._results = None
self._commands = None
self.connect()
def connect(self):
"""Connect to the helper."""
self._results = Pipe(f"/tmp/input-remapper-{USER}/results")
self._commands = Pipe(f"/tmp/input-remapper-{USER}/commands")
def are_new_groups_available(self):
"""Check if groups contains new devices.
The ui should then update its list.
"""
outdated = self._groups_updated
self._groups_updated = False # assume the ui will react accordingly
return outdated
def _get_event(self, message) -> Optional[InputEvent]:
"""Return an InputEvent if the message contains one. None otherwise."""
message_type = message["type"]
message_body = message["message"]
if message_type == MSG_GROUPS:
if message_body != groups.dumps():
groups.loads(message_body)
logger.debug("Received %d devices", len(groups))
self._groups_updated = True
return None
if message_type == MSG_EVENT:
return InputEvent(*message_body)
logger.error('Received unknown message "%s"', message)
return None
def read(self):
"""Get the newest key/combination as EventCombination object.
Only reports keys from down-events.
On key-down events the pipe returns changed combinations. Release
events won't cause that and the reader will return None as in
"nothing new to report". So In order to change a combination, one
of its keys has to be released and then a different one pressed.
Otherwise making combinations wouldn't be possible. Because at
some point the keys have to be released, and that shouldn't cause
the combination to get trimmed.
"""
# this is in some ways similar to the keycode_mapper and
# joystick_to_mouse, but its much simpler because it doesn't
# have to trigger anything, manage any macros and only
# reports key-down events. This function is called periodically
# by the window.
# remember the previous down-event from the pipe in order to
# be able to tell if the reader should return the updated combination
previous_event = self.previous_event
key_down_received = False
self._debounce_tick()
while self._results.poll():
message = self._results.recv()
event = self._get_event(message)
if event is None:
continue
gamepad = GAMEPAD in self.group.types
if not utils.should_map_as_btn(event, active_preset, gamepad):
continue
if event.value == 0:
logger.debug_key(event, "release")
self._release(event.type_and_code)
continue
if self._unreleased.get(event.type_and_code) == event:
logger.debug_key(event, "duplicate key down")
self._debounce_start(event.event_tuple)
continue
# to keep track of combinations.
# "I have got this release event, what was this for?" A release
# event for a D-Pad axis might be any direction, hence this maps
# from release to input in order to remember it. Since all release
# events have value 0, the value is not used in the combination.
key_down_received = True
logger.debug_key(event, "down")
self._unreleased[event.type_and_code] = event
self._debounce_start(event.event_tuple)
previous_event = event
if not key_down_received:
# This prevents writing a subset of the combination into
# result after keys were released. In order to control the gui,
# they have to be released.
return None
self.previous_event = previous_event
if len(self._unreleased) > 0:
result = EventCombination(self._unreleased.values())
if result == self.previous_result:
# don't return the same stuff twice
return None
self.previous_result = result
logger.debug_key(result, "read result")
return result
return None
def start_reading(self, group):
"""Start reading keycodes for a device."""
logger.debug('Sending start msg to helper for "%s"', group.key)
self._commands.send(group.key)
self.group = group
self.clear()
def terminate(self):
"""Stop reading keycodes for good."""
logger.debug("Sending close msg to helper")
self._commands.send(CMD_TERMINATE)
def refresh_groups(self):
"""Ask the helper for new device groups."""
self._commands.send(CMD_REFRESH_GROUPS)
def clear(self):
"""Next time when reading don't return the previous keycode."""
logger.debug("Clearing reader")
while self._results.poll():
# clear the results pipe and handle any non-event messages,
# otherwise a 'groups' message might get lost
message = self._results.recv()
self._get_event(message)
self._unreleased = {}
self.previous_event = None
self.previous_result = None
def get_unreleased_keys(self):
"""Get a EventCombination object of the current keyboard state."""
unreleased = list(self._unreleased.values())
if len(unreleased) == 0:
return None
return EventCombination(unreleased)
def _release(self, type_code):
"""Modify the state to recognize the releasing of the key."""
if type_code in self._unreleased:
del self._unreleased[type_code]
if type_code in self._debounce_remove:
del self._debounce_remove[type_code]
def _debounce_start(self, event_tuple):
"""Act like the key was released if no new event arrives in time."""
if not will_report_up(event_tuple[0]):
self._debounce_remove[event_tuple[:2]] = DEBOUNCE_TICKS
def _debounce_tick(self):
"""If the counter reaches 0, the key is not considered held down."""
for type_code in list(self._debounce_remove.keys()):
if type_code not in self._unreleased:
continue
# clear wheel events from unreleased after some time
if self._debounce_remove[type_code] == 0:
logger.debug_key(self._unreleased[type_code], "Considered as released")
self._release(type_code)
else:
self._debounce_remove[type_code] -= 1
reader = Reader()