input-remapper/inputremapper/input_event.py

#!/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/>.
from __future__ import annotations

import enum
from dataclasses import dataclass
from typing import Tuple, Union, Sequence, Callable, Optional

import evdev
from evdev import ecodes

from inputremapper.configs.system_mapping import system_mapping
from inputremapper.exceptions import InputEventCreationError
from inputremapper.gui.messages.message_broker import MessageType
from inputremapper.logger import logger

InputEventValidationType = Union[
    str,
    Tuple[int, int, int],
    evdev.InputEvent,
]


class EventActions(enum.Enum):
    """Additional information a InputEvent can send through the event pipeline"""

    as_key = enum.auto()  # treat this event as a key event
    recenter = enum.auto()  # recenter the axis when receiving this
    none = enum.auto()

    # used in combination with as_key, for originally abs or rel events
    positive_trigger = enum.auto()  # original event was positive direction
    negative_trigger = enum.auto()  # original event was negative direction


# Todo: add slots=True as soon as python 3.10 is in common distros
@dataclass(frozen=True)
class InputEvent:
    """The evnet used by inputremapper

    as a drop in replacement for evdev.InputEvent
    """

    message_type = MessageType.selected_event

    sec: int
    usec: int
    type: int
    code: int
    value: int
    actions: Tuple[EventActions, ...] = ()

    def __hash__(self):
        return hash((self.type, self.code, self.value))

    def __eq__(self, other):
        if isinstance(other, InputEvent) or isinstance(other, evdev.InputEvent):
            return self.event_tuple == (other.type, other.code, other.value)
        if isinstance(other, tuple):
            return self.event_tuple == other
        return False

    @classmethod
    def __get_validators__(cls):
        """Used by pydantic and EventCombination to create InputEvent objects."""
        yield cls.validate

    @classmethod
    def validate(cls, init_arg: InputEventValidationType) -> InputEvent:
        """Try all the different methods, and raise an error if none succeed."""
        if isinstance(init_arg, InputEvent):
            return init_arg

        event = None
        validators: Sequence[Callable[..., InputEvent]] = (
            cls.from_event,
            cls.from_string,
            cls.from_tuple,
        )
        for validator in validators:
            try:
                event = validator(init_arg)
                break
            except InputEventCreationError:
                pass

        if event:
            return event

        raise ValueError(f"failed to create InputEvent with {init_arg = }")

    @classmethod
    def from_event(cls, event: evdev.InputEvent) -> InputEvent:
        """Create a InputEvent from another InputEvent or evdev.InputEvent."""
        try:
            return cls(event.sec, event.usec, event.type, event.code, event.value)
        except AttributeError:
            raise InputEventCreationError(
                f"failed to create InputEvent from {event = }"
            )

    @classmethod
    def from_string(cls, string: str) -> InputEvent:
        """Create a InputEvent from a string like 'type, code, value'."""
        try:
            t, c, v = string.split(",")
            return cls(0, 0, int(t), int(c), int(v))
        except (ValueError, AttributeError):
            raise InputEventCreationError(
                f"failed to create InputEvent from {string = !r}"
            )

    @classmethod
    def from_tuple(cls, event_tuple: Tuple[int, int, int]) -> InputEvent:
        """Create a InputEvent from a (type, code, value) tuple."""
        try:
            if len(event_tuple) != 3:
                raise InputEventCreationError(
                    f"failed to create InputEvent {event_tuple = }"
                    f" must have length 3"
                )
            return cls(
                0,
                0,
                int(event_tuple[0]),
                int(event_tuple[1]),
                int(event_tuple[2]),
            )
        except ValueError:
            raise InputEventCreationError(
                f"failed to create InputEvent from {event_tuple = }"
            )
        except TypeError:
            raise InputEventCreationError(
                f"failed to create InputEvent from {type(event_tuple) = }"
            )

    @classmethod
    def btn_left(cls):
        return cls(0, 0, evdev.ecodes.EV_KEY, evdev.ecodes.BTN_LEFT, 1)

    @property
    def type_and_code(self) -> Tuple[int, int]:
        """Event type, code."""
        return self.type, self.code

    @property
    def event_tuple(self) -> Tuple[int, int, int]:
        """Event type, code, value."""
        return self.type, self.code, self.value

    @property
    def is_key_event(self) -> bool:
        """Whether this is interpreted as a key event."""
        return self.type == evdev.ecodes.EV_KEY or EventActions.as_key in self.actions

    def __str__(self):
        return f"InputEvent{self.event_tuple}"

    def description(self, exclude_threshold=False, exclude_direction=False) -> str:
        """get a human-readable description of the event"""
        return (
            f"{self.get_name()} "
            f"{self.get_direction() if not exclude_direction else ''} "
            f"{self.get_threshold() if not exclude_threshold else ''}".strip()
        )

    def timestamp(self):
        """Return the unix timestamp of when the event was seen."""
        return self.sec + self.usec / 1000000

    def modify(
        self,
        sec: int = None,
        usec: int = None,
        type: int = None,
        code: int = None,
        value: int = None,
        actions: Tuple[EventActions, ...] = None,
    ) -> InputEvent:
        """Return a new modified event."""
        return InputEvent(
            sec if sec is not None else self.sec,
            usec if usec is not None else self.usec,
            type if type is not None else self.type,
            code if code is not None else self.code,
            value if value is not None else self.value,
            actions if actions is not None else self.actions,
        )

    def json_key(self) -> str:
        return ",".join([str(self.type), str(self.code), str(self.value)])

    def get_name(self) -> Optional[str]:
        """human-readable name"""
        if self.type not in ecodes.bytype:
            logger.warning("Unknown type for %s", self)
            return f"unknown {self.type, self.code}"

        if self.code not in ecodes.bytype[self.type]:
            logger.warning("Unknown code for %s", self)
            return f"unknown {self.type, self.code}"

        key_name = None

        # first try to find the name in xmodmap to not display wrong
        # names due to the keyboard layout
        if self.type == ecodes.EV_KEY:
            key_name = system_mapping.get_name(self.code)

        if key_name is None:
            # if no result, look in the linux combination constants. On a german
            # keyboard for example z and y are switched, which will therefore
            # cause the wrong letter to be displayed.
            key_name = ecodes.bytype[self.type][self.code]
            if isinstance(key_name, list):
                key_name = key_name[0]

        key_name = key_name.replace("ABS_Z", "Trigger Left")
        key_name = key_name.replace("ABS_RZ", "Trigger Right")

        key_name = key_name.replace("ABS_HAT0X", "DPad-X")
        key_name = key_name.replace("ABS_HAT0Y", "DPad-Y")
        key_name = key_name.replace("ABS_HAT1X", "DPad-2-X")
        key_name = key_name.replace("ABS_HAT1Y", "DPad-2-Y")
        key_name = key_name.replace("ABS_HAT2X", "DPad-3-X")
        key_name = key_name.replace("ABS_HAT2Y", "DPad-3-Y")

        key_name = key_name.replace("ABS_X", "Joystick-X")
        key_name = key_name.replace("ABS_Y", "Joystick-Y")
        key_name = key_name.replace("ABS_RX", "Joystick-RX")
        key_name = key_name.replace("ABS_RY", "Joystick-RY")

        key_name = key_name.replace("BTN_", "Button ")
        key_name = key_name.replace("KEY_", "")

        key_name = key_name.replace("REL_", "")
        key_name = key_name.replace("HWHEEL", "Wheel")
        key_name = key_name.replace("WHEEL", "Wheel")

        key_name = key_name.replace("_", " ")
        key_name = key_name.replace("  ", " ")
        return key_name

    def get_direction(self) -> str:
        if self.type == ecodes.EV_KEY:
            return ""

        try:
            event = self.modify(value=self.value // abs(self.value))
        except ZeroDivisionError:
            return ""

        return {
            # D-Pad
            (ecodes.ABS_HAT0X, -1): "Left",
            (ecodes.ABS_HAT0X, 1): "Right",
            (ecodes.ABS_HAT0Y, -1): "Up",
            (ecodes.ABS_HAT0Y, 1): "Down",
            (ecodes.ABS_HAT1X, -1): "Left",
            (ecodes.ABS_HAT1X, 1): "Right",
            (ecodes.ABS_HAT1Y, -1): "Up",
            (ecodes.ABS_HAT1Y, 1): "Down",
            (ecodes.ABS_HAT2X, -1): "Left",
            (ecodes.ABS_HAT2X, 1): "Right",
            (ecodes.ABS_HAT2Y, -1): "Up",
            (ecodes.ABS_HAT2Y, 1): "Down",
            # joystick
            (ecodes.ABS_X, 1): "Right",
            (ecodes.ABS_X, -1): "Left",
            (ecodes.ABS_Y, 1): "Down",
            (ecodes.ABS_Y, -1): "Up",
            (ecodes.ABS_RX, 1): "Right",
            (ecodes.ABS_RX, -1): "Left",
            (ecodes.ABS_RY, 1): "Down",
            (ecodes.ABS_RY, -1): "Up",
            # wheel
            (ecodes.REL_WHEEL, -1): "Down",
            (ecodes.REL_WHEEL, 1): "Up",
            (ecodes.REL_HWHEEL, -1): "Left",
            (ecodes.REL_HWHEEL, 1): "Right",
        }.get((event.code, event.value)) or ("+" if event.value > 0 else "-")

    def get_threshold(self) -> str:
        if self.value == 0:
            return ""
        return {
            ecodes.EV_REL: f"{abs(self.value)}",
            ecodes.EV_ABS: f"{abs(self.value)}%",
        }.get(self.type) or ""