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Edit File: device.py
# -*- coding: latin-1 -*- # Copyright © 2017 Red Hat, Inc. # # Permission is hereby granted, free of charge, to any person obtaining a # copy of this software and associated documentation files (the "Software"), # to deal in the Software without restriction, including without limitation # the rights to use, copy, modify, merge, publish, distribute, sublicense, # and/or sell copies of the Software, and to permit persons to whom the # Software is furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice (including the next # paragraph) shall be included in all copies or substantial portions of the # Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER # DEALINGS IN THE SOFTWARE. import time import os import libevdev from ._clib import Libevdev, UinputDevice from ._clib import READ_FLAG_SYNC, READ_FLAG_NORMAL, READ_FLAG_FORCE_SYNC, READ_FLAG_BLOCKING from .event import InputEvent from .const import InputProperty class InvalidFileError(Exception): """ A file provided is not a valid file descriptor for libevdev or this device must not have a file descriptor """ pass class InvalidArgumentException(Exception): """ A function was called with an invalid argument. This indicates a bug in the calling program. .. attribute:: message A human-readable error message """ def __init__(self, msg=None): self.message = msg def __repr__(self): return self.message class DeviceGrabError(Exception): """ A device grab failed to be issued. A caller must not assume that it has exclusive access to the events on the device. """ class EventsDroppedException(Exception): """ Notification that the device has dropped events, raised in response to a EV_SYN SYN_DROPPED event. This exception is raised AFTER the EV_SYN, SYN_DROPPED event has been passed on. If SYN_DROPPED events are processed manually, then this exception can be ignored. Once received (or in response to a SYN_DROPPED event) a caller should call device.sync() and process the events accordingly (if any). Example:: fd = open("/dev/input/event0", "rb") ctx = libevdev.Device(fd) while True: try: for e in ctx.events(): print(e): except EventsDroppedException: print('State lost, re-synching:') for e in ctx.sync(): print(e) """ pass class InputAbsInfo(object): """ A class representing the struct input_absinfo for a given EV_ABS code. Any of the attributes may be set to None, those that are None are simply ignored by libevdev. .. attribute:: minimum the minimum value of this axis :property minimum: the minimum value for this axis :property maximum: the maximum value for this axis :property fuzz: the fuzz value for this axis :property flat: the flat value for this axis :property resolution: the resolution for this axis :property value: the current value of this axis """ def __init__(self, minimum=None, maximum=None, fuzz=None, flat=None, resolution=None, value=None): self.minimum = minimum self.maximum = maximum self.fuzz = fuzz self.flat = flat self.resolution = resolution self.value = value def __repr__(self): return 'min:{} max:{} fuzz:{} flat:{} resolution:{} value:{}'.format( self.minimum, self.maximum, self.fuzz, self.flat, self.resolution, self.value) def __eq__(self, other): return (self.minimum == other.minimum and self.maximum == other.maximum and self.value == other.value and self.resolution == other.resolution and self.fuzz == other.fuzz and self.flat == other.flat) class Device(object): """ This class represents an evdev device backed by libevdev. The device may represent a real device in the system or a constructed device where the caller supplies all properties of the device. If a file is given, the device initializes from that file, otherwise the device is uninitialized and needs to be set up by the caller:: fd = open("/dev/input/event0", "rb") l = libevdev.Device(fd) # l now represents the device on event0 l2 = libevdev.Device() l2.name = "test device" l2.enable(libevdev.EV_REL.REL_X) # l2 is an unbound device with the REL_X bit set Note that if a device is constructed manually, the fd of the device is always None. .. note:: The device is always set to CLOCK_MONOTONIC. :param fd: fd pointing to a ``/dev/input/eventX`` event node :type fd: A file-like object """ class _EventValueSet: def __init__(self, parent_device): self._device = parent_device def __getitem__(self, code): # calling device.value[slot axis] is a bug on MT devices if (code.type == libevdev.EV_ABS and code >= libevdev.EV_ABS.ABS_MT_SLOT and self._device.num_slots is not None): raise InvalidArgumentException('Cannot fetch value for MT axes') return self._device._libevdev.event_value(code.type.value, code.value) class _InputAbsInfoSet: def __init__(self, parent_device): self._device = parent_device def __getitem__(self, code): assert code.type == libevdev.EV_ABS r = self._device._libevdev.absinfo(code.value) if r is None: return r return InputAbsInfo(r['minimum'], r['maximum'], r['fuzz'], r['flat'], r['resolution'], r['value']) def __setitem__(self, code, absinfo): assert code.type == libevdev.EV_ABS if not self._device.has(code): raise InvalidArgumentException('Device does not have event code') data = {} if absinfo.minimum is not None: data['minimum'] = absinfo.minimum if absinfo.maximum is not None: data['maximum'] = absinfo.maximum if absinfo.fuzz is not None: data['fuzz'] = absinfo.fuzz if absinfo.flat is not None: data['flat'] = absinfo.flat if absinfo.resolution is not None: data['resolution'] = absinfo.resolution if absinfo.value is not None: data['value'] = absinfo.value self._device._libevdev.absinfo(code.value, data) class _SlotValue: def __init__(self, device, slot): self._device = device self._slot = slot def __getitem__(self, code): if (code.type is not libevdev.EV_ABS or code <= libevdev.EV_ABS.ABS_MT_SLOT): raise InvalidArgumentException('Event code must be one of EV_ABS.ABS_MT_*') if not self._device.has(code): return None return self._device._libevdev.slot_value(self._slot, code.value) def __setitem__(self, code, value): if (code.type is not libevdev.EV_ABS or code <= libevdev.EV_ABS.ABS_MT_SLOT): raise InvalidArgumentException('Event code must be one of EV_ABS.ABS_MT_*') if not self._device.has(code): raise InvalidArgumentException('Event code does not exist') self._device._libevdev.slot_value(self._slot, code.value, new_value=value) def __init__(self, fd=None): self._libevdev = Libevdev(fd) self._uinput = None self._is_grabbed = False self._values = Device._EventValueSet(self) self._absinfos = Device._InputAbsInfoSet(self) if fd is not None: try: self._libevdev.set_clock_id(time.CLOCK_MONOTONIC) except AttributeError: self._libevdev.set_clock_id(1) @property def name(self): """ :returns: the device name """ return self._libevdev.name @name.setter def name(self, name): self._libevdev.name = name @property def phys(self): """ :returns: the device's kernel phys or None. """ return self._libevdev.phys @phys.setter def phys(self, phys): self._libevdev.phys = phys @property def uniq(self): """ :returns: the device's uniq string or None """ return self._libevdev.uniq @uniq.setter def uniq(self, uniq): self._libevdev.uniq = uniq @property def driver_version(self): """ :returns: the device's driver version """ return self._libevdev.driver_version @property def id(self): """ :returns: A dict with the keys 'bustype', 'vendor', 'product', 'version'. When used as a setter, only existing keys are applied to the device. For example, to update the product ID only:: ctx = Device() id["property"] = 1234 ctx.id = id """ return self._libevdev.id @id.setter def id(self, vals): self._libevdev.id = vals @property def fd(self): """ This fd represents the file descriptor to this device, if any. If no fd was provided in the constructor, None is returned. If the device was used to create a uinput device, None is returned. The fd may only be changed if it was not initially None and then it overwrites the file object provided in the constructor (or a previous call to this function). The new file object becomes the object referencing this device, further events are polled from that file. .. warning:: A device initialized without a file descriptor may not change its fd. Note that libevdev does not synchronize the device and relies on the caller to ensure that the new file object points to the same device as this context. If the underlying device changes, the behavior is undefined. :raises: InvalidFileError - the file is invalid or this device does not allow a file to be set """ return self._libevdev.fd @fd.setter def fd(self, fileobj): if self._libevdev.fd is None: raise InvalidFileError() self._libevdev.fd = fileobj try: self._libevdev.set_clock_id(time.CLOCK_MONOTONIC) except AttributeError: self._libevdev.set_clock_id(1) if self._is_grabbed: self.grab() @property def evbits(self): """ Returns a dict with all supported event types and event codes, in the form of:: { libevdev.EV_ABS: [libevdev.EV_ABS.ABS_X, ...], libevdev.EV_KEY: [libevdev.EV_KEY.BTN_LEFT, ...], } """ types = {} for t in libevdev.types: if not self.has(t): continue codes = [] for c in t.codes: if not self.has(c): continue codes.append(c) types[t] = codes return types @property def properties(self): """ Returns a list of all supported input properties """ return [p for p in libevdev.props if self.has_property(p)] def has_property(self, prop): """ :param prop: a property :returns: True if the device has the property, False otherwise """ return self._libevdev.has_property(prop.value) def has(self, evcode): """ :param evcode: the event type or event code :type evcode: EventType or EventCode :returns: True if the device has the type and/or code, False otherwise """ try: return self._libevdev.has_event(evcode.type.value, evcode.value) except AttributeError: return self._libevdev.has_event(evcode.value) @property def num_slots(self): """ :returns: the number of slots on this device or ``None`` if this device does not support slots :note: Read-only """ return self._libevdev.num_slots @property def current_slot(self): """ :returns: the current slot on this device or ``None`` if this device does not support slots :note: Read-only """ return self._libevdev.current_slot @property def absinfo(self): """ Query the device's absinfo for the given event code. This attribute can both query and modify the :class:`InputAbsInfo` values of this device:: >>> ai = d.absinfo[libevdev.EV_ABS.ABS_X] >>> print(f'Resolution is {ai.resolution}') Resolution is 33 >>> ai = d.absinfo[libevdev.EV_ABS.ABS_Z] >>> print(ai) None The returned object is a dict-like object that only accepts event codes of type `EV_ABS` as keys. No other operation than key-based access is supported. When used as a setter, the provided :class:`InputAbsInfo` becomes the new absinfo of this axis:: >>> ai = d.absinfo[libevdev.EV_ABS.ABS_X] >>> print(f'Resolution is {ai.resolution}') Resolution is 33 >>> ai.resolution = 45 >>> d.absinfo[libevdev.EV_ABS.ABS_X] = ai >>> ai = d.absinfo[libevdev.EV_ABS.ABS_X] >>> print(f'Resolution is now {ai.resolution}') Resolution is now 45 When used as a setter, any attribute of :class:`InputAbsInfo` that is ``None`` is ignored:: >>> ai = InputAbsInfo(resolution=72) >>> d.absinfo[libevdev.EV_ABS.ABS_X] = ai >>> ai = d.absinfo[libevdev.EV_ABS.ABS_X] >>> print(f'Resolution is now {ai.resolution}') Resolution is now 72 .. warning:: Setting the absinfo for a non-existing EV_ABS code is invalid. Use :func:`enable()` instead. :returns: an class:`InputAbsInfo` struct or None if the device does not have the event code :raises: :class:`InvalidArgumentException` when trying to set an axis that is not enabled. """ return self._absinfos def sync_absinfo_to_kernel(self, code): """ Synchronizes our view of an absinfo axis to the kernel, thus updating the the device for every other client. This function should be used with care. Not only does it change the kernel device and thus may affect the behavior of other processes but it is racy: any client that has this device node open already may never see the updates. To use this function, update the absinfo for the desired axis first:: >>> fd = open('/dev/input/event0', 'rb') >>> d = libevdev.Device(fd) >>> ai = InputAbsInfo(resolution=72) >>> d.absinfo[libevdev.EV_ABS.ABS_X] = ai >>> d.sync_absinfo_to_kernel(libevdev.EV_ABS.ABS_X) """ a = self.absinfo[code] data = {"minimum": a.minimum, "maximum": a.maximum, "fuzz": a.fuzz, "flat": a.flat, "resolution": a.resolution} self._libevdev.absinfo(code.value, new_values=data, kernel=True) def events(self): """ Returns an iterable with currently pending events. Event processing should look like this:: fd = open("/dev/input/event0", "rb") ctx = libevdev.Device(fd) while True: for e in ctx.events(): print(e): This function detects if the file descriptor is in blocking or non-blocking mode and adjusts its behavior accordingly. If the file descriptor is in nonblocking mode and no events are available, this function returns immediately. If the file descriptor is blocking, this function blocks if there are no events available. :returns: an iterable with the currently pending events """ if self._libevdev.fd is None: return [] if os.get_blocking(self._libevdev.fd.fileno()): flags = READ_FLAG_BLOCKING else: flags = READ_FLAG_NORMAL ev = self._libevdev.next_event(flags) while ev is not None: code = libevdev.evbit(ev.type, ev.code) yield InputEvent(code, ev.value, ev.sec, ev.usec) if code == libevdev.EV_SYN.SYN_DROPPED: raise EventsDroppedException() ev = self._libevdev.next_event(flags) def sync(self, force=False): """ Returns an iterator with events pending to re-sync the caller's view of the device with the one from libevdev. :param force: if set, the device forces an internal sync. This is required after changing the fd of the device when the device state may have changed while libevdev was not processing events. """ if self._libevdev.fd is None: return [] if force: flags = READ_FLAG_FORCE_SYNC else: flags = READ_FLAG_SYNC ev = self._libevdev.next_event(flags) while ev is not None: code = libevdev.evbit(ev.type, ev.code) yield InputEvent(code, ev.value, ev.sec, ev.usec) ev = self._libevdev.next_event(flags) @property def value(self): """ Returns the current value for a given event code or None where the event code does not exist on the device:: >>> d = libevdev.Device(fd) >>> print(d.value[libevdev.EV_ABS.ABS_X]) 1024 >>> print(d.value[libevdev.EV_ABS.ABS_Y]) 512 >>> print(d.value[libevdev.EV_ABS.ABS_Z]) None The returned object is a dict-like object that only accepts event codes as keys. No other operation than key-based access is supported. The default value for all codes is 0. State-less axes like the ``EV_REL`` range always return 0 for all supported event codes. """ return self._values @property def slots(self): """ Returns a tuple with the available slots, each of which contains a wrapper object to access a slot value:: >>> d = libevdev.Device(fd) >>> print(d.slots[0][libevdev.EV_ABS.ABS_MT_POSITION_X]) 1000 >>> print(d.slots[0][libevdev.EV_ABS.ABS_MT_POSITION_Y]) 500 >>> print(d.slots[1][libevdev.EV_ABS.ABS_MT_POSITION_X]) 200 >>> print(d.slots[1][libevdev.EV_ABS.ABS_MT_POSITION_Y]) 300 Alternatively, the tuple can be iterated on:: xcode = libevdev.EV_ABS.ABS_MT_POSITION_X ycode = libevdev.EV_ABS.ABS_MT_POSITION_Y for s in d.slots: position = (s[xcode], s[ycode]) The only values available for each slot are the ones in the ``libevdev.EV_ABS.ABS_MT_*`` range (but not ``libevdev.EV_ABS.ABS_MT_SLOT``). """ if self.num_slots is None: raise InvalidArgumentException('Device has no slots') return tuple(Device._SlotValue(self, slot) for slot in range(self.num_slots)) def enable(self, event_code, data=None): """ Enable an event type or event code on this device, even if not supported by this device. If event_code is an :class:`EventType`, that type is enabled and data is ignored. If event_code is one of ``libevdev.EV_ABS.ABS_*``, then data must be a :class:`InputAbsInfo`. Any unset fields of the :class:`InputAbsInfo` are replaced with 0, i.e. the following example is valid and results in a fuzz/flat/resolution of zero:: ctx = libevdev.Device() abs = InputAbsInfo(minimum=0, maximum=100) ctx.enable(libevdev.EV_ABS.ABS_X, data) If event_code is one of ``libevdev.EV_REP.REP_``, then data must be an integer. If event_code is one of ``libevdev.INPUT_PROP_``, then the given input property is enabled. :param event_code: the event code :type event_code: EventCode or EventType :param data: if event_code is not ``None``, data points to the code-specific information. """ if isinstance(event_code, InputProperty): self._libevdev.enable_property(event_code.value) return try: if event_code.type == libevdev.EV_ABS: if data is None or not isinstance(data, InputAbsInfo): raise InvalidArgumentException('enabling EV_ABS codes requires an InputAbsInfo') data = {"minimum": data.minimum or 0, "maximum": data.maximum or 0, "fuzz": data.fuzz or 0, "flat": data.flat or 0, "resolution": data.resolution or 0} elif event_code.type == libevdev.EV_REP: if data is None: raise InvalidArgumentException('enabling EV_REP codes requires an integer') self._libevdev.enable(event_code.type.value, event_code.value, data) except AttributeError: self._libevdev.enable(event_code.value) def disable(self, event_code): """ Disable the given event type or event code on this device. If the device does not support this type or code, this function does nothing. Otherwise, all future events from this device that match this type or code will be discarded:: >>> d.disable(libevdev.EV_ABS) # All EV_ABS events are filtered now >>> d.disable(libevdev.EV_KEY.BTN_LEFT) # All BTN_LEFt events are filtered now To re-enable an event type or code, use :func:`enable()` :param event_code: the event type or code :type event_code: EventType or EventCode """ if isinstance(event_code, InputProperty): raise NotImplementedError() try: self._libevdev.disable(event_code.type.value, event_code.value) except AttributeError: self._libevdev.disable(event_code.value) @property def devnode(self): """ Returns the device node for this device. The device node is None if this device has not been created as uinput device. """ if not self._uinput: return None return self._uinput.devnode @property def syspath(self): """ Returns the syspath for this device. The syspath is None if this device has not been created as uinput device. """ if not self._uinput: return None return self._uinput.syspath def create_uinput_device(self, uinput_fd=None): """ Creates and returns a new :class:`Device` based on this libevdev device. The new device is equivalent to one created with ``libevdev.Device()``, i.e. it is one that does not have a file descriptor associated. To create a uinput device from an existing device:: fd = open('/dev/input/event0', 'rb') d = libevdev.Device(fd) d.name = 'duplicated device' d.create_uinput_device() # d is now a duplicate of the event0 device with a custom name fd.close() Or to create a new device from scratch:: d = libevdev.Device() d.name = 'test device' d.enable(libevdev.EV_KEY.BTN_LEFT) d.create_uinput_device() # d is now a device with a single button :param uinput_fd: A file descriptor to the /dev/input/uinput device. If None, the device is opened and closed automatically. :raises: OSError """ d = libevdev.Device() d.name = self.name d.id = self.id for t, cs in self.evbits.items(): for c in cs: if t == libevdev.EV_ABS: data = self.absinfo[c] elif t == libevdev.EV_REP: data = self.value[c] else: data = None d.enable(c, data) for p in self.properties: self.enable(p) d._uinput = UinputDevice(self._libevdev, uinput_fd) return d def send_events(self, events): """ Send the list of :class:`InputEvent` events through this device. All events must have a valid :class:`EventCode` and value, the timestamp in the event is ignored and the kernel fills in its own timestamp. This function may only be called on a uinput device, not on a normal device. .. warning:: an event list must always be terminated with a ``libevdev.EV_SYN.SYN_REPORT`` event or the kernel may delay processing. :param events: a list of :class:`InputEvent` events """ if not self._uinput: raise InvalidFileError() if None in [e.code for e in events]: raise InvalidArgumentException('All events must have an event code') if None in [e.value for e in events]: raise InvalidArgumentException('All events must have a value') for e in events: self._uinput.write_event(e.type.value, e.code.value, e.value) def grab(self): """ Exclusively grabs the device, preventing events from being seen by anyone else. This includes in-kernel consumers of the events (e.g. for rfkill) and should be used with care. A grab is valid until the file descriptor is closed or until :func:`ungrab` is called, whichever happens earlier. libevdev re-issues the grab on the device after changing the fd. If the original file descriptor is still open when changing the fd on the device, re-issuing the grab will fail silently:: fd1 = open("/dev/input/event0", "rb") d = libevdev.Device(fd1) d.grab() # device is now exclusively grabbed fd.close() fd2 = open("/dev/input/event0", "rb") d.fd = fd2 # device is now exclusively grabbed fd3 = open("/dev/input/event0", "rb") d.fd = fd3 # ERROR: fd2 is still open and the grab fails """ try: self._libevdev.grab() except OSError: raise DeviceGrabError() self._is_grabbed = True def ungrab(self): """ Removes an exclusive grabs on the device, see :func:`grab`. """ self._libevdev.grab(False) self._is_grabbed = False