# Copyright (c) 2018 Anki, Inc.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License in the file LICENSE.txt or at

#

# https://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""

Support for Vector's touch sensor.

The robot will forward a raw sensor reading representing the capacitance detected

on its back sensor. Accompanied with this value is a true/false flag that takes into

account other aspects of the robot's state to evaluate whether the robot thinks it is

being touched or not. This flag is the same value used internally for petting detection.

"""

# __all__ should order by constants, event classes, other classes, functions.

__all__ = ["TouchComponent", "TouchSensorData"]

from . import util

from .events import Events

from .messaging import protocol

class TouchSensorData:

"""A touch sample from the capacitive touch sensor, accompanied with the robot's

conclusion on whether this is considered a valid touch.

"""

def __init__(self, proto_data: protocol.TouchData):

self._raw_touch_value = proto_data.raw_touch_value

self._is_being_touched = proto_data.is_being_touched

@property

def raw_touch_value(self) -> int:

"""The detected sensitivity from the touch sensor.

This will not map to a constant raw value, as it may be impacted by various

environmental factors such as whether the robot is on its charger, being held, humidity, etc.

.. testcode::

import anki_vector

with anki_vector.Robot() as robot:

touch_data = robot.touch.last_sensor_reading

if touch_data is not None:

raw_touch_value = touch_data.raw_touch_value

"""

return self._raw_touch_value

@property

def is_being_touched(self) -> bool:

"""The robot's conclusion on whether the current value is considered

a valid touch.

.. testcode::

import anki_vector

with anki_vector.Robot() as robot:

touch_data = robot.touch.last_sensor_reading

if touch_data is not None:

is_being_touched = touch_data.is_being_touched

"""

return self._is_being_touched

class TouchComponent(util.Component):

"""Maintains the most recent touch sensor data

This will be updated with every broadcast RobotState, and can be queried at any time.

.. testcode::

import anki_vector

with anki_vector.Robot() as robot:

touch_data = robot.touch.last_sensor_reading

if touch_data is not None:

print('Touch sensor value: {0}, is being touched: {1}'.format(touch_data.raw_touch_value, touch_data.is_being_touched))

"""

def __init__(self, robot):

super().__init__(robot)

self._last_sensor_reading = None

# Subscribe to a callback that updates the robot's local properties - which includes touch data.

self._robot.events.subscribe(self._on_robot_state,

Events.robot_state,

on_connection_thread=True)

def close(self):

"""Closing the touch component will unsubscribe from robot state updates."""

self._robot.events.unsubscribe(self._on_robot_state,

Events.robot_state)

@property

def last_sensor_reading(self) -> TouchSensorData:

""":class:`anki_vector.touch.TouchSensorData`: The last reported sensor data.

.. testcode::

import anki_vector

with anki_vector.Robot() as robot:

touch_data = robot.touch.last_sensor_reading

"""

return self._last_sensor_reading

def _on_robot_state(self, _, msg):

self._last_sensor_reading = TouchSensorData(msg.touch_data)