# SPDX-FileCopyrightText: 2017 Dan Halbert for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
`adafruit_hid.keyboard.Keyboard`
====================================================
* Author(s): Scott Shawcroft, Dan Halbert
"""
import time
from micropython import const
from .keycode import Keycode
from . import find_device
_MAX_KEYPRESSES = const(6)
[docs]class Keyboard:
"""Send HID keyboard reports."""
LED_NUM_LOCK = 0x01
"""LED Usage ID for Num Lock"""
LED_CAPS_LOCK = 0x02
"""LED Usage ID for Caps Lock"""
LED_SCROLL_LOCK = 0x04
"""LED Usage ID for Scroll Lock"""
LED_COMPOSE = 0x08
"""LED Usage ID for Compose"""
# No more than _MAX_KEYPRESSES regular keys may be pressed at once.
def __init__(self, devices):
"""Create a Keyboard object that will send keyboard HID reports.
Devices can be a list of devices that includes a keyboard device or a keyboard device
itself. A device is any object that implements ``send_report()``, ``usage_page`` and
``usage``.
"""
self._keyboard_device = find_device(devices, usage_page=0x1, usage=0x06)
# Reuse this bytearray to send keyboard reports.
self.report = bytearray(8)
# report[0] modifiers
# report[1] unused
# report[2:8] regular key presses
# View onto byte 0 in report.
self.report_modifier = memoryview(self.report)[0:1]
# List of regular keys currently pressed.
# View onto bytes 2-7 in report.
self.report_keys = memoryview(self.report)[2:]
# Do a no-op to test if HID device is ready.
# If not, wait a bit and try once more.
try:
self.release_all()
except OSError:
time.sleep(1)
self.release_all()
[docs] def press(self, *keycodes):
"""Send a report indicating that the given keys have been pressed.
:param keycodes: Press these keycodes all at once.
:raises ValueError: if more than six regular keys are pressed.
Keycodes may be modifiers or regular keys.
No more than six regular keys may be pressed simultaneously.
Examples::
from adafruit_hid.keycode import Keycode
# Press ctrl-x.
kbd.press(Keycode.LEFT_CONTROL, Keycode.X)
# Or, more conveniently, use the CONTROL alias for LEFT_CONTROL:
kbd.press(Keycode.CONTROL, Keycode.X)
# Press a, b, c keys all at once.
kbd.press(Keycode.A, Keycode.B, Keycode.C)
"""
for keycode in keycodes:
self._add_keycode_to_report(keycode)
self._keyboard_device.send_report(self.report)
[docs] def release(self, *keycodes):
"""Send a USB HID report indicating that the given keys have been released.
:param keycodes: Release these keycodes all at once.
If a keycode to be released was not pressed, it is ignored.
Example::
# release SHIFT key
kbd.release(Keycode.SHIFT)
"""
for keycode in keycodes:
self._remove_keycode_from_report(keycode)
self._keyboard_device.send_report(self.report)
[docs] def release_all(self):
"""Release all pressed keys."""
for i in range(8):
self.report[i] = 0
self._keyboard_device.send_report(self.report)
[docs] def send(self, *keycodes):
"""Press the given keycodes and then release all pressed keys.
:param keycodes: keycodes to send together
"""
self.press(*keycodes)
self.release_all()
def _add_keycode_to_report(self, keycode):
"""Add a single keycode to the USB HID report."""
modifier = Keycode.modifier_bit(keycode)
if modifier:
# Set bit for this modifier.
self.report_modifier[0] |= modifier
else:
# Don't press twice.
# (I'd like to use 'not in self.report_keys' here, but that's not implemented.)
for i in range(_MAX_KEYPRESSES):
if self.report_keys[i] == keycode:
# Already pressed.
return
# Put keycode in first empty slot.
for i in range(_MAX_KEYPRESSES):
if self.report_keys[i] == 0:
self.report_keys[i] = keycode
return
# All slots are filled.
raise ValueError("Trying to press more than six keys at once.")
def _remove_keycode_from_report(self, keycode):
"""Remove a single keycode from the report."""
modifier = Keycode.modifier_bit(keycode)
if modifier:
# Turn off the bit for this modifier.
self.report_modifier[0] &= ~modifier
else:
# Check all the slots, just in case there's a duplicate. (There should not be.)
for i in range(_MAX_KEYPRESSES):
if self.report_keys[i] == keycode:
self.report_keys[i] = 0
@property
def led_status(self):
"""Returns the last received report"""
return self._keyboard_device.last_received_report
[docs] def led_on(self, led_code):
"""Returns whether an LED is on based on the led code
Examples::
import usb_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keycode import Keycode
import time
# Initialize Keybaord
kbd = Keyboard(usb_hid.devices)
# Press and release CapsLock.
kbd.press(Keycode.CAPS_LOCK)
time.sleep(.09)
kbd.release(Keycode.CAPS_LOCK)
# Check status of the LED_CAPS_LOCK
print(kbd.led_on(Keyboard.LED_CAPS_LOCK))
"""
return bool(self.led_status[0] & led_code)