# Copyright 2014 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Implementation of a USB HID keyboard.
Two classes are provided by this module. The KeyboardFeature class implements
the core functionality of a HID keyboard and can be included in any HID gadget.
The KeyboardGadget class implements an example keyboard gadget.
"""
import struct
import hid_constants
import hid_descriptors
import hid_gadget
import usb_constants
class KeyboardFeature(hid_gadget.HidFeature):
"""HID feature implementation for a keyboard.
REPORT_DESC provides an example HID report descriptor for a device including
this functionality.
"""
REPORT_DESC = hid_descriptors.ReportDescriptor(
hid_descriptors.UsagePage(0x01), # Generic Desktop
hid_descriptors.Usage(0x06), # Keyboard
hid_descriptors.Collection(
hid_constants.CollectionType.APPLICATION,
hid_descriptors.UsagePage(0x07), # Key Codes
hid_descriptors.UsageMinimum(224),
hid_descriptors.UsageMaximum(231),
hid_descriptors.LogicalMinimum(0, force_length=1),
hid_descriptors.LogicalMaximum(1),
hid_descriptors.ReportSize(1),
hid_descriptors.ReportCount(8),
hid_descriptors.Input(hid_descriptors.Data,
hid_descriptors.Variable,
hid_descriptors.Absolute),
hid_descriptors.ReportCount(1),
hid_descriptors.ReportSize(8),
hid_descriptors.Input(hid_descriptors.Constant),
hid_descriptors.ReportCount(5),
hid_descriptors.ReportSize(1),
hid_descriptors.UsagePage(0x08), # LEDs
hid_descriptors.UsageMinimum(1),
hid_descriptors.UsageMaximum(5),
hid_descriptors.Output(hid_descriptors.Data,
hid_descriptors.Variable,
hid_descriptors.Absolute),
hid_descriptors.ReportCount(1),
hid_descriptors.ReportSize(3),
hid_descriptors.Output(hid_descriptors.Constant),
hid_descriptors.ReportCount(6),
hid_descriptors.ReportSize(8),
hid_descriptors.LogicalMinimum(0, force_length=1),
hid_descriptors.LogicalMaximum(101),
hid_descriptors.UsagePage(0x07), # Key Codes
hid_descriptors.UsageMinimum(0, force_length=1),
hid_descriptors.UsageMaximum(101),
hid_descriptors.Input(hid_descriptors.Data, hid_descriptors.Array)
)
)
def __init__(self):
super(KeyboardFeature, self).__init__()
self._modifiers = 0
self._keys = [0, 0, 0, 0, 0, 0]
self._leds = 0
def ModifierDown(self, modifier):
self._modifiers |= modifier
if self.IsConnected():
self.SendReport(self.GetInputReport())
def ModifierUp(self, modifier):
self._modifiers &= ~modifier
if self.IsConnected():
self.SendReport(self.GetInputReport())
def KeyDown(self, keycode):
free = self._keys.index(0)
self._keys[free] = keycode
if self.IsConnected():
self.SendReport(self.GetInputReport())
def KeyUp(self, keycode):
free = self._keys.index(keycode)
self._keys[free] = 0
if self.IsConnected():
self.SendReport(self.GetInputReport())
def GetInputReport(self):
"""Construct an input report.
See Device Class Definition for Human Interface Devices (HID) Version 1.11
Appendix B.1.
Returns:
A packed input report.
"""
return struct.pack('BBBBBBBB', self._modifiers, 0, *self._keys)
def GetOutputReport(self):
"""Construct an output report.
See Device Class Definition for Human Interface Devices (HID) Version 1.11
Appendix B.1.
Returns:
A packed input report.
"""
return struct.pack('B', self._leds)
def SetOutputReport(self, data):
"""Handle an output report.
See Device Class Definition for Human Interface Devices (HID) Version 1.11
Appendix B.1.
Args:
data: Report data.
Returns:
True on success, None to stall the pipe.
"""
if len(data) >= 1:
self._leds, = struct.unpack('B', data)
return True
class KeyboardGadget(hid_gadget.HidGadget):
"""USB gadget implementation of a HID keyboard."""
def __init__(self, vendor_id=0x18D1, product_id=0xFF02):
self._feature = KeyboardFeature()
super(KeyboardGadget, self).__init__(
report_desc=KeyboardFeature.REPORT_DESC,
features={0: self._feature},
packet_size=8,
interval_ms=1,
out_endpoint=True,
vendor_id=usb_constants.VendorID.GOOGLE,
product_id=usb_constants.ProductID.GOOGLE_KEYBOARD_GADGET,
device_version=0x0100)
self.AddStringDescriptor(1, 'Google Inc.')
self.AddStringDescriptor(2, 'Keyboard Gadget')
def ModifierDown(self, modifier):
self._feature.ModifierDown(modifier)
def ModifierUp(self, modifier):
self._feature.ModifierUp(modifier)
def KeyDown(self, keycode):
self._feature.KeyDown(keycode)
def KeyUp(self, keycode):
self._feature.KeyUp(keycode)
def RegisterHandlers():
"""Registers web request handlers with the application server."""
from tornado import web
class WebConfigureHandler(web.RequestHandler):
def post(self):
server.SwitchGadget(KeyboardGadget())
class WebTypeHandler(web.RequestHandler):
def post(self):
string = self.get_argument('string')
for char in string:
if char in hid_constants.KEY_CODES:
code = hid_constants.KEY_CODES[char]
server.gadget.KeyDown(code)
server.gadget.KeyUp(code)
elif char in hid_constants.SHIFT_KEY_CODES:
code = hid_constants.SHIFT_KEY_CODES[char]
server.gadget.ModifierDown(hid_constants.ModifierKey.L_SHIFT)
server.gadget.KeyDown(code)
server.gadget.KeyUp(code)
server.gadget.ModifierUp(hid_constants.ModifierKey.L_SHIFT)
class WebPressHandler(web.RequestHandler):
def post(self):
code = hid_constants.KEY_CODES[self.get_argument('key')]
server.gadget.KeyDown(code)
server.gadget.KeyUp(code)
import server
server.app.add_handlers('.*$', [
(r'/keyboard/configure', WebConfigureHandler),
(r'/keyboard/type', WebTypeHandler),
(r'/keyboard/press', WebPressHandler),
])
Codebase Browser
chromium