[usb_gadget p05] Add a HID mouse gadget.

tools/usb_gadget/mouse_gadget.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# 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 mouse.
+
+Two classes are provided by this module. The MouseFeature class implements
+the core functionality of a HID mouse and can be included in any HID gadget.
+The MouseGadget class implements an example mouse gadget.
+"""
+
+import struct
+
+import hid_constants
+import hid_descriptors
+import hid_gadget
+import usb_constants
+
+
+class MouseFeature(hid_gadget.HidFeature):
+  """HID feature implementation for a mouse.
+
+  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(0x02),  # Mouse
+      hid_descriptors.Collection(
+          hid_constants.CollectionType.APPLICATION,
+          hid_descriptors.Usage(0x01),  # Pointer
+          hid_descriptors.Collection(
+              hid_constants.CollectionType.PHYSICAL,
+              hid_descriptors.UsagePage(0x09),  # Buttons
+              hid_descriptors.UsageMinimum(1),
+              hid_descriptors.UsageMaximum(3),
+              hid_descriptors.LogicalMinimum(0, force_length=1),
+              hid_descriptors.LogicalMaximum(1),
+              hid_descriptors.ReportCount(3),
+              hid_descriptors.ReportSize(1),
+              hid_descriptors.Input(hid_descriptors.Data,
+                                    hid_descriptors.Variable,
+                                    hid_descriptors.Absolute),
+              hid_descriptors.ReportCount(1),
+              hid_descriptors.ReportSize(5),
+              hid_descriptors.Input(hid_descriptors.Constant),
+              hid_descriptors.UsagePage(0x01),  # Generic Desktop
+              hid_descriptors.Usage(0x30),  # X
+              hid_descriptors.Usage(0x31),  # Y
+              hid_descriptors.LogicalMinimum(0x81),  # -127
+              hid_descriptors.LogicalMaximum(127),
+              hid_descriptors.ReportSize(8),
+              hid_descriptors.ReportCount(2),
+              hid_descriptors.Input(hid_descriptors.Data,
+                                    hid_descriptors.Variable,
+                                    hid_descriptors.Relative)
+          )
+      )
+  )
+
+  def __init__(self):
+    super(MouseFeature, self).__init__()
+    self._buttons = 0
+
+  def ButtonDown(self, button):
+    self._buttons |= button
+    if self.IsConnected():
+      self.SendReport(self.EncodeInputReport())
+
+  def ButtonUp(self, button):
+    self._buttons &= ~button
+    if self.IsConnected():
+      self.SendReport(self.EncodeInputReport())
+
+  def Move(self, x_displacement, y_displacement):
+    if self.IsConnected():
+      self.SendReport(self.EncodeInputReport(x_displacement, y_displacement))
+
+  def EncodeInputReport(self, x_displacement=0, y_displacement=0):
+    return struct.pack('Bbb', self._buttons, x_displacement, y_displacement)
+
+  def GetInputReport(self):
+    """Construct an input report.
+
+    See Device Class Definition for Human Interface Devices (HID) Version 1.11
+    Appendix B.2.
+
+    Returns:
+      A packed input report.
+    """
+    return self.EncodeInputReport()
+
+
+class MouseGadget(hid_gadget.HidGadget):
+  """USB gadget implementation of a HID mouse."""
+
+  def __init__(self):
+    self._feature = MouseFeature()
+    super(MouseGadget, self).__init__(
+        report_desc=MouseFeature.REPORT_DESC,
+        features={0: self._feature},
+        packet_size=8,
+        interval_ms=1,
+        out_endpoint=False,
+        vendor_id=usb_constants.VendorID.GOOGLE,
+        product_id=usb_constants.ProductID.GOOGLE_MOUSE_GADGET,
+        device_version=0x0100)
+    self.AddStringDescriptor(1, 'Google Inc.')
+    self.AddStringDescriptor(2, 'Mouse Gadget')
+
+  def ButtonDown(self, button):
+    self._feature.ButtonDown(button)
+
+  def ButtonUp(self, button):
+    self._feature.ButtonUp(button)
+
+  def Move(self, x_displacement, y_displacement):
+    self._feature.Move(x_displacement, y_displacement)