chromeos/dbus: Add fake D-Bus clients for GATT client-mode.

Added fake implementations of GATT service, characteristic, and descriptor
clients. A new "Low Energy" fake device is introduced, which uses the fake
GATT clients to simulate the Heart Rate Service.

BUG=351229
TEST=1. device_unittests, chromeos_unittests.
2. Build and run chrome for Linux with "chromeos=1". Run Bluetooth device
discovery, connect to the device named "Bluetooth 4.0 Heart Rate Monitor".
Watch the debug output (vmodule="*bluetooth_gatt*=2") for the GATT clients,
which should create fake heart rate service and descriptors and update the
measurement value at regular intervals.

R=keybuk@chromium.org, stevenjb@chromium.org

Review URL: https://codereview.chromium.org/206443009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@259022 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 342 insertions, 0 deletions

diff --git a/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
new file mode 100644
index 0000000..85408b8
--- /dev/null
+++ b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
@@ -0,0 +1,342 @@
+// 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.
+
+#include "chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "base/rand_util.h"
+#include "base/time/time.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+namespace chromeos {
+
+namespace {
+
+const int kHeartRateMeasurementNotificationIntervalMs = 2000;
+
+}  // namespace
+
+// static
+const char FakeBluetoothGattCharacteristicClient::
+    kHeartRateMeasurementPathComponent[] = "char0000";
+const char FakeBluetoothGattCharacteristicClient::
+    kBodySensorLocationPathComponent[] = "char0001";
+const char FakeBluetoothGattCharacteristicClient::
+    kHeartRateControlPointPathComponent[] = "char0002";
+
+// static
+const char FakeBluetoothGattCharacteristicClient::kHeartRateMeasurementUUID[] =
+    "00002a37-0000-1000-8000-00805f9b34fb";
+const char FakeBluetoothGattCharacteristicClient::kBodySensorLocationUUID[] =
+    "00002a38-0000-1000-8000-00805f9b34fb";
+const char FakeBluetoothGattCharacteristicClient::kHeartRateControlPointUUID[] =
+    "00002a39-0000-1000-8000-00805f9b34fb";
+
+FakeBluetoothGattCharacteristicClient::Properties::Properties(
+    const PropertyChangedCallback& callback)
+    : BluetoothGattCharacteristicClient::Properties(
+          NULL,
+          bluetooth_gatt_characteristic::kBluetoothGattCharacteristicInterface,
+          callback) {
+}
+
+FakeBluetoothGattCharacteristicClient::Properties::~Properties() {
+}
+
+void FakeBluetoothGattCharacteristicClient::Properties::Get(
+    dbus::PropertyBase* property,
+    dbus::PropertySet::GetCallback callback) {
+  VLOG(1) << "Get " << property->name();
+  callback.Run(false);
+}
+
+void FakeBluetoothGattCharacteristicClient::Properties::GetAll() {
+  VLOG(1) << "GetAll";
+}
+
+void FakeBluetoothGattCharacteristicClient::Properties::Set(
+    dbus::PropertyBase* property,
+    dbus::PropertySet::SetCallback callback) {
+  VLOG(1) << "Set " << property->name();
+  if (property->name() != value.name()) {
+    callback.Run(false);
+    return;
+  }
+  // Allow writing to only certain characteristics that are defined with the
+  // write permission.
+  // TODO(armansito): Actually check against the permissions property instead of
+  // UUID, once that property is fully defined in the API.
+  if (uuid.value() != kHeartRateControlPointUUID) {
+    callback.Run(false);
+    return;
+  }
+  callback.Run(true);
+  property->ReplaceValueWithSetValue();
+}
+
+FakeBluetoothGattCharacteristicClient::FakeBluetoothGattCharacteristicClient()
+    : heart_rate_visible_(false),
+      calories_burned_(0),
+      weak_ptr_factory_(this) {
+}
+
+FakeBluetoothGattCharacteristicClient::
+    ~FakeBluetoothGattCharacteristicClient() {
+}
+
+void FakeBluetoothGattCharacteristicClient::Init(dbus::Bus* bus) {
+}
+
+void FakeBluetoothGattCharacteristicClient::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void FakeBluetoothGattCharacteristicClient::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+std::vector<dbus::ObjectPath>
+FakeBluetoothGattCharacteristicClient::GetCharacteristics() {
+  std::vector<dbus::ObjectPath> paths;
+  if (IsHeartRateVisible()) {
+    paths.push_back(dbus::ObjectPath(heart_rate_measurement_path_));
+    paths.push_back(dbus::ObjectPath(body_sensor_location_path_));
+    paths.push_back(dbus::ObjectPath(heart_rate_control_point_path_));
+  }
+  return paths;
+}
+
+FakeBluetoothGattCharacteristicClient::Properties*
+FakeBluetoothGattCharacteristicClient::GetProperties(
+    const dbus::ObjectPath& object_path) {
+  if (object_path.value() == heart_rate_measurement_path_) {
+    DCHECK(heart_rate_measurement_properties_.get());
+    return heart_rate_measurement_properties_.get();
+  }
+  if (object_path.value() == body_sensor_location_path_) {
+    DCHECK(heart_rate_measurement_properties_.get());
+    return heart_rate_measurement_properties_.get();
+  }
+  if (object_path.value() == heart_rate_control_point_path_) {
+    DCHECK(heart_rate_control_point_properties_.get());
+    return heart_rate_control_point_properties_.get();
+  }
+  return NULL;
+}
+
+void FakeBluetoothGattCharacteristicClient::ExposeHeartRateCharacteristics(
+    const dbus::ObjectPath& service_path) {
+  if (IsHeartRateVisible()) {
+    VLOG(2) << "Fake Heart Rate characteristics are already visible.";
+    return;
+  }
+
+  VLOG(2) << "Exposing fake Heart Rate characteristics.";
+
+  // ==== Heart Rate Measurement Characteristic ====
+  heart_rate_measurement_path_ =
+      service_path.value() + "/" + kHeartRateMeasurementPathComponent;
+  heart_rate_measurement_properties_.reset(new Properties(base::Bind(
+      &FakeBluetoothGattCharacteristicClient::OnPropertyChanged,
+      weak_ptr_factory_.GetWeakPtr(),
+      dbus::ObjectPath(heart_rate_measurement_path_))));
+  heart_rate_measurement_properties_->uuid.ReplaceValue(
+      kHeartRateMeasurementUUID);
+  heart_rate_measurement_properties_->service.ReplaceValue(service_path);
+
+  // TODO(armansito): Fill out the flags field once bindings for the values have
+  // been added. For now, leave it empty.
+
+  std::vector<uint8> measurement_value = GetHeartRateMeasurementValue();
+  heart_rate_measurement_properties_->value.ReplaceValue(measurement_value);
+
+  // ==== Body Sensor Location Characteristic ====
+  body_sensor_location_path_ =
+      service_path.value() + "/" + kBodySensorLocationPathComponent;
+  body_sensor_location_properties_.reset(new Properties(base::Bind(
+      &FakeBluetoothGattCharacteristicClient::OnPropertyChanged,
+      weak_ptr_factory_.GetWeakPtr(),
+      dbus::ObjectPath(body_sensor_location_path_))));
+  body_sensor_location_properties_->uuid.ReplaceValue(kBodySensorLocationUUID);
+  body_sensor_location_properties_->service.ReplaceValue(service_path);
+
+  // TODO(armansito): Fill out the flags field once bindings for the values have
+  // been added. For now, leave it empty.
+
+  // The sensor is in the "Other" location.
+  std::vector<uint8> body_sensor_location_value;
+  body_sensor_location_value.push_back(0);
+  body_sensor_location_properties_->value.ReplaceValue(
+      body_sensor_location_value);
+
+  // ==== Heart Rate Control Point Characteristic ====
+  heart_rate_control_point_path_ =
+      service_path.value() + "/" + kHeartRateControlPointPathComponent;
+  heart_rate_control_point_properties_.reset(new Properties(base::Bind(
+      &FakeBluetoothGattCharacteristicClient::OnPropertyChanged,
+      weak_ptr_factory_.GetWeakPtr(),
+      dbus::ObjectPath(heart_rate_control_point_path_))));
+  heart_rate_control_point_properties_->uuid.ReplaceValue(
+      kHeartRateControlPointUUID);
+  heart_rate_control_point_properties_->service.ReplaceValue(service_path);
+
+  // TODO(armansito): Fill out the flags field once bindings for the values have
+  // been added. For now, leave it empty.
+
+  // Set the initial value to 0. Whenever this gets set to 1, we will reset the
+  // total calories burned and change the value back to 0.
+  std::vector<uint8> heart_rate_control_point_value;
+  heart_rate_control_point_value.push_back(0);
+  heart_rate_control_point_properties_->value.ReplaceValue(
+      heart_rate_control_point_value);
+
+  heart_rate_visible_ = true;
+
+  NotifyCharacteristicAdded(dbus::ObjectPath(heart_rate_measurement_path_));
+  NotifyCharacteristicAdded(dbus::ObjectPath(body_sensor_location_path_));
+  NotifyCharacteristicAdded(dbus::ObjectPath(heart_rate_control_point_path_));
+
+  // Set up notifications for heart rate measurement.
+  // TODO(armansito): Do this based on the value of the "client characteristic
+  // configuration" descriptor. Since it's still unclear how descriptors will
+  // be handled by BlueZ, automatically set up notifications for now.
+  ScheduleHeartRateMeasurementValueChange();
+
+  // TODO(armansito): Add descriptors.
+}
+
+void FakeBluetoothGattCharacteristicClient::HideHeartRateCharacteristics() {
+  VLOG(2) << "Hiding fake Heart Rate characteristics.";
+  heart_rate_measurement_properties_.reset();
+  body_sensor_location_properties_.reset();
+  heart_rate_control_point_properties_.reset();
+
+  std::string hrm_path = heart_rate_measurement_path_;
+  heart_rate_measurement_path_.clear();
+  std::string bsl_path =  body_sensor_location_path_;
+  body_sensor_location_path_.clear();
+  std::string hrcp_path = heart_rate_control_point_path_;
+  heart_rate_control_point_path_.clear();
+  heart_rate_visible_ = false;
+
+  NotifyCharacteristicRemoved(dbus::ObjectPath(hrm_path));
+  NotifyCharacteristicRemoved(dbus::ObjectPath(bsl_path));
+  NotifyCharacteristicRemoved(dbus::ObjectPath(hrcp_path));
+}
+
+void FakeBluetoothGattCharacteristicClient::OnPropertyChanged(
+    const dbus::ObjectPath& object_path,
+    const std::string& property_name) {
+  VLOG(2) << "Characteristic property changed: " << object_path.value()
+          << ": " << property_name;
+
+  FOR_EACH_OBSERVER(BluetoothGattCharacteristicClient::Observer, observers_,
+                    GattCharacteristicPropertyChanged(
+                        object_path, property_name));
+
+  // If the heart rate control point was set, reset the calories burned.
+  if (object_path.value() != heart_rate_control_point_path_)
+    return;
+  DCHECK(heart_rate_control_point_properties_.get());
+  dbus::Property<std::vector<uint8> >* value_prop =
+      &heart_rate_control_point_properties_->value;
+  if (property_name != value_prop->name())
+    return;
+
+  std::vector<uint8> value = value_prop->value();
+  DCHECK(value.size() == 1);
+  if (value[0] == 0)
+    return;
+
+  DCHECK(value[0] == 1);
+  calories_burned_ = 0;
+  value[0] = 0;
+  value_prop->ReplaceValue(value);
+}
+
+void FakeBluetoothGattCharacteristicClient::NotifyCharacteristicAdded(
+    const dbus::ObjectPath& object_path) {
+  VLOG(2) << "GATT characteristic added: " << object_path.value();
+  FOR_EACH_OBSERVER(BluetoothGattCharacteristicClient::Observer, observers_,
+                    GattCharacteristicAdded(object_path));
+}
+
+void FakeBluetoothGattCharacteristicClient::NotifyCharacteristicRemoved(
+    const dbus::ObjectPath& object_path) {
+  VLOG(2) << "GATT characteristic removed: " << object_path.value();
+  FOR_EACH_OBSERVER(BluetoothGattCharacteristicClient::Observer, observers_,
+                    GattCharacteristicRemoved(object_path));
+}
+
+void FakeBluetoothGattCharacteristicClient::
+    ScheduleHeartRateMeasurementValueChange() {
+  if (!IsHeartRateVisible())
+    return;
+  VLOG(2) << "Updating heart rate value.";
+  std::vector<uint8> measurement = GetHeartRateMeasurementValue();
+  heart_rate_measurement_properties_->value.ReplaceValue(measurement);
+
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&FakeBluetoothGattCharacteristicClient::
+                     ScheduleHeartRateMeasurementValueChange,
+                 weak_ptr_factory_.GetWeakPtr()),
+                 base::TimeDelta::FromMilliseconds(
+                     kHeartRateMeasurementNotificationIntervalMs));
+}
+
+std::vector<uint8>
+FakeBluetoothGattCharacteristicClient::GetHeartRateMeasurementValue() {
+  // TODO(armansito): We should make sure to properly pack this struct to ensure
+  // correct byte alignment and endianness. It doesn't matter too much right now
+  // as this is a fake and GCC on Linux seems to do the right thing.
+  struct {
+    uint8 flags;
+    uint8 bpm;
+    uint16 energy_expanded;
+    uint16 rr_interval;
+  } value;
+
+  // Flags in LSB:     0       11   1 1 000
+  //                   |       |    | | |
+  // 8-bit bpm format --       |    | | |
+  // Sensor contact supported --    | | |
+  // Energy expanded field present -- | |
+  // RR-Interval values present ------- |
+  // Reserved for future use ------------
+  value.flags = 0x0;
+  value.flags |= (0x03 << 1);
+  value.flags |= (0x01 << 3);
+  value.flags |= (0x01 << 4);
+
+  // Pick a value between 117 bpm and 153 bpm for heart rate.
+  value.bpm = static_cast<uint8>(base::RandInt(117, 153));
+
+  // Total calories burned in kJoules since the last reset. Increment this by 1
+  // every time. It's fine if it overflows: it becomes 0 when the user resets
+  // the heart rate monitor (or pretend that he had a lot of cheeseburgers).
+  value.energy_expanded = calories_burned_++;
+
+  // Include one RR-Interval value, in seconds.
+  value.rr_interval = 60/value.bpm;
+
+  // Return the bytes in an array.
+  uint8* bytes = reinterpret_cast<uint8*>(&value);
+  std::vector<uint8> return_value;
+  return_value.assign(bytes, bytes + sizeof(value));
+  return return_value;
+}
+
+bool FakeBluetoothGattCharacteristicClient::IsHeartRateVisible() const {
+  DCHECK(heart_rate_visible_ != heart_rate_measurement_path_.empty());
+  DCHECK(heart_rate_visible_ != body_sensor_location_path_.empty());
+  DCHECK(heart_rate_visible_ != heart_rate_control_point_path_.empty());
+  DCHECK(heart_rate_visible_ == !!heart_rate_measurement_properties_.get());
+  DCHECK(heart_rate_visible_ == !!body_sensor_location_properties_.get());
+  DCHECK(heart_rate_visible_ == !!heart_rate_control_point_properties_.get());
+  return heart_rate_visible_;
+}
+
+}  // namespace chromeos