Chrome OS: Add bluetooth dbus clients for device discovery

chrome/browser/chromeos/dbus/bluetooth_adapter_client.cc

+// Copyright (c) 2011 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 "chrome/browser/chromeos/dbus/bluetooth_adapter_client.h"
+
+#include <map>
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "chrome/browser/chromeos/system/runtime_environment.h"
+#include "dbus/bus.h"
+#include "dbus/message.h"
+#include "dbus/object_proxy.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+namespace {
+
+// Utility function to convert an array of dbus dict_entry objects into a
+// DictionaryValue object.
+//
+// The dict_entry objects must have keys that are strings and values that are
+// simple variants.
+//
+// When converting integral types, we use Integer Value objects to represent
+// uint8, int16, uint16, int32, and uint32 values and Double Value objects to
+// represent int64 and uint64 values.
+//
+// We intend to move this to the chrome dbus library's MessageReader class when
+// it's more fully baked.
+//
+// TODO(vlaviano):
+// - Can we handle integral types better?
+// - Add support for nested complex types.
+// - Write an equivalent function to convert in the opposite direction.
+// - Write unit tests.
+bool PopArrayOfDictEntries(dbus::MessageReader* reader,
+                           dbus::Message* message,
+                           DictionaryValue* dictionary) {
+  DCHECK(reader != NULL);
+  DCHECK(message != NULL);
+  DCHECK(dictionary != NULL);
+  dbus::MessageReader array_reader(message);
+  if (!reader->PopArray(&array_reader)) {
+    return false;
+  }
+  while (array_reader.HasMoreData()) {
+    dbus::MessageReader dict_entry_reader(message);
+    if (!array_reader.PopDictEntry(&dict_entry_reader)) {
+      return false;
+    }
+    std::string key;
+    if (!dict_entry_reader.PopString(&key)) {
+      return false;
+    }
+    dbus::MessageReader variant_reader(message);
+    if (!dict_entry_reader.PopVariant(&variant_reader)) {
+      return false;
+    }
+    const dbus::Message::DataType type = variant_reader.GetDataType();
+    switch (type) {
+      case dbus::Message::BYTE: {
+        uint8 value = 0;
+        if (!variant_reader.PopByte(&value)) {
+          return false;
+        }
+        dictionary->SetInteger(key, value);
+        break;
+      }
+      case dbus::Message::BOOL: {
+        bool value = false;
+        if (!variant_reader.PopBool(&value)) {
+          return false;
+        }
+        dictionary->SetBoolean(key, value);
+        break;
+      }
+      case dbus::Message::INT16: {
+        int16 value = 0;
+        if (!variant_reader.PopInt16(&value)) {
+          return false;
+        }
+        dictionary->SetInteger(key, value);
+        break;
+      }
+      case dbus::Message::UINT16: {
+        uint16 value = 0;
+        if (!variant_reader.PopUint16(&value)) {
+          return false;
+        }
+        dictionary->SetInteger(key, value);
+        break;
+      }
+      case dbus::Message::INT32: {
+        int32 value = 0;
+        if (!variant_reader.PopInt32(&value)) {
+          return false;
+        }
+        dictionary->SetInteger(key, value);
+        break;
+      }
+      case dbus::Message::UINT32: {
+        uint32 value = 0;
+        if (!variant_reader.PopUint32(&value)) {
+          return false;
+        }
+        dictionary->SetInteger(key, value);
+        break;
+      }
+      case dbus::Message::INT64: {
+        int64 value = 0;
+        if (!variant_reader.PopInt64(&value)) {
+          return false;
+        }
+        dictionary->SetDouble(key, value);
+        break;
+      }
+      case dbus::Message::UINT64: {
+        uint64 value = 0;
+        if (!variant_reader.PopUint64(&value)) {
+          return false;
+        }
+        dictionary->SetDouble(key, value);
+        break;
+      }
+      case dbus::Message::DOUBLE: {
+        double value = 0;
+        if (!variant_reader.PopDouble(&value)) {
+          return false;
+        }
+        dictionary->SetDouble(key, value);
+        break;
+      }
+      case dbus::Message::STRING: {
+        std::string value;
+        if (!variant_reader.PopString(&value)) {
+          return false;
+        }
+        dictionary->SetString(key, value);
+        break;
+      }
+      case dbus::Message::OBJECT_PATH: {
+        std::string value;
+        if (!variant_reader.PopObjectPath(&value)) {
+          return false;
+        }
+        dictionary->SetString(key, value);
+        break;
+      }
+      case dbus::Message::ARRAY: {
+        // Not yet supported.
+        return false;
+      }
+      case dbus::Message::STRUCT: {
+        // Not yet supported.
+        return false;
+      }
+      case dbus::Message::DICT_ENTRY: {
+        // Not yet supported.
+        return false;
+      }
+      case dbus::Message::VARIANT: {
+        // Not yet supported.
+        return false;
+      }
+      default:
+        LOG(FATAL) << "Unknown type: " << type;
+    }
+  }
+  return true;
+}
+
+}  // namespace
+
+namespace chromeos {
+
+// The BluetoothAdapterClient implementation used in production.
+class BluetoothAdapterClientImpl: public BluetoothAdapterClient {
+ public:
+  explicit BluetoothAdapterClientImpl(dbus::Bus* bus)
+      : weak_ptr_factory_(this),
+        bus_(bus) {
+    VLOG(1) << "Creating BluetoothAdapterClientImpl";
+  }
+
+  virtual ~BluetoothAdapterClientImpl() {
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void AddObserver(Observer* observer, const std::string& object_path) {
+    VLOG(1) << "AddObserver: " << object_path;
+    DCHECK(observer != NULL);

[satorux1, 2011/10/25 19:55:17]

I think DCHECK(observer) is more common in Chrome code.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+    observers_.AddObserver(observer);
+    AddObjectProxyForPath(object_path);
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void RemoveObserver(Observer* observer,
+                              const std::string& object_path) {
+    VLOG(1) << "RemoveObserver: " << object_path;
+    CHECK(observer != NULL);
+    observers_.RemoveObserver(observer);
+    RemoveObjectProxyForPath(object_path);
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void StartDiscovery(const std::string& object_path) {
+    VLOG(1) << "StartDiscovery: " << object_path;
+
+    dbus::MethodCall method_call(
+        bluetooth_adapter::kBluetoothAdapterInterface,
+        bluetooth_adapter::kStartDiscovery);
+
+    ProxyMap::iterator it = proxy_map_.find(object_path);
+    if (it == proxy_map_.end()) {
+      LOG(ERROR) << "Couldn't find proxy for object path " << object_path;
+      return;
+    }
+    dbus::ObjectProxy* adapter_proxy =
+        static_cast<dbus::ObjectProxy*>(it->second);

[satorux1, 2011/10/25 19:55:17]

I think the static cast is unnecessary here.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+    DCHECK(adapter_proxy != NULL);

[satorux1, 2011/10/25 19:55:17]

This may sound like an overuse of DCHECK(), but it's up to you.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+
+    adapter_proxy->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&BluetoothAdapterClientImpl::OnStartDiscovery,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void StopDiscovery(const std::string& object_path) {
+    VLOG(1) << "StopDiscovery: " << object_path;
+
+    dbus::MethodCall method_call(
+        bluetooth_adapter::kBluetoothAdapterInterface,
+        bluetooth_adapter::kStopDiscovery);
+
+    ProxyMap::iterator it = proxy_map_.find(object_path);
+    if (it == proxy_map_.end()) {
+      LOG(ERROR) << "Couldn't find proxy for object path " << object_path;
+      return;
+    }
+    dbus::ObjectProxy* adapter_proxy =
+        static_cast<dbus::ObjectProxy*>(it->second);

[satorux1, 2011/10/25 19:55:17]

ditto.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+    DCHECK(adapter_proxy != NULL);
+
+    adapter_proxy->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&BluetoothAdapterClientImpl::OnStopDiscovery,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+  }
+
+ private:
+  // Gets a dbus object proxy for an adapter with dbus object path |object_path|
+  // and stores it in our |proxy_map_| map.
+  void AddObjectProxyForPath(const std::string& object_path) {
+    VLOG(1) << "AddObjectProxyForPath: " << object_path;
+
+    DCHECK(bus_ != NULL);
+    dbus::ObjectProxy* adapter_proxy = bus_->GetObjectProxy(
+        bluetooth_adapter::kBluetoothAdapterServiceName, object_path);
+    DCHECK(adapter_proxy != NULL);

[satorux1, 2011/10/25 19:55:17]

we don't need this. GetObjectProxy guarantees not to return NULL.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+
+    proxy_map_[object_path] = adapter_proxy;
+
+    adapter_proxy->ConnectToSignal(
+        bluetooth_adapter::kBluetoothAdapterInterface,
+        bluetooth_adapter::kPropertyChangedSignal,
+        base::Bind(&BluetoothAdapterClientImpl::PropertyChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr(), object_path),
+        base::Bind(&BluetoothAdapterClientImpl::PropertyChangedConnected,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+
+    adapter_proxy->ConnectToSignal(
+        bluetooth_adapter::kBluetoothAdapterInterface,
+        bluetooth_adapter::kDeviceFoundSignal,
+        base::Bind(&BluetoothAdapterClientImpl::DeviceFoundReceived,
+                   weak_ptr_factory_.GetWeakPtr(), object_path),
+        base::Bind(&BluetoothAdapterClientImpl::DeviceFoundConnected,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+
+    adapter_proxy->ConnectToSignal(
+        bluetooth_adapter::kBluetoothAdapterInterface,
+        bluetooth_adapter::kDeviceDisappearedSignal,
+        base::Bind(&BluetoothAdapterClientImpl::DeviceDisappearedReceived,
+                   weak_ptr_factory_.GetWeakPtr(), object_path),
+        base::Bind(&BluetoothAdapterClientImpl::DeviceDisappearedConnected,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+  }
+
+  // Removes the dbus object proxy for the adapter with dbus object path
+  // |object_path| from our |proxy_map_| map.
+  void RemoveObjectProxyForPath(const std::string& object_path) {
+    VLOG(1) << "RemoveObjectProxyForPath: " << object_path;
+    proxy_map_.erase(object_path);
+  }
+
+  // Called by dbus:: when a PropertyChanged signal is received.
+  void PropertyChangedReceived(const std::string& object_path,
+                               dbus::Signal* signal) {
+    DCHECK(signal != NULL);
+    dbus::MessageReader reader(signal);
+    std::string property_name;
+    if (!reader.PopString(&property_name)) {
+      LOG(ERROR) << object_path
+          << ": PropertyChanged signal has incorrect parameters: "
+          << signal->ToString();
+      return;
+    }
+
+    if (property_name != bluetooth_adapter::kDiscoveringProperty) {
+      VLOG(1) << object_path << ": PropertyChanged: " << property_name;
+      // We don't care.
+      return;
+    }
+
+    bool discovering = false;
+    if (!reader.PopVariantOfBool(&discovering)) {
+      LOG(ERROR) << object_path
+          << ": PropertyChanged signal has incorrect parameters: "
+          << signal->ToString();
+      return;
+    }
+    VLOG(1) << object_path << ": PropertyChanged: Discovering = "
+        << discovering;
+
+    FOR_EACH_OBSERVER(Observer, observers_,
+                      DiscoveringPropertyChanged(object_path, discovering));
+  }
+
+  // Called by dbus:: when the PropertyChanged signal is initially connected.
+  void PropertyChangedConnected(const std::string& object_path,
+                                const std::string& interface_name,
+                                const std::string& signal_name,
+                                bool success) {
+    LOG_IF(WARNING, !success) << object_path
+        << ": Failed to connect to PropertyChanged signal.";
+  }
+
+  // Called by dbus:: when a DeviceFound signal is received.
+  void DeviceFoundReceived(const std::string& object_path,
+                           dbus::Signal* signal) {
+    DCHECK(signal != NULL);
+    dbus::MessageReader reader(signal);
+    std::string address;
+    if (!reader.PopString(&address)) {
+      LOG(ERROR) << object_path
+          << ": DeviceFound signal has incorrect parameters: "
+          << signal->ToString();
+      return;
+    }
+    VLOG(1) << object_path << ": Device found: " << address;
+
+    DictionaryValue device_properties;
+    if (!PopArrayOfDictEntries(&reader, signal, &device_properties)) {
+      LOG(ERROR) << object_path
+          << ": DeviceFound signal has incorrect parameters: "
+          << signal->ToString();
+      return;
+    }
+
+    FOR_EACH_OBSERVER(Observer, observers_, DeviceFound(object_path, address,
+                                                        device_properties));
+  }
+
+  // Called by dbus:: when the DeviceFound signal is initially connected.
+  void DeviceFoundConnected(const std::string& object_path,
+                            const std::string& interface_name,
+                            const std::string& signal_name,
+                            bool success) {
+    LOG_IF(WARNING, !success) << object_path
+        << ": Failed to connect to DeviceFound signal.";
+  }
+
+  // Called by dbus:: when a DeviceDisappeared signal is received.
+  void DeviceDisappearedReceived(const std::string&  object_path,
+                                 dbus::Signal* signal) {
+    DCHECK(signal != NULL);
+    dbus::MessageReader reader(signal);
+    std::string address;
+    if (!reader.PopString(&address)) {
+      LOG(ERROR) << object_path
+          << ": DeviceDisappeared signal has incorrect parameters: "
+          << signal->ToString();
+      return;
+    }
+    VLOG(1) << object_path << ": Device disappeared: " << address;
+    FOR_EACH_OBSERVER(Observer, observers_, DeviceDisappeared(object_path,
+                                                              address));
+  }
+
+  // Called by dbus:: when the DeviceDisappeared signal is initially connected.
+  void DeviceDisappearedConnected(const std::string& object_path,
+                                  const std::string& interface_name,
+                                  const std::string& signal_name,
+                                  bool success) {
+    LOG_IF(WARNING, !success) << object_path
+        << ": Failed to connect to DeviceDisappeared signal.";
+  }
+
+  // Called when a response for StartDiscovery() is received.
+  void OnStartDiscovery(const std::string& object_path,
+                        dbus::Response* response) {
+    VLOG(1) << "OnStartDiscovery: " << object_path;
+    DCHECK(response != NULL);

[satorux1, 2011/10/25 19:55:17]

LOG_IF(WARNING, response) << ... 

would be nicer. |response| is NULL if the method call is failed.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+  }
+
+  // Called when a response for StopDiscovery() is received.
+  void OnStopDiscovery(const std::string& object_path,
+                       dbus::Response* response) {
+    VLOG(1) << "OnStopDiscovery: " << object_path;
+    DCHECK(response != NULL);

[satorux1, 2011/10/25 19:55:17]

ditto.

[Vince Laviano, 2011/10/25 20:31:42]

Done.

+  }
+
+  // Weak pointer factory for generating 'this' pointers that might live longer
+  // than we do.
+  base::WeakPtrFactory<BluetoothAdapterClientImpl> weak_ptr_factory_;
+
+  dbus::Bus* bus_;
+
+  // We maintain a collection of dbus object proxies, one for each adapter.
+  typedef std::map<const std::string, dbus::ObjectProxy*> ProxyMap;
+  ProxyMap proxy_map_;
+
+  // List of observers interested in event notifications from us.
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(BluetoothAdapterClientImpl);
+};
+
+// The BluetoothAdapterClient implementation used on Linux desktop, which does
+// nothing.
+class BluetoothAdapterClientStubImpl : public BluetoothAdapterClient {
+ public:
+  // BluetoothAdapterClient override.
+  virtual void AddObserver(Observer* observer, const std::string& object_path) {
+    VLOG(1) << "AddObserver: " << object_path;
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void RemoveObserver(Observer* observer,
+                              const std::string& object_path) {
+    VLOG(1) << "RemoveObserver: " << object_path;
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void StartDiscovery(const std::string& object_path) {
+    VLOG(1) << "StartDiscovery: " << object_path;
+  }
+
+  // BluetoothAdapterClient override.
+  virtual void StopDiscovery(const std::string& object_path) {
+    VLOG(1) << "StopDiscovery: " << object_path;
+  }
+};
+
+BluetoothAdapterClient::BluetoothAdapterClient() {
+}
+
+BluetoothAdapterClient::~BluetoothAdapterClient() {
+}
+
+BluetoothAdapterClient* BluetoothAdapterClient::Create(dbus::Bus* bus) {
+  if (system::runtime_environment::IsRunningOnChromeOS()) {
+    return new BluetoothAdapterClientImpl(bus);
+  } else {
+    return new BluetoothAdapterClientStubImpl();
+  }
+}
+
+}  // namespace chromeos