chromeos/dbus/nfc_tag_client.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/dbus/nfc_tag_client.h"
   6
   7 #include "base/bind.h"
   8 #include "base/memory/weak_ptr.h"
   9 #include "base/observer_list.h"
  10 #include "base/strings/stringprintf.h"
  11 #include "chromeos/dbus/nfc_adapter_client.h"
  12 #include "dbus/bus.h"
  13 #include "dbus/message.h"
  14 #include "dbus/values_util.h"
  15 #include "third_party/cros_system_api/dbus/service_constants.h"
  16
  17 using chromeos::nfc_client_helpers::DBusObjectMap;
  18 using chromeos::nfc_client_helpers::ObjectProxyTree;
  19
  20 namespace chromeos {
  21
  22 NfcTagClient::Properties::Properties(
  23     dbus::ObjectProxy* object_proxy,
  24     const PropertyChangedCallback& callback)
  25     : NfcPropertySet(object_proxy,
  26                      nfc_tag::kNfcTagInterface,
  27                      callback) {
  28   RegisterProperty(nfc_tag::kTypeProperty, &type);
  29   RegisterProperty(nfc_tag::kProtocolProperty, &protocol);
  30   RegisterProperty(nfc_tag::kRecordsProperty, &records);
  31   RegisterProperty(nfc_tag::kReadOnlyProperty, &read_only);
  32 }
  33
  34 NfcTagClient::Properties::~Properties() {
  35 }
  36
  37 // The NfcTagClient implementation used in production.
  38 class NfcTagClientImpl : public NfcTagClient,
  39                          public NfcAdapterClient::Observer,
  40                          public DBusObjectMap::Delegate {
  41  public:
  42   explicit NfcTagClientImpl(NfcAdapterClient* adapter_client)
  43       : bus_(NULL),
  44         adapter_client_(adapter_client),
  45         weak_ptr_factory_(this) {
  46     DCHECK(adapter_client);
  47   }
  48
  49   ~NfcTagClientImpl() override {
  50     DCHECK(adapter_client_);
  51     adapter_client_->RemoveObserver(this);
  52   }
  53
  54   // NfcTagClient override.
  55   void AddObserver(NfcTagClient::Observer* observer) override {
  56     DCHECK(observer);
  57     observers_.AddObserver(observer);
  58   }
  59
  60   // NfcTagClient override.
  61   void RemoveObserver(NfcTagClient::Observer* observer) override {
  62     DCHECK(observer);
  63     observers_.RemoveObserver(observer);
  64   }
  65
  66   // NfcTagClient override.
  67   std::vector<dbus::ObjectPath> GetTagsForAdapter(
  68       const dbus::ObjectPath& adapter_path) override {
  69     DBusObjectMap* object_map =
  70         adapters_to_object_maps_.GetObjectMap(adapter_path);
  71     if (!object_map)
  72       return std::vector<dbus::ObjectPath>();
  73     return object_map->GetObjectPaths();
  74   }
  75
  76   // NfcTagClient override.
  77   Properties* GetProperties(const dbus::ObjectPath& object_path) override {
  78     return static_cast<Properties*>(
  79         adapters_to_object_maps_.FindObjectProperties(object_path));
  80   }
  81
  82   // NfcTagClient override.
  83   void Write(const dbus::ObjectPath& object_path,
  84              const base::DictionaryValue& attributes,
  85              const base::Closure& callback,
  86              const nfc_client_helpers::ErrorCallback& error_callback) override {
  87     dbus::ObjectProxy* object_proxy =
  88         adapters_to_object_maps_.FindObjectProxy(object_path);
  89     if (!object_proxy) {
  90       std::string error_message =
  91           base::StringPrintf("NFC tag with object path \"%s\" does not exist.",
  92                              object_path.value().c_str());
  93       LOG(ERROR) << error_message;
  94       error_callback.Run(nfc_client_helpers::kUnknownObjectError,
  95                          error_message);
  96       return;
  97     }
  98
  99     // |attributes| should not be empty.
 100     if (attributes.empty()) {
 101       std::string error_message =
 102           "Cannot write data to tag with empty arguments.";
 103       LOG(ERROR) << error_message;
 104       error_callback.Run(nfc_error::kInvalidArguments, error_message);
 105       return;
 106     }
 107
 108     // Create the arguments.
 109     dbus::MethodCall method_call(nfc_tag::kNfcTagInterface, nfc_tag::kWrite);
 110     dbus::MessageWriter writer(&method_call);
 111     dbus::AppendValueData(&writer, attributes);
 112
 113     object_proxy->CallMethodWithErrorCallback(
 114         &method_call,
 115         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
 116         base::Bind(&nfc_client_helpers::OnSuccess, callback),
 117         base::Bind(&nfc_client_helpers::OnError, error_callback));
 118   }
 119
 120  protected:
 121   // DBusClient override.
 122   void Init(dbus::Bus* bus) override {
 123     VLOG(1) << "Creating NfcTagClientImpl";
 124     DCHECK(bus);
 125     bus_ = bus;
 126     DCHECK(adapter_client_);
 127     adapter_client_->AddObserver(this);
 128   }
 129
 130  private:
 131   // NfcAdapterClient::Observer override.
 132   void AdapterAdded(const dbus::ObjectPath& object_path) override {
 133     VLOG(1) << "Adapter added. Creating map for tag proxies belonging to "
 134             << "adapter: " << object_path.value();
 135     adapters_to_object_maps_.CreateObjectMap(
 136         object_path, nfc_tag::kNfcTagServiceName, this, bus_);
 137   }
 138
 139   // NfcAdapterClient::Observer override.
 140   void AdapterRemoved(const dbus::ObjectPath& object_path) override {
 141     // Neard doesn't send out property changed signals for the tags that
 142     // are removed when the adapter they belong to is removed. Clean up the
 143     // object proxies for devices that are managed by the removed adapter.
 144     // Note: DBusObjectMap guarantees that the Properties structure for the
 145     // removed adapter will be valid before this method returns.
 146     VLOG(1) << "Adapter removed. Cleaning up tag proxies belonging to "
 147             << "adapter: " << object_path.value();
 148     adapters_to_object_maps_.RemoveObjectMap(object_path);
 149   }
 150
 151   // NfcAdapterClient::Observer override.
 152   void AdapterPropertyChanged(const dbus::ObjectPath& object_path,
 153                               const std::string& property_name) override {
 154     // Update the tag proxies.
 155     DCHECK(adapter_client_);
 156     NfcAdapterClient::Properties *adapter_properties =
 157         adapter_client_->GetProperties(object_path);
 158     DCHECK(adapter_properties);
 159     if (!adapter_properties) {
 160       LOG(ERROR) << "No property structure found for adapter: "
 161                  << object_path.value();
 162       return;
 163     }
 164
 165     // Ignore changes to properties other than "Tags".
 166     if (property_name != adapter_properties->tags.name())
 167       return;
 168
 169     // Update the known tags.
 170     VLOG(1) << "NFC tags changed.";
 171     const std::vector<dbus::ObjectPath>& received_tags =
 172         adapter_properties->tags.value();
 173     DBusObjectMap* object_map =
 174         adapters_to_object_maps_.GetObjectMap(object_path);
 175     DCHECK(object_map);
 176     object_map->UpdateObjects(received_tags);
 177   }
 178
 179   // nfc_client_helpers::DBusObjectMap::Delegate override.
 180   NfcPropertySet* CreateProperties(dbus::ObjectProxy* object_proxy) override {
 181     Properties* properties = new Properties(
 182         object_proxy,
 183         base::Bind(&NfcTagClientImpl::OnPropertyChanged,
 184                    weak_ptr_factory_.GetWeakPtr(),
 185                    object_proxy->object_path()));
 186     properties->SetAllPropertiesReceivedCallback(
 187         base::Bind(&NfcTagClientImpl::OnPropertiesReceived,
 188                    weak_ptr_factory_.GetWeakPtr(),
 189                    object_proxy->object_path()));
 190     return properties;
 191   }
 192
 193   // nfc_client_helpers::DBusObjectMap::Delegate override.
 194   void ObjectAdded(const dbus::ObjectPath& object_path) override {
 195     FOR_EACH_OBSERVER(NfcTagClient::Observer, observers_,
 196                       TagAdded(object_path));
 197   }
 198
 199   void ObjectRemoved(const dbus::ObjectPath& object_path) override {
 200     FOR_EACH_OBSERVER(NfcTagClient::Observer, observers_,
 201                       TagRemoved(object_path));
 202   }
 203
 204   // Called by NfcPropertySet when a property value is changed, either by
 205   // result of a signal or response to a GetAll() or Get() call.
 206   void OnPropertyChanged(const dbus::ObjectPath& object_path,
 207                          const std::string& property_name) {
 208     VLOG(1) << "Tag property changed; Path: " << object_path.value()
 209             << " Property: " << property_name;
 210     FOR_EACH_OBSERVER(NfcTagClient::Observer, observers_,
 211                       TagPropertyChanged(object_path, property_name));
 212   }
 213
 214   // Called by NfcPropertySet when all properties have been processed as a
 215   // result of a call to GetAll.
 216   void OnPropertiesReceived(const dbus::ObjectPath& object_path) {
 217     VLOG(1) << "All tag properties received; Path: " << object_path.value();
 218     FOR_EACH_OBSERVER(NfcTagClient::Observer, observers_,
 219                       TagPropertiesReceived(object_path));
 220   }
 221
 222   // We maintain a pointer to the bus to be able to request proxies for
 223   // new NFC tags that appear.
 224   dbus::Bus* bus_;
 225
 226   // List of observers interested in event notifications.
 227   base::ObserverList<NfcTagClient::Observer> observers_;
 228
 229   // Mapping from object paths to object proxies and properties structures that
 230   // were already created by us. This stucture stores a different DBusObjectMap
 231   // for each known NFC adapter object path.
 232   ObjectProxyTree adapters_to_object_maps_;
 233
 234   // The adapter client that we listen to events notifications from.
 235   NfcAdapterClient* adapter_client_;
 236
 237   // Weak pointer factory for generating 'this' pointers that might live longer
 238   // than we do.
 239   // Note: This should remain the last member so it'll be destroyed and
 240   // invalidate its weak pointers before any other members are destroyed.
 241   base::WeakPtrFactory<NfcTagClientImpl> weak_ptr_factory_;
 242
 243   DISALLOW_COPY_AND_ASSIGN(NfcTagClientImpl);
 244 };
 245
 246 NfcTagClient::NfcTagClient() {
 247 }
 248
 249 NfcTagClient::~NfcTagClient() {
 250 }
 251
 252 NfcTagClient* NfcTagClient::Create(NfcAdapterClient* adapter_client) {
 253   return new NfcTagClientImpl(adapter_client);
 254 }
 255
 256 }  // namespace chromeos