src/chromeos/dbus/system_clock_client.cc

   1 // Copyright (c) 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/system_clock_client.h"
   6
   7 #include "base/bind.h"
   8 #include "base/callback.h"
   9 #include "base/observer_list.h"
  10 #include "dbus/bus.h"
  11 #include "dbus/message.h"
  12 #include "dbus/object_path.h"
  13 #include "dbus/object_proxy.h"
  14 #include "third_party/cros_system_api/dbus/service_constants.h"
  15
  16 namespace chromeos {
  17
  18 // The SystemClockClient implementation used in production.
  19 class SystemClockClientImpl : public SystemClockClient {
  20  public:
  21   SystemClockClientImpl()
  22       : can_set_time_(false),
  23         can_set_time_initialized_(false),
  24         system_clock_proxy_(NULL),
  25         weak_ptr_factory_(this) {}
  26
  27   virtual ~SystemClockClientImpl() {
  28   }
  29
  30   virtual void AddObserver(Observer* observer) override {
  31     observers_.AddObserver(observer);
  32   }
  33
  34   virtual void RemoveObserver(Observer* observer) override {
  35     observers_.RemoveObserver(observer);
  36   }
  37
  38   virtual bool HasObserver(Observer* observer) override {
  39     return observers_.HasObserver(observer);
  40   }
  41
  42   virtual void SetTime(int64 time_in_seconds) override {
  43     // Always try to set the time, because |can_set_time_| may be stale.
  44     dbus::MethodCall method_call(system_clock::kSystemClockInterface,
  45                                  system_clock::kSystemClockSet);
  46     dbus::MessageWriter writer(&method_call);
  47     writer.AppendInt64(time_in_seconds);
  48     system_clock_proxy_->CallMethod(&method_call,
  49                                     dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
  50                                     dbus::ObjectProxy::EmptyResponseCallback());
  51   }
  52
  53   virtual bool CanSetTime() override { return can_set_time_; }
  54
  55  protected:
  56   virtual void Init(dbus::Bus* bus) override {
  57     system_clock_proxy_ = bus->GetObjectProxy(
  58         system_clock::kSystemClockServiceName,
  59         dbus::ObjectPath(system_clock::kSystemClockServicePath));
  60
  61     // Check whether the system clock can be set.
  62     GetCanSet();
  63
  64     // Monitor the D-Bus signal for TimeUpdated changes.
  65     system_clock_proxy_->ConnectToSignal(
  66         system_clock::kSystemClockInterface,
  67         system_clock::kSystemClockUpdated,
  68         base::Bind(&SystemClockClientImpl::TimeUpdatedReceived,
  69                    weak_ptr_factory_.GetWeakPtr()),
  70         base::Bind(&SystemClockClientImpl::TimeUpdatedConnected,
  71                    weak_ptr_factory_.GetWeakPtr()));
  72   }
  73
  74  private:
  75   // Called when a TimeUpdated signal is received.
  76   void TimeUpdatedReceived(dbus::Signal* signal) {
  77     VLOG(1) << "TimeUpdated signal received: " << signal->ToString();
  78     dbus::MessageReader reader(signal);
  79     FOR_EACH_OBSERVER(Observer, observers_, SystemClockUpdated());
  80
  81     // Check if the system clock can be changed now.
  82     GetCanSet();
  83   }
  84
  85   // Called when the TimeUpdated signal is initially connected.
  86   void TimeUpdatedConnected(const std::string& interface_name,
  87                             const std::string& signal_name,
  88                             bool success) {
  89     LOG_IF(ERROR, !success)
  90         << "Failed to connect to TimeUpdated signal.";
  91   }
  92
  93   // Callback for CanSetTime method.
  94   void OnGetCanSet(dbus::Response* response) {
  95     if (!response) {
  96       VLOG(1) << "CanSetTime request failed.";
  97       return;
  98     }
  99
 100     dbus::MessageReader reader(response);
 101     bool can_set_time;
 102     if (!reader.PopBool(&can_set_time)) {
 103       LOG(ERROR) << "CanSetTime response invalid: " << response->ToString();
 104       return;
 105     }
 106
 107     // Nothing to do if the CanSetTime response hasn't changed.
 108     if (can_set_time_initialized_ && can_set_time_ == can_set_time)
 109       return;
 110
 111     can_set_time_initialized_ = true;
 112     can_set_time_ = can_set_time;
 113
 114     FOR_EACH_OBSERVER(
 115         Observer, observers_, SystemClockCanSetTimeChanged(can_set_time));
 116   }
 117
 118   // Check whether the time can be set.
 119   void GetCanSet() {
 120     dbus::MethodCall method_call(system_clock::kSystemClockInterface,
 121                                  system_clock::kSystemClockCanSet);
 122     dbus::MessageWriter writer(&method_call);
 123     system_clock_proxy_->CallMethod(
 124         &method_call,
 125         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
 126         base::Bind(&SystemClockClientImpl::OnGetCanSet,
 127                    weak_ptr_factory_.GetWeakPtr()));
 128   }
 129
 130   // Whether the time can be set. Value is false until the first
 131   // CanSetTime response is received.
 132   bool can_set_time_;
 133   bool can_set_time_initialized_;
 134   dbus::ObjectProxy* system_clock_proxy_;
 135   ObserverList<Observer> observers_;
 136
 137   base::WeakPtrFactory<SystemClockClientImpl> weak_ptr_factory_;
 138
 139   DISALLOW_COPY_AND_ASSIGN(SystemClockClientImpl);
 140 };
 141
 142 void SystemClockClient::Observer::SystemClockUpdated() {
 143 }
 144
 145 void SystemClockClient::Observer::SystemClockCanSetTimeChanged(
 146     bool can_set_time) {
 147 }
 148
 149 SystemClockClient::SystemClockClient() {
 150 }
 151
 152 SystemClockClient::~SystemClockClient() {
 153 }
 154
 155 // static
 156 SystemClockClient* SystemClockClient::Create() {
 157   return new SystemClockClientImpl();
 158 }
 159
 160 }  // namespace chromeos