[chromeos] New PowerManagerClient observer to collect power data.

chromeos/power/power_data_collector.cc

+// Copyright (c) 2013 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/power/power_data_collector.h"
+
+#include "base/logging.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/power_manager/power_supply_properties.pb.h"
+
+namespace chromeos {
+
+namespace {
+
+// The global PowerDataCollector instance.
+PowerDataCollector* g_power_data_collector = NULL;
+
+}  // namespace
+
+// static
+void PowerDataCollector::Initialize() {
+  // Check that power data collector is initialized only after the
+  // DBusThreadManager is initialized.
+  CHECK(DBusThreadManager::Get());
+  CHECK(g_power_data_collector == NULL);
+  g_power_data_collector = new PowerDataCollector();
+}
+
+// static
+void PowerDataCollector::Shutdown() {
+  // Shutdown only if initialized.
+  CHECK(g_power_data_collector);
+  delete g_power_data_collector;
+  g_power_data_collector = NULL;
+}
+
+// static
+PowerDataCollector* PowerDataCollector::Get() {
+  CHECK(g_power_data_collector);
+  return g_power_data_collector;
+}
+
+void PowerDataCollector::PowerChanged(
+    const power_manager::PowerSupplyProperties& prop) {
+  PowerSupplySnapshot snapshot;
+  snapshot.time = base::TimeTicks::Now();
+  snapshot.external_power = (prop.external_power() !=
+      power_manager::PowerSupplyProperties::DISCONNECTED);
+  snapshot.battery_percent = prop.battery_percent();
+
+  power_supply_data_.push_back(snapshot);
+}
+
+PowerDataCollector::PowerDataCollector() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
+}
+
+PowerDataCollector::~PowerDataCollector() {
+  DBusThreadManager* dbus_manager = DBusThreadManager::Get();
+  CHECK(dbus_manager);
+  dbus_manager->GetPowerManagerClient()->RemoveObserver(this);
+}
+
+PowerDataCollector::PowerSupplySnapshot::PowerSupplySnapshot()
+    : time(base::TimeTicks::Now()),
+      external_power(false),
+      battery_percent(0) {
+}
+
+}  // namespace chromeos