[NO SUBMIT] Battery Status API skeleton implementation ASYNC

content/browser/battery_status/battery_status_service.cc

+// Copyright 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 "content/browser/battery_status/battery_status_service.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace content {
+
+static void AddCallback(std::vector<BatteryStatusService::BatteryStatusUpdateCallback>& callbacks,
+    const BatteryStatusService::BatteryStatusUpdateCallback& callback) {
+  for (size_t i = 0; i < callbacks.size(); ++i) {
+    if (callbacks[i].Equals(callback))
+      return;
+  }
+  callbacks.push_back(callback);
+}
+
+static void RemoveCallback(std::vector<BatteryStatusService::BatteryStatusUpdateCallback>& callbacks,
+    const BatteryStatusService::BatteryStatusUpdateCallback& callback) {
+  for (size_t i = 0; i < callbacks.size(); ++i) {
+    if (callbacks[i].Equals(callback)) {
+      callbacks[i] = callbacks.back();
+      callbacks.pop_back();
+      return;
+    }
+  }
+}
+
+BatteryStatusService::BatteryStatusService() : is_shutdown_(false) {
+}
+
+BatteryStatusService::~BatteryStatusService() {
+}
+
+BatteryStatusService* BatteryStatusService::GetInstance() {
+  return Singleton<BatteryStatusService,
+                   LeakySingletonTraits<BatteryStatusService> >::get();
+}
+
+void BatteryStatusService::AddConsumer(const BatteryStatusService::BatteryStatusUpdateCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!battery_fetcher_)
+    battery_fetcher_.reset(new BatteryStatusManagerAndroid);
+
+  if (callbacks_.empty())
+    battery_fetcher_->StartListeningBatteryChange();
+
+  AddCallback(callbacks_, callback);
+}
+
+void BatteryStatusService::RemoveConsumer(const BatteryStatusService::BatteryStatusUpdateCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  RemoveCallback(callbacks_, callback);
+
+  if (callbacks_.empty())
+    battery_fetcher_->StopListeningBatteryChange();
+}
+
+const blink::WebBatteryStatus& BatteryStatusService::GetBatteryStatus() const {
+  return status_;
+}
+
+void BatteryStatusService::UpdateBatteryStatus(bool charging,
+    double chargingTime, double dischargingTime, double level) {
+  status_.charging = charging;
+  status_.chargingTime = chargingTime;
+  status_.dischargingTime = dischargingTime;
+  status_.level = level;
+  BrowserThread::PostTask(BrowserThread::IO,
+                          FROM_HERE,
+                          base::Bind(&BatteryStatusService::NotifyConsumers,
+                                     base::Unretained(this)));
+}
+
+void BatteryStatusService::NotifyConsumers() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  std::vector<BatteryStatusUpdateCallback>::const_iterator it = callbacks_.begin();
+  for (; it != callbacks_.end(); ++it)
+    (*it).Run(status_);
+}
+
+void BatteryStatusService::Shutdown() {
+  battery_fetcher_.reset();
+  is_shutdown_ = true;
+}
+
+}  // namespace content