[chromeos] Add an about:power UI.

chrome/browser/ui/webui/chromeos/power_ui.cc

Index: chrome/browser/ui/webui/chromeos/power_ui.cc
diff --git a/chrome/browser/ui/webui/chromeos/power_ui.cc b/chrome/browser/ui/webui/chromeos/power_ui.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fb264c8e0adda73e81578bf12b2a7c065388e5f3
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/power_ui.cc
@@ -0,0 +1,104 @@
+// Copyright 2014 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/ui/webui/chromeos/power_ui.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/compiler_specific.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/time/time.h"
+#include "base/values.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/url_constants.h"
+#include "chromeos/power/power_data_collector.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "content/public/browser/web_ui_message_handler.h"
+#include "grit/browser_resources.h"
+#include "grit/generated_resources.h"
+
+namespace chromeos {
+
+namespace {
+
+const char kStringsJsFile[] = "strings.js";
+const char kRequestBatteryChargeDataCallback[] = "requestBatteryChargeData";
+const char kOnRequestBatteryChargeDataFunction[] =
+    "PowerUI.showBatteryChargeData";
+
+class PowerMessageHandler : public content::WebUIMessageHandler {
+ public:
+  PowerMessageHandler();
+  virtual ~PowerMessageHandler();
+
+  // WebUIMessageHandler implementation.
+  virtual void RegisterMessages() OVERRIDE;
+
+ private:
+  void OnGetBatteryChargeData(const base::ListValue* value);
+};
+
+PowerMessageHandler::PowerMessageHandler() {
+}
+
+PowerMessageHandler::~PowerMessageHandler() {
+}
+
+void PowerMessageHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      kRequestBatteryChargeDataCallback,
+      base::Bind(&PowerMessageHandler::OnGetBatteryChargeData,
+                 base::Unretained(this)));
+}
+
+void PowerMessageHandler::OnGetBatteryChargeData(const base::ListValue* value) {
+  const std::vector<PowerDataCollector::PowerSupplySnapshot>& power_supply =
+      PowerDataCollector::Get()->power_supply_data();
+  base::ListValue data;
+
+  base::TimeTicks now = base::TimeTicks::Now();
+  for (unsigned int i = 0; i < power_supply.size(); ++i) {
+    PowerDataCollector::PowerSupplySnapshot snapshot = power_supply[i];

[Daniel Erat, 2014/01/03 16:40:47]

use "const PowerDataCollector::PowerSupplySnapshot& snapshot" to avoid a copy
here

[Siva Chandra, 2014/01/03 23:34:59]

Done.

+    base::TimeDelta time_delta = base::TimeDelta::FromMicroseconds(
+        now.ToInternalValue() - power_supply[i].time.ToInternalValue());

[Daniel Erat, 2014/01/03 16:40:47]

you don't need ToInternalValue() here; just do "now - power_supply[i].time"

[Siva Chandra, 2014/01/03 23:34:59]

Done.

+
+    base::DictionaryValue *element = new base::DictionaryValue;

[Daniel Erat, 2014/01/03 16:40:47]

nit: base::DictionaryValue*

also, safer to use:

  scoped_ptr<base::DictionaryValue> element(new base::DictionaryValue);

here and then use:

  data.Append(element.release());

below

[Siva Chandra, 2014/01/03 23:34:59]

Done.

+    element->SetDouble("battery_percent", snapshot.battery_percent);
+    element->SetInteger("time_past", time_delta.InSeconds());

[Daniel Erat, 2014/01/03 16:40:47]

nit: seconds_past?

[Siva Chandra, 2014/01/03 23:34:59]

Done.

+    element->SetBoolean("external_power", snapshot.external_power);
+
+    data.Append(element);
+  }
+
+  web_ui()->CallJavascriptFunction(kOnRequestBatteryChargeDataFunction, data);
+}
+
+}  // namespace
+
+PowerUI::PowerUI(content::WebUI* web_ui) : content::WebUIController(web_ui) {
+  web_ui->AddMessageHandler(new PowerMessageHandler());
+
+  content::WebUIDataSource* html =
+      content::WebUIDataSource::Create(chrome::kChromeUIPowerHost);
+  html->SetUseJsonJSFormatV2();
+
+  html->AddLocalizedString("titleText", IDS_POWER_TITLE);
+  html->AddLocalizedString("reloadButton", IDS_POWER_RELOAD_BUTTON);
+  html->AddLocalizedString("batteryChargeHeader",
+                           IDS_POWER_BATTERY_CHARGE_HEADER);
+  html->SetJsonPath(kStringsJsFile);
+
+  html->AddResourcePath("power.css", IDR_POWER_CSS);
+  html->AddResourcePath("power.js", IDR_POWER_JS);
+  html->SetDefaultResource(IDR_POWER_HTML);
+
+  Profile* profile = Profile::FromWebUI(web_ui);
+  content::WebUIDataSource::Add(profile, html);
+}
+
+PowerUI::~PowerUI() {
+}
+
+}  // namespace chromeos