MD Settings: Date and Time page, part 1/3

chrome/browser/ui/webui/settings/chromeos/date_time_handler.cc

+// Copyright 2016 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/settings/chromeos/date_time_handler.h"
+
+#include "base/command_line.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/policy/proto/chrome_device_policy.pb.h"
+#include "chrome/browser/chromeos/system/timezone_util.h"
+#include "chrome/common/pref_names.h"
+#include "chromeos/chromeos_switches.h"
+#include "components/prefs/pref_service.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+
+namespace chromeos {
+namespace settings {
+
+namespace {
+
+// Returns whether the system's automatic time zone detection setting is
+// managed, which may override the user's setting.
+bool IsSystemTimezoneAutomaticDetectionManaged() {
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableSystemTimezoneAutomaticDetectionPolicy)) {
+    return false;
+  }
+  return g_browser_process->local_state()->IsManagedPreference(
+      prefs::kSystemTimezoneAutomaticDetectionPolicy);
+}
+
+// Returns the system's current automatic time zone detection policy value,
+// which corresponds to the SystemTimezoneProto's AutomaticTimezoneDetectionType
+// enum and determines whether the user's setting will be overridden.
+int GetSystemTimezoneAutomaticDetectionPolicyValue() {
+  DCHECK(IsSystemTimezoneAutomaticDetectionManaged());
+
+  return g_browser_process->local_state()->GetInteger(
+      prefs::kSystemTimezoneAutomaticDetectionPolicy);
+}
+
+}  // namespace
+
+DateTimeHandler::DateTimeHandler() {}
+
+DateTimeHandler::~DateTimeHandler() {}
+
+DateTimeHandler* DateTimeHandler::Create(
+    content::WebUIDataSource* html_source) {
+  html_source->AddBoolean("systemTimeZoneManaged",
+      chromeos::system::HasSystemTimezonePolicy());
+
+  bool system_time_zone_automatic_detection_managed =
+      IsSystemTimezoneAutomaticDetectionManaged();
+  html_source->AddBoolean("systemTimeZoneDetectionManaged",
+      system_time_zone_automatic_detection_managed);
+  if (system_time_zone_automatic_detection_managed) {
+    html_source->AddInteger("systemTimeZoneDetectionPolicyValue",
+        GetSystemTimezoneAutomaticDetectionPolicyValue());
+  }
+
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          chromeos::switches::kDisableTimeZoneTrackingOption)) {
+    html_source->AddBoolean("hideTimeZoneDetection", true);

[dpapad, 2016/10/06 18:01:14]

How about always setting this boolean, so that you don't have to call both
valueExists() and getBoolean() in JS?

html_source->AddBoolean(
    "hideTimeZoneDetection",
    base::CommandLine::ForCurrentProcess()->HasSwitch(
        chromeos::switches::kDisableTimeZoneTrackingOption));

[michaelpg, 2016/10/06 18:22:50]

There's enough precedence in the codebase for "optional" loadTimeData bools. 
Since this is a flag, it's not considered normal operation... I know it's an
insignificant number of bytes, but would prefer to omit it.

+  }
+
+  return new DateTimeHandler;
+}
+
+void DateTimeHandler::RegisterMessages() {
+  // TODO(michaelpg): Add time zone message handlers.
+}
+
+void DateTimeHandler::OnJavascriptAllowed() {
+  // TODO(michaelpg): Add policy observers.
+}
+
+void DateTimeHandler::OnJavascriptDisallowed() {
+  // TODO(michaelpg): Remove policy observers.
+}
+
+}  // namespace settings
+}  // namespace chromeos