The Tor Browser: dom/system/gonk/TimeZoneSettingObserver.cpp@b8a032363ba2 (annotated)

dom/system/gonk/TimeZoneSettingObserver.cpp@b8a032363ba2 (annotated)

dom/system/gonk/TimeZoneSettingObserver.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "base/message_loop.h"
 #include "jsapi.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/Hal.h"
 #include "mozilla/Services.h"
 #include "mozilla/StaticPtr.h"
 #include "nsCOMPtr.h"
 #include "nsDebug.h"
 #include "nsIObserver.h"
 #include "nsIObserverService.h"
 #include "nsISettingsService.h"
 #include "nsJSUtils.h"
 #include "nsServiceManagerUtils.h"
 #include "nsString.h"
 #include "TimeZoneSettingObserver.h"
 #include "xpcpublic.h"
 #include "nsContentUtils.h"
 #include "nsCxPusher.h"
 #include "nsPrintfCString.h"
 #undef LOG
 #define LOG(args...)  __android_log_print(ANDROID_LOG_INFO, "Time Zone Setting" , ## args)
 #define ERR(args...)  __android_log_print(ANDROID_LOG_ERROR, "Time Zone Setting" , ## args)
 #define TIME_TIMEZONE       "time.timezone"
 #define MOZSETTINGS_CHANGED "mozsettings-changed"
 using namespace mozilla;
 namespace {
 class TimeZoneSettingObserver : public nsIObserver
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIOBSERVER
   TimeZoneSettingObserver();
   virtual ~TimeZoneSettingObserver();
   static nsresult SetTimeZone(const JS::Value &aValue, JSContext *aContext);
 };
 class TimeZoneSettingCb MOZ_FINAL : public nsISettingsServiceCallback
 {
 public:
   NS_DECL_ISUPPORTS
   TimeZoneSettingCb() {}
   NS_IMETHOD Handle(const nsAString &aName, JS::Handle<JS::Value> aResult) {
     JSContext *cx = nsContentUtils::GetCurrentJSContext();
     NS_ENSURE_TRUE(cx, NS_OK);
     // If we don't have time.timezone value in the settings, we need
     // to initialize the settings based on the current system timezone
     // to make settings consistent with system. This usually happens
     // at the very first boot. After that, settings must have a value.
     if (aResult.isNull()) {
       // Get the current system time zone offset. Note that we need to
       // convert the value to a UTC representation in the format of
       // "UTC{+,-}hh:mm", so that the Gaia end can know how to interpret.
       // E.g., -480 is "UTC+08:00"; 630 is "UTC-10:30".
       int32_t timeZoneOffset = hal::GetTimezoneOffset();
       nsPrintfCString curTimeZone("UTC%+03d:%02d",
                                   -timeZoneOffset / 60,
                                   abs(timeZoneOffset) % 60);
       // Convert it to a JS string.
       NS_ConvertUTF8toUTF16 utf16Str(curTimeZone);
       JS::Rooted<JSString*> jsStr(cx, JS_NewUCStringCopyN(cx,
                                                           utf16Str.get(),
                                                           utf16Str.Length()));
       if (!jsStr) {
         return NS_ERROR_OUT_OF_MEMORY;
       }
       // Set the settings based on the current system timezone.
       nsCOMPtr<nsISettingsServiceLock> lock;
       nsCOMPtr<nsISettingsService> settingsService =
         do_GetService("@mozilla.org/settingsService;1");
       if (!settingsService) {
         ERR("Failed to get settingsLock service!");
         return NS_OK;
       }
       settingsService->CreateLock(nullptr, getter_AddRefs(lock));
       JS::Rooted<JS::Value> value(cx, JS::StringValue(jsStr));
       lock->Set(TIME_TIMEZONE, value, nullptr, nullptr);
       return NS_OK;
     }
     // Set the system timezone based on the current settings.
     if (aResult.isString()) {
       return TimeZoneSettingObserver::SetTimeZone(aResult, cx);
     }
     return NS_OK;
   }
   NS_IMETHOD HandleError(const nsAString &aName) {
     ERR("TimeZoneSettingCb::HandleError: %s\n", NS_LossyConvertUTF16toASCII(aName).get());
     return NS_OK;
   }
 };
 NS_IMPL_ISUPPORTS(TimeZoneSettingCb, nsISettingsServiceCallback)
 TimeZoneSettingObserver::TimeZoneSettingObserver()
 {
   // Setup an observer to watch changes to the setting.
   nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
   if (!observerService) {
     ERR("GetObserverService failed");
     return;
   }
   nsresult rv;
   rv = observerService->AddObserver(this, MOZSETTINGS_CHANGED, false);
   if (NS_FAILED(rv)) {
     ERR("AddObserver failed");
     return;
   }
   // Read the 'time.timezone' setting in order to start with a known
   // value at boot time. The handle() will be called after reading.
   nsCOMPtr<nsISettingsServiceLock> lock;
   nsCOMPtr<nsISettingsService> settingsService =
     do_GetService("@mozilla.org/settingsService;1");
   if (!settingsService) {
     ERR("Failed to get settingsLock service!");
     return;
   }
   settingsService->CreateLock(nullptr, getter_AddRefs(lock));
   nsCOMPtr<nsISettingsServiceCallback> callback = new TimeZoneSettingCb();
   lock->Get(TIME_TIMEZONE, callback);
 }
 nsresult TimeZoneSettingObserver::SetTimeZone(const JS::Value &aValue, JSContext *aContext)
 {
   // Convert the JS value to a nsCString type.
   // The value should be a JS string like "America/Chicago" or "UTC-05:00".
   nsDependentJSString valueStr;
   if (!valueStr.init(aContext, aValue.toString())) {
     ERR("Failed to convert JS value to nsCString");
     return NS_ERROR_FAILURE;
   }
   NS_ConvertUTF16toUTF8 newTimezone(valueStr);
   // Hal expects opposite sign from general notations,
   // so we need to flip it.
   if (newTimezone.Find(NS_LITERAL_CSTRING("UTC+")) == 0) {
     if (!newTimezone.SetCharAt('-', 3)) {
       return NS_ERROR_FAILURE;
     }
   } else if (newTimezone.Find(NS_LITERAL_CSTRING("UTC-")) == 0) {
     if (!newTimezone.SetCharAt('+', 3)) {
       return NS_ERROR_FAILURE;
     }
   }
   // Set the timezone only when the system timezone is not identical.
   nsCString curTimezone = hal::GetTimezone();
   if (!curTimezone.Equals(newTimezone)) {
     hal::SetTimezone(newTimezone);
   }
   return NS_OK;
 }
 TimeZoneSettingObserver::~TimeZoneSettingObserver()
 {
   nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
   if (observerService) {
     observerService->RemoveObserver(this, MOZSETTINGS_CHANGED);
   }
 }
 NS_IMPL_ISUPPORTS(TimeZoneSettingObserver, nsIObserver)
 NS_IMETHODIMP
 TimeZoneSettingObserver::Observe(nsISupports *aSubject,
                      const char *aTopic,
                      const char16_t *aData)
 {
   if (strcmp(aTopic, MOZSETTINGS_CHANGED) != 0) {
     return NS_OK;
   }
   // Note that this function gets called for any and all settings changes,
   // so we need to carefully check if we have the one we're interested in.
   //
   // The string that we're interested in will be a JSON string that looks like:
   // {"key":"time.timezone","value":"America/Chicago"} or
   // {"key":"time.timezone","value":"UTC-05:00"}
   AutoSafeJSContext cx;
   // Parse the JSON value.
   nsDependentString dataStr(aData);
   JS::Rooted<JS::Value> val(cx);
   if (!JS_ParseJSON(cx, dataStr.get(), dataStr.Length(), &val) ||
       !val.isObject()) {
     return NS_OK;
   }
   // Get the key, which should be the JS string "time.timezone".
   JS::Rooted<JSObject*> obj(cx, &val.toObject());
   JS::Rooted<JS::Value> key(cx);
   if (!JS_GetProperty(cx, obj, "key", &key) ||
       !key.isString()) {
     return NS_OK;
   }
   bool match;
   if (!JS_StringEqualsAscii(cx, key.toString(), TIME_TIMEZONE, &match) ||
       !match) {
     return NS_OK;
   }
   // Get the value, which should be a JS string like "America/Chicago".
   JS::Rooted<JS::Value> value(cx);
   if (!JS_GetProperty(cx, obj, "value", &value) ||
       !value.isString()) {
     return NS_OK;
   }
   // Set the system timezone.
   return SetTimeZone(value, cx);
 }
 } // anonymous namespace
 static mozilla::StaticRefPtr<TimeZoneSettingObserver> sTimeZoneSettingObserver;
 namespace mozilla {
 namespace system {
 void
 InitializeTimeZoneSettingObserver()
 {
   sTimeZoneSettingObserver = new TimeZoneSettingObserver();
   ClearOnShutdown(&sTimeZoneSettingObserver);
 }
 } // namespace system
 } // namespace mozilla

The Tor Browser / annotate

dom/system/gonk/TimeZoneSettingObserver.cpp@b8a032363ba2 (annotated)

dom/system/gonk/TimeZoneSettingObserver.cpp