dom/time/TimeChangeObserver.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "TimeChangeObserver.h"
   7 #include "mozilla/Hal.h"
   8 #include "mozilla/Observer.h"
   9 #include "mozilla/HalTypes.h"
  10 #include "nsWeakPtr.h"
  11 #include "nsTObserverArray.h"
  12 #include "mozilla/ClearOnShutdown.h"
  13 #include "mozilla/Services.h"
  14 #include "mozilla/StaticPtr.h"
  15 #include "nsPIDOMWindow.h"
  16 #include "nsContentUtils.h"
  17 #include "nsIObserverService.h"
  18 #include "nsIDocument.h"
  19
  20 using namespace mozilla;
  21 using namespace mozilla::hal;
  22 using namespace mozilla::services;
  23
  24 class nsSystemTimeChangeObserver : public SystemClockChangeObserver,
  25                                    public SystemTimezoneChangeObserver
  26 {
  27   typedef nsTObserverArray<nsWeakPtr> ListenerArray;
  28 public:
  29   static nsSystemTimeChangeObserver* GetInstance();
  30   virtual ~nsSystemTimeChangeObserver();
  31
  32   // Implementing hal::SystemClockChangeObserver::Notify()
  33   void Notify(const int64_t& aClockDeltaMS);
  34
  35   // Implementing hal::SystemTimezoneChangeObserver::Notify()
  36   void Notify(
  37     const mozilla::hal::SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo);
  38
  39   nsresult AddWindowListenerImpl(nsPIDOMWindow* aWindow);
  40   nsresult RemoveWindowListenerImpl(nsPIDOMWindow* aWindow);
  41
  42 private:
  43   nsSystemTimeChangeObserver() { };
  44   ListenerArray mWindowListeners;
  45   void FireMozTimeChangeEvent();
  46 };
  47
  48 StaticAutoPtr<nsSystemTimeChangeObserver> sObserver;
  49
  50 nsSystemTimeChangeObserver* nsSystemTimeChangeObserver::GetInstance()
  51 {
  52   if (!sObserver) {
  53     sObserver = new nsSystemTimeChangeObserver();
  54     ClearOnShutdown(&sObserver);
  55   }
  56   return sObserver;
  57 }
  58
  59 nsSystemTimeChangeObserver::~nsSystemTimeChangeObserver()
  60 {
  61   UnregisterSystemClockChangeObserver(this);
  62   UnregisterSystemTimezoneChangeObserver(this);
  63 }
  64
  65 void
  66 nsSystemTimeChangeObserver::FireMozTimeChangeEvent()
  67 {
  68   ListenerArray::ForwardIterator iter(mWindowListeners);
  69   while (iter.HasMore()) {
  70     nsWeakPtr weakWindow = iter.GetNext();
  71     nsCOMPtr<nsPIDOMWindow> innerWindow = do_QueryReferent(weakWindow);
  72     nsCOMPtr<nsPIDOMWindow> outerWindow;
  73     nsCOMPtr<nsIDocument> document;
  74     if (!innerWindow ||
  75         !(document = innerWindow->GetExtantDoc()) ||
  76         !(outerWindow = innerWindow->GetOuterWindow())) {
  77       mWindowListeners.RemoveElement(weakWindow);
  78       continue;
  79     }
  80
  81     nsContentUtils::DispatchTrustedEvent(document, outerWindow,
  82       NS_LITERAL_STRING("moztimechange"), /* bubbles = */ true,
  83       /* canceable = */ false);
  84   }
  85 }
  86
  87 void
  88 nsSystemTimeChangeObserver::Notify(const int64_t& aClockDeltaMS)
  89 {
  90   // Notify observers that the system clock has been adjusted.
  91   nsCOMPtr<nsIObserverService> observerService = GetObserverService();
  92   if (observerService) {
  93     nsString dataStr;
  94     dataStr.AppendFloat(static_cast<double>(aClockDeltaMS));
  95     observerService->NotifyObservers(
  96       nullptr, "system-clock-change", dataStr.get());
  97   }
  98
  99   FireMozTimeChangeEvent();
 100 }
 101
 102 void
 103 nsSystemTimeChangeObserver::Notify(
 104   const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo)
 105 {
 106   FireMozTimeChangeEvent();
 107 }
 108
 109 nsresult
 110 mozilla::time::AddWindowListener(nsPIDOMWindow* aWindow)
 111 {
 112   return nsSystemTimeChangeObserver::GetInstance()->AddWindowListenerImpl(aWindow);
 113 }
 114
 115 nsresult
 116 nsSystemTimeChangeObserver::AddWindowListenerImpl(nsPIDOMWindow* aWindow)
 117 {
 118   if (!aWindow) {
 119     return NS_ERROR_ILLEGAL_VALUE;
 120   }
 121
 122   if (aWindow->IsOuterWindow()) {
 123     aWindow = aWindow->GetCurrentInnerWindow();
 124     if (!aWindow) {
 125       return NS_ERROR_FAILURE;
 126     }
 127   }
 128
 129   nsWeakPtr windowWeakRef = do_GetWeakReference(aWindow);
 130   NS_ASSERTION(windowWeakRef, "nsIDOMWindow implementations shuld support weak ref");
 131
 132   if (mWindowListeners.IndexOf(windowWeakRef) !=
 133       ListenerArray::array_type::NoIndex) {
 134     return NS_OK;
 135   }
 136
 137   if (mWindowListeners.IsEmpty()) {
 138     RegisterSystemClockChangeObserver(sObserver);
 139     RegisterSystemTimezoneChangeObserver(sObserver);
 140   }
 141
 142   mWindowListeners.AppendElement(windowWeakRef);
 143   return NS_OK;
 144 }
 145
 146 nsresult
 147 mozilla::time::RemoveWindowListener(nsPIDOMWindow* aWindow)
 148 {
 149   if (!sObserver) {
 150     return NS_OK;
 151   }
 152
 153   return nsSystemTimeChangeObserver::GetInstance()->RemoveWindowListenerImpl(aWindow);
 154 }
 155
 156 nsresult
 157 nsSystemTimeChangeObserver::RemoveWindowListenerImpl(nsPIDOMWindow* aWindow)
 158 {
 159   if (!aWindow) {
 160     return NS_OK;
 161   }
 162
 163   if (aWindow->IsOuterWindow()) {
 164     aWindow = aWindow->GetCurrentInnerWindow();
 165     if (!aWindow) {
 166       return NS_ERROR_FAILURE;
 167     }
 168   }
 169
 170   nsWeakPtr windowWeakRef = do_GetWeakReference(aWindow);
 171   mWindowListeners.RemoveElement(windowWeakRef);
 172
 173   if (mWindowListeners.IsEmpty()) {
 174     UnregisterSystemClockChangeObserver(sObserver);
 175     UnregisterSystemTimezoneChangeObserver(sObserver);
 176   }
 177
 178   return NS_OK;
 179 }