dom/power/WakeLock.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "WakeLock.h"
   8 #include "mozilla/dom/ContentParent.h"
   9 #include "mozilla/dom/Event.h"  // for Event
  10 #include "mozilla/Hal.h"
  11 #include "mozilla/HalWakeLock.h"
  12 #include "nsError.h"
  13 #include "mozilla/dom/Document.h"
  14 #include "nsPIDOMWindow.h"
  15 #include "nsIPropertyBag2.h"
  16
  17 using namespace mozilla::hal;
  18
  19 namespace mozilla::dom {
  20
  21 NS_INTERFACE_MAP_BEGIN(WakeLock)
  22   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMEventListener)
  23   NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
  24   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
  25   NS_INTERFACE_MAP_ENTRY(nsIWakeLock)
  26 NS_INTERFACE_MAP_END
  27
  28 NS_IMPL_ADDREF(WakeLock)
  29 NS_IMPL_RELEASE(WakeLock)
  30
  31 WakeLock::~WakeLock() {
  32   DoUnlock();
  33   DetachEventListener();
  34 }
  35
  36 nsresult WakeLock::Init(const nsAString& aTopic, nsPIDOMWindowInner* aWindow) {
  37   // Don't Init() a WakeLock twice.
  38   MOZ_ASSERT(mTopic.IsEmpty());
  39
  40   if (aTopic.IsEmpty()) {
  41     return NS_ERROR_INVALID_ARG;
  42   }
  43
  44   mTopic.Assign(aTopic);
  45
  46   mWindow = do_GetWeakReference(aWindow);
  47
  48   /**
  49    * Null windows are allowed. A wake lock without associated window
  50    * is always considered invisible.
  51    */
  52   if (aWindow) {
  53     nsCOMPtr<Document> doc = aWindow->GetExtantDoc();
  54     NS_ENSURE_STATE(doc);
  55     mHidden = doc->Hidden();
  56   }
  57
  58   AttachEventListener();
  59   DoLock();
  60
  61   return NS_OK;
  62 }
  63
  64 void WakeLock::DoLock() {
  65   if (!mLocked) {
  66     // Change the flag immediately to prevent recursive reentering
  67     mLocked = true;
  68
  69     hal::ModifyWakeLock(
  70         mTopic, hal::WAKE_LOCK_ADD_ONE,
  71         mHidden ? hal::WAKE_LOCK_ADD_ONE : hal::WAKE_LOCK_NO_CHANGE);
  72   }
  73 }
  74
  75 void WakeLock::DoUnlock() {
  76   if (mLocked) {
  77     // Change the flag immediately to prevent recursive reentering
  78     mLocked = false;
  79
  80     hal::ModifyWakeLock(
  81         mTopic, hal::WAKE_LOCK_REMOVE_ONE,
  82         mHidden ? hal::WAKE_LOCK_REMOVE_ONE : hal::WAKE_LOCK_NO_CHANGE);
  83   }
  84 }
  85
  86 void WakeLock::AttachEventListener() {
  87   if (nsCOMPtr<nsPIDOMWindowInner> window = do_QueryReferent(mWindow)) {
  88     nsCOMPtr<Document> doc = window->GetExtantDoc();
  89     if (doc) {
  90       doc->AddSystemEventListener(u"visibilitychange"_ns, this,
  91                                   /* useCapture = */ true,
  92                                   /* wantsUntrusted = */ false);
  93
  94       nsCOMPtr<EventTarget> target = do_QueryInterface(window);
  95       target->AddSystemEventListener(u"pagehide"_ns, this,
  96                                      /* useCapture = */ true,
  97                                      /* wantsUntrusted = */ false);
  98       target->AddSystemEventListener(u"pageshow"_ns, this,
  99                                      /* useCapture = */ true,
 100                                      /* wantsUntrusted = */ false);
 101     }
 102   }
 103 }
 104
 105 void WakeLock::DetachEventListener() {
 106   if (nsCOMPtr<nsPIDOMWindowInner> window = do_QueryReferent(mWindow)) {
 107     nsCOMPtr<Document> doc = window->GetExtantDoc();
 108     if (doc) {
 109       doc->RemoveSystemEventListener(u"visibilitychange"_ns, this,
 110                                      /* useCapture = */ true);
 111       nsCOMPtr<EventTarget> target = do_QueryInterface(window);
 112       target->RemoveSystemEventListener(u"pagehide"_ns, this,
 113                                         /* useCapture = */ true);
 114       target->RemoveSystemEventListener(u"pageshow"_ns, this,
 115                                         /* useCapture = */ true);
 116     }
 117   }
 118 }
 119
 120 void WakeLock::Unlock(ErrorResult& aRv) {
 121   /*
 122    * We throw NS_ERROR_DOM_INVALID_STATE_ERR on double unlock.
 123    */
 124   if (!mLocked) {
 125     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
 126     return;
 127   }
 128
 129   DoUnlock();
 130   DetachEventListener();
 131 }
 132
 133 void WakeLock::GetTopic(nsAString& aTopic) { aTopic.Assign(mTopic); }
 134
 135 NS_IMETHODIMP
 136 WakeLock::HandleEvent(Event* aEvent) {
 137   nsAutoString type;
 138   aEvent->GetType(type);
 139
 140   if (type.EqualsLiteral("visibilitychange")) {
 141     nsCOMPtr<Document> doc = do_QueryInterface(aEvent->GetTarget());
 142     NS_ENSURE_STATE(doc);
 143
 144     bool oldHidden = mHidden;
 145     mHidden = doc->Hidden();
 146
 147     if (mLocked && oldHidden != mHidden) {
 148       hal::ModifyWakeLock(
 149           mTopic, hal::WAKE_LOCK_NO_CHANGE,
 150           mHidden ? hal::WAKE_LOCK_ADD_ONE : hal::WAKE_LOCK_REMOVE_ONE);
 151     }
 152
 153     return NS_OK;
 154   }
 155
 156   if (type.EqualsLiteral("pagehide")) {
 157     DoUnlock();
 158     return NS_OK;
 159   }
 160
 161   if (type.EqualsLiteral("pageshow")) {
 162     DoLock();
 163     return NS_OK;
 164   }
 165
 166   return NS_OK;
 167 }
 168
 169 NS_IMETHODIMP
 170 WakeLock::Unlock() {
 171   ErrorResult error;
 172   Unlock(error);
 173   return error.StealNSResult();
 174 }
 175
 176 nsPIDOMWindowInner* WakeLock::GetParentObject() const {
 177   nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(mWindow);
 178   return window;
 179 }
 180
 181 }  // namespace mozilla::dom