michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 et cindent: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "AudioDestinationNode.h"
michael@0: #include "mozilla/dom/AudioDestinationNodeBinding.h"
michael@0: #include "mozilla/Preferences.h"
michael@0: #include "AudioChannelAgent.h"
michael@0: #include "AudioChannelService.h"
michael@0: #include "AudioNodeEngine.h"
michael@0: #include "AudioNodeStream.h"
michael@0: #include "MediaStreamGraph.h"
michael@0: #include "OfflineAudioCompletionEvent.h"
michael@0: #include "nsIInterfaceRequestorUtils.h"
michael@0: #include "nsIDocShell.h"
michael@0: #include "nsIPermissionManager.h"
michael@0: #include "nsIScriptObjectPrincipal.h"
michael@0: #include "nsServiceManagerUtils.h"
michael@0: #include "nsIAppShell.h"
michael@0: #include "nsWidgetsCID.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: static uint8_t gWebAudioOutputKey;
michael@0: 
michael@0: class OfflineDestinationNodeEngine : public AudioNodeEngine
michael@0: {
michael@0: public:
michael@0:   typedef AutoFallibleTArray<nsAutoArrayPtr<float>, 2> InputChannels;
michael@0: 
michael@0:   OfflineDestinationNodeEngine(AudioDestinationNode* aNode,
michael@0:                                uint32_t aNumberOfChannels,
michael@0:                                uint32_t aLength,
michael@0:                                float aSampleRate)
michael@0:     : AudioNodeEngine(aNode)
michael@0:     , mWriteIndex(0)
michael@0:     , mLength(aLength)
michael@0:     , mSampleRate(aSampleRate)
michael@0:   {
michael@0:     // These allocations might fail if content provides a huge number of
michael@0:     // channels or size, but it's OK since we'll deal with the failure
michael@0:     // gracefully.
michael@0:     if (mInputChannels.SetLength(aNumberOfChannels)) {
michael@0:       static const fallible_t fallible = fallible_t();
michael@0:       for (uint32_t i = 0; i < aNumberOfChannels; ++i) {
michael@0:         mInputChannels[i] = new(fallible) float[aLength];
michael@0:         if (!mInputChannels[i]) {
michael@0:           mInputChannels.Clear();
michael@0:           break;
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   virtual void ProcessBlock(AudioNodeStream* aStream,
michael@0:                             const AudioChunk& aInput,
michael@0:                             AudioChunk* aOutput,
michael@0:                             bool* aFinished) MOZ_OVERRIDE
michael@0:   {
michael@0:     // Do this just for the sake of political correctness; this output
michael@0:     // will not go anywhere.
michael@0:     *aOutput = aInput;
michael@0: 
michael@0:     // Handle the case of allocation failure in the input buffer
michael@0:     if (mInputChannels.IsEmpty()) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (mWriteIndex >= mLength) {
michael@0:       NS_ASSERTION(mWriteIndex == mLength, "Overshot length");
michael@0:       // Don't record any more.
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // Record our input buffer
michael@0:     MOZ_ASSERT(mWriteIndex < mLength, "How did this happen?");
michael@0:     const uint32_t duration = std::min(WEBAUDIO_BLOCK_SIZE, mLength - mWriteIndex);
michael@0:     const uint32_t commonChannelCount = std::min(mInputChannels.Length(),
michael@0:                                                  aInput.mChannelData.Length());
michael@0:     // First, copy as many channels in the input as we have
michael@0:     for (uint32_t i = 0; i < commonChannelCount; ++i) {
michael@0:       if (aInput.IsNull()) {
michael@0:         PodZero(mInputChannels[i] + mWriteIndex, duration);
michael@0:       } else {
michael@0:         const float* inputBuffer = static_cast<const float*>(aInput.mChannelData[i]);
michael@0:         if (duration == WEBAUDIO_BLOCK_SIZE) {
michael@0:           // Use the optimized version of the copy with scale operation
michael@0:           AudioBlockCopyChannelWithScale(inputBuffer, aInput.mVolume,
michael@0:                                          mInputChannels[i] + mWriteIndex);
michael@0:         } else {
michael@0:           if (aInput.mVolume == 1.0f) {
michael@0:             PodCopy(mInputChannels[i] + mWriteIndex, inputBuffer, duration);
michael@0:           } else {
michael@0:             for (uint32_t j = 0; j < duration; ++j) {
michael@0:               mInputChannels[i][mWriteIndex + j] = aInput.mVolume * inputBuffer[j];
michael@0:             }
michael@0:           }
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:     // Then, silence all of the remaining channels
michael@0:     for (uint32_t i = commonChannelCount; i < mInputChannels.Length(); ++i) {
michael@0:       PodZero(mInputChannels[i] + mWriteIndex, duration);
michael@0:     }
michael@0:     mWriteIndex += duration;
michael@0: 
michael@0:     if (mWriteIndex >= mLength) {
michael@0:       NS_ASSERTION(mWriteIndex == mLength, "Overshot length");
michael@0:       // Go to finished state. When the graph's current time eventually reaches
michael@0:       // the end of the stream, then the main thread will be notified and we'll
michael@0:       // shut down the AudioContext.
michael@0:       *aFinished = true;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   void FireOfflineCompletionEvent(AudioDestinationNode* aNode)
michael@0:   {
michael@0:     AudioContext* context = aNode->Context();
michael@0:     context->Shutdown();
michael@0:     // Shutdown drops self reference, but the context is still referenced by aNode,
michael@0:     // which is strongly referenced by the runnable that called
michael@0:     // AudioDestinationNode::FireOfflineCompletionEvent.
michael@0: 
michael@0:     AutoPushJSContext cx(context->GetJSContext());
michael@0:     if (!cx) {
michael@0: 
michael@0:       return;
michael@0:     }
michael@0:     JSAutoRequest ar(cx);
michael@0: 
michael@0:     // Create the input buffer
michael@0:     ErrorResult rv;
michael@0:     nsRefPtr<AudioBuffer> renderedBuffer =
michael@0:       AudioBuffer::Create(context, mInputChannels.Length(),
michael@0:                           mLength, mSampleRate, cx, rv);
michael@0:     if (rv.Failed()) {
michael@0:       return;
michael@0:     }
michael@0:     for (uint32_t i = 0; i < mInputChannels.Length(); ++i) {
michael@0:       renderedBuffer->SetRawChannelContents(cx, i, mInputChannels[i]);
michael@0:     }
michael@0: 
michael@0:     nsRefPtr<OfflineAudioCompletionEvent> event =
michael@0:         new OfflineAudioCompletionEvent(context, nullptr, nullptr);
michael@0:     event->InitEvent(renderedBuffer);
michael@0:     context->DispatchTrustedEvent(event);
michael@0:   }
michael@0: 
michael@0:   virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
michael@0:   {
michael@0:     size_t amount = AudioNodeEngine::SizeOfExcludingThis(aMallocSizeOf);
michael@0:     amount += mInputChannels.SizeOfExcludingThis(aMallocSizeOf);
michael@0:     return amount;
michael@0:   }
michael@0: 
michael@0:   virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
michael@0:   {
michael@0:     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   // The input to the destination node is recorded in the mInputChannels buffer.
michael@0:   // When this buffer fills up with mLength frames, the buffered input is sent
michael@0:   // to the main thread in order to dispatch OfflineAudioCompletionEvent.
michael@0:   InputChannels mInputChannels;
michael@0:   // An index representing the next offset in mInputChannels to be written to.
michael@0:   uint32_t mWriteIndex;
michael@0:   // How many frames the OfflineAudioContext intends to produce.
michael@0:   uint32_t mLength;
michael@0:   float mSampleRate;
michael@0: };
michael@0: 
michael@0: class DestinationNodeEngine : public AudioNodeEngine
michael@0: {
michael@0: public:
michael@0:   explicit DestinationNodeEngine(AudioDestinationNode* aNode)
michael@0:     : AudioNodeEngine(aNode)
michael@0:     , mVolume(1.0f)
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   virtual void ProcessBlock(AudioNodeStream* aStream,
michael@0:                             const AudioChunk& aInput,
michael@0:                             AudioChunk* aOutput,
michael@0:                             bool* aFinished) MOZ_OVERRIDE
michael@0:   {
michael@0:     *aOutput = aInput;
michael@0:     aOutput->mVolume *= mVolume;
michael@0:   }
michael@0: 
michael@0:   virtual void SetDoubleParameter(uint32_t aIndex, double aParam) MOZ_OVERRIDE
michael@0:   {
michael@0:     if (aIndex == VOLUME) {
michael@0:       mVolume = aParam;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   enum Parameters {
michael@0:     VOLUME,
michael@0:   };
michael@0: 
michael@0:   virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
michael@0:   {
michael@0:     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   float mVolume;
michael@0: };
michael@0: 
michael@0: static bool UseAudioChannelService()
michael@0: {
michael@0:   return Preferences::GetBool("media.useAudioChannelService");
michael@0: }
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION_INHERITED(AudioDestinationNode, AudioNode,
michael@0:                                    mAudioChannelAgent)
michael@0: 
michael@0: NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(AudioDestinationNode)
michael@0:   NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
michael@0:   NS_INTERFACE_MAP_ENTRY(nsIAudioChannelAgentCallback)
michael@0:   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
michael@0: NS_INTERFACE_MAP_END_INHERITING(AudioNode)
michael@0: 
michael@0: NS_IMPL_ADDREF_INHERITED(AudioDestinationNode, AudioNode)
michael@0: NS_IMPL_RELEASE_INHERITED(AudioDestinationNode, AudioNode)
michael@0: 
michael@0: AudioDestinationNode::AudioDestinationNode(AudioContext* aContext,
michael@0:                                            bool aIsOffline,
michael@0:                                            AudioChannel aChannel,
michael@0:                                            uint32_t aNumberOfChannels,
michael@0:                                            uint32_t aLength,
michael@0:                                            float aSampleRate)
michael@0:   : AudioNode(aContext,
michael@0:               aIsOffline ? aNumberOfChannels : 2,
michael@0:               ChannelCountMode::Explicit,
michael@0:               ChannelInterpretation::Speakers)
michael@0:   , mFramesToProduce(aLength)
michael@0:   , mAudioChannel(AudioChannel::Normal)
michael@0:   , mIsOffline(aIsOffline)
michael@0:   , mHasFinished(false)
michael@0:   , mExtraCurrentTime(0)
michael@0:   , mExtraCurrentTimeSinceLastStartedBlocking(0)
michael@0:   , mExtraCurrentTimeUpdatedSinceLastStableState(false)
michael@0: {
michael@0:   MediaStreamGraph* graph = aIsOffline ?
michael@0:                             MediaStreamGraph::CreateNonRealtimeInstance(aSampleRate) :
michael@0:                             MediaStreamGraph::GetInstance();
michael@0:   AudioNodeEngine* engine = aIsOffline ?
michael@0:                             new OfflineDestinationNodeEngine(this, aNumberOfChannels,
michael@0:                                                              aLength, aSampleRate) :
michael@0:                             static_cast<AudioNodeEngine*>(new DestinationNodeEngine(this));
michael@0: 
michael@0:   mStream = graph->CreateAudioNodeStream(engine, MediaStreamGraph::EXTERNAL_STREAM);
michael@0:   mStream->SetAudioChannelType(aChannel);
michael@0:   mStream->AddMainThreadListener(this);
michael@0:   mStream->AddAudioOutput(&gWebAudioOutputKey);
michael@0: 
michael@0:   if (aChannel != AudioChannel::Normal) {
michael@0:     ErrorResult rv;
michael@0:     SetMozAudioChannelType(aChannel, rv);
michael@0:   }
michael@0: 
michael@0:   if (!aIsOffline && UseAudioChannelService()) {
michael@0:     nsCOMPtr<nsIDOMEventTarget> target = do_QueryInterface(GetOwner());
michael@0:     if (target) {
michael@0:       target->AddSystemEventListener(NS_LITERAL_STRING("visibilitychange"), this,
michael@0:                                      /* useCapture = */ true,
michael@0:                                      /* wantsUntrusted = */ false);
michael@0:     }
michael@0: 
michael@0:     CreateAudioChannelAgent();
michael@0:   }
michael@0: }
michael@0: 
michael@0: size_t
michael@0: AudioDestinationNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
michael@0: {
michael@0:   size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
michael@0:   // Might be useful in the future:
michael@0:   // - mAudioChannelAgent
michael@0:   return amount;
michael@0: }
michael@0: 
michael@0: size_t
michael@0: AudioDestinationNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
michael@0: {
michael@0:   return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::DestroyMediaStream()
michael@0: {
michael@0:   if (mAudioChannelAgent && !Context()->IsOffline()) {
michael@0:     mAudioChannelAgent->StopPlaying();
michael@0:     mAudioChannelAgent = nullptr;
michael@0: 
michael@0:     nsCOMPtr<nsIDOMEventTarget> target = do_QueryInterface(GetOwner());
michael@0:     NS_ENSURE_TRUE_VOID(target);
michael@0: 
michael@0:     target->RemoveSystemEventListener(NS_LITERAL_STRING("visibilitychange"), this,
michael@0:                                       /* useCapture = */ true);
michael@0:   }
michael@0: 
michael@0:   if (!mStream)
michael@0:     return;
michael@0: 
michael@0:   mStream->RemoveMainThreadListener(this);
michael@0:   MediaStreamGraph* graph = mStream->Graph();
michael@0:   if (graph->IsNonRealtime()) {
michael@0:     MediaStreamGraph::DestroyNonRealtimeInstance(graph);
michael@0:   }
michael@0:   AudioNode::DestroyMediaStream();
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::NotifyMainThreadStateChanged()
michael@0: {
michael@0:   if (mStream->IsFinished() && !mHasFinished) {
michael@0:     mHasFinished = true;
michael@0:     if (mIsOffline) {
michael@0:       nsCOMPtr<nsIRunnable> runnable =
michael@0:         NS_NewRunnableMethod(this, &AudioDestinationNode::FireOfflineCompletionEvent);
michael@0:       NS_DispatchToCurrentThread(runnable);
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::FireOfflineCompletionEvent()
michael@0: {
michael@0:   AudioNodeStream* stream = static_cast<AudioNodeStream*>(Stream());
michael@0:   OfflineDestinationNodeEngine* engine =
michael@0:     static_cast<OfflineDestinationNodeEngine*>(stream->Engine());
michael@0:   engine->FireOfflineCompletionEvent(this);
michael@0: }
michael@0: 
michael@0: uint32_t
michael@0: AudioDestinationNode::MaxChannelCount() const
michael@0: {
michael@0:   return Context()->MaxChannelCount();
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::SetChannelCount(uint32_t aChannelCount, ErrorResult& aRv)
michael@0: {
michael@0:   if (aChannelCount > MaxChannelCount()) {
michael@0:     aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   AudioNode::SetChannelCount(aChannelCount, aRv);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::Mute()
michael@0: {
michael@0:   MOZ_ASSERT(Context() && !Context()->IsOffline());
michael@0:   SendDoubleParameterToStream(DestinationNodeEngine::VOLUME, 0.0f);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::Unmute()
michael@0: {
michael@0:   MOZ_ASSERT(Context() && !Context()->IsOffline());
michael@0:   SendDoubleParameterToStream(DestinationNodeEngine::VOLUME, 1.0f);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::OfflineShutdown()
michael@0: {
michael@0:   MOZ_ASSERT(Context() && Context()->IsOffline(),
michael@0:              "Should only be called on a valid OfflineAudioContext");
michael@0: 
michael@0:   MediaStreamGraph::DestroyNonRealtimeInstance(mStream->Graph());
michael@0:   mOfflineRenderingRef.Drop(this);
michael@0: }
michael@0: 
michael@0: JSObject*
michael@0: AudioDestinationNode::WrapObject(JSContext* aCx)
michael@0: {
michael@0:   return AudioDestinationNodeBinding::Wrap(aCx, this);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::StartRendering()
michael@0: {
michael@0:   mOfflineRenderingRef.Take(this);
michael@0:   mStream->Graph()->StartNonRealtimeProcessing(TrackRate(Context()->SampleRate()), mFramesToProduce);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::SetCanPlay(bool aCanPlay)
michael@0: {
michael@0:   mStream->SetTrackEnabled(AudioNodeStream::AUDIO_TRACK, aCanPlay);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: AudioDestinationNode::HandleEvent(nsIDOMEvent* aEvent)
michael@0: {
michael@0:   nsAutoString type;
michael@0:   aEvent->GetType(type);
michael@0: 
michael@0:   if (!type.EqualsLiteral("visibilitychange")) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsIDocShell> docshell = do_GetInterface(GetOwner());
michael@0:   NS_ENSURE_TRUE(docshell, NS_ERROR_FAILURE);
michael@0: 
michael@0:   bool isActive = false;
michael@0:   docshell->GetIsActive(&isActive);
michael@0: 
michael@0:   mAudioChannelAgent->SetVisibilityState(isActive);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: AudioDestinationNode::CanPlayChanged(int32_t aCanPlay)
michael@0: {
michael@0:   SetCanPlay(aCanPlay == AudioChannelState::AUDIO_CHANNEL_STATE_NORMAL);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: AudioDestinationNode::WindowVolumeChanged()
michael@0: {
michael@0:   MOZ_ASSERT(mAudioChannelAgent);
michael@0: 
michael@0:   if (!mStream) {
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   float volume;
michael@0:   nsresult rv = mAudioChannelAgent->GetWindowVolume(&volume);
michael@0:   NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:   mStream->SetAudioOutputVolume(&gWebAudioOutputKey, volume);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: AudioChannel
michael@0: AudioDestinationNode::MozAudioChannelType() const
michael@0: {
michael@0:   return mAudioChannel;
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::SetMozAudioChannelType(AudioChannel aValue, ErrorResult& aRv)
michael@0: {
michael@0:   if (Context()->IsOffline()) {
michael@0:     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (aValue != mAudioChannel &&
michael@0:       CheckAudioChannelPermissions(aValue)) {
michael@0:     mAudioChannel = aValue;
michael@0: 
michael@0:     if (mAudioChannelAgent) {
michael@0:       CreateAudioChannelAgent();
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: bool
michael@0: AudioDestinationNode::CheckAudioChannelPermissions(AudioChannel aValue)
michael@0: {
michael@0:   if (!Preferences::GetBool("media.useAudioChannelService")) {
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Only normal channel doesn't need permission.
michael@0:   if (aValue == AudioChannel::Normal) {
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Maybe this audio channel is equal to the default one.
michael@0:   if (aValue == AudioChannelService::GetDefaultAudioChannel()) {
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsIPermissionManager> permissionManager =
michael@0:     do_GetService(NS_PERMISSIONMANAGER_CONTRACTID);
michael@0:   if (!permissionManager) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(GetOwner());
michael@0:   NS_ASSERTION(sop, "Window didn't QI to nsIScriptObjectPrincipal!");
michael@0:   nsCOMPtr<nsIPrincipal> principal = sop->GetPrincipal();
michael@0: 
michael@0:   uint32_t perm = nsIPermissionManager::UNKNOWN_ACTION;
michael@0: 
michael@0:   nsCString channel;
michael@0:   channel.AssignASCII(AudioChannelValues::strings[uint32_t(aValue)].value,
michael@0:                       AudioChannelValues::strings[uint32_t(aValue)].length);
michael@0:   permissionManager->TestExactPermissionFromPrincipal(principal,
michael@0:     nsCString(NS_LITERAL_CSTRING("audio-channel-") + channel).get(),
michael@0:     &perm);
michael@0: 
michael@0:   return perm == nsIPermissionManager::ALLOW_ACTION;
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::CreateAudioChannelAgent()
michael@0: {
michael@0:   if (mAudioChannelAgent) {
michael@0:     mAudioChannelAgent->StopPlaying();
michael@0:   }
michael@0: 
michael@0:   mAudioChannelAgent = new AudioChannelAgent();
michael@0:   mAudioChannelAgent->InitWithWeakCallback(GetOwner(),
michael@0:                                            static_cast<int32_t>(mAudioChannel),
michael@0:                                            this);
michael@0: 
michael@0:   nsCOMPtr<nsIDocShell> docshell = do_GetInterface(GetOwner());
michael@0:   if (docshell) {
michael@0:     bool isActive = false;
michael@0:     docshell->GetIsActive(&isActive);
michael@0:     mAudioChannelAgent->SetVisibilityState(isActive);
michael@0:   }
michael@0: 
michael@0:   int32_t state = 0;
michael@0:   mAudioChannelAgent->StartPlaying(&state);
michael@0:   SetCanPlay(state == AudioChannelState::AUDIO_CHANNEL_STATE_NORMAL);
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::NotifyStableState()
michael@0: {
michael@0:   mExtraCurrentTimeUpdatedSinceLastStableState = false;
michael@0: }
michael@0: 
michael@0: static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::ScheduleStableStateNotification()
michael@0: {
michael@0:   nsCOMPtr<nsIAppShell> appShell = do_GetService(kAppShellCID);
michael@0:   if (appShell) {
michael@0:     nsCOMPtr<nsIRunnable> event =
michael@0:       NS_NewRunnableMethod(this, &AudioDestinationNode::NotifyStableState);
michael@0:     appShell->RunInStableState(event);
michael@0:   }
michael@0: }
michael@0: 
michael@0: double
michael@0: AudioDestinationNode::ExtraCurrentTime()
michael@0: {
michael@0:   if (!mStartedBlockingDueToBeingOnlyNode.IsNull() &&
michael@0:       !mExtraCurrentTimeUpdatedSinceLastStableState) {
michael@0:     mExtraCurrentTimeUpdatedSinceLastStableState = true;
michael@0:     mExtraCurrentTimeSinceLastStartedBlocking =
michael@0:       (TimeStamp::Now() - mStartedBlockingDueToBeingOnlyNode).ToSeconds();
michael@0:     ScheduleStableStateNotification();
michael@0:   }
michael@0:   return mExtraCurrentTime + mExtraCurrentTimeSinceLastStartedBlocking;
michael@0: }
michael@0: 
michael@0: void
michael@0: AudioDestinationNode::SetIsOnlyNodeForContext(bool aIsOnlyNode)
michael@0: {
michael@0:   if (!mStartedBlockingDueToBeingOnlyNode.IsNull() == aIsOnlyNode) {
michael@0:     // Nothing changed.
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (!mStream) {
michael@0:     // DestroyMediaStream has been called, presumably during CC Unlink().
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (mIsOffline) {
michael@0:     // Don't block the destination stream for offline AudioContexts, since
michael@0:     // we expect the zero data produced when there are no other nodes to
michael@0:     // show up in its result buffer. Also, we would get confused by adding
michael@0:     // ExtraCurrentTime before StartRendering has even been called.
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (aIsOnlyNode) {
michael@0:     mStream->ChangeExplicitBlockerCount(1);
michael@0:     mStartedBlockingDueToBeingOnlyNode = TimeStamp::Now();
michael@0:     // Don't do an update of mExtraCurrentTimeSinceLastStartedBlocking until the next stable state.
michael@0:     mExtraCurrentTimeUpdatedSinceLastStableState = true;
michael@0:     ScheduleStableStateNotification();
michael@0:   } else {
michael@0:     // Force update of mExtraCurrentTimeSinceLastStartedBlocking if necessary
michael@0:     ExtraCurrentTime();
michael@0:     mExtraCurrentTime += mExtraCurrentTimeSinceLastStartedBlocking;
michael@0:     mExtraCurrentTimeSinceLastStartedBlocking = 0;
michael@0:     mStream->ChangeExplicitBlockerCount(-1);
michael@0:     mStartedBlockingDueToBeingOnlyNode = TimeStamp();
michael@0:   }
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: }