Bug 1249579 - part2 : audio competing suspend/resume methods. r=snorp, baku.

MozReview-Commit-ID: EjNvKELCiAy

--HG--
extra : transplant_source : %AE%20%21e%E1%94%DE%29B%9C%F5%04%13%C6%3Dr%D3%9Aj%B4

dom/audiochannel/AudioChannelService.cpp

@@ -384,7 +384,8 @@ AudioChannelService::GetState(nsPIDOMWindowOuter* aWindow, uint32_t aAudioChanne
     }
 
     *aVolume *= window->GetAudioVolume();
-    *aMuted = *aMuted || window->GetAudioMuted();
+    // TODO : distiguish between suspend and mute, it would be done in bug1242874.
+    *aMuted = *aMuted || window->GetMediaSuspended() || window->GetAudioMuted();
 
     nsCOMPtr<nsPIDOMWindowOuter> win = window->GetScriptableParent();
     if (window == win) {

dom/base/nsDOMWindowUtils.cpp

@@ -3679,6 +3679,26 @@ nsDOMWindowUtils::PostRestyleSelfEvent(nsIDOMElement* aElement)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDOMWindowUtils::GetMediaSuspended(bool* aSuspended)
+{
+  nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(mWindow);
+  NS_ENSURE_STATE(window);
+
+  *aSuspended = window->GetMediaSuspended();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWindowUtils::SetMediaSuspended(bool aSuspended)
+{
+  nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(mWindow);
+  NS_ENSURE_STATE(window);
+
+  window->SetMediaSuspended(aSuspended);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDOMWindowUtils::GetAudioMuted(bool* aMuted)
 {

dom/base/nsGlobalWindow.cpp

@@ -614,7 +614,7 @@ nsPIDOMWindow<T>::nsPIDOMWindow(nsPIDOMWindowOuter *aOuterWindow)
   mMayHavePointerEnterLeaveEventListener(false),
   mInnerObjectsFreed(false),
   mIsModalContentWindow(false),
-  mIsActive(false), mIsBackground(false),
+  mIsActive(false), mIsBackground(false), mMediaSuspended(false),
   mAudioMuted(false), mAudioVolume(1.0), mAudioCaptured(false),
   mDesktopModeViewport(false), mInnerWindow(nullptr),
   mOuterWindow(aOuterWindow),
@@ -3673,6 +3673,32 @@ nsPIDOMWindowInner::CreatePerformanceObjectIfNeeded()
   }
 }
 
+bool
+nsPIDOMWindowOuter::GetMediaSuspended() const
+{
+  if (IsInnerWindow()) {
+    return mOuterWindow->GetMediaSuspended();
+  }
+
+  return mMediaSuspended;
+}
+
+void
+nsPIDOMWindowOuter::SetMediaSuspended(bool aSuspended)
+{
+  if (IsInnerWindow()) {
+    mOuterWindow->SetMediaSuspended(aSuspended);
+    return;
+  }
+
+  if (mMediaSuspended == aSuspended) {
+    return;
+  }
+
+  mMediaSuspended = aSuspended;
+  RefreshMediaElements();
+}
+
 bool
 nsPIDOMWindowOuter::GetAudioMuted() const
 {

dom/base/nsPIDOMWindow.h

@@ -649,6 +649,7 @@ protected:
   // "active".  Only used on outer windows.
   bool                   mIsBackground;
 
+  bool                   mMediaSuspended;
   bool                   mAudioMuted;
   float                  mAudioVolume;
 
@@ -855,6 +856,9 @@ public:
   }
 
   // Audio API
+  bool GetMediaSuspended() const;
+  void SetMediaSuspended(bool aSuspended);
+
   bool GetAudioMuted() const;
   void SetAudioMuted(bool aMuted);
 

dom/interfaces/base/nsIDOMWindowUtils.idl

@@ -1750,6 +1750,12 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   void postRestyleSelfEvent(in nsIDOMElement aElement);
 
+  /**
+   * Used to pause or resume all MediaElements in this window. Use-cases are
+   * audio competing and remote media control.
+   */
+  attribute boolean mediaSuspended;
+
   /**
    * With this it's possible to mute all the MediaElements in this window.
    * We have audioMuted and audioVolume to preserve the volume across

mobile/android/app/mobile.js

@@ -985,3 +985,7 @@ pref("identity.sync.tokenserver.uri", "https://token.services.mozilla.com/1.0/sy
 // Enable Presentation API
 pref("dom.presentation.enabled", true);
 pref("dom.presentation.discovery.enabled", true);
+
+// TODO : remove it after landing bug1242874 because now it's the only way to
+// suspend the MediaElement.
+pref("media.useAudioChannelAPI", true);

toolkit/content/browser-content.js

@@ -719,6 +719,8 @@ var AudioPlaybackListener = {
 
   init() {
     Services.obs.addObserver(this, "audio-playback", false);
+    Services.obs.addObserver(this, "AudioFocusChanged", false);
+
     addMessageListener("AudioPlaybackMute", this);
     addEventListener("unload", () => {
       AudioPlaybackListener.uninit();
@@ -727,6 +729,8 @@ var AudioPlaybackListener = {
 
   uninit() {
     Services.obs.removeObserver(this, "audio-playback");
+    Services.obs.removeObserver(this, "AudioFocusChanged");
+
     removeMessageListener("AudioPlaybackMute", this);
   },
 
@@ -737,6 +741,21 @@ var AudioPlaybackListener = {
         name += (data === "active") ? "Start" : "Stop";
         sendAsyncMessage(name);
       }
+    } else if (topic == "AudioFocusChanged") {
+      let utils = global.content.QueryInterface(Ci.nsIInterfaceRequestor)
+                                .getInterface(Ci.nsIDOMWindowUtils);
+      switch (data) {
+        // The AudioFocus:LossTransient means the media would be resumed after
+        // the interruption ended, but AudioFocus:Loss doesn't.
+        // TODO : distinguish these types, it would be done in bug1242874.
+        case "Loss":
+        case "LossTransient":
+          utils.mediaSuspended = true;
+          break;
+        case "Gain":
+          utils.mediaSuspended = false;
+          break;
+      }
     }
   },