Bug 815452: Hook up FM radio to the audio manager. r=sicking a=blocking-basecamp

dom/fm/DOMFMRadioChild.js

@@ -73,6 +73,19 @@ DOMFMRadioChild.prototype = {
                       "DOMFMRadio:powerStateChange",
                       "DOMFMRadio:antennaChange"];
     this.initHelper(aWindow, messages);
+
+    let els = Cc["@mozilla.org/eventlistenerservice;1"]
+                .getService(Ci.nsIEventListenerService);
+
+    els.addSystemEventListener(aWindow, "visibilitychange",
+                               this._updateVisibility.bind(this),
+                               /* useCapture = */ true);
+
+    this._visibility = aWindow.document.visibilityState;
+    // Unlike the |enabled| getter, this is true if *this* DOM window
+    // has successfully enabled the FM radio more recently than
+    // disabling it.
+    this._haveEnabledRadio = false;
   },
 
   // Called from DOMRequestIpcHelper
@@ -130,6 +143,18 @@ DOMFMRadioChild.prototype = {
     this.dispatchEvent(e);
   },
 
+  _updateVisibility: function(evt) {
+    this._visibility = evt.target.visibilityState;
+    // Only notify visibility state when we "own" the radio stream.
+    if (this._haveEnabledRadio) {
+      this._notifyVisibility();
+    }
+  },
+
+  _notifyVisibility: function() {
+    cpmm.sendAsyncMessage("DOMFMRadio:updateVisibility", this._visibility);
+  },
+
   receiveMessage: function(aMessage) {
     let msg = aMessage.json;
     if (msg.mid && msg.mid != this._id) {
@@ -153,6 +178,7 @@ DOMFMRadioChild.prototype = {
         Services.DOMRequest.fireError(request, "Failed to turn on the FM radio");
         break;
       case "DOMFMRadio:disable:Return:OK":
+        this._haveEnabledRadio = false;
         request = this.takeRequest(msg.rid);
         if (!request) {
           return;
@@ -160,6 +186,10 @@ DOMFMRadioChild.prototype = {
         Services.DOMRequest.fireSuccess(request, null);
         break;
       case "DOMFMRadio:disable:Return:NO":
+        // If disabling the radio failed, but the hardware is still
+        // on, this DOM window is still responsible for the continued
+        // playback.
+        this._haveEnabledRadio = this.enabled;
         request = this.takeRequest(msg.rid);
         if (!request) {
           return;
@@ -291,6 +321,10 @@ DOMFMRadioChild.prototype = {
   },
 
   enable: function nsIDOMFMRadio_enable(frequency) {
+    // FMRadio::Enable() needs the most recent visibility state
+    // synchronously.
+    this._haveEnabledRadio = true;
+    this._notifyVisibility();
     return this._call("enable", frequency);
   },
 

dom/fm/DOMFMRadioParent.jsm

@@ -101,7 +101,8 @@ this.DOMFMRadioParent = {
                       "DOMFMRadio:getPowerState", "DOMFMRadio:getFrequency",
                       "DOMFMRadio:getAntennaState",
                       "DOMFMRadio:seekUp", "DOMFMRadio:seekDown",
-                      "DOMFMRadio:cancelSeek"
+                      "DOMFMRadio:cancelSeek",
+                      "DOMFMRadio:updateVisibility",
                      ];
     this._messages.forEach(function(msgName) {
       ppmm.addMessageListener(msgName, this);
@@ -458,6 +459,9 @@ this.DOMFMRadioParent = {
           self._sendMessage("DOMFMRadio:cancelSeek:Return", true, null, msg);
         }
         break;
+      case "DOMFMRadio:updateVisibility":
+        FMRadio.updateVisible(msg == 'visible');
+        break;
     }
   }
 };

dom/fm/FMRadio.cpp

@@ -38,6 +38,7 @@ using mozilla::Preferences;
 FMRadio::FMRadio()
   : mHeadphoneState(SWITCH_STATE_OFF)
   , mHasInternalAntenna(false)
+  , mHidden(true)
 {
   LOG("FMRadio is initialized.");
 
@@ -114,6 +115,23 @@ NS_IMETHODIMP FMRadio::Enable(nsIFMRadioSettings *settings)
 
   int32_t upperLimit, lowerLimit, channelWidth;
 
+  if (!mAudioChannelAgent) {
+    nsresult rv;
+    mAudioChannelAgent = do_CreateInstance("@mozilla.org/audiochannelagent;1", &rv);
+    if (!mAudioChannelAgent) {
+      return NS_ERROR_FAILURE;
+    }
+    mAudioChannelAgent->Init(AUDIO_CHANNEL_CONTENT, this);
+  }
+
+  bool canPlay;
+  mAudioChannelAgent->SetVisibilityState(!mHidden);
+  mAudioChannelAgent->StartPlaying(&canPlay);
+  // We enable the hardware, but mute the audio stream, in order to
+  // simplify state handling.  This is simpler but worse for battery
+  // life; followup is bug 820282.
+  CanPlayChanged(canPlay);
+
   settings->GetUpperLimit(&upperLimit);
   settings->GetLowerLimit(&lowerLimit);
   settings->GetChannelWidth(&channelWidth);
@@ -140,12 +158,17 @@ NS_IMETHODIMP FMRadio::Disable()
   // DisableFMRadio should be called before SetFmRadioAudioEnabled to prevent
   // the annoying beep sound.
   DisableFMRadio();
-  
+
   nsCOMPtr<nsIAudioManager> audioManager =
     do_GetService(NS_AUDIOMANAGER_CONTRACTID);
   NS_ENSURE_TRUE(audioManager, NS_OK);
 
   audioManager->SetFmRadioAudioEnabled(false);
+
+  if (mAudioChannelAgent) {
+    mAudioChannelAgent->StopPlaying();
+    mAudioChannelAgent = nullptr;
+  }
   return NS_OK;
 }
 
@@ -189,6 +212,15 @@ NS_IMETHODIMP FMRadio::SetFrequency(int32_t frequency)
   return NS_OK;
 }
 
+NS_IMETHODIMP FMRadio::UpdateVisible(bool aVisible)
+{
+  mHidden = !aVisible;
+  if (mAudioChannelAgent) {
+    mAudioChannelAgent->SetVisibilityState(!mHidden);
+  }
+  return NS_OK;
+}
+
 void FMRadio::Notify(const SwitchEvent& aEvent)
 {
   if (mHeadphoneState != aEvent.status()) {
@@ -211,5 +243,27 @@ void FMRadio::Notify(const FMRadioOperationInformation& info)
     case FM_RADIO_OPERATION_SEEK:
       DispatchTrustedEvent(RADIO_SEEK_COMPLETE_EVENT_NAME);
       break;
+    default:
+      MOZ_NOT_REACHED();
+      return;
   }
 }
+
+/* void canPlayChanged (in boolean canPlay); */
+NS_IMETHODIMP FMRadio::CanPlayChanged(bool canPlay)
+{
+  nsCOMPtr<nsIAudioManager> audioManager =
+    do_GetService(NS_AUDIOMANAGER_CONTRACTID);
+  NS_ENSURE_TRUE(audioManager, NS_OK);
+  /* mute fm first, it should be better to stop&resume fm */
+  if (canPlay) {
+    int32_t volIdx = 0;
+    // Restore fm volume, that value is sync as music type
+    audioManager->GetStreamVolumeIndex(nsIAudioManager::STREAM_TYPE_MUSIC, &volIdx);
+    audioManager->SetStreamVolumeIndex(nsIAudioManager::STREAM_TYPE_FM, volIdx);
+  } else {
+    audioManager->SetStreamVolumeIndex(nsIAudioManager::STREAM_TYPE_FM, 0);
+  }
+  return NS_OK;
+}
+

dom/fm/FMRadio.h

@@ -11,6 +11,7 @@
 #include "mozilla/HalTypes.h"
 #include "nsDOMEventTargetHelper.h"
 #include "nsIFMRadio.h"
+#include "AudioChannelService.h"
 
 #define NS_FMRADIO_CONTRACTID "@mozilla.org/fmradio;1"
 // 9cb91834-78a9-4029-b644-7806173c5e2d
@@ -26,10 +27,12 @@ class FMRadio : public nsDOMEventTargetHelper
               , public nsIFMRadio
               , public hal::FMRadioObserver
               , public hal::SwitchObserver
+              , public nsIAudioChannelAgentCallback
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIFMRADIO
+  NS_DECL_NSIAUDIOCHANNELAGENTCALLBACK
 
   NS_FORWARD_NSIDOMEVENTTARGET(nsDOMEventTargetHelper::)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
@@ -41,8 +44,11 @@ public:
 
 private:
   ~FMRadio();
-  bool mHasInternalAntenna;
+
   hal::SwitchState mHeadphoneState;
+  bool mHasInternalAntenna;
+  bool mHidden;
+  nsCOMPtr<nsIAudioChannelAgent> mAudioChannelAgent;
 };
 
 } // namespace fm

dom/fm/nsIFMRadio.idl

@@ -26,7 +26,7 @@ interface nsIFMRadioSettings : nsISupports
  *
  * If the WebFM API is re-written in c++ some day, this interface will be useless.
  */
-[scriptable, builtinclass, uuid(26288adc-d2c1-4fbc-86b5-ecd8173fbf90)]
+[scriptable, builtinclass, uuid(9586bc9c-738e-4bcd-907c-ad340a6adc8b)]
 interface nsIFMRadio : nsIDOMEventTarget {
     const long SEEK_DIRECTION_UP   = 0;
     const long SEEK_DIRECTION_DOWN = 1;
@@ -79,6 +79,11 @@ interface nsIFMRadio : nsIDOMEventTarget {
      */
     void setFrequency(in long frequency);
 
+    /**
+     * Update the visibility state of our client.
+     */
+    void updateVisible(in boolean visible);
+
     /**
      * Fired when the antenna state is changed.
      */