Bug 1654045 - part2 : add 'onactivated/ondeactivated' event handlers and 'isActive' on the media control webidl interface. r=chunmin

Add an event handler `onactivated/ondeactivated` and a readonly attribute `isActive` on the media control webidl interface, and they can be used in testing and the future plan of supporting media hub.

Differential Revision: https://phabricator.services.mozilla.com/D85229

dom/chrome-webidl/MediaController.webidl

@@ -27,9 +27,13 @@ enum MediaControlKey {
  */
 [Exposed=Window, ChromeOnly]
 interface MediaController : EventTarget {
+  readonly attribute boolean isActive;
+
   [Frozen, Cached, Pure]
   readonly attribute sequence<MediaControlKey> supportedKeys;
 
+  attribute EventHandler onactivated;
+  attribute EventHandler ondeactivated;
   attribute EventHandler onpositionstatechange;
   attribute EventHandler onsupportedkeyschange;
 

dom/media/mediacontrol/MediaController.cpp

@@ -148,6 +148,8 @@ bool MediaController::IsAudible() const { return IsMediaAudible(); }
 
 bool MediaController::IsPlaying() const { return IsMediaPlaying(); }
 
+bool MediaController::IsActive() const { return mIsActive; };
+
 void MediaController::UpdateMediaControlActionToContentMediaIfNeeded(
     const MediaControlAction& aAction) {
   // If the controller isn't active or it has been shutdown, we don't need to
@@ -306,6 +308,7 @@ void MediaController::Activate() {
     LOG("Activate");
     mIsActive = service->RegisterActiveMediaController(this);
     MOZ_ASSERT(mIsActive, "Fail to register controller!");
+    DispatchAsyncEvent(u"activated"_ns);
   }
 }
 
@@ -318,6 +321,7 @@ void MediaController::Deactivate() {
       LOG("Deactivate");
       mIsActive = !service->UnregisterActiveMediaController(this);
       MOZ_ASSERT(!mIsActive, "Fail to unregister controller!");
+      DispatchAsyncEvent(u"deactivated"_ns);
     }
   }
 }

dom/media/mediacontrol/MediaController.h

@@ -46,6 +46,7 @@ class IMediaController {
   virtual uint64_t Id() const = 0;
   virtual bool IsAudible() const = 0;
   virtual bool IsPlaying() const = 0;
+  virtual bool IsActive() const = 0;
 };
 
 /**
@@ -87,6 +88,8 @@ class MediaController final : public DOMEventTargetHelper,
   JSObject* WrapObject(JSContext* aCx,
                        JS::Handle<JSObject*> aGivenProto) override;
   void GetSupportedKeys(nsTArray<MediaControlKey>& aRetVal) const;
+  IMPL_EVENT_HANDLER(activated);
+  IMPL_EVENT_HANDLER(deactivated);
   IMPL_EVENT_HANDLER(supportedkeyschange);
   IMPL_EVENT_HANDLER(positionstatechange);
 
@@ -105,6 +108,7 @@ class MediaController final : public DOMEventTargetHelper,
   uint64_t Id() const override;
   bool IsAudible() const override;
   bool IsPlaying() const override;
+  bool IsActive() const override;
 
   // IMediaInfoUpdater's methods
   void NotifyMediaPlaybackChanged(uint64_t aBrowsingContextId,

xpcom/ds/StaticAtoms.py

@@ -2383,6 +2383,8 @@ STATIC_ATOMS = [
     Atom("onboundary", "onboundary"),
 
     # Media Controller
+    Atom("onactivated", "onactivated"),
+    Atom("ondeactivated", "ondeactivated"),
     Atom("onpositionstatechange", "onpositionstatechange"),
     Atom("onsupportedkeyschange", "onsupportedkeyschange"),