Initial safari compatibility (#1609)

* Update environment info to return the 'safari' browser

* Fix popup display on Safari

* Update environment assignment

* Add data-loading-stalled property when loading takes longer than expected

* Add notification when loading has stalled

* Allow getDictionaryInfo invocation on non-privileged contexts

* Update _validatePrivilegedMessageSender

* Don't listen to 'voiceschanged' event unless addEventListener is present

Also expose an event

1 files changed, 12 insertions, 6 deletions

diff --git a/ext/js/media/audio-system.js b/ext/js/media/audio-system.js
index cf63511f..cc2bcfc0 100644
--- a/ext/js/media/audio-system.js
+++ b/ext/js/media/audio-system.js
@@ -19,18 +19,20 @@
  * TextToSpeechAudio
  */
 
-class AudioSystem {
+class AudioSystem extends EventDispatcher {
     constructor() {
+        super();
         this._fallbackAudio = null;
     }
 
     prepare() {
         // speechSynthesis.getVoices() will not be populated unless some API call is made.
-        if (typeof speechSynthesis === 'undefined') { return; }
-
-        const eventListeners = new EventListenerCollection();
-        const onVoicesChanged = () => { eventListeners.removeAllEventListeners(); };
-        eventListeners.addEventListener(speechSynthesis, 'voiceschanged', onVoicesChanged, false);
+        if (
+            typeof speechSynthesis !== 'undefined' &&
+            typeof speechSynthesis.addEventListener === 'function'
+        ) {
+            speechSynthesis.addEventListener('voiceschanged', this._onVoicesChanged.bind(this), false);
+        }
     }
 
     getFallbackAudio() {
@@ -64,6 +66,10 @@ class AudioSystem {
 
     // Private
 
+    _onVoicesChanged(e) {
+        this.trigger('voiceschanged', e);
+    }
+
     _isAudioValid(audio, source) {
         switch (source) {
             case 'jpod101':