Bug 960267 - Use settings speech volume and rate, when available. r=yzen

accessible/src/jsat/AccessFu.jsm

@@ -506,23 +506,52 @@ var Output = {
 
     webspeechEnabled: false,
 
+    deferredOutputs: [],
+
     init: function init() {
       let window = Utils.win;
       this.webspeechEnabled = !!window.speechSynthesis;
 
+      let settingsToGet = 2;
+      let settingsCallback = (aName, aSetting) => {
+        if (--settingsToGet > 0) {
+          return;
+        }
+
+        this.inited = true;
+
+        for (let actions of this.deferredOutputs) {
+          this.output(actions);
+        }
+      };
+
+      this._volumeSetting = new SettingCache(
+        'accessibility.screenreader-volume', settingsCallback,
+        { defaultValue: 1, callbackNow: true, callbackOnce: true });
+      this._rateSetting = new SettingCache(
+        'accessibility.screenreader-rate', settingsCallback,
+        { defaultValue: 0, callbackNow: true, callbackOnce: true });
+
       for (let earcon of this.EARCONS) {
         let earconName = /(^.*)\..*$/.exec(earcon)[1];
         this.earconBuffers[earconName] = new WeakMap();
         this.earconBuffers[earconName].set(
           window, new window.Audio('chrome://global/content/accessibility/' + earcon));
       }
+    },
 
-      this.inited = true;
+    uninit: function uninit() {
+      if (this.inited) {
+        delete this._volumeSetting;
+        delete this._rateSetting;
+      }
+      this.inited = false;
     },
 
     output: function output(aActions) {
       if (!this.inited) {
-        this.init();
+        this.deferredOutputs.push(aActions);
+        return;
       }
 
       for (let action of aActions) {
@@ -535,12 +564,18 @@ var Output = {
         }
 
         if (action.method === 'speak' && this.webspeechEnabled) {
-          window.speechSynthesis.speak(
-            new window.SpeechSynthesisUtterance(action.data));
+          let utterance = new window.SpeechSynthesisUtterance(action.data);
+          let requestedRate = this._rateSetting.value;
+          utterance.volume = this._volumeSetting.value;
+          utterance.rate = requestedRate >= 0 ?
+            requestedRate + 1 : 1 / (Math.abs(requestedRate) + 1);
+          window.speechSynthesis.speak(utterance);
         } else if (action.method === 'playEarcon') {
           let audioBufferWeakMap = this.earconBuffers[action.data];
           if (audioBufferWeakMap) {
-            audioBufferWeakMap.get(window).cloneNode(false).play();
+            let node = audioBufferWeakMap.get(window).cloneNode(false);
+            node.volume = this._volumeSetting.value;
+            node.play();
           }
         }
       }
@@ -549,6 +584,7 @@ var Output = {
 
   start: function start() {
     Cu.import('resource://gre/modules/Geometry.jsm');
+    this.speechHelper.init();
   },
 
   stop: function stop() {
@@ -561,6 +597,8 @@ var Output = {
       Utils.win.document.documentElement.removeChild(this.announceBox.get());
       delete this.announceBox;
     }
+
+    this.speechHelper.uninit();
   },
 
   Speech: function Speech(aDetails, aBrowser) {