Update speech extension to use new audio engine api since the old version no longer exists. (#1272)

src/extensions/scratch3_speech/index.js

@@ -155,18 +155,18 @@ class Scratch3SpeechBlocks {
         this._audioPromise = null;
 
         /**
-         * Audio buffer for sound to indicate that listending has started.
-         * @type {bufferSourceNode}
+         * Player for sound to indicate that listending has started.
+         * @type {SoundPlayer}
          * @private
          */
-        this._startSoundBuffer = null;
+        this._startSoundPlayer = null;
 
         /**
-         * Audio buffer for sound to indicate that listending has ended.
-         * @type {bufferSourceNode}
+         * Player for for sound to indicate that listending has ended.
+         * @type {SoundPlayer}
          * @private
          */
-        this._endSoundBuffer = null;
+        this._endSoundPlayer = null;
 
 
         /**
@@ -198,13 +198,13 @@ class Scratch3SpeechBlocks {
      */
     _loadUISounds () {
         const startSoundBuffer = assetData['speech-rec-start.mp3'];
-        this._decodeSound(startSoundBuffer).then(buffer => {
-            this._startSoundBuffer = buffer;
+        this._decodeSound(startSoundBuffer).then(player => {
+            this._startSoundPlayer = player;
         });
 
         const endSoundBuffer = assetData['speech-rec-end.mp3'];
-        this._decodeSound(endSoundBuffer).then(buffer => {
-            this._endSoundBuffer = buffer;
+        this._decodeSound(endSoundBuffer).then(player => {
+            this._endSoundPlayer = player;
         });
     }
 
@@ -215,43 +215,39 @@ class Scratch3SpeechBlocks {
      * @private
      */
     _decodeSound (soundBuffer) {
-        const context = this.runtime.audioEngine && this.runtime.audioEngine.audioContext;
+        const engine = this.runtime.audioEngine;
 
-        if (!context) {
-            return Promise.reject(new Error('No Audio Context Detected'));
+        if (!engine) {
+            return Promise.reject(new Error('No Audio Engine Detected'));
         }
 
         // Check for newer promise-based API
-        if (context.decodeAudioData.length === 1) {
-            return context.decodeAudioData(soundBuffer);
-        } else { // eslint-disable-line no-else-return
-            // Fall back to callback API
-            return new Promise((resolve, reject) =>
-                context.decodeAudioData(soundBuffer,
-                    buffer => resolve(buffer),
-                    error => reject(error)
-                )
-            );
-        }
+        return engine.decodeSoundPlayer({data: {buffer: soundBuffer}});
     }
 
     /**
      * Play the given sound.
-     * @param {ArrayBuffer} buffer The audio buffer to play.
+     * @param {SoundPlayer} player The audio buffer to play.
      * @returns {Promise} A promise that resoloves when the sound is done playing.
      * @private
      */
-    _playSound (buffer) {
+    _playSound (player) {
         if (this.runtime.audioEngine === null) return;
-        const context = this.runtime.audioEngine.audioContext;
-        const bufferSource = context.createBufferSource();
-        bufferSource.buffer = buffer;
-        bufferSource.connect(this.runtime.audioEngine.input);
-        bufferSource.start();
+        if (player.isPlaying) {
+            // Take the internal player state and create a new player with it.
+            // `.play` does this internally but then instructs the sound to
+            // stop.
+            player.take();
+        }
+
+        const engine = this.runtime.audioEngine;
+        const chain = engine.createEffectChain();
+        player.connect(chain);
+        player.play();
         return new Promise(resolve => {
-            bufferSource.onended = () => {
+            player.once('stop', () => {
                 resolve();
-            };
+            });
         });
     }
 
@@ -727,7 +723,7 @@ class Scratch3SpeechBlocks {
         // to be some lag between when the sound starts and when the socket message
         // callback is received. Perhaps we should play the sound after the socket is setup.
         // TODO: Question - Should we only play the sound if listening isn't already in progress?
-        return this._playSound(this._startSoundBuffer).then(() => {
+        return this._playSound(this._startSoundPlayer).then(() => {
             this._phraseList = this._scanBlocksForPhraseList();
             this._utteranceForEdgeTrigger = '';
             const speechPromise = new Promise(resolve => {
@@ -737,7 +733,7 @@ class Scratch3SpeechBlocks {
                     this._startListening();
                 }
             });
-            return speechPromise.then(() => this._playSound(this._endSoundBuffer));
+            return speechPromise.then(() => this._playSound(this._endSoundPlayer));
         });
     }