Full Implementation of Audio for the Chrome Os Device Emulator

chrome/browser/resources/chromeos/emulator/audio_settings.js

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/** @enum {string} */ var AudioNodeType = {
+  HEADPHONE: 'HEADPHONE',
+  MIC: 'MIC',
+  USB: 'USB',
+  BLUETOOTH: 'BLUETOOTH',
+  HDMI: 'HDMI',
+  INTERNAL_SPEAKER: 'INTERNAL_SPEAKER',
+  INTERNAL_MIC: 'INTERNAL_MIC',
+  KEYBOARD_MIC: 'KEYBOARD_MIC',
+  AOKR: 'AOKR',
+  POST_MIX_LOOPBACK: 'POST_MIX_LOOPBACK',
+  POST_DSP_LOOPBACK: 'POST_DSP_LOOPBACK',
+  OTHER: 'OTHER',
+  NONE: '',
+};
+
+/**
+ * An audio node. Based on the struct AudioNode found in audio_node.h.
+ * @constructor
+ */
+var AudioNode = function() {
+  // Whether node will input or output audio.
+  this.isInput = false;
+
+  // Node ID. Set to arbitrary default.
+  this.id = '30001';
+
+  // Display name of the node. When this is empty, cras will automatically
+  // use |this.deviceName| as the display name.
+  this.name = '';
+
+  // The text label of the selected node name.
+  this.deviceName = 'New Device';
+
+  // Based on the AudioNodeType enum.
+  this.type = AudioNodeType.HEADPHONE;
+
+  // Whether the node is active or not.
+  this.active = false;
+
+  // The time the node was plugged in (in seconds).
+  this.pluggedTime = 0;
+};
+
+Polymer({
+  is: 'audio-settings',
+
+  properties: {
+    /**
+     * The title to be displayed in a heading element for the element.
+     */
+    title: {type: String},
+
+    /**
+     * A set of audio nodes.
+     * @type !Array<!AudioNode>
+     */
+    nodes: {type: Array, value: function() { return []; }},
+
+    /**
+     * A set of options for the possible audio node types.
+     * AudioNodeType |type| is based on the AudioType emumation.
+     * {@type !Array<!{name: string, type: string}>}

[stevenjb, 2015/08/10 21:47:34]

Shouldn't this be !Array<!{name: string, type: AudioNodeType}> ?

[mozartalouis, 2015/08/10 23:02:07]

michaelpg@ suggested that in order for the pre-submit to to stop complaining, to
wrap the whole thing in {} but will remove

[michaelpg, 2015/08/11 00:25:09]

We've been following the @type {...} convention from the closure docs in most
WebUI.

This code doesn't include the outer braces, which I don't care too much about
right now, but that's what is causing the presubmit warning on this particular
line.

+     */
+    nodeTypeOptions: {
+      type: Array,
+      value: function() {
+        return [
+          {name: 'Headphones', type: AudioNodeType.HEADPHONE},
+          {name: 'Mic', type: AudioNodeType.MIC},
+          {name: 'Usb', type: AudioNodeType.USB},
+          {name: 'Bluetooth', type: AudioNodeType.BLUETOOTH},
+          {name: 'HDMI', type: AudioNodeType.HDMI},
+          {name: 'Internal Speaker', type: AudioNodeType.INTERNAL_SPEAKER},
+          {name: 'Internal Mic', type: AudioNodeType.INTERNAL_MIC},
+          {name: 'Keyboard Mic', type: AudioNodeType.KEYBOARD_MIC},
+          {name: 'Aokr', type: AudioNodeType.AOKR},
+          {name: 'Post Mix Loopback', type: AudioNodeType.POST_MIX_LOOPBACK},
+          {name: 'Post Dsp Loopback', type: AudioNodeType.POST_DSP_LOOPBACK},
+          {name: 'Other', type: AudioNodeType.OTHER}
+        ];
+      }
+    },
+  },
+
+  ready: function() { this.title = 'Audio Settings'; },
+
+  /**
+   * Adds a new node with default settings to the list of nodes.
+   */
+  appendNewNode: function() {
+    this.push('nodes', new AudioNode());
+  },
+
+  /**
+   * This adds or modifies an audio node to the AudioNodeList.
+   * @param {model: {index: number}} e Event with a model containing
+   *     the index in |nodes| to add.
+   */
+  insertAudioNode: function(e) {
+    // Create a new audio node and add all the properties from |nodes[i]|.
+    // Also, send the corresponding type value based on the name of |info.type|.
+    var info = this.nodes[e.model.index];
+    chrome.send('insertAudioNode', [info, this.getAudioTypeForName(info.type)]);

[stevenjb, 2015/08/10 21:47:34]

I still don't understand why we are passing info.type, which is of type
AudioNodeType to getAudioTypeForName() which takes a 'name' parameter which is a
string.

[mozartalouis, 2015/08/10 23:02:07]

You have to pass info.type because with insertAudioNode is called from HTML,
|info| doesn't get the enum representation of type meaning if the type it
headphone I receive the name but not the type.

ex. info.type will return 'Headphones',
this.getAudioTypeForName(info.type) will return 'HEADPHONE' which is needed in
the C++ to determine the correct enum value

[stevenjb, 2015/08/10 23:14:09]

This is super confusing. At minimum this needs to be commented in the code, but
see my suggestion in the .html comment.

+  },
+
+  /**
+   * Removes the audio node with id |id|.
+   * @param {model: {index: number}} e Event with a model containing
+   *     the index in |nodes| to add.
+   */
+  removeAudioNode: function(e) {
+    var info = this.nodes[e.model.index];
+    chrome.send('removeAudioNode', [info.id]);
+  },
+
+  /**
+   * Returns the text for the label that corresponds to |type|.
+   * @param {string} type A string representing an AudioType
+   *     of a node.

[stevenjb, 2015/08/10 21:47:34]

Shouldn't |type| be of type {AudioNodeType} ?

[mozartalouis, 2015/08/10 23:02:07]

Done. should i rename them 

getAudioTypeName

getAudioType? to make more sense

+   * @return {string} The display name corresponding to |type|.
+   */
+  getNameForAudioType: function(type) {
+    for (var i = 0; i < this.nodeTypeOptions.length; ++i) {
+      if (this.nodeTypeOptions[i].type == type)
+        return this.nodeTypeOptions[i].name;
+    }
+  },
+
+  /**
+   * Returns the text for the label that corresponds to |name|.
+   * @param {string} name A string representing an AudioType
+   *     of a nodes name.
+   * @return {string} The label which represents |name|.

[stevenjb, 2015/08/10 21:47:34]

Sill unclear. This returns this.nodeTypeOptions[i].type which looks like it
should be AudioNodeType, not a label.

[mozartalouis, 2015/08/10 23:02:07]

Done.

+   */
+  getAudioTypeForName: function(name) {
+    for (var i = 0; i < this.nodeTypeOptions.length; ++i) {
+      if (this.nodeTypeOptions[i].name == name)
+        return this.nodeTypeOptions[i].type;
+    }
+  },
+
+  /**
+   * Called by the WebUI which provides a list of nodes.
+   * @param {!Array<!AudioNode>} nodeList A list of audio nodes.
+   */
+  updateAudioNodes: function(nodeList) {
+    /** @type {!Array<!AudioNode>} */ var newNodeList = [];
+    for (var i = 0; i < nodeList.length; ++i) {
+      // create a new audio node and add all the properties from |nodeList[i]|
+      var node = new AudioNode();
+
+      node.isInput = nodeList[i]['isInput'];
+      node.id = nodeList[i]['id'];
+      node.deviceName = nodeList[i]['deviceName'];
+      node.type = this.getNameForAudioType(nodeList[i]['type']);
+      node.name = nodeList[i]['name'];
+      node.active = nodeList[i]['active'];

[stevenjb, 2015/08/10 21:47:34]

Now we can do:

Object.assign(node, nodeList[i]);

[mozartalouis, 2015/08/10 23:02:07]

Done.

+
+      newNodeList.push(node);
+    }
+    this.nodes = newNodeList;
+  }
+});