bluetooth: Componentize device list in chrome://bluetooth-internals.

chrome/browser/resources/bluetooth_internals/adapter_broker.js

+// Copyright 2016 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.
+
+/**
+ * Javascript for AdapterBroker, served from
+ *     chrome://bluetooth-internals/.
+ */
+cr.define('adapter_broker', function() {
+  /**
+   * The proxy class of an adapter and router of adapter events.
+   * Exposes an EventTarget interface that allows other object to subscribe to
+   * to specific AdapterClient events.
+   * Provides proxy access to Adapter functions. Converts parameters to Mojo
+   * handles and back when necessary.
+   * @constructor
+   * @extends {cr.EventTarget}
+   * @param {!interfaces.BluetoothAdapter.Adapter.proxyClass} adapter
+   */
+  var AdapterBroker = function(adapter) {
+    this.adapter_ = adapter;
+    this.adapterClient_ = new AdapterClient(this);
+    this.setClient(this.adapterClient_);
+  };
+
+  AdapterBroker.prototype = {
+    __proto__: cr.EventTarget.prototype,
+
+    /**
+     * Sets client of Adapter service.
+     * @param {interfaces.BluetoothAdapter.AdapterClient} adapterClient
+     */
+    setClient: function(adapterClient) {
+      this.adapter_.setClient(interfaces.Connection.bindStubDerivedImpl(
+          adapterClient));
+    },
+
+    /**
+     * Gets an array of currently detectable devices from the Adapter service.
+     * @return {Array<interfaces.BluetoothDevice.DeviceInfo>}
+     */
+    getDevices: function() {
+      return this.adapter_.getDevices();
+    },
+
+    /**
+     * Gets the current state of the Adapter.
+     * @return {interfaces.BluetoothAdapter.AdapterInfo}
+     */
+    getInfo: function() {
+      return this.adapter_.getInfo();
+    }
+  };
+
+  /**
+   * The implementation of AdapterClient in
+   * device/bluetooth/public/interfaces/adapter.mojom. Dispatches events
+   * through AdapterBroker to notify client objects of changes to the Adapter
+   * service.
+   * @constructor
+   * @param {!AdapterBroker} adapterBroker Broker to dispatch events through.
+   */
+  var AdapterClient = function(adapterBroker) {
+    this.adapterBroker_ = adapterBroker;
+  };
+
+  AdapterClient.prototype = {
+    /**
+     * Fires deviceadded event.
+     * @param {!interfaces.BluetoothDevice.DeviceInfo} deviceInfo
+     */
+    deviceAdded: function(deviceInfo) {
+      var event = new Event('deviceadded');

[dpapad, 2016/11/04 17:19:59]

How about using a CustomEvent instead? Seems more appropriate than augmenting
|deviceInfo| on a standard Event instance. See example at
https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent.

[mbrunson, 2016/11/04 22:57:40]

Done.

+      event.deviceInfo = deviceInfo;
+      this.adapterBroker_.dispatchEvent(event);
+    },
+
+    /**
+     * Fires deviceremoved event.
+     * @param {!interfaces.BluetoothDevice.DeviceInfo} deviceInfo
+     */
+    deviceRemoved: function(deviceInfo) {
+      var event = new Event('deviceremoved');
+      event.deviceInfo = deviceInfo;
+      this.adapterBroker_.dispatchEvent(event);
+    },
+
+    /**
+     * Fires devicechanged event.
+     * @param {!interfaces.BluetoothDevice.DeviceInfo} deviceInfo
+     */
+    deviceChanged: function(deviceInfo) {
+      console.log(new Date(), deviceInfo);

[dpapad, 2016/11/04 17:19:59]

Can we remove this now?

[mbrunson, 2016/11/04 22:57:40]

Done.

+
+      var event = new Event('devicechanged');
+      event.deviceInfo = deviceInfo;
+      this.adapterBroker_.dispatchEvent(event);
+    }
+  };
+
+  var adapterBroker = null;
+
+  /**
+   * Initializes an AdapterBroker if one doesn't exist.
+   * @return {Promise<AdapterBroker>} resolves with AdapterBroker,
+   *     rejects if Bluetooth is not supported.
+   */
+  function getAdapterBroker() {
+    if (adapterBroker) {
+      return Promise.resolve(adapterBroker);
+    }
+
+    return interfaces.importInterfaces().then(function(adapter) {
+      // Hook up the instance properties.
+      AdapterClient.prototype.__proto__ =
+          interfaces.BluetoothAdapter.AdapterClient.stubClass.prototype;
+
+      var adapterFactory = interfaces.Connection.bindHandleToProxy(
+          interfaces.FrameInterfaces.getInterface(
+              interfaces.BluetoothAdapter.AdapterFactory.name),
+          interfaces.BluetoothAdapter.AdapterFactory);
+
+      // Get an Adapter service.
+      return adapterFactory.getAdapter();
+    }).then(function(response) {
+      if (!response.adapter) {
+        throw new Error('Bluetooth Not Supported on this platform.');
+      }
+
+      var adapter = interfaces.Connection.bindHandleToProxy(
+          response.adapter,
+          interfaces.BluetoothAdapter.Adapter);
+
+      adapterBroker = new AdapterBroker(adapter);
+      return adapterBroker;
+    });
+  }
+
+  return {
+    getAdapterBroker: getAdapterBroker,
+  };
+});