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>}

[Dan Beam, 2016/11/09 18:00:32]

can we add more !, i.e. !Array<!interfaces.BluetoothDevice.DeviceInfo>

[mbrunson, 2016/11/10 01:02:13]

Done.

+     */
+    getDevices: function() {
+      return this.adapter_.getDevices();
+    },
+
+    /**
+     * Gets the current state of the Adapter.
+     * @return {interfaces.BluetoothAdapter.AdapterInfo}

[Dan Beam, 2016/11/09 18:00:32]

can you use ? or !

[mbrunson, 2016/11/10 01:02:13]

Done.

+     */
+    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 CustomEvent('deviceadded', {
+        detail: {

[Dan Beam, 2016/11/09 18:00:31]

don't you want just new CustomEvent('deviceadded', {deviceInfo: deviceInfo}) or
just new CustomEvent('deviceadded', deviceInfo) here in all these cases?

[mbrunson, 2016/11/10 01:02:13]

CustomEvent spec [1] requires second parameter dictionary to have a 'detail'
key.

[1] https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent

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

[Dan Beam, 2016/11/09 18:00:32]

no curlies

[mbrunson, 2016/11/10 01:02:13]

Done.

+
+    return interfaces.importInterfaces().then(function(adapter) {

[Dan Beam, 2016/11/09 18:00:32]

can we call this like setupInterfaces()?

[mbrunson, 2016/11/10 01:02:13]

Done.

+      // Hook up the instance properties.
+      AdapterClient.prototype.__proto__ =

[Dan Beam, 2016/11/09 18:00:32]

why is this necessary?

[mbrunson, 2016/11/10 01:02:13]

The Mojo connection libraries [1] require client interfaces to be subclasses of
the auto-generated stubClass in order to create a handle for that object. There
are a few places where this is done [2][3].

[1]
https://cs.chromium.org/chromium/src/mojo/public/js/connection.js?rcl=0&l=172
[2]
https://cs.chromium.org/chromium/src/chrome/browser/resources/omnibox/omnibox...
[3]
https://cs.chromium.org/chromium/src/chrome/browser/resources/plugins.js?rcl=...

+          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.');
+      }

[Dan Beam, 2016/11/09 18:00:32]

no curlies

[mbrunson, 2016/11/10 01:02:13]

This doesn't fit on one line.

https://engdoc.corp.google.com/eng/doc/devguide/js/styleguide.shtml?cl=head#f...

Unless we're using a different style guide?

[Dan Beam, 2016/11/10 03:22:54]

yeah, that doc deals with ES6 (we're using ES5 in chrome still, generally) and
is internal and google-specific (we have some chrome-specific changes).

there are also notes on the bottom of pretty much every style guide (C++, JS,
etc.) that says "be consistent".  trust me when i say that most webui code (in
general) omits curlies even if each separate line fits in 80 cols

+
+      var adapter = interfaces.Connection.bindHandleToProxy(
+          response.adapter,
+          interfaces.BluetoothAdapter.Adapter);
+
+      adapterBroker = new AdapterBroker(adapter);
+      return adapterBroker;
+    });
+  }
+
+  return {
+    getAdapterBroker: getAdapterBroker,
+  };
+});