bluetooth: Add basic scanning to 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() {
+  /** @typedef {interfaces.BluetoothAdapter.Adapter.ptrClass} */
+  var AdapterPtr;
+  /** @typedef {interfaces.BluetoothDevice.Device.ptrClass} */
+  var DevicePtr;
+  /** @typedef {interfaces.BluetoothAdapter.DiscoverySession.ptrClass} */
+  var DiscoverySessionPtr;
+
   /**
    * 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.AdapterPtr} adapter
+   * @param {!AdapterPtr} adapter
    */
   var AdapterBroker = function(adapter) {
     this.adapter_ = adapter;
     this.adapterClient_ = new AdapterClient(this);
     this.setClient(this.adapterClient_);
   };
 
   AdapterBroker.prototype = {
     __proto__: cr.EventTarget.prototype,
 
     /**
      * Creates a GATT connection to the device with |address|.
      * @param {string} address
-     * @return {!Promise<!interfaces.BluetoothDevice.DevicePtr>}
+     * @return {!Promise<!DevicePtr>}
      */
     connectToDevice: function(address) {
       return this.adapter_.connectToDevice(address).then(function(response) {
         if (response.result !=
             interfaces.BluetoothAdapter.ConnectResult.SUCCESS) {
           // TODO(crbug.com/663394): Replace with more descriptive error
           // messages.
           var ConnectResult = interfaces.BluetoothAdapter.ConnectResult;
           var errorString = Object.keys(ConnectResult).find(function(key) {
             return ConnectResult[key] === response.result;
           });
 
           throw new Error(errorString);
         }
 
         return response.device;
       });
     },
 
     /**
+     * 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();
+    },
+
+    /**
      * Sets client of Adapter service.
      * @param {!interfaces.BluetoothAdapter.AdapterClient} adapterClient
      */
     setClient: function(adapterClient) {
       adapterClient.binding = new interfaces.Bindings.Binding(
           interfaces.BluetoothAdapter.AdapterClient,
           adapterClient);
 
       this.adapter_.setClient(
           adapterClient.binding.createInterfacePtrAndBind());
     },
 
     /**
-     * Gets an array of currently detectable devices from the Adapter service.
-     * @return {!Array<!interfaces.BluetoothDevice.DeviceInfo>}
+     * Requests the adapter to start a new discovery session.
+     * @return {!Promise<!DiscoverySessionPtr>}
      */
-    getDevices: function() {
-      return this.adapter_.getDevices();
+    startDiscoverySession: function() {
+      return this.adapter_.startDiscoverySession().then(function(response) {
+        if (!response.session.ptr.isBound()) {
+          throw new Error('Discovery session failed to start');
+        }
+
+        return response.session;
+      });
     },
-
-    /**
-     * 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 adapterchanged event.
+     * @param {boolean} discovering
+     */
+    discoveringChanged: function(discovering) {
+      var event = new CustomEvent('adapterchanged', {

[dpapad, 2017/01/05 23:30:33]

Is this the only case where an 'adapterchanged' event is fired? If so can we
simplify the payload to simply include the current value? Do we need the
'property' field? Or are you planning to fire more such events in future CLs?

If you still need the 'property' field, can we put all the possible property
values in an enum and re-use instead of repeating string literals across this
file and bluetooth_internals.js?

[mbrunson, 2017/01/06 01:18:56]

There are a batch of these change events concerning the adapter[1]. So, the
property field will stay, but I've added the enum here. Done.

[1]
https://cs.chromium.org/chromium/src/device/bluetooth/bluetooth_adapter.h?rcl...

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

[dpapad, 2017/01/05 23:30:33]

Nit (optional): I think is more readable if you separate words with a dash,
inside event names, like device-changed, device-removed etc.

[mbrunson, 2017/01/06 01:18:56]

If I do this I'd want to do this for all the custom events in one change, so I
probably won't do it here. The naming convention for event names is all over the
place.

         detail: {
           deviceInfo: deviceInfo
         }
       });
       this.adapterBroker_.dispatchEvent(event);
     },
 
     /**
-     * Fires devicechanged event.
+     * Fires deviceremoved event.
      * @param {!interfaces.BluetoothDevice.DeviceInfo} deviceInfo
      */
-    deviceChanged: function(deviceInfo) {
-      var event = new CustomEvent('devicechanged', {
+    deviceRemoved: function(deviceInfo) {
+      var event = new CustomEvent('deviceremoved', {
         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() {
@@ skipping 13 matching lines @@
 
       adapterBroker = new AdapterBroker(response.adapter);
       return adapterBroker;
     });
   }
 
   return {
     getAdapterBroker: getAdapterBroker,
   };
 });