bluetooth: Add Device service for chrome://bluetooth-internals.

chrome/browser/resources/bluetooth_internals/bluetooth_internals.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 bluetooth_internals.html, served from
  *     chrome://bluetooth-internals/.
  */
 
 /**
  * The implementation of AdapterClient in
  *     device/bluetooth/public/interfaces/adapter.mojom.
  */
 var AdapterClient = function() {};
 AdapterClient.prototype = {
   /**
    * Prints added device to console.
-   * @param {!Object} device the device that was added
+   * @param {!bluetoothDevice.DeviceInfo} device the device that was added

[dpapad, 2016/10/11 21:58:32]

Nit: Per styleguide at
https://google.github.io/styleguide/javascriptguide.xml?showone=Comments#Comm...,
consider either removing the description (does not add much value), or using
proper punctuation.

@param {!bluetoothDevice.DeviceInfo} device
or
@param {!bluetoothDevice.DeviceInfo} device The device that was added.

[mbrunson, 2016/10/11 23:15:33]

Done.

    */
-  deviceAdded: function(device) {
-    console.log('Device added');
-    console.log(device);
-  },
+  deviceAdded: function(device) { console.log('Device added', device); },
 
   /**
    * Prints removed device to console.
-   * @param {!Object} device the device that was removed
+   * @param {!bluetoothDevice.DeviceInfo} device the device that was removed
    */
-  deviceRemoved: function(device) {
-    console.log('Device removed');
-    console.log(device);
-  }
+  deviceRemoved: function(device) { console.log('Device removed', device); }
 };
 
 (function() {
-  var adapter, adapterClient;
+  var adapter, adapterClient, bluetoothAdapter, bluetoothDevice, connection;
 
   /**
-   * TODO: Move to shared location. See http://crbug.com/652361.
+   * TODO(crbug.com/652361): Move to shared location.
    * Helper to convert callback-based define() API to a promise-based API.
    * @param {!Array<string>} moduleNames
    * @return {!Promise}
    */
   function importModules(moduleNames) {
     return new Promise(function(resolve, reject) {
       define(moduleNames, function(var_args) {
         resolve(Array.prototype.slice.call(arguments, 0));
       });
     });
   }
 
   /**
    * Initializes Mojo proxies for page and Bluetooth services.
    * @return {!Promise} resolves if adapter is acquired, rejects if Bluetooth
    *     is not supported.
    */
   function initializeProxies() {
     return importModules([
       'content/public/renderer/frame_interfaces',
       'device/bluetooth/public/interfaces/adapter.mojom',
+      'device/bluetooth/public/interfaces/device.mojom',
       'mojo/public/js/connection',
-    ]).then(function([frameInterfaces, bluetoothAdapter, connection]) {
+    ]).then(function([frameInterfaces, ...modules]) {
       console.log('Loaded modules');
 
+      // Destructure here to assign global variables.
+      [bluetoothAdapter, bluetoothDevice, connection] = modules;
+
       // Hook up the instance properties.
       AdapterClient.prototype.__proto__ =
           bluetoothAdapter.AdapterClient.stubClass.prototype;
 
       var adapterFactory = connection.bindHandleToProxy(
           frameInterfaces.getInterface(bluetoothAdapter.AdapterFactory.name),
           bluetoothAdapter.AdapterFactory);
 
       // Get an Adapter service.
-      return adapterFactory.getAdapter().then(function(response) {
-          if (!response.adapter) {
-            throw new Error('Bluetooth Not Supported on this platform.');
-          }
+      return adapterFactory.getAdapter();
+    }).then(function(response) {
+      if (!response.adapter) {
+        throw new Error('Bluetooth Not Supported on this platform.');
+      }
 
-          adapter = connection.bindHandleToProxy(response.adapter,
-                                                 bluetoothAdapter.Adapter);
+      adapter = connection.bindHandleToProxy(response.adapter,
+                                              bluetoothAdapter.Adapter);

[dpapad, 2016/10/11 21:58:32]

Indentation off.

[mbrunson, 2016/10/11 23:15:33]

Done.

 
-          // Create a message pipe and bind one end to client
-          // implementation and the other to the Adapter service.
-          adapterClient = new AdapterClient();
-          adapter.setClient(connection.bindStubDerivedImpl(adapterClient));
+      // Create a message pipe and bind one end to client
+      // implementation and the other to the Adapter service.
+      adapterClient = new AdapterClient();
+      adapter.setClient(connection.bindStubDerivedImpl(adapterClient));
+    });
+  }
+
+  /**
+   * Prints device info from the device service.
+   * @param {!bluetoothDevice.DeviceInfo} deviceInfo the device for which to
+   *     get the information.
+   * @return {!Promise} resolves if device service is retrieved, rejects
+   *     otherwise.
+   */
+  function logDevice(deviceInfo) {
+    return adapter.getDevice(deviceInfo.address)

[dpapad, 2016/10/11 21:58:32]

Regarding promise callback indentation style, I know different teams have
different prefs (and AFAIK the styleguide does not specify one style), but here
are two different styles I have encountered extensively in Chromium (and
elsewhere)

// Version 1: Keep it all in one line if it fits.
return adapter.getDevice(deviceInfo.address).then(function(response) {
  // Do stuff here.
}).then(function() {
  // Do more stuff here.
});

OR

// Version 2: Break line after "then("
return adapter.getDevice(deviceInfo.address).then(
    functon(response) {
      // Do stuff here.
    }).then(function() {
      // Do more stuff here.
    });

I find both of these more readable than breaking line before ".then()"

[mbrunson, 2016/10/11 23:15:33]

Done.

+      .then(function(response) {
+        var deviceHandle = response.device;
+
+        if (deviceHandle) {

[dpapad, 2016/10/11 21:58:32]

Can you reverse this logic? I think it is more readable this way.

if (!deviceHandle)
   throw new Error('Device cannot be found.');

// Do the normal case stuff here.
...

[mbrunson, 2016/10/11 23:15:32]

Done.

+          var device = connection.bindHandleToProxy(

[dpapad, 2016/10/11 21:58:32]

I don't think this is meant to be called every time logDevice is called. Isn't
this a one-time only setup, similar to the adapter initialization at line 78?

[mbrunson, 2016/10/11 23:15:32]

adapter.GetDevice creates a new handle for each request even if it's the same
device. I figured the handle has to be bound to a proxy each time it's created.

+              deviceHandle, bluetoothDevice.Device);
+          return device.getInfo();
+        }
+
+        throw new Error('Device cannot be found.');
+      })
+      .then(function(response) {
+        console.log(deviceInfo.name, response.info);
       });
-    });
   }
 
   document.addEventListener('DOMContentLoaded', function() {
     initializeProxies()
-      .then(function() {return adapter.getInfo(); })
-      .then(function(response) { console.log('info', response.info); })
+      .then(function() { return adapter.getInfo(); })
+      .then(function(response) { console.log('adapter', response.info); })
       .then(function() { return adapter.getDevices(); })
-      .then(function(response) { console.log('devices', response.devices); })
+      .then(function(response) {
+        var devices = response.devices;
+        console.log('devices', devices.length);
+
+        devices.forEach(function(deviceInfo) {
+          logDevice(deviceInfo)
+            .catch(function(error) { console.error(deviceInfo.name, error); });

[dpapad, 2016/10/11 21:58:32]

Do you really want a dedicated error handler for each device? Could you go away
with something as follows

Promise.all(devices.map(logDevice)).catch(function(error) { ...});

Where there is a single error handler for all devices?

[mbrunson, 2016/10/11 23:15:32]

I could do this. I'll just move the device name to the log function so I don't
need it here.

+        });
+      })
       .catch(function(error) { console.error(error); });
   });
 })();