bluetooth: Add device list retrieval 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/.
  */
+(function() {
+  let adapterService = null;
 
-document.addEventListener('DOMContentLoaded', function() {
-  console.log('Welcome to Bluetooth Internals.');
-});
+  /**
+   * Retrieves a list of devices from the Bluetooth Adapter service.
+   * @return {!Promise} promise with array of devices
+   */
+  function getDevices() {
+    return adapterService.getDevices(0, 5).then((response) => response.devices);
+  }
+
+  /**
+   * 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) {

[ortuno, 2016/09/22 08:32:53]

q: Does this need to be a function? Could it be an arrow function? Also you
don't need the reject, I think.

[scheib, 2016/09/23 20:53:51]

These are good suggestions, but ortuno FYI this is 'boilerplate copy-paste' from
other Javascript mojo pages -- mojo team knows that the bindings are terrible
and need an update, and they'll be doing that. I think it's OK to remain
consistent with the previous pattern, which will ease refactoring when the mojo
team does a clean up.

[mbrunson, 2016/09/24 01:05:46]

The define callback has to be a function. I've run into issues trying to do it
with arrow functions before. As scheib said, this is just copy-paste from some
other page so I think leaving it is fine for now.

[ortuno, 2016/09/26 01:57:55]

Ah got it. Thanks for the explanation.

+      define(moduleNames, function(var_args) {

[ortuno, 2016/09/22 08:32:53]

var_args seems unused?

[mbrunson, 2016/09/24 01:05:46]

Done.

[ortuno, 2016/09/26 01:57:55]

Did you mean to delete the argument or are you leaving it there because of the
previous comment?

[mbrunson, 2016/09/28 02:18:21]

I'm just going to leave this entire function alone for now.

+        resolve(Array.prototype.slice.call(arguments, 0));

[ortuno, 2016/09/22 08:32:53]

I believe you can use the spread operator here. So just:

resolve(...arguments);

[ortuno, 2016/09/22 08:32:53]

I believe you can use the spread operator here. So just:

resolve(...arguments);

[mbrunson, 2016/09/24 01:05:46]

I believe the promise spec only allows a single value.

[ortuno, 2016/09/26 01:57:55]

Right. In ES2015 you can use either the spread operator or Array.from to turn
'arguments' into an array.

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions/argu...

+      });
+    });
+  }
+
+  /**
+   * Initializes Mojo proxies for page and Bluetooth services.
+   * @return {!Promise}
+   */
+  function initializeProxies() {
+    return importModules([
+             'content/public/renderer/frame_interfaces',
+             'chrome/browser/ui/webui/bluetooth_internals/' +
+                 'bluetooth_internals.mojom',
+             'device/bluetooth/public/interfaces/bluetooth.mojom',
+             'mojo/public/js/connection',
+           ])
+        .then((modules) => {

[ortuno, 2016/09/22 08:32:53]

.then(([frameInterfaces, mojom, bluetooth, connection]) => {
  // ...

That way you wouldn't need to initialize each variable :)

[mbrunson, 2016/09/24 01:05:46]

In which case this has to be one variable; however, I can use destructuring for
this. I still have to get used to ES6 features. :-)

+          let frameInterfaces = modules[0];
+          let mojom = modules[1];
+          let bluetooth = modules[2];
+          let connection = modules[3];
+
+          let pageHandler = connection.bindHandleToProxy(
+              frameInterfaces.getInterface(mojom.InternalsPageHandler.name),
+              mojom.InternalsPageHandler);
+
+          let AdapterClientImpl = function() {};
+
+          // Create adapter client implementation
+          AdapterClientImpl.prototype = {

[ortuno, 2016/09/22 08:32:53]

Is it possible to use ES6 classes?

https://cs.chromium.org/chromium/src/third_party/WebKit/LayoutTests/webshare/...

[mbrunson, 2016/09/24 01:05:46]

Done.

+            __proto__: bluetooth.AdapterClient.stubClass.prototype,
+            /**
+             * Prints added device to console
+             * @param {!Object} device the device that was added
+             */
+            deviceAdded(device) {
+              console.log('Device added');
+              console.log(device);
+            },
+
+            /**
+             * Prints removed device to console
+             * @param {!Object} device the device that was removed
+             */
+            deviceRemoved(device) {
+              console.log('Device added');
+              console.log(device);
+            }
+          };
+
+          let adapterClient = new AdapterClientImpl();
+
+          // Create adapter service interface request
+          let adapter = connection.bindProxy2(bluetooth.Adapter);
+
+          adapterService = adapter.proxy;
+          let adapterHandle = adapter.handle;
+
+          // Create a message pipe and bind one end to client implementation
+          let clientHandle = connection.bindStubDerivedImpl(adapterClient);
+
+          // Send interface request and other end of client message pipe to C++
+          pageHandler.getAdapterService(adapterHandle, clientHandle);
+        });
+  }
+
+  document.addEventListener('DOMContentLoaded', function() {
+    initializeProxies()
+        .then(() => getDevices())
+        .then((devices) => console.log(devices));
+  });
+})();