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

chrome/browser/resources/bluetooth_internals/interfaces.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 Mojo interface helpers, served from
+ *     chrome://bluetooth-internals/.
+ */
+
+cr.define('interfaces', function() {
+
+
+  /**
+   * 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, bluetoothDevice,
+        connection]) {
+      Object.assign(interfaces, {
+        BluetoothAdapter: bluetoothAdapter,
+        BluetoothDevice: bluetoothDevice,
+        Connection: connection,
+      });
+
+      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.');
+      }
+
+      adapter = interfaces.Connection.bindHandleToProxy(
+          response.adapter,
+          interfaces.BluetoothAdapter.Adapter);
+
+      Object.assign(interfaces, {
+        DefaultAdapter: adapter,
+      });
+    });
+  }
+
+  var initialized = false;
+  var initializePromise = null;
+
+  function initialize() {
+    if (initialized) {
+      return Promise.resolve();
+    }
+
+    if (initializePromise) {
+      return initializePromise;
+    }
+
+    initializePromise = initializeProxies().then(function() {
+      initialized = true;
+    });
+
+    return initializePromise;
+  }
+
+  return {
+    initialize: initialize,
+  };
+});