Bluetooth: add Device events, and cleanup JS API

chrome/renderer/resources/extensions/bluetooth_custom_bindings.js

-// Copyright (c) 2012 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.
-
-// Custom binding for the Bluetooth API.
-
-var binding = require('binding').Binding.create('bluetooth');
-
-var chrome = requireNative('chrome').GetChrome();
-var Event = require('event_bindings').Event;
-var lastError = require('lastError');
-var sendRequest = require('sendRequest').sendRequest;
-
-// Use custom binding to create an undocumented event listener that will
-// receive events about device discovery and call the event listener that was
-// provided with the request to begin discovery.
-binding.registerCustomHook(function(api) {
-  var apiFunctions = api.apiFunctions;
-
-  var bluetooth = {};
-
-  function callCallbackIfPresent(name, args, error) {
-    var callback = args[args.length - 1];
-    if (typeof(callback) == 'function')
-      lastError.run(name, error, callback);
-  }
-
-  bluetooth.deviceDiscoveredHandler = null;
-  bluetooth.onDeviceDiscovered = new Event('bluetooth.onDeviceDiscovered');
-  function clearDeviceDiscoveredHandler() {
-    bluetooth.onDeviceDiscovered.removeListener(
-        bluetooth.deviceDiscoveredHandler);
-    bluetooth.deviceDiscoveredHandler = null;
-  }
-  apiFunctions.setHandleRequest('startDiscovery',
-      function() {
-        var args = arguments;
-        if (args.length > 0 && args[0] && args[0].deviceCallback) {
-          if (bluetooth.deviceDiscoveredHandler != null) {
-            callCallbackIfPresent('bluetooth.startDiscovery',
-                                  args,
-                                  'Concurrent discovery is not allowed.');
-            return;
-          }
-
-          bluetooth.deviceDiscoveredHandler = args[0].deviceCallback;
-          bluetooth.onDeviceDiscovered.addListener(
-              bluetooth.deviceDiscoveredHandler);
-          sendRequest(this.name,
-                      args,
-                      this.definition.parameters,
-                      {customCallback:this.customCallback});
-        } else {
-          callCallbackIfPresent(
-            'bluetooth.startDiscovery',
-            args,
-            'deviceCallback is required in the options object');
-          return;
-        }
-      });
-  apiFunctions.setCustomCallback('startDiscovery',
-      function(name, request, response) {
-        if (chrome.runtime.lastError) {
-          clearDeviceDiscoveredHandler();
-          return;
-        }
-      });
-  apiFunctions.setHandleRequest('stopDiscovery',
-      function() {
-        clearDeviceDiscoveredHandler();
-        sendRequest(this.name, arguments, this.definition.parameters);
-      });
-
-  // An object to hold state during one call to getDevices.
-  bluetooth.getDevicesState = null;
-
-  // Hidden events used to deliver getDevices data to the client callbacks
-  bluetooth.onDeviceSearchResult = new Event('bluetooth.onDeviceSearchResult');
-  bluetooth.onDeviceSearchFinished =
-      new Event('bluetooth.onDeviceSearchFinished');
-
-  function deviceSearchResultHandler(device) {
-    bluetooth.getDevicesState.actualEvents++;
-    bluetooth.getDevicesState.deviceCallback(device);
-    maybeFinishDeviceSearch();
-  }
-
-  function deviceSearchFinishedHandler(info) {
-    bluetooth.getDevicesState.expectedEventCount = info.expectedEventCount;
-    maybeFinishDeviceSearch();
-  }
-
-  function addDeviceSearchListeners() {
-    bluetooth.onDeviceSearchResult.addListener(deviceSearchResultHandler);
-    bluetooth.onDeviceSearchFinished.addListener(deviceSearchFinishedHandler);
-  }
-
-  function removeDeviceSearchListeners() {
-    bluetooth.onDeviceSearchResult.removeListener(deviceSearchResultHandler);
-    bluetooth.onDeviceSearchFinished.removeListener(
-        deviceSearchFinishedHandler);
-  }
-
-  function maybeFinishDeviceSearch() {
-    var state = bluetooth.getDevicesState;
-    if (typeof(state.expectedEventCount) != 'undefined' &&
-        state.actualEvents >= state.expectedEventCount) {
-      finishDeviceSearch();
-    }
-  }
-
-  function finishDeviceSearch() {
-    var finalCallback = bluetooth.getDevicesState.finalCallback;
-    removeDeviceSearchListeners();
-    bluetooth.getDevicesState = null;
-
-    if (finalCallback) {
-      finalCallback();
-    }
-  }
-
-  apiFunctions.setUpdateArgumentsPostValidate('getDevices',
-      function() {
-        var args = $Array.slice(arguments);
-
-        if (bluetooth.getDevicesState != null) {
-          throw new Error('Concurrent calls to getDevices are not allowed.');
-        }
-
-        var state = { actualEvents: 0 };
-
-        if (typeof(args[args.length - 1]) == 'function') {
-          state.finalCallback = args.pop();
-          $Array.push(args,
-              function() {
-                if (chrome.runtime.lastError) {
-                  finishDeviceSearch();
-                }
-              });
-        } else {
-          throw new Error('getDevices must have a final callback parameter.');
-        }
-
-        if (typeof(args[0].deviceCallback) == 'function') {
-          state.deviceCallback = args[0].deviceCallback;
-        } else {
-          throw new Error('getDevices must be passed options with a ' +
-              'deviceCallback.');
-        }
-
-        bluetooth.getDevicesState = state;
-        addDeviceSearchListeners();
-
-        return args;
-      });
-});
-
-exports.binding = binding.generate();