| // 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 tts API. |
| |
| var binding = require('binding').Binding.create('tts'); |
| |
| var idGenerator = requireNative('id_generator'); |
| var sendRequest = require('sendRequest').sendRequest; |
| var lazyBG = requireNative('lazy_background_page'); |
| |
| binding.registerCustomHook(function(api) { |
| var apiFunctions = api.apiFunctions; |
| var tts = api.compiledApi; |
| var handlers = {}; |
| |
| function ttsEventListener(event) { |
| var eventHandler = handlers[event.srcId]; |
| if (eventHandler) { |
| eventHandler({ |
| type: event.type, |
| charIndex: event.charIndex, |
| errorMessage: event.errorMessage |
| }); |
| if (event.isFinalEvent) { |
| delete handlers[event.srcId]; |
| // Balanced in 'speak' handler. |
| lazyBG.DecrementKeepaliveCount(); |
| } |
| } |
| } |
| |
| // This file will get run if an extension needs the ttsEngine permission, but |
| // it doesn't necessarily have the tts permission. If it doesn't, trying to |
| // add a listener to chrome.tts.onEvent will fail. |
| // See http://crbug.com/122474. |
| try { |
| tts.onEvent.addListener(ttsEventListener); |
| } catch (e) {} |
| |
| apiFunctions.setHandleRequest('speak', function() { |
| var args = arguments; |
| if (args.length > 1 && args[1] && args[1].onEvent) { |
| var id = idGenerator.GetNextId(); |
| args[1].srcId = id; |
| handlers[id] = args[1].onEvent; |
| // Keep the page alive until the event finishes. |
| // Balanced in eventHandler. |
| lazyBG.IncrementKeepaliveCount(); |
| } |
| sendRequest(this.name, args, this.definition.parameters); |
| return id; |
| }); |
| }); |
| |
| exports.$set('binding', binding.generate()); |