src/chrome/common/extensions/docs/examples/extensions/speak_selection/background.js

   1 /**
   2  * Copyright (c) 2011 The Chromium Authors. All rights reserved.
   3  * Use of this source code is governed by a BSD-style license that can be
   4  * found in the LICENSE file.
   5  */
   6
   7 var lastUtterance = '';
   8 var speaking = false;
   9 var globalUtteranceIndex = 0;
  10
  11 if (localStorage['lastVersionUsed'] != '1') {
  12   localStorage['lastVersionUsed'] = '1';
  13   chrome.tabs.create({
  14     url: chrome.extension.getURL('options.html')
  15   });
  16 }
  17
  18 function speak(utterance) {
  19   if (speaking && utterance == lastUtterance) {
  20     chrome.tts.stop();
  21     return;
  22   }
  23
  24   speaking = true;
  25   lastUtterance = utterance;
  26   globalUtteranceIndex++;
  27   var utteranceIndex = globalUtteranceIndex;
  28
  29   chrome.browserAction.setIcon({path: 'SpeakSel19-active.png'});
  30
  31   var rate = localStorage['rate'] || 1.0;
  32   var pitch = localStorage['pitch'] || 1.0;
  33   var volume = localStorage['volume'] || 1.0;
  34   var voice = localStorage['voice'];
  35   chrome.tts.speak(
  36       utterance,
  37       {voiceName: voice,
  38        rate: parseFloat(rate),
  39        pitch: parseFloat(pitch),
  40        volume: parseFloat(volume),
  41        onEvent: function(evt) {
  42          if (evt.type == 'end' ||
  43              evt.type == 'interrupted' ||
  44              evt.type == 'cancelled' ||
  45              evt.type == 'error') {
  46            if (utteranceIndex == globalUtteranceIndex) {
  47              speaking = false;
  48              chrome.browserAction.setIcon({path: 'SpeakSel19.png'});
  49            }
  50          }
  51        }
  52       });
  53 }
  54
  55 function initBackground() {
  56   loadContentScriptInAllTabs();
  57
  58   var defaultKeyString = getDefaultKeyString();
  59   var keyString = localStorage['speakKey'];
  60   if (keyString == undefined) {
  61     keyString = defaultKeyString;
  62     localStorage['speakKey'] = keyString;
  63   }
  64   sendKeyToAllTabs(keyString);
  65
  66   chrome.extension.onRequest.addListener(
  67       function(request, sender, sendResponse) {
  68         if (request['init']) {
  69           sendResponse({'key': localStorage['speakKey']});
  70         } else if (request['speak']) {
  71           speak(request['speak']);
  72         }
  73       });
  74
  75   chrome.browserAction.onClicked.addListener(
  76       function(tab) {
  77         chrome.tabs.sendRequest(
  78             tab.id,
  79             {'speakSelection': true});
  80       });
  81 }
  82
  83 initBackground();