Home | History | Annotate | Download | only in console_tts_engine 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 var timeoutId;
      6 var ttsId = -1;
      7 var ttsWindow;
      8 var milliseconds;
      9 var curOptions;
     10 
     11 function areNewOptions(options) {
     12   var properties = ['voiceName', 'lang', 'gender', 'rate', 'pitch', 'volume'];
     13 
     14   for (var i = 0; i < properties.length; ++i) {
     15     if (options[properties[i]] != curOptions[properties[i]]) {
     16       return true;
     17     }
     18   }
     19 
     20   return false;
     21 }
     22 
     23 function getTtsElement(element) {
     24   return ttsWindow.document.getElementById(element);
     25 }
     26 
     27 function appendText(text) {
     28   getTtsElement("text").innerHTML += text;
     29 }
     30 
     31 function logOptions() {
     32   getTtsElement("voiceName").innerHTML = curOptions.voiceName;
     33   getTtsElement("lang").innerHTML = curOptions.lang;
     34   getTtsElement("gender").innerHTML = curOptions.gender;
     35   getTtsElement("rate").innerHTML = curOptions.rate;
     36   getTtsElement("pitch").innerHTML = curOptions.pitch;
     37   getTtsElement("volume").innerHTML = curOptions.volume;
     38 }
     39 
     40 function logUtterance(utterance, index, sendTtsEvent) {
     41   if (index == utterance.length) {
     42     sendTtsEvent({'type': 'end', 'charIndex': utterance.length});
     43     return;
     44   }
     45 
     46   appendText(utterance[index]);
     47 
     48   if (utterance[index] == ' ') {
     49     sendTtsEvent({'type': 'word', 'charIndex': index});
     50   }
     51   else if (utterance[index] == '.' ||
     52       utterance[index] == '?' ||
     53       utterance[index] == '!') {
     54     sendTtsEvent({'type': 'sentence', 'charIndex': index});
     55   }
     56 
     57   timeoutId = setTimeout(function() {
     58     logUtterance(utterance, ++index, sendTtsEvent)
     59   }, milliseconds);
     60 }
     61 
     62 var speakListener = function(utterance, options, sendTtsEvent) {
     63   clearTimeout(timeoutId);
     64 
     65   sendTtsEvent({'type': 'start', 'charIndex': 0});
     66 
     67   if (ttsId == -1) {
     68     // Create a new window that overlaps the bottom 40% of the current window
     69     chrome.windows.getCurrent(function(curWindow) {
     70       chrome.windows.create(
     71           {"url": "console_tts_engine.html",
     72            "focused": false,
     73            "top": Math.round(curWindow.top + 6/10 * curWindow.height),
     74            "left": curWindow.left,
     75            "width": curWindow.width,
     76            "height": Math.round(4/10 * curWindow.height)},
     77           function(newWindow) {
     78             ttsId = newWindow.id;
     79             ttsWindow = chrome.extension.getViews({"windowId": ttsId})[0];
     80 
     81             curOptions = options;
     82             logOptions();
     83 
     84             // Fastest timeout == 1 ms (@ options.rate = 10.0)
     85             milliseconds = 10 / curOptions.rate;
     86             logUtterance(utterance, 0, sendTtsEvent);
     87           }
     88       );
     89     });
     90   } else {
     91     if (areNewOptions(options)) {
     92       curOptions = options;
     93       logOptions();
     94 
     95       milliseconds = 10 / curOptions.rate;
     96     }
     97 
     98     logUtterance(utterance, 0, sendTtsEvent);
     99   }
    100 
    101 };
    102 
    103 var stopListener = function() {
    104   clearTimeout(timeoutId);
    105 };
    106 
    107 var removedListener = function(windowId, removeInfo) {
    108   if (ttsId == windowId) {
    109     ttsId = -1;
    110   }
    111 }
    112 
    113 chrome.ttsEngine.onSpeak.addListener(speakListener);
    114 chrome.ttsEngine.onStop.addListener(stopListener);
    115 chrome.windows.onRemoved.addListener(removedListener);
    116