native_client_sdk/src/gonacl_appengine/static/bullet/NaClAM.js

   1 // Copyright (c) 2013 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 function NaClAMMessage() {
   6   this.header = {};
   7   this.frames = new Array();
   8 }
   9
  10 NaClAMMessage.prototype.reset = function() {
  11   this.header = {};
  12   this.frames = new Array();
  13 }
  14
  15 function NaClAM(embedId) {
  16   this.embedId = embedId;
  17   this.requestId = 0;
  18   this.message = new NaClAMMessage();
  19   this.state = 0;
  20   this.framesLeft = 0;
  21   this.listeners_ = Object.create(null);
  22   this.handleMesssage_ = this.handleMesssage_.bind(this);
  23 }
  24
  25 NaClAM.prototype.enable = function() {
  26   window.addEventListener('message', this.handleMesssage_, true);
  27 }
  28
  29 NaClAM.prototype.disable = function() {
  30   window.removeEventListener('message', this.handleMesssage_, true);
  31 }
  32
  33 NaClAM.prototype.log_ = function(msg) {
  34   console.log(msg);
  35 }
  36
  37 NaClAM.prototype.handleMesssage_ = function(event) {
  38   var STATE_WAITING_FOR_HEADER = 0;
  39   var STATE_COLLECTING_FRAMES = 1;
  40   if (this.state == STATE_WAITING_FOR_HEADER) {
  41     var header;
  42     try {
  43       header = JSON.parse(String(event.data));
  44     } catch (e) {
  45       console.log(e);
  46       console.log(event.data);
  47       return;
  48     }
  49     // Special case our log print command
  50     if (header['cmd'] == 'NaClAMPrint') {
  51       this.log_(header['print'])
  52         return;
  53     }
  54     if (typeof(header['request']) != "number") {
  55       console.log('Header message requestId is not a number.');
  56       return;
  57     }
  58     if (typeof(header['frames']) != "number") {
  59       console.log('Header message frames is not a number.');
  60       return;
  61     }
  62     this.framesLeft = header['frames'];
  63     this.state = STATE_COLLECTING_FRAMES;
  64     this.message.header = header;
  65   } else if (this.state == STATE_COLLECTING_FRAMES) {
  66     this.framesLeft--;
  67     this.message.frames.push(event.data);
  68   }
  69   if (this.state == STATE_COLLECTING_FRAMES && this.framesLeft == 0) {
  70     this.dispatchEvent(this.message);
  71     this.message.reset();
  72     this.state = STATE_WAITING_FOR_HEADER;
  73   }
  74 }
  75
  76 NaClAM.prototype.messageHeaderIsValid_ = function(header) {
  77   if (header['cmd'] == undefined) {
  78     console.log('NaClAM: Message header does not contain cmd.');
  79     return false;
  80   }
  81   if (typeof(header['cmd']) != "string") {
  82     console.log('NaClAm: Message cmd is not a string.');
  83     return false;
  84   }
  85   if (header['frames'] == undefined) {
  86     console.log('NaClAM: Message header does not contain frames.');
  87     return false;
  88   }
  89   if (typeof(header['frames']) != "number") {
  90     console.log('NaClAm: Message frames is not a number.');
  91     return false;
  92   }
  93   if (header['request'] == undefined) {
  94     console.log('NaClAM: Message header does not contain request.');
  95     return false;
  96   }
  97   if (typeof(header['request']) != "number") {
  98     console.log('NaClAm: Message request is not a number.');
  99     return false;
 100   }
 101   return true;
 102 }
 103
 104 NaClAM.prototype.framesIsValid_ = function(frames) {
 105   var i;
 106   if (!frames) {
 107     // No frames.
 108     return true;
 109   }
 110   if (Array.isArray(frames) == false) {
 111     console.log('NaClAM: Frames must be an array.');
 112     return false;
 113   }
 114   for (i = 0; i < frames.length; i++) {
 115     var e = frames[i];
 116     if (typeof(e) == "string") {
 117       continue;
 118     }
 119     if ((e instanceof ArrayBuffer) == false) {
 120       console.log('NaClAM: Frame is not a string or ArrayBuffer');
 121       return false;
 122     }
 123   }
 124   return true;
 125 }
 126
 127 NaClAM.prototype.framesLength_ = function(frames) {
 128   if (!frames) {
 129     // No frames.
 130     return 0;
 131   }
 132   return frames.length;
 133 }
 134
 135 NaClAM.prototype.sendMessage = function(cmdName, arguments, frames) {
 136   if (this.framesIsValid_(frames) == false) {
 137     console.log('NaClAM: Not sending message because frames is invalid.');
 138     return undefined;
 139   }
 140   var numFrames = this.framesLength_(frames);
 141   this.requestId++;
 142   var msgHeader = {
 143     cmd: cmdName,
 144     frames: numFrames,
 145     request: this.requestId,
 146     args: arguments
 147   };
 148   if (this.messageHeaderIsValid_(msgHeader) == false) {
 149     console.log('NaClAM: Not sending message because header is invalid.');
 150     return undefined;
 151   }
 152   var AM = document.getElementById(this.embedId);
 153   if (!AM) {
 154     console.log('NaClAM: Not sending message because Acceleration Module is not there.');
 155     return undefined;
 156   }
 157   AM.postMessage(JSON.stringify(msgHeader));
 158   var i;
 159   for (i = 0; i < numFrames; i++) {
 160     AM.postMessage(frames[i]);
 161   }
 162   return this.requestId;
 163 }
 164
 165 /**
 166  * Adds an event listener to this Acceleration Module.
 167  * @param {string} type The name of the command.
 168  * @param handler The handler for the cmomand. This is called whenever the command is received.
 169  */
 170 NaClAM.prototype.addEventListener = function(type, handler) {
 171   if (!this.listeners_) {
 172     this.listeners_ = Object.create(null);
 173   }
 174   if (!(type in this.listeners_)) {
 175     this.listeners_[type] = [handler];
 176   } else {
 177     var handlers = this.listeners_[type];
 178     if (handlers.indexOf(handler) < 0) {
 179       handlers.push(handler);
 180     }
 181   }
 182 }
 183
 184 /**
 185  * Removes an event listener from this Acceleration Module.
 186  * @param {string} type The name of the command.
 187  * @param handler The handler for the cmomand. This is called whenever the command is received.
 188  */
 189 NaClAM.prototype.removeEventListener = function(type, handler) {
 190   if (!this.listeners_) {
 191     // No listeners
 192     return;
 193   }
 194   if (type in this.listeners_) {
 195     var handlers = this.listeners_[type];
 196     var index = handlers.indexOf(handler);
 197     if (index >= 0) {
 198       if (handlers.length == 1) {
 199         // Listeners list would be empty, delete it
 200         delete this.listeners_[type];
 201       } else {
 202         // Remove the handler
 203         handlers.splice(index, 1);
 204       }
 205     }
 206   }
 207 }
 208
 209 /**
 210  *
 211  */
 212 NaClAM.prototype.dispatchEvent = function(event) {
 213   if (!this.listeners_) {
 214     return true;
 215   }
 216   var type = event.header.cmd;
 217   if (type in this.listeners_) {
 218     // Make a copy to walk over
 219     var handlers = this.listeners_[type].concat();
 220     for (var i = 0, handler; handler = handlers[i]; i++) {
 221       handler.call(this, event);
 222     }
 223   }
 224 }