native_client_sdk/src/examples/tutorial/load_progress/example.js

   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 // Called by the common.js module.
   6 function domContentLoaded(name, tc, config, width, height) {
   7   var listener = document.getElementById('listener');
   8   listener.addEventListener('loadstart', moduleDidStartLoad, true);
   9   listener.addEventListener('progress', moduleLoadProgress, true);
  10   listener.addEventListener('error', moduleLoadError, true);
  11   listener.addEventListener('abort', moduleLoadAbort, true);
  12   listener.addEventListener('load', moduleDidLoad, true);
  13   listener.addEventListener('loadend', moduleDidEndLoad, true);
  14   listener.addEventListener('message', handleMessage, true);
  15
  16   common.createNaClModule(name, tc, config, width, height);
  17 }
  18
  19 // Handler that gets called when the NaCl module starts loading.  This
  20 // event is always triggered when an <EMBED> tag has a MIME type of
  21 // application/x-nacl.
  22 function moduleDidStartLoad() {
  23   common.logMessage('loadstart');
  24 }
  25
  26 // Progress event handler.  |event| contains a couple of interesting
  27 // properties that are used in this example:
  28 //     total The size of the NaCl module in bytes.  Note that this value
  29 //         is 0 until |lengthComputable| is true.  In particular, this
  30 //         value is 0 for the first 'progress' event.
  31 //     loaded The number of bytes loaded so far.
  32 //     lengthComputable A boolean indicating that the |total| field
  33 //         represents a valid length.
  34 //
  35 // event The ProgressEvent that triggered this handler.
  36 function moduleLoadProgress(event) {
  37   var loadPercent = 0.0;
  38   var loadPercentString;
  39   if (event.lengthComputable && event.total > 0) {
  40     loadPercent = event.loaded / event.total * 100.0;
  41     loadPercentString = loadPercent + '%';
  42     common.logMessage('progress: ' + event.url + ' ' + loadPercentString +
  43                      ' (' + event.loaded + ' of ' + event.total + ' bytes)');
  44   } else {
  45     // The total length is not yet known.
  46     common.logMessage('progress: Computing...');
  47   }
  48 }
  49
  50 // Handler that gets called if an error occurred while loading the NaCl
  51 // module.  Note that the event does not carry any meaningful data about
  52 // the error, you have to check lastError on the <EMBED> element to find
  53 // out what happened.
  54 function moduleLoadError() {
  55   common.logMessage('error: ' + common.naclModule.lastError);
  56 }
  57
  58 // Handler that gets called if the NaCl module load is aborted.
  59 function moduleLoadAbort() {
  60   common.logMessage('abort');
  61 }
  62
  63 // When the NaCl module has loaded indicate success.
  64 function moduleDidLoad() {
  65   common.logMessage('load');
  66   common.updateStatus('LOADED');
  67 }
  68
  69 // Handler that gets called when the NaCl module loading has completed.
  70 // You will always get one of these events, regardless of whether the NaCl
  71 // module loaded successfully or not.  For example, if there is an error
  72 // during load, you will get an 'error' event and a 'loadend' event.  Note
  73 // that if the NaCl module loads successfully, you will get both a 'load'
  74 // event and a 'loadend' event.
  75 function moduleDidEndLoad() {
  76   common.logMessage('loadend');
  77   var lastError = event.target.lastError;
  78   if (lastError == undefined || lastError.length == 0) {
  79     lastError = '<none>';
  80   }
  81   common.logMessage('lastError: ' + lastError);
  82 }
  83
  84 // Handle a message coming from the NaCl module.
  85 function handleMessage(message_event) {
  86   common.logMessage('Received PostMessage: ' + message_event.data);
  87 }