Refactored web-app

remoting/webapp/me2mom/remoting.js

Index: remoting/webapp/me2mom/remoting.js
diff --git a/remoting/webapp/me2mom/remoting.js b/remoting/webapp/me2mom/remoting.js
index 2f4250b0fe2d8ee6252c9a757a34a145cfc5ae69..3e86b05c8af7746b7a53f9ee031ae9773f230be7 100644
--- a/remoting/webapp/me2mom/remoting.js
+++ b/remoting/webapp/me2mom/remoting.js
@@ -7,202 +7,31 @@
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
-/**
- * Whether or not the plugin should scale itself.
- * @type {boolean}
- */
-remoting.scaleToFit = false;
-
-/** @type {remoting.ClientSession} */
-remoting.session = null;
-
-/** @type {string} */ remoting.accessCode = '';
-/** @type {number} */ remoting.accessCodeTimerId = 0;
-/** @type {number} */ remoting.accessCodeExpiresIn = 0;
-/** @type {remoting.AppMode} */ remoting.currentMode;
-/** @type {string} */ remoting.hostJid = '';
-/** @type {string} */ remoting.hostPublicKey = '';
-/** @type {boolean} */ remoting.lastShareWasCancelled = false;
-/** @type {boolean} */ remoting.timerRunning = false;
-/** @type {string} */ remoting.username = '';
-
-/** @enum {string} */
-remoting.AppMode = {
-  HOME: 'home',
-  UNAUTHENTICATED: 'auth',
-  CLIENT: 'client',
-    CLIENT_UNCONNECTED: 'client.unconnected',
-    CLIENT_CONNECTING: 'client.connecting',
-    CLIENT_CONNECT_FAILED: 'client.connect-failed',
-    CLIENT_SESSION_FINISHED: 'client.session-finished',
-  HOST: 'host',
-    HOST_WAITING_FOR_CODE: 'host.waiting-for-code',
-    HOST_WAITING_FOR_CONNECTION: 'host.waiting-for-connection',
-    HOST_SHARED: 'host.shared',
-    HOST_SHARE_FAILED: 'host.share-failed',
-    HOST_SHARE_FINISHED: 'host.share-finished',
-  IN_SESSION: 'in-session'
-};
+/** @type {remoting.HostSession} */ remoting.hostSession = null;
 
 (function() {
 
-window.addEventListener('blur', pluginLostFocus_, false);
-
-function pluginLostFocus_() {
-  // If the plug loses input focus, release all keys as a precaution against
-  // leaving them 'stuck down' on the host.
-  if (remoting.session && remoting.session.plugin) {
-    remoting.session.plugin.releaseAllKeys();
-  }
-}
-
-/** @type {string} */
-remoting.HOST_PLUGIN_ID = 'host-plugin-id';
-
-/** @enum {string} */
-remoting.ClientError = {
-  NO_RESPONSE: /*i18n-content*/'ERROR_NO_RESPONSE',
-  INVALID_ACCESS_CODE: /*i18n-content*/'ERROR_INVALID_ACCESS_CODE',
-  MISSING_PLUGIN: /*i18n-content*/'ERROR_MISSING_PLUGIN',
-  OAUTH_FETCH_FAILED: /*i18n-content*/'ERROR_AUTHENTICATION_FAILED',
-  HOST_IS_OFFLINE: /*i18n-content*/'ERROR_HOST_IS_OFFLINE',
-  INCOMPATIBLE_PROTOCOL: /*i18n-content*/'ERROR_INCOMPATIBLE_PROTOCOL',
-  BAD_PLUGIN_VERSION: /*i18n-content*/'ERROR_BAD_PLUGIN_VERSION',
-  OTHER_ERROR: /*i18n-content*/'ERROR_GENERIC'
-};
-
-// Constants representing keys used for storing persistent application state.
-var KEY_APP_MODE_ = 'remoting-app-mode';
-var KEY_EMAIL_ = 'remoting-email';
-var KEY_USE_P2P_API_ = 'remoting-use-p2p-api';
-
-// Some constants for pretty-printing the access code.
-/** @type {number} */ var kSupportIdLen = 7;
-/** @type {number} */ var kHostSecretLen = 5;
-/** @type {number} */ var kAccessCodeLen = kSupportIdLen + kHostSecretLen;
-/** @type {number} */ var kDigitsPerGroup = 4;
-
 /**
- * @param {string} classes A space-separated list of classes.
- * @param {string} cls The class to check for.
- * @return {boolean} True if |cls| is found within |classes|.
+ * Entry point for app initialization.
  */
-function hasClass(classes, cls) {
-  return classes.match(new RegExp('(\\s|^)' + cls + '(\\s|$)')) != null;
-}
-
-/**
- * @param {Element} element The element to which to add the class.
- * @param {string} cls The new class.
- * @return {void} Nothing.
- */
-function addClass(element, cls) {
-  if (!hasClass(element.className, cls)) {
-    var padded = element.className == '' ? '' : element.className + ' ';
-    element.className = padded + cls;
-  }
-}
-
-/**
- * @param {Element} element The element from which to remove the class.
- * @param {string} cls The new class.
- * @return {void} Nothing.
- */
-function removeClass(element, cls) {
-  element.className =
-      element.className.replace(new RegExp('\\b' + cls + '\\b', 'g'), '')
-                       .replace('  ', ' ');
-}
-
-function retrieveEmail_(access_token) {
-  var headers = {
-    'Authorization': 'OAuth ' + remoting.oauth2.getAccessToken()
-  };
-
-  /** @param {XMLHttpRequest} xhr The XHR response. */
-  var onResponse = function(xhr) {
-    if (xhr.status != 200) {
-      // TODO(ajwong): Have a better way of showing an error.
-      remoting.debug.log('Unable to get email');
-      document.getElementById('current-email').innerText = '???';
-      return;
-    }
-
-    // TODO(ajwong): See if we can't find a JSON endpoint.
-    setEmail(xhr.responseText.split('&')[0].split('=')[1]);
-  };
-
-  // TODO(ajwong): Update to new v2 API.
-  remoting.xhr.get('https://www.googleapis.com/userinfo/email',
-                   onResponse, '', headers);
-}
-
-function refreshEmail_() {
-  if (!getEmail() && remoting.oauth2.isAuthenticated()) {
-    remoting.oauth2.callWithToken(retrieveEmail_);
-  }
-}
-
-/**
- * @param {string} value The email address to place in local storage.
- * @return {void} Nothing.
- */
-function setEmail(value) {
-  window.localStorage.setItem(KEY_EMAIL_, value);
-  document.getElementById('current-email').innerText = value;
-}
-
-/**
- * @return {?string} The email address associated with the auth credentials.
- */
-function getEmail() {
-  var result = window.localStorage.getItem(KEY_EMAIL_);
-  return typeof result == 'string' ? result : null;
-}
-
-function exchangedCodeForToken_() {
-  if (!remoting.oauth2.isAuthenticated()) {
-    alert('Your OAuth2 token was invalid. Please try again.');
-  }
-  /** @param {string} token The auth token. */
-  var retrieveEmail = function(token) { retrieveEmail_(token); }
-  remoting.oauth2.callWithToken(retrieveEmail);
-}
-
-remoting.clearOAuth2 = function() {
-  remoting.oauth2.clear();
-  window.localStorage.removeItem(KEY_EMAIL_);
-  remoting.setMode(remoting.AppMode.UNAUTHENTICATED);
-}
-
-remoting.toggleDebugLog = function() {
-  var debugLog = document.getElementById('debug-log');
-  if (debugLog.hidden) {
-    debugLog.hidden = false;
-  } else {
-    debugLog.hidden = true;
-  }
-}
-
 remoting.init = function() {
   l10n.localize();
   var button = document.getElementById('toggle-scaling');
   button.title = chrome.i18n.getMessage(/*i18n-content*/'TOOLTIP_SCALING');
   // Create global objects.
   remoting.oauth2 = new remoting.OAuth2();
-  remoting.debug =
-      new remoting.DebugLog(document.getElementById('debug-messages'));
-  /** @type {XMLHttpRequest} */
-  remoting.supportHostsXhr = null;
+  remoting.debug = new remoting.DebugLog(
+      document.getElementById('debug-messages'),
+      document.getElementById('statistics'));
 
   refreshEmail_();
-  var email = getEmail();
+  var email = remoting.oauth2.getCachedEmail();
   if (email) {
     document.getElementById('current-email').innerText = email;
   }
 
-  remoting.setMode(getAppStartupMode());
-  if (isHostModeSupported()) {
+  remoting.setMode(getAppStartupMode_());
+  if (isHostModeSupported_()) {
     var unsupported = document.getElementById('client-footer-text-cros');
     unsupported.parentNode.removeChild(unsupported);
   } else {
@@ -211,553 +40,106 @@ remoting.init = function() {
     document.getElementById('client-footer-text-cros').id =
         'client-footer-text';
   }
-}
-
-/**
- * Change the app's modal state to |mode|, which is considered to be a dotted
- * hierachy of modes. For example, setMode('host.shared') will show any modal
- * elements with an data-ui-mode attribute of 'host' or 'host.shared' and hide
- * all others.
- *
- * @param {remoting.AppMode} mode The new modal state, expressed as a dotted
- * hiearchy.
- */
-remoting.setMode = function(mode) {
-  var modes = mode.split('.');
-  for (var i = 1; i < modes.length; ++i)
-    modes[i] = modes[i - 1] + '.' + modes[i];
-  var elements = document.querySelectorAll('[data-ui-mode]');
-  for (var i = 0; i < elements.length; ++i) {
-    /** @type {Element} */ var element = elements[i];
-    var hidden = true;
-    for (var m = 0; m < modes.length; ++m) {
-      if (hasClass(element.getAttribute('data-ui-mode'), modes[m])) {
-        hidden = false;
-        break;
-      }
-    }
-    element.hidden = hidden;
-  }
-  remoting.debug.log('App mode: ' + mode);
-  remoting.currentMode = mode;
-  if (mode == remoting.AppMode.IN_SESSION) {
-    document.removeEventListener('keydown', remoting.checkHotkeys, false);
-  } else {
-    document.addEventListener('keydown', remoting.checkHotkeys, false);
-  }
-}
-
-/**
- * Get the major mode that the app is running in.
- * @return {string} The app's current major mode.
- */
-remoting.getMajorMode = function() {
-  return remoting.currentMode.split('.')[0];
-}
-
-remoting.tryShare = function() {
-  remoting.debug.log('Attempting to share...');
-  remoting.lastShareWasCancelled = false;
-  if (remoting.oauth2.needsNewAccessToken()) {
-    remoting.debug.log('Refreshing token...');
-    remoting.oauth2.refreshAccessToken(function() {
-      if (remoting.oauth2.needsNewAccessToken()) {
-        // If we still need it, we're going to infinite loop.
-        showShareError_(/*i18n-content*/'ERROR_AUTHENTICATION_FAILED');
-        throw 'Unable to get access token';
-      }
-      remoting.tryShare();
-    });
-    return;
-  }
-
-  remoting.setMode(remoting.AppMode.HOST_WAITING_FOR_CODE);
-  document.getElementById('cancel-button').disabled = false;
-  disableTimeoutCountdown_();
-
-  var div = document.getElementById('host-plugin-container');
-  var plugin = /** @type {remoting.HostPlugin} */
-      document.createElement('embed');
-  plugin.type = remoting.PLUGIN_MIMETYPE;
-  plugin.id = remoting.HOST_PLUGIN_ID;
-  // Hiding the plugin means it doesn't load, so make it size zero instead.
-  plugin.width = 0;
-  plugin.height = 0;
-  div.appendChild(plugin);
-  onNatTraversalPolicyChanged_(true);  // Hide warning by default.
-  plugin.onNatTraversalPolicyChanged = onNatTraversalPolicyChanged_;
-  plugin.onStateChanged = onStateChanged_;
-  plugin.logDebugInfo = debugInfoCallback_;
-  plugin.localize(chrome.i18n.getMessage);
-  plugin.connect(/** @type {string} */ (getEmail()),
-                 'oauth2:' + remoting.oauth2.getAccessToken());
-}
 
-function disableTimeoutCountdown_() {
-  if (remoting.timerRunning) {
-    clearInterval(remoting.accessCodeTimerId);
-    remoting.timerRunning = false;
-    updateTimeoutStyles_();
-  }
+  window.addEventListener('blur', pluginLostFocus_, false);
 }
 
-var ACCESS_CODE_TIMER_DISPLAY_THRESHOLD = 30;
-var ACCESS_CODE_RED_THRESHOLD = 10;
-
-/**
- * Show/hide or restyle various elements, depending on the remaining countdown
- * and timer state.
- *
- * @return {boolean} True if the timeout is in progress, false if it has
- * expired.
- */
-function updateTimeoutStyles_() {
-  if (remoting.timerRunning) {
-    if (remoting.accessCodeExpiresIn <= 0) {
+remoting.cancelPendingOperation = function() {
+  document.getElementById('cancel-button').disabled = true;
+  switch (remoting.getMajorMode()) {
+    case remoting.AppMode.HOST:
       remoting.cancelShare();
-      return false;
-    }
-    if (remoting.accessCodeExpiresIn <= ACCESS_CODE_RED_THRESHOLD) {
-      addClass(document.getElementById('access-code-display'), 'expiring');
-    } else {
-      removeClass(document.getElementById('access-code-display'), 'expiring');
-    }
-  }
-  document.getElementById('access-code-countdown').hidden =
-      (remoting.accessCodeExpiresIn > ACCESS_CODE_TIMER_DISPLAY_THRESHOLD) ||
-      !remoting.timerRunning;
-  return true;
-}
-
-remoting.decrementAccessCodeTimeout_ = function() {
-  --remoting.accessCodeExpiresIn;
-  remoting.updateAccessCodeTimeoutElement_();
-}
-
-remoting.updateAccessCodeTimeoutElement_ = function() {
-  var pad = (remoting.accessCodeExpiresIn < 10) ? '0:0' : '0:';
-  l10n.localizeElement(document.getElementById('seconds-remaining'),
-                       pad + remoting.accessCodeExpiresIn);
-  if (!updateTimeoutStyles_()) {
-    disableTimeoutCountdown_();
+      break;
+    case remoting.AppMode.CLIENT:
+      remoting.cancelConnect();
+      break;
   }
 }
 
 /**
- * Callback to show or hide the NAT traversal warning when the policy changes.
- * @param {boolean} enabled True if NAT traversal is enabled.
- * @return {void} Nothing.
- */
-function onNatTraversalPolicyChanged_(enabled) {
-  var container = document.getElementById('nat-box-container');
-  container.hidden = enabled;
-}
-
-/**
- * Callback for the host plugin to notify the web app of state changes.
- * @param {number} state The new state of the plugin.
+ * If the client is connected, or the host is shared, prompt before closing.
+ *
+ * @return {?string} The prompt string if a connection is active.
  */
-function onStateChanged_(state) {
-  var plugin = /** @type {remoting.HostPlugin} */
-      document.getElementById(remoting.HOST_PLUGIN_ID);
-  if (state == plugin.STARTING) {
-    // Nothing to do here.
-    remoting.debug.log('Host plugin state: STARTING');
-  } else if (state == plugin.REQUESTED_ACCESS_CODE) {
-    // Nothing to do here.
-    remoting.debug.log('Host plugin state: REQUESTED_ACCESS_CODE');
-  } else if (state == plugin.RECEIVED_ACCESS_CODE) {
-    remoting.debug.log('Host plugin state: RECEIVED_ACCESS_CODE');
-    var accessCode = plugin.accessCode;
-    var accessCodeDisplay = document.getElementById('access-code-display');
-    accessCodeDisplay.innerText = '';
-    // Display the access code in groups of four digits for readability.
-    for (var i = 0; i < accessCode.length; i += kDigitsPerGroup) {
-      var nextFourDigits = document.createElement('span');
-      nextFourDigits.className = 'access-code-digit-group';
-      nextFourDigits.innerText = accessCode.substring(i, i + kDigitsPerGroup);
-      accessCodeDisplay.appendChild(nextFourDigits);
-    }
-    remoting.accessCodeExpiresIn = plugin.accessCodeLifetime;
-    if (remoting.accessCodeExpiresIn > 0) {  // Check it hasn't expired.
-      remoting.accessCodeTimerId = setInterval(
-          'remoting.decrementAccessCodeTimeout_()', 1000);
-      remoting.timerRunning = true;
-      remoting.updateAccessCodeTimeoutElement_();
-      updateTimeoutStyles_();
-      remoting.setMode(remoting.AppMode.HOST_WAITING_FOR_CONNECTION);
-    } else {
-      // This can only happen if the cloud tells us that the code lifetime is
-      // <= 0s, which shouldn't happen so we don't care how clean this UX is.
-      remoting.debug.log('Access code already invalid on receipt!');
-      remoting.cancelShare();
-    }
-  } else if (state == plugin.CONNECTED) {
-    remoting.debug.log('Host plugin state: CONNECTED');
-    var element = document.getElementById('host-shared-message');
-    var client = plugin.client;
-    l10n.localizeElement(element, client);
-    remoting.setMode(remoting.AppMode.HOST_SHARED);
-    disableTimeoutCountdown_();
-  } else if (state == plugin.DISCONNECTING) {
-    remoting.debug.log('Host plugin state: DISCONNECTING');
-  } else if (state == plugin.DISCONNECTED) {
-    remoting.debug.log('Host plugin state: DISCONNECTED');
-    if (remoting.currentMode != remoting.AppMode.HOST_SHARE_FAILED) {
-      // If an error is being displayed, then the plugin should not be able to
-      // hide it by setting the state. Errors must be dismissed by the user
-      // clicking OK, which puts the app into mode HOME.
-      if (remoting.lastShareWasCancelled) {
-        remoting.setMode(remoting.AppMode.HOME);
-      } else {
-        remoting.setMode(remoting.AppMode.HOST_SHARE_FINISHED);
-      }
-    }
-    plugin.parentNode.removeChild(plugin);
-  } else if (state == plugin.ERROR) {
-    remoting.debug.log('Host plugin state: ERROR');
-    showShareError_(/*i18n-content*/'ERROR_GENERIC');
-  } else {
-    remoting.debug.log('Unknown state -> ' + state);
+remoting.promptClose = function() {
+  switch (remoting.currentMode) {
+    case remoting.AppMode.CLIENT_CONNECTING:
+    case remoting.AppMode.HOST_WAITING_FOR_CODE:
+    case remoting.AppMode.HOST_WAITING_FOR_CONNECTION:
+    case remoting.AppMode.HOST_SHARED:
+    case remoting.AppMode.IN_SESSION:
+      var result = chrome.i18n.getMessage(/*i18n-content*/'CLOSE_PROMPT');
+      return result;
+    default:
+      return null;
   }
 }
 
 /**
- * This is the callback that the host plugin invokes to indicate that there
- * is additional debug log info to display.
- * @param {string} msg The message (which will not be localized) to be logged.
- */
-function debugInfoCallback_(msg) {
-  remoting.debug.log('plugin: ' + msg);
-}
-
-/**
- * Show a host-side error message.
- *
- * @param {string} errorTag The error message to be localized and displayed.
- * @return {void} Nothing.
+ * Sign the user out of Chromoting by clearing the OAuth refresh token.
  */
-function showShareError_(errorTag) {
-  var errorDiv = document.getElementById('host-plugin-error');
-  l10n.localizeElementFromTag(errorDiv, errorTag);
-  remoting.debug.log('Sharing error: ' + errorTag);
-  remoting.setMode(remoting.AppMode.HOST_SHARE_FAILED);
+remoting.clearOAuth2 = function() {
+  remoting.oauth2.clear();
+  window.localStorage.removeItem(KEY_EMAIL_);
+  remoting.setMode(remoting.AppMode.UNAUTHENTICATED);
 }
 
 /**
- * Cancel an active or pending share operation.
- *
- * @return {void} Nothing.
+ * Callback function called when the browser window loses focus. In this case,
+ * release all keys to prevent them becoming 'stuck down' on the host.
  */
-remoting.cancelShare = function() {
-  remoting.debug.log('Canceling share...');
-  remoting.lastShareWasCancelled = true;
-  var plugin = /** @type {remoting.HostPlugin} */
-      document.getElementById(remoting.HOST_PLUGIN_ID);
-  try {
-    plugin.disconnect();
-  } catch (error) {
-    // Hack to force JSCompiler type-safety.
-    var errorTyped = /** @type {{description: string}} */ error;
-    remoting.debug.log('Error disconnecting: ' + errorTyped.description +
-                       '. The host plugin probably crashed.');
-    // TODO(jamiewalch): Clean this up. We should have a class representing
-    // the host plugin, like we do for the client, which should handle crash
-    // reporting and it should use a more detailed error message than the
-    // default 'generic' one. See crbug.com/94624
-    showShareError_(/*i18n-content*/'ERROR_GENERIC');
+function pluginLostFocus_() {
+  if (remoting.clientSession && remoting.clientSession.plugin) {
+    remoting.clientSession.plugin.releaseAllKeys();
   }
-  disableTimeoutCountdown_();
 }
 
 /**
- * Cancel an incomplete connect operation.
- *
- * @return {void} Nothing.
+ * If the user is authenticated, but there is no email address cached, get one.
  */
-remoting.cancelConnect = function() {
-  if (remoting.supportHostsXhr) {
-    remoting.supportHostsXhr.abort();
-    remoting.supportHostsXhr = null;
-  }
-  if (remoting.session) {
-    remoting.session.removePlugin();
-    remoting.session = null;
-  }
-  remoting.setMode(remoting.AppMode.HOME);
-}
-
-function updateStatistics() {
-  if (!remoting.session)
-    return;
-  if (remoting.session.state != remoting.ClientSession.State.CONNECTED)
-    return;
-  var stats = remoting.session.stats();
-
-  var units = '';
-  var videoBandwidth = stats['video_bandwidth'];
-  if (videoBandwidth < 1024) {
-    units = 'Bps';
-  } else if (videoBandwidth < 1048576) {
-    units = 'KiBps';
-    videoBandwidth = videoBandwidth / 1024;
-  } else if (videoBandwidth < 1073741824) {
-    units = 'MiBps';
-    videoBandwidth = videoBandwidth / 1048576;
-  } else {
-    units = 'GiBps';
-    videoBandwidth = videoBandwidth / 1073741824;
-  }
-
-  var statistics = document.getElementById('statistics');
-  statistics.innerText =
-      'Bandwidth: ' + videoBandwidth.toFixed(2) + units +
-      ', Frame Rate: ' +
-          (stats['video_frame_rate'] ?
-           stats['video_frame_rate'].toFixed(2) + ' fps' : 'n/a') +
-      ', Capture: ' + stats['capture_latency'].toFixed(2) + 'ms' +
-      ', Encode: ' + stats['encode_latency'].toFixed(2) + 'ms' +
-      ', Decode: ' + stats['decode_latency'].toFixed(2) + 'ms' +
-      ', Render: ' + stats['render_latency'].toFixed(2) + 'ms' +
-      ', Latency: ' + stats['roundtrip_latency'].toFixed(2) + 'ms';
-
-  // Update the stats once per second.
-  window.setTimeout(updateStatistics, 1000);
-}
-
-function showToolbarPreview_() {
-  var toolbar = document.getElementById('session-toolbar');
-  addClass(toolbar, 'toolbar-preview');
-  window.setTimeout(removeClass, 3000, toolbar, 'toolbar-preview');
-}
-
-/** @param {number} oldState The previous state of the plugin. */
-function onClientStateChange_(oldState) {
-  if (!remoting.session) {
-    // If the connection has been cancelled, then we no longer have a reference
-    // to the session object and should ignore any state changes.
-    return;
-  }
-  var state = remoting.session.state;
-  if (state == remoting.ClientSession.State.CREATED) {
-    remoting.debug.log('Created plugin');
-  } else if (state == remoting.ClientSession.State.BAD_PLUGIN_VERSION) {
-    showConnectError_(remoting.ClientError.BAD_PLUGIN_VERSION);
-  } else if (state == remoting.ClientSession.State.CONNECTING) {
-    remoting.debug.log('Connecting as ' + remoting.username);
-  } else if (state == remoting.ClientSession.State.INITIALIZING) {
-    remoting.debug.log('Initializing connection');
-  } else if (state == remoting.ClientSession.State.CONNECTED) {
-    if (remoting.session) {
-      remoting.setMode(remoting.AppMode.IN_SESSION);
-      recenterToolbar_();
-      showToolbarPreview_();
-      updateStatistics();
-    }
-  } else if (state == remoting.ClientSession.State.CLOSED) {
-    if (oldState == remoting.ClientSession.State.CONNECTED) {
-      remoting.session.removePlugin();
-      remoting.session = null;
-      remoting.debug.log('Connection closed by host');
-      remoting.setMode(remoting.AppMode.CLIENT_SESSION_FINISHED);
-    } else {
-      // The transition from CONNECTING to CLOSED state may happen
-      // only with older client plugins. Current version should go the
-      // FAILED state when connection fails.
-      showConnectError_(remoting.ClientError.INVALID_ACCESS_CODE);
-    }
-  } else if (state == remoting.ClientSession.State.CONNECTION_FAILED) {
-    remoting.debug.log('Client plugin reported connection failed: ' +
-                       remoting.session.error);
-    if (remoting.session.error ==
-        remoting.ClientSession.ConnectionError.HOST_IS_OFFLINE) {
-      showConnectError_(remoting.ClientError.HOST_IS_OFFLINE);
-    } else if (remoting.session.error ==
-               remoting.ClientSession.ConnectionError.SESSION_REJECTED) {
-      showConnectError_(remoting.ClientError.INVALID_ACCESS_CODE);
-    } else if (remoting.session.error ==
-               remoting.ClientSession.ConnectionError.INCOMPATIBLE_PROTOCOL) {
-      showConnectError_(remoting.ClientError.INCOMPATIBLE_PROTOCOL);
-    } else if (remoting.session.error ==
-               remoting.ClientSession.ConnectionError.NETWORK_FAILURE) {
-      showConnectError_(remoting.ClientError.OTHER_ERROR);
-    } else {
-      showConnectError_(remoting.ClientError.OTHER_ERROR);
-    }
-  } else {
-    remoting.debug.log('Unexpected client plugin state: ' + state);
-    // This should only happen if the web-app and client plugin get out of
-    // sync, and even then the version check should allow compatibility.
-    showConnectError_(remoting.ClientError.MISSING_PLUGIN);
+function refreshEmail_() {
+  if (!getEmail_() && remoting.oauth2.isAuthenticated()) {
+    remoting.oauth2.getEmail(setEmail_);
   }
 }
 
-function startSession_() {
-  remoting.debug.log('Starting session...');
-  var accessCode = document.getElementById('access-code-entry');
-  accessCode.value = '';  // The code has been validated and won't work again.
-  remoting.username =
-      /** @type {string} email must be non-NULL to get here */ getEmail();
-  remoting.session =
-      new remoting.ClientSession(remoting.hostJid, remoting.hostPublicKey,
-                                 remoting.accessCode, remoting.username,
-                                 onClientStateChange_);
-  /** @param {string} token The auth token. */
-  var createPluginAndConnect = function(token) {
-    remoting.session.createPluginAndConnect(
-        document.getElementById('session-mode'),
-        token);
-  };
-  remoting.oauth2.callWithToken(createPluginAndConnect);
-}
+/** The key under which the email address is stored. */
+var KEY_EMAIL_ = 'remoting-email';
 
 /**
- * Show a client-side error message.
+ * Save the user's email address in local storage.
  *
- * @param {remoting.ClientError} errorTag The error to be localized and
- * displayed.
- * @return {void} Nothing.
- */
-function showConnectError_(errorTag) {
-  remoting.debug.log('Connection failed: ' + errorTag);
-  var errorDiv = document.getElementById('connect-error-message');
-  l10n.localizeElementFromTag(errorDiv, /** @type {string} */ (errorTag));
-  remoting.accessCode = '';
-  if (remoting.session) {
-    remoting.session.disconnect();
-    remoting.session = null;
-  }
-  remoting.setMode(remoting.AppMode.CLIENT_CONNECT_FAILED);
-}
-
-/**
- * @param {XMLHttpRequest} xhr The XMLHttpRequest object.
+ * @param {?string} email The email address to place in local storage.
  * @return {void} Nothing.
  */
-function parseServerResponse_(xhr) {
-  remoting.supportHostsXhr = null;
-  remoting.debug.log('parseServerResponse: status = ' + xhr.status);
-  if (xhr.status == 200) {
-    var host = /** @type {{data: {jabberId: string, publicKey: string}}} */
-        JSON.parse(xhr.responseText);
-    if (host.data && host.data.jabberId && host.data.publicKey) {
-      remoting.hostJid = host.data.jabberId;
-      remoting.hostPublicKey = host.data.publicKey;
-      var split = remoting.hostJid.split('/');
-      document.getElementById('connected-to').innerText = split[0];
-      startSession_();
-      return;
-    }
-  }
-  var errorMsg = remoting.ClientError.OTHER_ERROR;
-  if (xhr.status == 404) {
-    errorMsg = remoting.ClientError.INVALID_ACCESS_CODE;
-  } else if (xhr.status == 0) {
-    errorMsg = remoting.ClientError.NO_RESPONSE;
-  } else {
-    remoting.debug.log('The server responded: ' + xhr.responseText);
-  }
-  showConnectError_(errorMsg);
-}
-
-/** @param {string} accessCode The access code, as entered by the user.
- *  @return {string} The normalized form of the code (whitespace removed). */
-function normalizeAccessCode_(accessCode) {
-  // Trim whitespace.
-  // TODO(sergeyu): Do we need to do any other normalization here?
-  return accessCode.replace(/\s/g, '');
-}
-
-/** @param {string} supportId The canonicalized support ID. */
-function resolveSupportId(supportId) {
-  var headers = {
-    'Authorization': 'OAuth ' + remoting.oauth2.getAccessToken()
-  };
-
-  remoting.supportHostsXhr = remoting.xhr.get(
-      'https://www.googleapis.com/chromoting/v1/support-hosts/' +
-          encodeURIComponent(supportId),
-      parseServerResponse_,
-      '',
-      headers);
-}
-
-remoting.tryConnect = function() {
-  document.getElementById('cancel-button').disabled = false;
-  if (remoting.oauth2.needsNewAccessToken()) {
-    remoting.oauth2.refreshAccessToken(function(xhr) {
-      if (remoting.oauth2.needsNewAccessToken()) {
-        // Failed to get access token
-        remoting.debug.log('tryConnect: OAuth2 token fetch failed');
-        showConnectError_(remoting.ClientError.OAUTH_FETCH_FAILED);
-        return;
-      }
-      remoting.tryConnectWithAccessToken();
-    });
+function setEmail_(email) {
+  if (email) {
+    document.getElementById('current-email').innerText = email;
   } else {
-    remoting.tryConnectWithAccessToken();
+    // TODO(ajwong): Have a better way of showing an error.
+    document.getElementById('current-email').innerText = '???';
   }
 }
 
-remoting.tryConnectWithAccessToken = function() {
-  if (!remoting.wcsLoader) {
-    remoting.wcsLoader = new remoting.WcsLoader();
-  }
-  /** @param {function(string):void} setToken The callback function. */
-  var callWithToken = function(setToken) {
-    remoting.oauth2.callWithToken(setToken);
-  };
-  remoting.wcsLoader.start(
-      remoting.oauth2.getAccessToken(),
-      callWithToken,
-      remoting.tryConnectWithWcs);
-}
-
 /**
- * WcsLoader callback, called when the wcs script has been loaded, or on error.
- * @param {boolean} success True if the script was loaded successfully.
+ * Read the user's email address from local storage.
+ *
+ * @return {?string} The email address associated with the auth credentials.
  */
-remoting.tryConnectWithWcs = function(success) {
-  if (success) {
-    var accessCode = document.getElementById('access-code-entry').value;
-    remoting.accessCode = normalizeAccessCode_(accessCode);
-    // At present, only 12-digit access codes are supported, of which the first
-    // 7 characters are the supportId.
-    if (remoting.accessCode.length != kAccessCodeLen) {
-      remoting.debug.log('Bad access code length');
-      showConnectError_(remoting.ClientError.INVALID_ACCESS_CODE);
-    } else {
-      var supportId = remoting.accessCode.substring(0, kSupportIdLen);
-      remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
-      resolveSupportId(supportId);
-    }
-  } else {
-    showConnectError_(remoting.ClientError.OAUTH_FETCH_FAILED);
-  }
-}
-
-remoting.cancelPendingOperation = function() {
-  document.getElementById('cancel-button').disabled = true;
-  switch (remoting.getMajorMode()) {
-    case remoting.AppMode.HOST:
-      remoting.cancelShare();
-      break;
-    case remoting.AppMode.CLIENT:
-      remoting.cancelConnect();
-      break;
-  }
+function getEmail_() {
+  var result = window.localStorage.getItem(KEY_EMAIL_);
+  return typeof result == 'string' ? result : null;
 }
-
 /**
  * Gets the major-mode that this application should start up in.
  *
  * @return {remoting.AppMode} The mode to start in.
  */
-function getAppStartupMode() {
+function getAppStartupMode_() {
   if (!remoting.oauth2.isAuthenticated()) {
     return remoting.AppMode.UNAUTHENTICATED;
   }
-  if (isHostModeSupported()) {
+  if (isHostModeSupported_()) {
     return remoting.AppMode.HOME;
   } else {
     return remoting.AppMode.CLIENT_UNCONNECTED;
@@ -769,86 +151,8 @@ function getAppStartupMode() {
  *
  * @return {boolean} True if Host mode is supported.
  */
-function isHostModeSupported() {
+function isHostModeSupported_() {
   // Currently, sharing on Chromebooks is not supported.
   return !navigator.userAgent.match(/\bCrOS\b/);
 }
-
-/**
- * Enable or disable scale-to-fit.
- *
- * @param {Element} button The scale-to-fit button. The style of this button is
- * updated to reflect the new scaling state.
- * @return {void} Nothing.
- */
-remoting.toggleScaleToFit = function(button) {
-  remoting.scaleToFit = !remoting.scaleToFit;
-  if (remoting.scaleToFit) {
-    addClass(button, 'toggle-button-active');
-  } else {
-    removeClass(button, 'toggle-button-active');
-  }
-  remoting.session.updateDimensions();
-}
-
-/**
- * Update the remoting client layout in response to a resize event.
- *
- * @return {void} Nothing.
- */
-remoting.onResize = function() {
-  if (remoting.session)
-    remoting.session.onWindowSizeChanged();
-  recenterToolbar_();
-}
-
-/**
- * Disconnect the remoting client.
- *
- * @return {void} Nothing.
- */
-remoting.disconnect = function() {
-  if (remoting.session) {
-    remoting.session.disconnect();
-    remoting.session = null;
-    remoting.debug.log('Disconnected.');
-    remoting.setMode(remoting.AppMode.CLIENT_SESSION_FINISHED);
-  }
-}
-
-/**
- * If the client is connected, or the host is shared, prompt before closing.
- *
- * @return {?string} The prompt string if a connection is active.
- */
-remoting.promptClose = function() {
-  switch (remoting.currentMode) {
-    case remoting.AppMode.CLIENT_CONNECTING:
-    case remoting.AppMode.HOST_WAITING_FOR_CODE:
-    case remoting.AppMode.HOST_WAITING_FOR_CONNECTION:
-    case remoting.AppMode.HOST_SHARED:
-    case remoting.AppMode.IN_SESSION:
-      var result = chrome.i18n.getMessage(/*i18n-content*/'CLOSE_PROMPT');
-      return result;
-    default:
-      return null;
-  }
-}
-
-/**
- * @param {Event} event The keyboard event.
- * @return {void} Nothing.
- */
-remoting.checkHotkeys = function(event) {
-  if (String.fromCharCode(event.which) == 'D') {
-    remoting.toggleDebugLog();
-  }
-}
-
-function recenterToolbar_() {
-  var toolbar = document.getElementById('session-toolbar');
-  var toolbarX = (window.innerWidth - toolbar.clientWidth) / 2;
-  toolbar.style['left'] = toolbarX + 'px';
-}
-
 }());