Refactored web-app

remoting/webapp/me2mom/host_screen.js

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview
+ * Functions related to the 'host screen' for Chromoting.
+ */
+
+'use strict';
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+
+(function() {
+
+/**
+ * @type {boolean} Whether or not the last share was cancelled by the user.
+ *     This controls what screen is shown when the host plugin signals
+ *     completion.
+ */
+var lastShareWasCancelled_ = false;
+
+/**
+ * Start a host session. This is the main entry point for the host screen,
+ * called directly from the onclick action of a button on the home screen.
+ */
+remoting.tryShare = function() {
+  remoting.debug.log('Attempting to share...');
+  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;
+  }
+
+  onNatTraversalPolicyChanged_(true);  // Hide warning by default.
+  remoting.setMode(remoting.AppMode.HOST_WAITING_FOR_CODE);
+  document.getElementById('cancel-button').disabled = false;
+  disableTimeoutCountdown_();
+
+  var div = document.getElementById('host-plugin-container');
+  remoting.hostSession = new remoting.HostSession();
+  remoting.hostSession.createPluginAndConnect(
+      document.getElementById('host-plugin-container'),
+      /** @type {string} */(remoting.oauth2.getCachedEmail()),
+      remoting.oauth2.getAccessToken(),
+      onNatTraversalPolicyChanged_,
+      onHostStateChanged_,
+      logDebugInfo_);
+};
+
+/**
+ * Callback for the host plugin to notify the web app of state changes.
+ * @param {remoting.HostSession.State} state The new state of the plugin.
+ */
+function onHostStateChanged_(state) {
+  if (state == remoting.HostSession.State.STARTING) {
+    // Nothing to do here.
+    remoting.debug.log('Host plugin state: STARTING');
+
+  } else if (state == remoting.HostSession.State.REQUESTED_ACCESS_CODE) {
+    // Nothing to do here.
+    remoting.debug.log('Host plugin state: REQUESTED_ACCESS_CODE');
+
+  } else if (state == remoting.HostSession.State.RECEIVED_ACCESS_CODE) {
+    remoting.debug.log('Host plugin state: RECEIVED_ACCESS_CODE');
+    var accessCode = remoting.hostSession.getAccessCode();
+    var accessCodeDisplay = document.getElementById('access-code-display');
+    accessCodeDisplay.innerText = '';
+    // Display the access code in groups of four digits for readability.
+    var kDigitsPerGroup = 4;
+    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);
+    }
+    accessCodeExpiresIn_ = remoting.hostSession.getAccessCodeLifetime();
+    if (accessCodeExpiresIn_ > 0) {  // Check it hasn't expired.
+      accessCodeTimerId_ = setInterval(
+          'remoting.decrementAccessCodeTimeout_()', 1000);
+      timerRunning_ = true;
+      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 == remoting.HostSession.State.CONNECTED) {
+    remoting.debug.log('Host plugin state: CONNECTED');
+    var element = document.getElementById('host-shared-message');
+    var client = remoting.hostSession.getClient();
+    l10n.localizeElement(element, client);
+    remoting.setMode(remoting.AppMode.HOST_SHARED);
+    disableTimeoutCountdown_();
+
+  } else if (state == remoting.HostSession.State.DISCONNECTING) {
+    remoting.debug.log('Host plugin state: DISCONNECTING');
+
+  } else if (state == remoting.HostSession.State.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 (lastShareWasCancelled_) {
+        remoting.setMode(remoting.AppMode.HOME);
+      } else {
+        remoting.setMode(remoting.AppMode.HOST_SHARE_FINISHED);
+      }
+    }
+    remoting.hostSession.removePlugin();
+
+  } else if (state == remoting.HostSession.State.ERROR) {
+    remoting.debug.log('Host plugin state: ERROR');
+    showShareError_(/*i18n-content*/'ERROR_GENERIC');
+  } else {
+    remoting.debug.log('Unknown state -> ' + state);
+  }
+}
+
+/**
+ * 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 logDebugInfo_(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.
+ */
+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);
+}
+
+/**
+ * Cancel an active or pending share operation.
+ *
+ * @return {void} Nothing.
+ */
+remoting.cancelShare = function() {
+  remoting.debug.log('Canceling share...');
+  remoting.lastShareWasCancelled = true;
+  try {
+    remoting.hostSession.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');
+  }
+  disableTimeoutCountdown_();
+};
+
+/**
+ * @type {boolean} Whether or not the access code timeout countdown is running.
+ */
+var timerRunning_ = false;
+
+/**
+ * @type {number} The id of the access code expiry countdown timer.
+ */
+var accessCodeTimerId_ = 0;
+
+/**
+ * @type {number} The number of seconds until the access code expires.
+ */
+var accessCodeExpiresIn_ = 0;
+
+/**
+ * The timer callback function, which needs to be visible from the global
+ * namespace.
+ */
+remoting.decrementAccessCodeTimeout_ = function() {
+  --accessCodeExpiresIn_;
+  updateAccessCodeTimeoutElement_();
+};
+
+/**
+ * Stop the access code timeout countdown if it is running.
+ */
+function disableTimeoutCountdown_() {
+  if (timerRunning_) {
+    clearInterval(accessCodeTimerId_);
+    timerRunning_ = false;
+    updateTimeoutStyles_();
+  }
+}
+
+/**
+ * Constants controlling the access code timer countdown display.
+ */
+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 (timerRunning_) {
+    if (accessCodeExpiresIn_ <= 0) {
+      remoting.cancelShare();
+      return false;
+    }
+    if (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 =
+      (accessCodeExpiresIn_ > ACCESS_CODE_TIMER_DISPLAY_THRESHOLD_) ||
+      !timerRunning_;
+  return true;
+}
+
+/**
+ * Update the text and appearance of the access code timeout element to
+ * reflect the time remaining.
+ */
+function updateAccessCodeTimeoutElement_() {
+  var pad = (accessCodeExpiresIn_ < 10) ? '0:0' : '0:';
+  l10n.localizeElement(document.getElementById('seconds-remaining'),
+                       pad + accessCodeExpiresIn_);
+  if (!updateTimeoutStyles_()) {
+    disableTimeoutCountdown_();
+  }
+}
+
+/**
+ * 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;
+}
+
+}());