Refactored web-app

remoting/webapp/me2mom/client_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 'client screen' for Chromoting.
+ */
+
+'use strict';
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+
+/** @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'
+};
+
+(function() {
+
+/**
+ * @type {boolean} Whether or not the plugin should scale itself.
+ */
+remoting.scaleToFit = false;

[garykac, 2011/10/27 22:32:39]

nit: I assume these should have underscores at the end.

[Jamie, 2011/10/27 22:51:37]

No, anything exported to the remoting namespace is public and doesn't have
underscores. Now, whether or not they would need to be exported in a perfect
system is another question.

+
+/**
+ * @type {remoting.ClientSession} The client session object, set once the
+ *     access code has been successfully verified.
+ */
+remoting.clientSession = null;
+
+/**
+ * @type {string} The normalized access code.
+ */
+remoting.accessCode = '';
+
+/**
+ * @type {string} The host's JID, returned by the server.
+ */
+remoting.hostJid = '';
+
+/**
+ * @type {string} The host's public key, returned by the server.
+ */
+remoting.hostPublicKey = '';
+
+/**
+ * @type {XMLHttpRequest} The XHR object corresponding to the current
+ *     support-hosts request, if there is one outstanding.
+ */
+remoting.supportHostsXhr_ = null;
+
+/**
+ * Entry point for the 'connect' functionality. This function checks for the
+ * existence of an OAuth2 token, and either requests one asynchronously, or
+ * calls through directly to tryConnectWithAccessToken_.
+ */
+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;
+      }
+      tryConnectWithAccessToken_();
+    });
+  } else {
+    tryConnectWithAccessToken_();
+  }
+}
+
+/**
+ * Cancel an incomplete connect operation.
+ *
+ * @return {void} Nothing.
+ */
+remoting.cancelConnect = function() {
+  if (remoting.supportHostsXhr_) {
+    remoting.supportHostsXhr_.abort();
+    remoting.supportHostsXhr_ = null;
+  }
+  if (remoting.clientSession) {
+    remoting.clientSession.removePlugin();
+    remoting.clientSession = null;
+  }
+  remoting.setMode(remoting.AppMode.HOME);
+}
+
+/**
+ * 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.clientSession.updateDimensions();
+}
+
+/**
+ * Update the remoting client layout in response to a resize event.
+ *
+ * @return {void} Nothing.
+ */
+remoting.onResize = function() {
+  if (remoting.clientSession)
+    remoting.clientSession.onWindowSizeChanged();
+  recenterToolbar_();
+}
+
+/**
+ * Disconnect the remoting client.
+ *
+ * @return {void} Nothing.
+ */
+remoting.disconnect = function() {
+  if (remoting.clientSession) {
+    remoting.clientSession.disconnect();
+    remoting.clientSession = null;
+    remoting.debug.log('Disconnected.');
+    remoting.setMode(remoting.AppMode.CLIENT_SESSION_FINISHED);
+  }
+}
+
+/**
+ * Second stage of the 'connect' functionality. Once an access token is
+ * available, load the WCS widget asynchronously and call through to
+ * tryConnectWithWcs_ when ready.
+ */
+function tryConnectWithAccessToken_() {
+  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,
+      tryConnectWithWcs_);
+}
+
+/**
+ * Final stage of the 'connect' functionality, called when the wcs widget has
+ * been loaded, or on error.
+ *
+ * @param {boolean} success True if the script was loaded successfully.
+ */
+function tryConnectWithWcs_(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.
+    var kSupportIdLen = 7;
+    var kHostSecretLen = 5;
+    var kAccessCodeLen = kSupportIdLen + kHostSecretLen;
+    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);
+  }
+}
+
+/**
+ * Callback function called when the state of the client plugin changes. The
+ * current state is available via the |state| member variable.
+ *
+ * @param {number} oldState The previous state of the plugin.
+ */
+// TODO(jamiewalch): Make this pass both the current and old states to avoid
+// race conditions.
+function onClientStateChange_(oldState) {
+  if (!remoting.clientSession) {
+    // 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.clientSession.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.oauth2.getCachedEmail());
+
+  } else if (state == remoting.ClientSession.State.INITIALIZING) {
+    remoting.debug.log('Initializing connection');
+
+  } else if (state == remoting.ClientSession.State.CONNECTED) {
+    if (remoting.clientSession) {
+      remoting.setMode(remoting.AppMode.IN_SESSION);
+      recenterToolbar_();
+      showToolbarPreview_();
+      updateStatistics_();
+    }
+
+  } else if (state == remoting.ClientSession.State.CLOSED) {
+    if (oldState == remoting.ClientSession.State.CONNECTED) {
+      remoting.clientSession.removePlugin();
+      remoting.clientSession = 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.clientSession.error);
+    if (remoting.clientSession.error ==
+        remoting.ClientSession.ConnectionError.HOST_IS_OFFLINE) {
+      showConnectError_(remoting.ClientError.HOST_IS_OFFLINE);
+    } else if (remoting.clientSession.error ==
+               remoting.ClientSession.ConnectionError.SESSION_REJECTED) {
+      showConnectError_(remoting.ClientError.INVALID_ACCESS_CODE);
+    } else if (remoting.clientSession.error ==
+               remoting.ClientSession.ConnectionError.INCOMPATIBLE_PROTOCOL) {
+      showConnectError_(remoting.ClientError.INCOMPATIBLE_PROTOCOL);
+    } else if (remoting.clientSession.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);
+  }
+}
+
+/**
+ * Create the client session object and initiate the connection.
+ *
+ * @return {void} Nothing.
+ */
+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.clientSession =
+      new remoting.ClientSession(
+          remoting.hostJid, remoting.hostPublicKey,
+          remoting.accessCode,
+          /** @type {string} */ (remoting.oauth2.getCachedEmail()),
+          onClientStateChange_);
+  /** @param {string} token The auth token. */
+  var createPluginAndConnect = function(token) {
+    remoting.clientSession.createPluginAndConnect(
+        document.getElementById('session-mode'),
+        token);
+  };
+  remoting.oauth2.callWithToken(createPluginAndConnect);
+}
+
+/**
+ * Show a client-side error message.
+ *
+ * @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.clientSession) {
+    remoting.clientSession.disconnect();
+    remoting.clientSession = null;
+  }
+  remoting.setMode(remoting.AppMode.CLIENT_CONNECT_FAILED);
+}
+
+/**
+ * Parse the response from the server to a request to resolve a support id.
+ *
+ * @param {XMLHttpRequest} xhr The XMLHttpRequest object.
+ * @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);
+}
+
+/**
+ * Normalize the access code entered by the user.
+ *
+ * @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, '');
+}
+
+/**
+ * Initiate a request to the server to resolve a support ID.
+ *
+ * @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);
+}
+
+/**
+ * Timer callback to update the statistics panel.
+ */
+function updateStatistics_() {
+  if (!remoting.clientSession ||
+      remoting.clientSession.state != remoting.ClientSession.State.CONNECTED) {
+    return;
+  }
+  remoting.debug.updateStatistics(remoting.clientSession.stats());
+  // Update the stats once per second.
+  window.setTimeout(updateStatistics_, 1000);
+}
+
+/**
+ * Force-show the tool-bar for three seconds to aid discoverability.
+ */
+function showToolbarPreview_() {
+  var toolbar = document.getElementById('session-toolbar');
+  addClass(toolbar, 'toolbar-preview');
+  window.setTimeout(removeClass, 3000, toolbar, 'toolbar-preview');
+}
+
+/**
+ * Update the horizontal position of the tool-bar to center it.
+ */
+function recenterToolbar_() {
+  var toolbar = document.getElementById('session-toolbar');
+  var toolbarX = (window.innerWidth - toolbar.clientWidth) / 2;
+  toolbar.style['left'] = toolbarX + 'px';
+}
+
+
+}());