Revert of Remove NPAPI plugin from chromoting webapp.

remoting/webapp/host_dispatcher.js

 // Copyright 2013 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
  * This class provides an interface between the HostController and either the
- * NativeMessaging Host.
+ * NativeMessaging Host or the Host NPAPI plugin, depending on whether or not
+ * NativeMessaging is supported. Since the test for NativeMessaging support is
+ * asynchronous, this class stores any requests on a queue, pending the result
+ * of the test.
+ * Once the test is complete, the pending requests are performed on either the
+ * NativeMessaging host, or the NPAPI plugin.
+ *
+ * If necessary, the HostController is instructed (via a callback) to
+ * instantiate the NPAPI plugin, and return a reference to it here.
  */
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /**
  * @constructor
+ * @param {function():remoting.HostPlugin} createPluginCallback Callback to
+ *     instantiate the NPAPI plugin when NativeMessaging is determined to be
+ *     unsupported.
  */
-remoting.HostDispatcher = function() {
+remoting.HostDispatcher = function(createPluginCallback) {
   /** @type {remoting.HostNativeMessaging} @private */
   this.nativeMessagingHost_ = new remoting.HostNativeMessaging();
 
+  /** @type {remoting.HostPlugin} @private */
+  this.npapiHost_ = null;
+
   /** @type {remoting.HostDispatcher.State} @private */
   this.state_ = remoting.HostDispatcher.State.UNKNOWN;
 
   /** @type {Array.<function()>} @private */
   this.pendingRequests_ = [];
 
+  /** @type {function():remoting.HostPlugin} @private */
+  this.createPluginCallback_ = createPluginCallback;
+
   this.tryToInitialize_();
 }
 
 /** @enum {number} */
 remoting.HostDispatcher.State = {
   UNKNOWN: 0,
   NATIVE_MESSAGING: 1,
-  NOT_INSTALLED: 2
+  NPAPI: 2,
+  NOT_INSTALLED: 3
 };
 
 remoting.HostDispatcher.prototype.tryToInitialize_ = function() {
   /** @type {remoting.HostDispatcher} */
   var that = this;
 
   if (this.state_ != remoting.HostDispatcher.State.UNKNOWN)
     return;
 
   function sendPendingRequests() {
     var pendingRequests = that.pendingRequests_;
     that.pendingRequests_ = [];
     for (var i = 0; i < pendingRequests.length; i++) {
       pendingRequests[i]();
     }
   }
 
   function onNativeMessagingInit() {
     that.state_ = remoting.HostDispatcher.State.NATIVE_MESSAGING;
     sendPendingRequests();
   }
 
   function onNativeMessagingFailed(error) {
-    that.state_ = remoting.HostDispatcher.State.NOT_INSTALLED;
+    that.npapiHost_ = that.createPluginCallback_();
+
+    that.state_ = that.npapiHost_ ? remoting.HostDispatcher.State.NPAPI
+                                  : remoting.HostDispatcher.State.NOT_INSTALLED;
     sendPendingRequests();
   }
 
   this.nativeMessagingHost_.initialize(onNativeMessagingInit,
                                        onNativeMessagingFailed);
 };
 
 /**
+ * @return {remoting.HostPlugin}
+ */
+remoting.HostDispatcher.prototype.getNpapiHost = function() {
+  return this.npapiHost_;
+}
+
+/**
  * @param {remoting.HostController.Feature} feature The feature to test for.
  * @param {function(boolean):void} onDone
  * @return {void}
  */
 remoting.HostDispatcher.prototype.hasFeature = function(
     feature, onDone) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.hasFeature.bind(this, feature, onDone));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       onDone(this.nativeMessagingHost_.hasFeature(feature));
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      // If this is an old NPAPI plugin that doesn't list supportedFeatures,
+      // assume it is an old plugin that doesn't support any new feature.
+      var supportedFeatures = [];
+      if (typeof(this.npapiHost_.supportedFeatures) == 'string') {
+        supportedFeatures = this.npapiHost_.supportedFeatures.split(' ');
+      }
+      onDone(supportedFeatures.indexOf(feature) >= 0);
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onDone(false);
       break;
   }
 };
 
 /**
  * @param {function(string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getHostName = function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getHostName.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getHostName(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getHostName(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {string} hostId
  * @param {string} pin
  * @param {function(string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getPinHash =
     function(hostId, pin, onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getPinHash.bind(this, hostId, pin, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getPinHash(hostId, pin, onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getPinHash(hostId, pin, onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(string, string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.generateKeyPair = function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.generateKeyPair.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.generateKeyPair(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.generateKeyPair(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {Object} config
  * @param {function(remoting.HostController.AsyncResult):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.updateDaemonConfig =
     function(config, onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.updateDaemonConfig.bind(this, config, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.updateDaemonConfig(config, onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.updateDaemonConfig(JSON.stringify(config), onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(Object):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getDaemonConfig = function(onDone, onError) {
+  /**
+   * Converts the config string from the NPAPI plugin to an Object, to pass to
+   * |onDone|.
+   * @param {string} configStr
+   * @return {void}
+   */
+  function callbackForNpapi(configStr) {
+    var config = jsonParseSafe(configStr);
+    if (typeof(config) != 'object') {
+      onError(remoting.Error.UNEXPECTED);
+    } else {
+      onDone(/** @type {Object} */ (config));
+    }
+  }
+
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getDaemonConfig.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getDaemonConfig(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getDaemonConfig(callbackForNpapi);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onDone({});
       break;
   }
 };
 
 /**
  * @param {function(string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getDaemonVersion = function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getDaemonVersion.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       onDone(this.nativeMessagingHost_.getDaemonVersion());
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getDaemonVersion(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(boolean, boolean, boolean):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getUsageStatsConsent =
     function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getUsageStatsConsent.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getUsageStatsConsent(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getUsageStatsConsent(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
+      break;
+  }
+};
+
+/**
+ * This function installs the host using the NPAPI plugin and should only be
+ * called on Windows.
+ *
+ * @param {function(remoting.HostController.AsyncResult):void} onDone
+ * @param {function(remoting.Error):void} onError
+ * @return {void}
+ */
+remoting.HostDispatcher.prototype.installHost = function(onDone, onError) {
+  switch (this.state_) {
+    case remoting.HostDispatcher.State.UNKNOWN:
+      this.pendingRequests_.push(this.installHost.bind(this, onDone, onError));
+      break;
+    case remoting.HostDispatcher.State.NATIVE_MESSAGING:
+      // Host already installed, no action needed.
+      onDone(remoting.HostController.AsyncResult.OK);
+      break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.installHost(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
+    case remoting.HostDispatcher.State.NOT_INSTALLED:
+      onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {Object} config
  * @param {boolean} consent
  * @param {function(remoting.HostController.AsyncResult):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.startDaemon =
     function(config, consent, onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.startDaemon.bind(this, config, consent, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.startDaemon(config, consent, onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.startDaemon(JSON.stringify(config), consent, onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(remoting.HostController.AsyncResult):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.stopDaemon = function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(this.stopDaemon.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.stopDaemon(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.stopDaemon(onDone);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(remoting.HostController.State):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
@@ skipping 17 matching lines @@
 remoting.HostDispatcher.prototype.getDaemonStateInternal_ =
     function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getDaemonStateInternal_.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getDaemonState(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      // Call the callback directly, since NPAPI exposes the state directly as
+      // a field member, rather than an asynchronous method.
+      var state = this.npapiHost_.daemonState;
+      if (state === undefined) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      } else {
+        onDone(state);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onDone(remoting.HostController.State.NOT_INSTALLED);
       break;
   }
 };
 
 /**
  * @param {function(Array.<remoting.PairedClient>):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getPairedClients = function(onDone, onError) {
+  /**
+   * Converts the JSON string from the NPAPI plugin to Array.<PairedClient>, to
+   * pass to |onDone|.
+   * @param {string} pairedClientsJson
+   * @return {void}
+   */
+  function callbackForNpapi(pairedClientsJson) {
+    var pairedClients = remoting.PairedClient.convertToPairedClientArray(
+        jsonParseSafe(pairedClientsJson));
+    if (pairedClients != null) {
+      onDone(pairedClients);
+    } else {
+      onError(remoting.Error.UNEXPECTED);
+    }
+  }
+
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getPairedClients.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getPairedClients(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.getPairedClients(callbackForNpapi);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * The pairing API returns a boolean to indicate success or failure, but
  * the JS API is defined in terms of onDone and onError callbacks. This
  * function converts one to the other.
@@ skipping 21 matching lines @@
   var callback =
       remoting.HostDispatcher.runCallback_.bind(null, onDone, onError);
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
         this.clearPairedClients.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.clearPairedClients(callback, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.clearPairedClients(callback);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {string} client
  * @param {function():void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.deletePairedClient =
     function(client, onDone, onError) {
   var callback =
       remoting.HostDispatcher.runCallback_.bind(null, onDone, onError);
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
         this.deletePairedClient.bind(this, client, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.deletePairedClient(client, callback, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      try {
+        this.npapiHost_.deletePairedClient(client, callback);
+      } catch (err) {
+        onError(remoting.Error.MISSING_PLUGIN);
+      }
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {function(string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getHostClientId =
     function(onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getHostClientId.bind(this, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getHostClientId(onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      // The NPAPI plugin is packaged with the webapp, not the host, so it
+      // doesn't have access to the API keys baked into the installed host.
+      onError(remoting.Error.UNEXPECTED);
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
 
 /**
  * @param {string} authorizationCode
  * @param {function(string, string):void} onDone
  * @param {function(remoting.Error):void} onError
  * @return {void}
  */
 remoting.HostDispatcher.prototype.getCredentialsFromAuthCode =
     function(authorizationCode, onDone, onError) {
   switch (this.state_) {
     case remoting.HostDispatcher.State.UNKNOWN:
       this.pendingRequests_.push(
           this.getCredentialsFromAuthCode.bind(
               this, authorizationCode, onDone, onError));
       break;
     case remoting.HostDispatcher.State.NATIVE_MESSAGING:
       this.nativeMessagingHost_.getCredentialsFromAuthCode(
           authorizationCode, onDone, onError);
       break;
+    case remoting.HostDispatcher.State.NPAPI:
+      // The NPAPI plugin is packaged with the webapp, not the host, so it
+      // doesn't have access to the API keys baked into the installed host.
+      onError(remoting.Error.UNEXPECTED);
+      break;
     case remoting.HostDispatcher.State.NOT_INSTALLED:
       onError(remoting.Error.MISSING_PLUGIN);
       break;
   }
 };
+
+/**
+ * Returns true if the NPAPI plugin is being used.
+ * @return {boolean}
+ */
+remoting.HostDispatcher.prototype.usingNpapiPlugin = function() {
+  return this.state_ == remoting.HostDispatcher.State.NPAPI;
+}