Refactor print preview web ui

chrome/browser/resources/print_preview/print_preview_cloud.js

 // Copyright (c) 2012 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.
 
 cr.define('cloudprint', function() {
-
-  // The URL to use to access the cloud print servers.
-  // Set by a call to setBaseURL.
-  var cloudPrintBaseURL = '';
-
-  // Headers to set for most cloud print API calls.
-  var xCloudPrintURLHeader = {'Content-Type':
-                              'application/x-www-form-urlencoded',
-                              'X-CloudPrint-Proxy': 'ChromePrintPreview'};
-
-  // Headers to set when sending multipart data to cloud print APIs.
-  // Currently only used when submitting a job.
-  var xCloudPrintFormHeader = {'Content-Type':
-        'multipart/form-data; boundary=----CloudPrintFormBoundaryjc9wuprokl8i',
-        'X-CloudPrint-Proxy': 'ChromePrintPreview'};
-
-  // The last received XSRF token.  This should be sent with each request
-  // to prevent XSRF.
-  var lastXSRFToken = '';
-
-  /**
-   * Sets the base URL to be used for communicating with cloud print
-   * servers.
-   * @param {string} cloudPrintURL The URL to use.
-   */
-  function setBaseURL(cloudPrintURL) {
-    cloudPrintBaseURL = cloudPrintURL;
-  }
-
-  /**
-   * Gets the base URL to be used for communicating with cloud print
-   * servers.
-   * @return {string} The URL.
-   */
-  function getBaseURL() {
-    return cloudPrintBaseURL;
-  }
-
-  /**
-   * Extracts the XSRF token from each response to be used in the next
-   * request.
-   * @param {XMLHttpRequest} xhr The object used to make the request.
-   * @return {string} The extracted XSRF token.
-   */
-  function extractXSRFtoken(xhr) {
-    if (xhr.status == 200) {
-      var result = JSON.parse(xhr.responseText);
-      return result['xsrf_token'];
-    } else {
-      return null;
+  'use strict';
+
+  /**
+   * API to the Google Cloud Print service.
+   *
+   * @param {string} baseUrl Base part of the Google Cloud Print service URL
+   *     with no trailing slash. For example,
+   *     'https://www.google.com/cloudprint'.
+   * @constructor
+   * @extends {cr.EventTarget}
+   */
+  function CloudPrintInterface(baseUrl) {
+    /**
+     * The base URL of the Google Cloud Print API.
+     * @type {string}
+     * @private
+     */
+    this.baseURL_ = baseUrl;
+
+    /**
+     * Last received XSRF token. Sent as a parameter in every request.
+     * @type {string}
+     * @private
+     */
+    this.xsrfToken_ = '';
+  };
+
+  /**
+   * Enumeration of events dispatched.
+   * @enum {string}
+   */
+  CloudPrintInterface.Event = {
+    ERROR: 'cloudprint.CloudPrintInterface.ERROR',
+    PRINTER_DONE: 'cloudprint.CloudPrintInterface.PRINTER_DONE',
+    SEARCH_DONE: 'cloudprint.CloudPrintInterface.SEARCH_DONE',
+    SUBMIT_DONE: 'cloudprint.CloudPrintInterface.SUBMIT_DONE'
+  };
+
+  /**
+   * Content type header value for a URL encoded HTTP request.
+   * @type {string}
+   * @private
+   */
+  CloudPrintInterface.URL_ENCODED_CONTENT_TYPE_ =
+      'application/x-www-form-urlencoded';
+
+  /**
+   * Content type header value for a multipart HTTP request.
+   * @type {string}
+   * @private
+   */
+  CloudPrintInterface.MULTIPART_CONTENT_TYPE_ =
+      'multipart/form-data; boundary=----CloudPrintFormBoundaryjc9wuprokl8i';
+
+  CloudPrintInterface.prototype = {
+    __proto__: cr.EventTarget.prototype,
+
+    /**
+     * Sends a Google Cloud Print search API request.
+     * @param {boolean} isRecent Whether to search for only recently used
+     *     printers.
+     */
+    search: function(isRecent) {
+      var params = {};
+      if (isRecent) {
+        params['q'] = '^recent';
+      }
+      this.sendRequest_('GET', 'search', params, null, this.onSearchDone_);
+    },
+
+    /**
+     * Sends a Google Cloud Print submit API request.
+     * @param {string} body Body of the HTTP post request to send.
+     */
+    submit: function(body) {
+      this.sendRequest_('POST', 'submit', null, body, this.onSubmitDone_);
+    },
+
+    /**
+     * Sends a Google Cloud Print printer API request.
+     * @param {string} printerId ID of the printer to lookup.
+     */
+    printer: function(printerId) {
+      var params = {'printerid': printerId};
+      this.sendRequest_('GET', 'printer', params, null, this.onPrinterDone_);
+    },
+
+    /**
+     * Sends a request to the Google Cloud Print API.
+     * @param {string} method HTTP method of the request.
+     * @param {string} action Google Cloud Print action to perform.
+     * @param {!Object} params HTTP parameters to include in the request.
+     * @param {string} body HTTP multi-part encoded body.
+     * @param {function(Object)} successCallback Callback to invoke when request
+     *     completes successfully.
+     */
+    sendRequest_: function(method, action, params, body, successCallback) {
+      if (!this.xsrfToken_) {
+        // TODO Should throw an error if not a read-only action or issue an
+        // xsrf token request.
+      }
+      var url = this.baseURL_ + '/' + action + '?xsrf=' + this.xsrfToken_;
+
+      if (params) {
+        for (var paramName in params) {
+          url += '&' + paramName + '=' + encodeURIComponent(params[paramName]);
+        }
+      }
+
+      var headers = {};
+      headers['X-CloudPrint-Proxy'] = 'ChromePrintPreview';
+      if (method == 'GET') {
+        headers['Content-Type'] = CloudPrintInterface.URL_ENCODED_CONTENT_TYPE_;
+      } else if (method == 'POST') {
+        headers['Content-Type'] = CloudPrintInterface.MULTIPART_CONTENT_TYPE_;
+      }
+
+      var xhr = new XMLHttpRequest();
+      xhr.onreadystatechange = this.onReadyStateChange_.bind(
+          this, xhr, successCallback.bind(this));
+      xhr.open(method, url, true);
+      xhr.withCredentials = true;
+      for (var header in headers) {
+        xhr.setRequestHeader(header, headers[header]);
+      }
+      xhr.send(body);
+    },
+
+    /**
+     * Dispatches an ERROR event with the given error message.
+     * @param {string} message Error message to include in the ERROR event.
+     * @private
+     */
+    dispatchErrorEvent_: function(message) {
+      var errorEvt = new cr.Event(CloudPrintInterface.Event.ERROR);
+      errorEvt.message = message;
+      this.dispatchEvent(errorEvt);
+    },
+
+    /**
+     * Called when the ready-state of a XML http request changes.
+     * Calls the successCallback with the result or dispatches an ERROR event.
+     * @param {XMLHttpRequest} xhr XML http request that changed.
+     * @param {function(Object)} successCallback Callback to call if the request
+     *     was successful.
+     * @private
+     */
+    onReadyStateChange_: function(xhr, successCallback) {
+      if (xhr.readyState == 4) {
+        if (xhr.status == 200) {
+          var result = JSON.parse(xhr.responseText);
+          if (result['success']) {
+            this.xsrfToken_ = result['xsrf_token'];
+            successCallback(result);
+          } else {
+            this.dispatchErrorEvent_(result['message']);
+          }
+        } else {
+          this.dispatchErrorEvent_(xhr.status + '');
+        }
+      }
+    },
+
+    /**
+     * Called when the search request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onSearchDone_: function(result) {
+      var printerListJson = result['printers'] || [];
+      var printerList = [];
+      for (var printerJson, i = 0; printerJson = printerListJson[i]; i++) {
+        try {
+          printerList.push(cloudprint.CloudDestinationParser.parse(
+              printerJson));
+        } catch (err) {
+          // TODO Handle error case
+        }
+      }
+      var isRecent = result['request']['params']['q'] == '^recent';
+      var searchDoneEvt = new cr.Event(CloudPrintInterface.Event.SEARCH_DONE);
+      searchDoneEvt.printers = printerList;
+      searchDoneEvt.isRecent = isRecent;
+      searchDoneEvt.email = result['request']['user'];
+      this.dispatchEvent(searchDoneEvt);
+    },
+
+    /**
+     * Called when the submit request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onSubmitDone_: function(result) {
+      this.dispatchEvent(new cr.Event(CloudPrintInterface.Event.SUBMIT_DONE));
+    },
+
+    /**
+     * Called when the printer request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onPrinterDone_: function(result) {
+      // TODO Better error handling here.
+      var printerJson = result['printers'][0];
+      var printer;
+      try {
+        printer = cloudprint.CloudDestinationParser.parse(printerJson);
+        printer.capabilities = cloudprint.CloudCapabilitiesParser.parse(
+            printerJson['capabilities']);
+      } catch (err) {
+        // TODO Handle error case
+        return;
+      }
+      var printerDoneEvt = new cr.Event(CloudPrintInterface.Event.PRINTER_DONE);
+      printerDoneEvt.printer = printer;
+      this.dispatchEvent(printerDoneEvt);
     }
-  }
-
-  /**
-   * Makes a request to cloud print servers.
-   * @param {string} method The HTTP method to be used.
-   * @param {string} action The cloud print API to call.
-   * @param {Array} headers Headers to send with the request.
-   * @param {string} body Body to be sent with POST requests.
-   * @param {function} callback Function to be called to process response.
-   * @param {boolean} async True if we want the request made asyncronously.
-   */
-  function sendCloudPrintRequest(method,
-                                 action,
-                                 headers,
-                                 params,
-                                 body,
-                                 callback) {
-    var xhr = new XMLHttpRequest();
-    if (callback != null) {
-      xhr.onreadystatechange = function() {
-        if (xhr.readyState == 4) {
-          var updatedXSRFToken = extractXSRFtoken(xhr);
-          if (updatedXSRFToken != null) {
-            lastXSRFToken = updatedXSRFToken;
-          }
-          callback.call(this, xhr);
-        }
-      };
-    }
-    var url = cloudPrintBaseURL + '/' + action;
-    if (params == null) {
-      params = new Array;
-    }
-    if (lastXSRFToken.length != 0) {
-      params.push('xsrf=' + lastXSRFToken);
-    }
-    if (params.length != 0) {
-      url = url + '?';
-      for (param in params) {
-        url = url + params[param] + '&';
-      }
-    }
-    xhr.open(method, url, true);
-    xhr.withCredentials = true;
-    if (headers) {
-      for (var header in headers) {
-        if (headers.hasOwnProperty(header)) {
-          xhr.setRequestHeader(header, headers[header]);
-        }
-      }
-    }
-    xhr.send(body);
-    return xhr;
-  }
-
-  /**
-   * Parse the response from the fetchPrinters call.
-   * @param {function} callback Function to be called to process response.
-   * @param {XMLHttpRequest} xhr The object used to make the request.
-   */
-  function fetchPrintersResponse(callback, xhr) {
-    if (xhr.status == 200) {
-      var searchResult = JSON.parse(xhr.responseText);
-      if (searchResult['success']) {
-        var printerList = searchResult['printers'];
-        addCloudPrinters(printerList, callback);
-        return;
-      }
-    }
-    addCloudPrinters(null, callback);
-  }
-
-  /**
-   * Retrieve the list of printers available via cloud print.
-   * @param {function} callback Function to be called to process response.
-   */
-  function fetchPrinters(callback, all) {
-   var query = 'q=^recent';
-   if (all) {
-     query = '';
-   }
-   sendCloudPrintRequest('GET',
-                         'search',
-                         xCloudPrintURLHeader,
-                         [query],
-                         null,
-                         fetchPrintersResponse.bind(this, callback));
-  }
-
-  /**
-   * Handle the response from printing to cloud print.
-   * @param {function} callback Function to be called to process response.
-   * @param {XMLHttpRequest} xhr The object used to make the request.
-   */
-  function printToCloudResponse(callback, xhr) {
-    if (xhr.status == 200) {
-      var printResult = JSON.parse(xhr.responseText);
-      if (printResult['success']) {
-        callback.call();
-      }
-    }
-    // TODO(abodenha@chromium.org) Catch and handle failures.
-  }
-
-  /**
-   * Send the current document to cloud print.
-   * @param {string} data The document to be printed.
-   * @param {function} callback Function to be called to process response.
-   */
-  function printToCloud(data, callback) {
-    // TODO(abodenha@chromium.org) Make sure we have an XSRF token before
-    // sending a submit.  Right now if the user clicks print before we
-    // complete any request we wont have an XSRF and the submit will fail.
-    sendCloudPrintRequest('POST',
-                          'submit',
-                          xCloudPrintFormHeader,
-                          null,
-                          data,
-                          printToCloudResponse.bind(this, callback));
-  }
-
-  /**
-   * Gets the JSON string used to control the behavior of the current
-   * print job.
-   * @param {Object} printer The printer object to get the ticket for.
-   * @return {string} The print ticket or null if not a cloud printer.
-   */
-  function getPrintTicketJSON(printer) {
-    if (isCloudPrint(printer)) {
-      return JSON.stringify({'capabilities':
-                            [printer.cloudPrintOptions.colorOption]});
-    } else {
-      return null;
-    }
-  }
+  };
 
   /**
    * Process the response from cloud print containing the capabilities
    * for the printer.
    * @param {function} callback Function to be called to process response.
-   * @param {Object} printer The printer object to get the capabilites for.
+   * @param {Object} printer The printer object to get the capabilities for.
    * @param {XMLHttpRequest} xhr The object used to make the request.
    */
   function updatePrinterCapsResponse(callback, printer, xhr) {
     if (xhr.status == 200) {
       var printResult = JSON.parse(xhr.responseText);
       if (printResult['success']) {
         if (!printer.cloudPrintOptions)
           printer.cloudPrintOptions = new Object;
         printer.cloudPrintOptions.capsDownloaded = true;
         printer.cloudPrintOptions.colorOption = null;
@@ skipping 17 matching lines @@
                 printer.cloudPrintOptions.colorOption.options = [opt];
                 printer.cloudPrintOptions.colorIsDefault =
                     opt.name == printer.cloudPrintOptions.colorOnOption.name;
               }
             }
           }
         }
         callback.call(this, printer);
       }
     }
-  }
+  };
 
-  /**
-   * Retrieve capabilities for a printer.
-   * @param {Object} printer The printer object to get the capabilities for.
-   * @param {function} callback Function to be called to process response.
-   */
-  function updatePrinterCaps(printer, callback) {
-    if (isCloudPrint(printer) && !printer.cloudPrintOptions.capsDownloaded) {
-      sendCloudPrintRequest('GET',
-                            'printer?printerid=' +
-                                printer.value +
-                                '&output=json',
-                            xCloudPrintURLHeader,
-                            null,
-                            null,
-                            updatePrinterCapsResponse.bind(this,
-                                                           callback,
-                                                           printer));
-    } else {
-      callback.call(this, printer);
-    }
-  }
-
-  /**
-   * @param {Object} printer The printer object to get the data for.
-   * @return {boolean} true if the printer supports color.
-   */
-  function supportsColor(printer) {
-    return isCloudPrint(printer) &&
-           printer.cloudPrintOptions.colorOption != null;
-  }
-
-  /**
-   * @param {Object} printer The printer object to get the data for.
-   * @return {boolean} true if the printer defaults to color.
-   */
-  function colorIsDefault(printer) {
-    // For now assume that unsupported color means we just don't know
-    // and assume color.
-    return !supportsColor(printer) ||
-        (isCloudPrint(printer) && printer.cloudPrintOptions.colorIsDefault);
-  }
-
-  /**
-   * Turn color on or off for the specified printer.
-   * @param {Object} printer The printer object to turn color on/off for.
-   * @param {boolean} color True to turn color on.
-   */
-  function setColor(printer, color) {
-    if (isCloudPrint(printer) && supportsColor(printer)) {
-      if (color) {
-        printer.cloudPrintOptions.colorOption.options =
-            [printer.cloudPrintOptions.colorOnOption];
-      } else {
-        printer.cloudPrintOptions.colorOption.options =
-            [printer.cloudPrintOptions.colorOffOption];
-      }
-    }
-  }
-
-  /**
-   * Creates a cloud print printer and sets it as the default printer.
-   * @param {string} printer_name The name of the printer to create.
-   * @param {Object} cloud_print_data Data to be stored in cloudPrintOptions.
-   * @param {function} add_callback The callback to be called to add the new
-   *     printer to the print preview UI.
-   * @param {function} update_caps_callback The callback to be called to update
-   *     capabilities on the new printer.
-   */
-  function setDefaultPrinter(printer_name,
-                             cloud_print_data,
-                             add_callback,
-                             update_caps_callback) {
-    var printer = addCloudPrinters([JSON.parse(cloud_print_data)],
-                                   add_callback);
-    if (printer)
-      update_caps_callback(printer);
-  }
-
-  /**
-   * Returns the data necessary to serialize a cloud print printer.
-   * @param {Object} printer The printer object to get data for.
-   * @return {string} A JSON string that can be used to recreate the
-   *     cloud print portion of the printer object, or and empty string if
-   *     there is no data to save.
-   */
-  function getData(printer) {
-    if (isCloudPrint(printer)) {
-      return JSON.stringify(printer.cloudPrintOptions);
-    } else {
-      return '';
-    }
-  }
-
-  /**
-   * Test if a printer is a cloud print printer.
-   * @param {Object} printer The printer to test.
-   * @return {boolean} true iff the printer is a cloud print printer.
-   */
-  function isCloudPrint(printer) {
-    return printer && printer.cloudPrintOptions != null;
-  }
-
-  /**
-   * Mark a printer as a cloud print printer and record its name and id.
-   * @param {Object} printer The printer to mark.
-   * @param {string} name The user visible name of the printer.
-   * @param {string} id The id of the printer used by cloud print to
-   *     identify it.
-   */
-  function setCloudPrint(printer, name, id) {
-    if (!printer.cloudPrintOptions) {
-      printer.cloudPrintOptions = new Object;
-    }
-    printer.cloudPrintOptions.name = name;
-    printer.cloudPrintOptions.id = id;
-  }
-
-  /**
-   * Test if a particular cloud printer has already been added to the
-   * printer dropdown.
-   * @param {string} id A unique value to track this printer.
-   * @return {boolean} True if |id| has previously been passed to
-   *     trackCloudPrinterAdded.
-   */
-  function cloudPrinterAlreadyAdded(id) {
-    return addedCloudPrinters[id];
-  }
-
-  /**
-   * Test if a particular printer has already been added to the printers
-   * dropdown.  Records it if not.
-   * @param {string} id A unique value to track this printer.
-   * @return {boolean} False if adding this printer would exceed
-   *     |maxCloudPrinters|.
-   */
-  function trackCloudPrinterAdded(id) {
-    if (Object.keys(addedCloudPrinters).length < maxCloudPrinters) {
-      addedCloudPrinters[id] = true;
-      return true;
-    } else {
-      return false;
-    }
-  }
-
-  /**
-   * Add cloud printers to the list drop down.
-   * Called from the cloudprint object on receipt of printer information from
-   * the cloud print server.
-   * @param {Array} printers Array of printer info objects.
-   * @return {Object} The currently selected printer.
-   */
-  function addCloudPrinters(printers, addDestinationListOptionAtPosition) {
-    var isFirstPass = false;
-    var printerList = $('printer-list');
-
-    if (firstCloudPrintOptionPos == lastCloudPrintOptionPos) {
-      isFirstPass = true;
-      // Remove empty entry added by setDefaultPrinter.
-      if (printerList[0] && printerList[0].textContent == '')
-        printerList.remove(0);
-    }
-    if (printers != null) {
-      for (var i = 0; i < printers.length; i++) {
-        if (!cloudPrinterAlreadyAdded(printers[i]['id'])) {
-          if (!trackCloudPrinterAdded(printers[i]['id'])) {
-            break;
-          }
-          if (printers[i]['displayName'] && printers[i]['displayName'] != '')
-            var name = printers[i]['displayName'];
-          else
-            var name = printers[i]['name'];
-
-          var option = addDestinationListOptionAtPosition(
-              lastCloudPrintOptionPos++,
-              name,
-              printers[i]['id'],
-              name == defaultOrLastUsedPrinterName,
-              false,
-              false);
-          cloudprint.setCloudPrint(option,
-                                   name,
-                                   printers[i]['id']);
-        }
-      }
-    } else {
-      if (!cloudPrinterAlreadyAdded(SIGN_IN)) {
-        addDestinationListOptionAtPosition(lastCloudPrintOptionPos++,
-                                           localStrings.getString('signIn'),
-                                           SIGN_IN,
-                                           false,
-                                           false,
-                                           false);
-        trackCloudPrinterAdded(SIGN_IN);
-        chrome.send('signIn');
-      }
-    }
-    var selectedPrinter = printerList.selectedIndex;
-    if (selectedPrinter < 0)
-      return null;
-    return printerList.options[selectedPrinter];
-  }
-
+  // Export
   return {
-    addCloudPrinters: addCloudPrinters,
-    colorIsDefault: colorIsDefault,
-    fetchPrinters: fetchPrinters,
-    getBaseURL: getBaseURL,
-    getData: getData,
-    getPrintTicketJSON: getPrintTicketJSON,
-    isCloudPrint: isCloudPrint,
-    printToCloud: printToCloud,
-    setBaseURL: setBaseURL,
-    setCloudPrint: setCloudPrint,
-    setColor: setColor,
-    setDefaultPrinter: setDefaultPrinter,
-    supportsColor: supportsColor,
-    updatePrinterCaps: updatePrinterCaps
+    CloudPrintInterface: CloudPrintInterface
   };
 });