Initial support for cloudprint in print preview

chrome/browser/resources/print_preview/print_preview_cloud.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.
+
+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;
+    }
+  }
+
+  /**
+   * 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'];
+        callback.call(this, printerList, false);
+      } else {
+        callback.call(this, null, false);
+      }
+    } else {
+      callback.call(this, null, false);
+    }
+  }
+
+  /**
+   * 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 {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;
+        printer.cloudPrintOptions.colorIsDefault = false;
+        var detailedCapabilities = printResult.printers[0].capabilities;
+        for (var capability in detailedCapabilities) {
+          var cap = detailedCapabilities[capability];
+          if (cap.name == 'ns1:Colors') {
+            printer.cloudPrintOptions.colorOption = new Object;
+            printer.cloudPrintOptions.colorOption.name = cap.name;
+            printer.cloudPrintOptions.colorOption.type = cap.type;
+            for (var option in cap.options) {
+              var opt = cap.options[option];
+              if (opt.name == "Color") {
+                printer.cloudPrintOptions.colorOnOption = opt;
+              }
+              if (opt.name == "Grey_K") {
+                printer.cloudPrintOptions.colorOffOption = opt;
+              }
+              if (opt.default) {
+                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) {
+    return 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 = add_callback([JSON.parse(cloud_print_data)], false);
+    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
+   *                  an 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;
+  }
+
+  return {
+    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
+  };
+});