Initial support for cloudprint in print preview

chrome/browser/resources/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() {
+
+  var cloudPrintBaseURL = '';
+
+  // Sets the base URL to be used for communicating with cloud print
+  // servers.
+  function setBaseURL(cloudPrintURL) {
+    cloudPrintBaseURL = cloudPrintURL;
+  }
+
+  // Gets the base URL to be used for communicating with cloud print
+  // servers.
+  function getBaseURL() {
+    return cloudPrintBaseURL;
+  }
+
+  // Makes a request to cloud print servers.
+  function sendCloudPrintRequest(method,
+                                 action,
+                                 headers,
+                                 body,
+                                 callback,
+                                 async) {
+    var xhr = new XMLHttpRequest();
+    if (callback != null) {
+      xhr.onreadystatechange = function() {
+        if (xhr.readyState == 4) {
+          callback.call(this, xhr);
+        }
+      };
+    }
+    var url = cloudPrintBaseURL + '/' + action
+    xhr.open(method, url, async);
+    xhr.setRequestHeader("Content-Type",
+        "multipart/form-data; boundary=----CloudPrintFormBoundaryjc9wuprokl8i");
+    if (headers) {
+      for (var header in headers) {
+        if (headers.hasOwnProperty(header)) {
+          xhr.setRequestHeader(header, headers[header]);
+        }
+      }
+    }
+    xhr.send(body);
+    return xhr;
+  }
+
+  // Retrieve the list of printers available via cloud print.
+  function fetchPrinters(callback) {
+    try {
+      var xhr = sendCloudPrintRequest('POST',
+                                    'search',
+                                    {'Content-Type':
+                                     'application/x-www-form-urlencoded',
+                                     'X-CloudPrint-Proxy':
+                                     'ChromePrintPreview'},
+                                    '',
+                                    null,
+                                    false);
+      var searchResult = JSON.parse(xhr.responseText);
+      if (searchResult['success']) {
+        var printerList = searchResult['printers'];
+        callback.call(this, printerList);
+      }
+    } catch (err) {
+      callback.call(this, null);
+    }
+  }
+
+  // Handle the response from printing to cloud print.
+  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.
+  function printToCloud(data, callback) {
+    sendCloudPrintRequest('POST',
+                          'submit',
+                          {'X-CloudPrint-Proxy': 'ChromePrintPreview'},
+                          data,
+                          printToCloudResponse.bind(this, callback),
+                          true);
+  }
+
+  // Gets the JSON string used to control the behavior of the current
+  // print job.
+  function getPrintTicketJSON(printer) {
+    return JSON.stringify({'capabilities':
+                          [printer.cloudprintOptions.colorOption]});
+  }
+
+  // Process the response from cloud print containing the capabilities
+  // for the printer.
+  function updatePrinterCapsResponse(callback, printer, xhr) {
+    if (xhr.status == 200) {
+      var printResult = JSON.parse(xhr.responseText);
+      if (printResult['success']) {
+        printer.cloudprintOptions = new Object;
+        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.
+  function updatePrinterCaps(printer, callback) {
+    sendCloudPrintRequest('GET',
+                          'printer?printerid=' + printer.value + '&output=json',
+                          {'X-CloudPrint-Proxy': 'ChromePrintPreview'},

[sanjeevr, 2011/06/10 18:13:48]

You should probably define a constant for header values like
'ChromePrintPreview'.

[Albert Bodenhamer, 2011/06/10 23:13:45]

Done.

+                          null,
+                          updatePrinterCapsResponse.bind(this,
+                                                         callback,
+                                                         printer),
+                          true);
+  }
+
+  // Returns true if the printer supports color.
+  function supportsColor(printer) {
+    return printer.cloudprintOptions.colorOption != null;
+  }
+
+  // Returns true if the printer has color enabled by default.
+  function colorIsDefault(printer) {
+    return printer.cloudprintOptions.colorIsDefault;
+  }
+
+  // Turn color on or off for the specified printer.
+  function setColor(printer, color) {
+    if (color) {
+      printer.cloudprintOptions.colorOption.options =
+          [printer.cloudprintOptions.colorOnOption];
+    } else {
+      printer.cloudprintOptions.colorOption.options =
+          [printer.cloudprintOptions.colorOffOption];
+    }
+  }
+
+  return {
+    colorIsDefault: colorIsDefault,
+    fetchPrinters: fetchPrinters,
+    getPrintTicketJSON: getPrintTicketJSON,
+    getBaseURL: getBaseURL,
+    supportsColor: supportsColor,
+    printToCloud: printToCloud,
+    setBaseURL: setBaseURL,
+    setColor: setColor,
+    updatePrinterCaps: updatePrinterCaps
+  };
+});