Print Preview: Hook up the print button to initiate printing without displaying a print dialog.

chrome/browser/resources/print_preview.js

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
 var localStrings = new LocalStrings();
 var hasPDFPlugin = true;
 var expectedPageCount = 0;
 
 /**
  * Window onload handler, sets up the page.
  */
 function load() {
-  $('print-button').addEventListener('click', function(e) {
-    chrome.send('print');
-  });
+  $('print-button').addEventListener('click', printFile);
+
   $('cancel-button').addEventListener('click', function(e) {
     window.close();
   });
 
   chrome.send('getPrinters');
 };
 
 /**
+ * Page range text validation.
+ * Returns true if |printFromText| and |printToText| are valid page numbers.
+ * TODO (kmadhusu): Get the expected page count and validate the page range
+ * with total number of pages.
+ */
+function isValidPageRange(printFromText, printToText) {
+  var numericExp = /^[0-9]+$/;
+  if (numericExp.test(printFromText) && numericExp.test(printToText)) {
+    var printFrom = Number(printFromText);
+    var printTo = Number(printToText);
+    if (printFrom <= printTo && printFrom != 0 && printTo != 0)
+      return true;
+  }
+  return false;
+}
+
+/**
+ * Parse page range text.
+ * Eg: If page range is specified as '1-3,7-9,8'. Create an array with three
+ * elements. Each array element contains the range information.
+ * [{from:1, to:3}, {from:7, to:9}, {from:8, to:8}]
+ * TODO (kmadhusu): Handle invalid characters.
+ */
+function getPageRanges() {
+  var pageRangesInfo = [];
+  var pageRangeText = $('pages').value;
+  var pageRangeList = pageRangeText.split(',');

[arv (Not doing code reviews), 2011/02/23 19:38:52]

Should we not support white spaces in the text as well? If so, just remove them
before the split.


pageRangeText.replace(/\s/g, '').split(',');

[kmadhusu, 2011/02/24 02:11:34]

Done.

+  for (var i = 0; i < pageRangeList.length; i++) {
+    var tempRange = pageRangeList[i].split('-');
+    var printFrom;
+    var printTo;
+    if (tempRange.length > 1) {
+      printFrom = tempRange[0];
+      printTo = tempRange[1];
+    } else {
+      printFrom = tempRange[0];
+      printTo = tempRange[0];
+    }
+    // Validate the page range information.
+    if (isValidPageRange(printFrom, printTo)) {
+      pageRangesInfo.push({'from': parseInt(printFrom, 10),
+                           'to': parseInt(printTo, 10)});
+    }
+  }
+  return pageRangesInfo;
+}
+
+function printFile() {
+  var selectedPrinter = $('printer-list').selectedIndex;
+  var printerName = $('printer-list').options[selectedPrinter].textContent;
+  var pageRanges = getPageRanges();
+  var printAll = $('all-pages').checked;
+  var twoSided = $('two-sided').checked;
+  var copies = $('copies').value;
+  var collate = $('collate').checked;
+  var layout = $('layout').options[$('layout').selectedIndex].value;
+  var color = $('color').options[$('color').selectedIndex].value;
+
+  var jobSettings = JSON.stringify({'printerName': printerName,
+                                    'pageRange': pageRanges,
+                                    'printAll': printAll,
+                                    'twoSided': twoSided,
+                                    'copies': copies,
+                                    'collate': collate,
+                                    'layout': layout,
+                                    'color': color});
+  chrome.send('print', [jobSettings]);
+}
+
+/**
  * Fill the printer list drop down.
  */
 function setPrinters(printers) {
   if (printers.length > 0) {
     for (var i = 0; i < printers.length; ++i) {
       var option = document.createElement('option');
       option.textContent = printers[i];
       $('printer-list').add(option);
     }
   } else {
@@ skipping 40 matching lines @@
   if (!pdfPlugin.onload) {
     hasPDFPlugin = false;
     mainView.removeChild(pdfPlugin);
     $('no-plugin').classList.remove('hidden');
     return;
   }
   pdfPlugin.onload('onPDFLoad()');
 }
 
 window.addEventListener('DOMContentLoaded', load);