PrintPreview: Preview generation should not block print button.

chrome/browser/resources/print_preview.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.
 
 var localStrings = new LocalStrings();
 
 // The total page count of the previewed document regardless of which pages the
 // user has selected.
 var totalPageCount = -1;
 
@@ skipping 12 matching lines @@
 // Used to disable some printing options when the preview is not modifiable.
 var previewModifiable = false;
 
 // Destination list special value constants.
 const PRINT_TO_PDF = 'Print To PDF';
 const MANAGE_PRINTERS = 'Manage Printers';
 
 // State of the print preview settings.
 var printSettings = new PrintSettings();
 
+// Total number of print preview requests submitted.
+var previewRequestCount = 0;
+
+// True when a pending print file request exists.
+var hasPendingPrintFileRequest = false;
+
 /**
  * Window onload handler, sets up the page and starts print preview by getting
  * the printer list.
  */
 function onLoad() {
-  $('system-dialog-link').addEventListener('click', showSystemDialog);
   $('cancel-button').addEventListener('click', handleCancelButtonClick);
 
   if (!checkCompatiblePluginExists()) {
     displayErrorMessage(localStrings.getString('noPlugin'), false);
     $('mainview').parentElement.removeChild($('dummy-viewer'));
+    $('print-button').addEventListener('click', showSystemDialog);
     return;
   }
+  $('system-dialog-link').addEventListener('click', showSystemDialog);

[dpapad, 2011/06/06 18:07:35]

Why move this line? If the there is no compatible plugin this line will never
get executed and Chromium users will not be able to print at all. 

[kmadhusu, 2011/06/06 18:44:08]

Print button is now enabled. In line #49, I have associated the print button to
show the system native dialog for Chromium users.

   $('mainview').parentElement.removeChild($('dummy-viewer'));
 
   $('printer-list').disabled = true;
-  $('print-button').disabled = true;
+  $('print-button').onclick = printFile;
+
+  addEventListenersToPagesControls();
+  addEventListenersToCopiesControl();
   showLoadingAnimation();
   chrome.send('getDefaultPrinter');
 }
 
 /**
- * Adds event listeners to the settings controls.
+ * Adds event listeners to the pages section controls.
  */
-function addEventListeners() {
-  $('print-button').onclick = printFile;
-
-  // Controls that require preview rendering.
+function addEventListenersToPagesControls() {
   $('all-pages').onclick = onPageSelectionMayHaveChanged;
   $('print-pages').onclick = handleIndividualPagesCheckbox;
   var individualPages = $('individual-pages');
   individualPages.onblur = function() {
       clearTimeout(timerId);
       onPageSelectionMayHaveChanged();
   };
   individualPages.onfocus = addTimerToPageRangeField;
   individualPages.oninput = resetPageRangeFieldTimer;
-  $('landscape').onclick = onLayoutModeToggle;
-  $('portrait').onclick = onLayoutModeToggle;
-  $('printer-list').onchange = updateControlsWithSelectedPrinterCapabilities;
+}
 
-  // Controls that dont require preview rendering.
+/**
+ * Adds event listeners to the copies controls.
+ */
+function addEventListenersToCopiesControl() {

[dpapad, 2011/06/06 18:07:35]

rename to addEventListenersToCopiesControls for consistency with the previous
function.

[kmadhusu, 2011/06/06 18:44:08]

Done.

   $('copies').oninput = function() {
     copiesFieldChanged();
     updatePrintButtonState();
     updatePrintSummary();
   };
-  $('two-sided').onclick = handleTwoSidedClick;
-  $('color').onclick = function() { setColor(true); };
-  $('bw').onclick = function() { setColor(false); };
   $('increment').onclick = function() {
     onCopiesButtonsClicked(1);
     updatePrintButtonState();
     updatePrintSummary();
   };
   $('decrement').onclick = function() {
     onCopiesButtonsClicked(-1);
     updatePrintButtonState();
     updatePrintSummary();
   };
 }
 
 /**
+ * Adds event listeners to the settings controls.
+ */
+function addEventListeners() {
+  // Controls that require preview rendering.
+  $('landscape').onclick = onLayoutModeToggle;
+  $('portrait').onclick = onLayoutModeToggle;
+  $('printer-list').onchange = updateControlsWithSelectedPrinterCapabilities;
+
+  // Controls that dont require preview rendering.
+  $('two-sided').onclick = handleTwoSidedClick;
+  $('color').onclick = function() { setColor(true); };
+  $('bw').onclick = function() { setColor(false); };
+}
+
+/**
  * Removes event listeners from the settings controls.
  */
 function removeEventListeners() {
   // Controls that require preview rendering.
-  $('print-button').disabled = true;
-  $('all-pages').onclick = null;
-  $('print-pages').onclick = null;
-  var individualPages = $('individual-pages');
-  individualPages.onblur = null;
-  individualPages.onfocus = null;
-  individualPages.oninput = null;
-  clearTimeout(timerId);
   $('landscape').onclick = null;
   $('portrait').onclick = null;
   $('printer-list').onchange = null;
 
   // Controls that dont require preview rendering.
-  $('copies').oninput = copiesFieldChanged;
   $('two-sided').onclick = null;
   $('color').onclick = null;
   $('bw').onclick = null;
-  $('increment').onclick = function() { onCopiesButtonsClicked(1); };
-  $('decrement').onclick = function() { onCopiesButtonsClicked(-1); };
 }
 
 /**
  * Asks the browser to close the preview tab.
  */
 function handleCancelButtonClick() {
   chrome.send('closePrintPreviewTab');
 }
 
 /**
  * Asks the browser to show the native print dialog for printing.
  */
 function showSystemDialog() {
   chrome.send('showSystemDialog');
 }
 
 /**
  * Disables the controls which need the initiator tab to generate preview
  * data. This function is called when the initiator tab is closed.
  * @param {string} initiatorTabURL The URL of the initiator tab.
  */
 function onInitiatorTabClosed(initiatorTabURL) {
   $('reopen-page').addEventListener('click', function() {
       window.location = initiatorTabURL;
   });
   displayErrorMessage(localStrings.getString('initiatorTabClosed'), true);
+  $('print-button').disabled = true;
 }
 
 /**
  * Gets the selected printer capabilities and updates the controls accordingly.
  */
 function updateControlsWithSelectedPrinterCapabilities() {
   var printerList = $('printer-list');
   var selectedIndex = printerList.selectedIndex;
   if (selectedIndex < 0)
     return;
@@ skipping 164 matching lines @@
   var deviceName = '';
   if (selectedPrinter >= 0)
     deviceName = printerList.options[selectedPrinter].value;
   return deviceName;
 }
 
 /**
  * Asks the browser to print the preview PDF based on current print settings.
  */
 function printFile() {
+  $('print-summary').innerHTML = localStrings.getString('printing');

[dpapad, 2011/06/06 18:07:35]

I suspect that if you select Print to PDF, the hit print and then hit cancel the
print summary will keep displaying "Printing...". If so, move this line within
the "if (getSelectedPrinterName() != PRINT_TO_PDF)" block as before.

[kmadhusu, 2011/06/06 18:44:08]

Done.

+
+  if (previewRequestCount > 0)
+    hasPendingPrintFileRequest = true;
+  else
+    hasPendingPrintFileRequest = false;

[dpapad, 2011/06/06 18:07:35]

Replace if/else with
hasPendingPrintFileRequest = previewRequestCount > 0 ? true : false;

[kmadhusu, 2011/06/06 18:44:08]

Done.

+
+  if (hasPendingPrintFileRequest) {
+    if (getSelectedPrinterName() != PRINT_TO_PDF)
+      chrome.send('hidePreview');
+    return;
+  }
+
   if (getSelectedPrinterName() != PRINT_TO_PDF) {
     $('print-button').classList.add('loading');
     $('cancel-button').classList.add('loading');
-    $('print-summary').innerHTML = localStrings.getString('printing');
+
     removeEventListeners();
-    window.setTimeout(function() { chrome.send('print', [getSettingsJSON()]); },
+    window.setTimeout(function() {chrome.send('print', [getSettingsJSON()]); },
                       1000);
-  } else
+  } else {
     chrome.send('print', [getSettingsJSON()]);
+  }
 }
 
 /**
  * Asks the browser to generate a preview PDF based on current print settings.
  */
 function requestPrintPreview() {
+  previewRequestCount++;
   removeEventListeners();
   printSettings.save();
   showLoadingAnimation();
   chrome.send('getPreview', [getSettingsJSON()]);
 }
 
 /**
  * Set the default printer. If there is one, generate a print preview.
  * @param {string} printer Name of the default printer. Empty if none.
  */
@@ skipping 136 matching lines @@
  * @param {string} jobTitle The print job title.
  * @param {boolean} modifiable If the preview is modifiable.
  * @param {string} previewUid Preview unique identifier.
  */
 function updatePrintPreview(pageCount, jobTitle, modifiable, previewUid) {
   var tempPrintSettings = new PrintSettings();
   tempPrintSettings.save();
 
   previewModifiable = modifiable;
 
+  if (previewRequestCount > 0)
+    previewRequestCount--;
+
   if (totalPageCount == -1)
     totalPageCount = pageCount;
 
   if (previouslySelectedPages.length == 0)
     for (var i = 0; i < totalPageCount; i++)
       previouslySelectedPages.push(i+1);
 
   if (printSettings.deviceName != tempPrintSettings.deviceName) {
     updateControlsWithSelectedPrinterCapabilities();
     return;
   } else if (printSettings.isLandscape != tempPrintSettings.isLandscape) {
     setDefaultValuesAndRegeneratePreview();
     return;
   } else if (getSelectedPagesValidityLevel() == 1) {
     var currentlySelectedPages = getSelectedPagesSet();
     if (!areArraysEqual(previouslySelectedPages, currentlySelectedPages)) {
       previouslySelectedPages = currentlySelectedPages;
       requestPrintPreview();
       return;
     }
   }
 
   if (getSelectedPagesValidityLevel() != 1)
     pageRangesFieldChanged();
 
   // Update the current tab title.
   document.title = localStrings.getStringF('printPreviewTitleFormat', jobTitle);
 
   createPDFPlugin(previewUid);
+
+  if (previewRequestCount == 0 && hasPendingPrintFileRequest) {
+    printFile();
+    return;
+  }
+
   updatePrintSummary();
   updatePrintButtonState();
   addEventListeners();
 }
 
 /**
  * Create the PDF plugin or reload the existing one.
  * @param {string} previewUid Preview unique identifier.
  */
 function createPDFPlugin(previewUid) {
@@ skipping 425 matching lines @@
   this.isLandscape = '';
 }
 
 /**
  * Takes a snapshot of the print settings.
  */
 PrintSettings.prototype.save = function() {
   this.deviceName = getSelectedPrinterName();
   this.isLandscape = isLandscape();
 }