Print Preview Cleanup: Creating enum with all custom events used.

chrome/browser/resources/print_preview/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.
 
 // require: cr/ui/print_preview_cloud.js
 
 var localStrings = new LocalStrings();
 
 // If useCloudPrint is true we attempt to connect to cloud print
 // and populate the list of printers with cloud print printers.
@@ skipping 85 matching lines @@
 // A dictionary of cloud printers that have been added to the printer
 // dropdown.
 var addedCloudPrinters = {};
 
 // The maximum number of cloud printers to allow in the dropdown.
 const maxCloudPrinters = 10;
 
 const MIN_REQUEST_ID = 0;
 const MAX_REQUEST_ID = 32000;
 
+// Names of all the custom events used.
+var customEvents = {
+  // Fired when the mouse moves while a margin line is being dragged.
+  MARGIN_LINE_DRAG: 'marginLineDrag',
+  // Fired when a mousedown event occurs on a margin line.
+  MARGIN_LINE_MOUSE_DOWN: 'marginLineMouseDown',
+  // Fired when a margin textbox gains focus.
+  MARGIN_TEXTBOX_FOCUSED: 'marginTextboxFocused',
+  // Fired when a new preview might be needed because of margin changes.
+  MARGINS_MAY_HAVE_CHANGED: 'marginsMayHaveChanged',
+  // Fired when a pdf generation related error occurs.
+  PDF_GENERATION_ERROR: 'PDFGenerationError',
+  // Fired once the first page of the pdf document is loaded in the plugin.
+  PDF_LOADED: 'PDFLoaded',
+  // Fired when the selected printer capabilities change.
+  PRINTER_CAPABILITIES_UPDATED: 'printerCapabilitiesUpdated',
+  // Fired when the print button needs to be updated.
+  UPDATE_PRINT_BUTTON: 'updatePrintButton',
+  // Fired when the print summary needs to be updated.
+  UPDATE_SUMMARY: 'updateSummary',
+}
+
 /**
  * Window onload handler, sets up the page and starts print preview by getting
  * the printer list.
  */
 function onLoad() {
   cr.enablePlatformSpecificCSSRules();
   initialPreviewRequestID = randomInteger(MIN_REQUEST_ID, MAX_REQUEST_ID);
   lastPreviewRequestID = initialPreviewRequestID;
 
   previewArea = print_preview.PreviewArea.getInstance();
   printHeader = print_preview.PrintHeader.getInstance();
-  document.addEventListener('PDFGenerationError', cancelPendingPrintRequest);
+  document.addEventListener(customEvents.PDF_GENERATION_ERROR,
+                            cancelPendingPrintRequest);
 
   if (!checkCompatiblePluginExists()) {
     disableInputElementsInSidebar();
     previewArea.displayErrorMessageWithButtonAndNotify(
         localStrings.getString('noPlugin'),
         localStrings.getString('launchNativeDialog'),
         launchNativePrintDialog);
     $('mainview').parentElement.removeChild($('dummy-viewer'));
     return;
   }
@@ skipping 147 matching lines @@
   updateWithPrinterCapabilities(settings);
   var printerList = $('printer-list');
   var selectedIndex = printerList.selectedIndex;
   lastSelectedPrinterIndex = selectedIndex;
 
   // Regenerate the preview data based on selected printer settings.
   setDefaultValuesAndRegeneratePreview(true);
 }
 
 /**
- * Updates the controls with printer capabilities information.
+ * Notifies listeners of |customEvents.PRINTER_CAPABILITIES_UPDATED| about the
+ * capabilities of the currently selected printer. It is called from C++ too.
  * @param {Object} settingInfo printer setting information.
  */
 function updateWithPrinterCapabilities(settingInfo) {
-  var customEvent = new cr.Event("printerCapabilitiesUpdated");
+  var customEvent = new cr.Event(customEvents.PRINTER_CAPABILITIES_UPDATED);
   customEvent.printerCapabilities = settingInfo;
   document.dispatchEvent(customEvent);
 }
 
 /**
  * Turn on the integration of Cloud Print.
  * @param {string} cloudPrintUrl The URL to use for cloud print servers.
  */
 function setUseCloudPrint(cloudPrintURL) {
   useCloudPrint = true;
@@ skipping 181 matching lines @@
 /**
  * Loads the selected preview pages.
  */
 function loadSelectedPages() {
   pageSettings.updatePageSelection();
   var pageSet = pageSettings.previouslySelectedPages;
   var pageCount = pageSet.length;
   if (pageCount == 0 || currentPreviewUid == '')
     return;
 
-  cr.dispatchSimpleEvent(document, 'updateSummary');
+  cr.dispatchSimpleEvent(document, customEvents.UPDATE_SUMMARY);
   for (var i = 0; i < pageCount; i++)
     onDidPreviewPage(pageSet[i] - 1, currentPreviewUid, lastPreviewRequestID);
 }
 
 /**
  * Asks the browser to generate a preview PDF based on current print settings.
  */
 function requestPrintPreview() {
   if (!isTabHidden)
     previewArea.showLoadingAnimation();
@@ skipping 224 matching lines @@
       localStrings.getString('invalidPrinterSettings'));
 }
 
 /**
  * Called when the PDF plugin loads its document.
  */
 function onPDFLoad() {
   if (previewModifiable) {
     setPluginPreviewPageCount();
   }
-  cr.dispatchSimpleEvent(document, 'PDFLoaded');
+  cr.dispatchSimpleEvent(document, customEvents.PDF_LOADED);
   isFirstPageLoaded = true;
   checkAndHideOverlayLayerIfValid();
   sendPrintDocumentRequestIfNeeded();
 }
 
 function setPluginPreviewPageCount() {
   $('pdf-viewer').printPreviewPageCount(
       pageSettings.previouslySelectedPages.length);
 }
 
 /**
  * Update the page count and check the page range.
  * Called from PrintPreviewUI::OnDidGetPreviewPageCount().
  * @param {number} pageCount The number of pages.
  * @param {boolean} isModifiable Indicates whether the previewed document can be
  *     modified.
  * @param {number} previewResponseId The preview request id that resulted in
  *     this response.
  */
 function onDidGetPreviewPageCount(pageCount, isModifiable, previewResponseId) {
   if (!isExpectedPreviewResponse(previewResponseId))
     return;
   pageSettings.updateState(pageCount);
   previewModifiable = isModifiable;
   if (!previewModifiable && pageSettings.requestPrintPreviewIfNeeded())
     return;
 
-  cr.dispatchSimpleEvent(document, 'updateSummary');
+  cr.dispatchSimpleEvent(document, customEvents.UPDATE_SUMMARY);
 }
 
 /**
  * @param {printing::PageSizeMargins} pageLayout The default layout of the page
  *     in points.
  */
 function onDidGetDefaultPageLayout(pageLayout) {
   marginSettings.currentDefaultPageLayout = new print_preview.PageLayout(
       pageLayout.contentWidth,
       pageLayout.contentHeight,
@@ skipping 22 matching lines @@
 /**
  * Called when no pipelining previewed pages.
  * @param {string} previewUid Preview unique identifier.
  * @param {number} previewResponseId The preview request id that resulted in
  *     this response.
  */
 function reloadPreviewPages(previewUid, previewResponseId) {
   if (!isExpectedPreviewResponse(previewResponseId))
     return;
 
-  cr.dispatchSimpleEvent(document, 'updatePrintButton');
+  cr.dispatchSimpleEvent(document, customEvents.UPDATE_PRINT_BUTTON);
   checkAndHideOverlayLayerIfValid();
   var pageSet = pageSettings.previouslySelectedPages;
   for (var i = 0; i < pageSet.length; i++)
     $('pdf-viewer').loadPreviewPage(getPageSrcURL(previewUid, pageSet[i]-1), i);
 
   hasPendingPreviewRequest = false;
   isPrintReadyMetafileReady = true;
   previewArea.pdfLoaded = true;
   sendPrintDocumentRequestIfNeeded();
 }
@@ skipping 50 matching lines @@
     return;
   isPrintReadyMetafileReady = true;
 
   if (!previewModifiable) {
     // If the preview is not modifiable the plugin has not been created yet.
     currentPreviewUid = previewUid;
     hasPendingPreviewRequest = false;
     createPDFPlugin(PRINT_READY_DATA_INDEX);
   }
 
-  cr.dispatchSimpleEvent(document, 'updatePrintButton');
+  cr.dispatchSimpleEvent(document, customEvents.UPDATE_PRINT_BUTTON);
   if (previewModifiable)
     sendPrintDocumentRequestIfNeeded();
 }
 
 /**
  * Checks to see if the requested print data is available for printing and
  * sends a print document request if needed.
  */
 function sendPrintDocumentRequestIfNeeded() {
   if (!hasPendingPrintDocumentRequest || !isFirstPageLoaded)
@@ skipping 180 matching lines @@
 <include src="copies_settings.js"/>
 <include src="header_footer_settings.js"/>
 <include src="layout_settings.js"/>
 <include src="color_settings.js"/>
 <include src="margin_settings.js"/>
 <include src="margin_textbox.js"/>
 <include src="margin_utils.js"/>
 <include src="margins_ui.js"/>
 <include src="margins_ui_pair.js"/>
 <include src="preview_area.js"/>