New fast NTP that uses a single iframe

chrome/browser/resources/local_ntp/local_ntp_fast.js

Index: chrome/browser/resources/local_ntp/local_ntp_fast.js
diff --git a/chrome/browser/resources/local_ntp/local_ntp.js b/chrome/browser/resources/local_ntp/local_ntp_fast.js
similarity index 56%
copy from chrome/browser/resources/local_ntp/local_ntp.js
copy to chrome/browser/resources/local_ntp/local_ntp_fast.js
index c398058c8c86362916764db8f44926f3168c43aa..58eba1c22814dcd69bc071274bdead7aa286fe0e 100644
--- a/chrome/browser/resources/local_ntp/local_ntp.js
+++ b/chrome/browser/resources/local_ntp/local_ntp_fast.js
@@ -1,4 +1,4 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
+// Copyright 2015 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.
 
@@ -13,11 +13,10 @@
  * @return {Object} A limited interface for testing the local NTP.
  */
 function LocalNTP() {
-<include src="../../../../ui/webui/resources/js/assert.js">
-<include src="local_ntp_design.js">
-<include src="local_ntp_util.js">
-<include src="window_disposition_util.js">
+  'use strict';
 
+<include src="../../../../ui/webui/resources/js/util.js">
+<include src='local_ntp_design.js'>
 
 /**
  * Enum for classnames.
@@ -26,34 +25,18 @@ function LocalNTP() {
  */
 var CLASSES = {
   ALTERNATE_LOGO: 'alternate-logo', // Shows white logo if required by theme
-  BLACKLIST: 'mv-blacklist', // triggers tile blacklist animation
-  BLACKLIST_BUTTON: 'mv-x',
-  BLACKLIST_BUTTON_INNER: 'mv-x-inner',
   DARK: 'dark',
   DEFAULT_THEME: 'default-theme',
   DELAYED_HIDE_NOTIFICATION: 'mv-notice-delayed-hide',
-  DOT: 'dot',
   FAKEBOX_DISABLE: 'fakebox-disable', // Makes fakebox non-interactive
   FAKEBOX_FOCUS: 'fakebox-focused', // Applies focus styles to the fakebox
   // Applies drag focus style to the fakebox
   FAKEBOX_DRAG_FOCUS: 'fakebox-drag-focused',
-  FAVICON: 'mv-favicon',
-  FAVICON_FALLBACK: 'mv-favicon-fallback',
-  FOCUSED: 'mv-focused',
-  HIDE_BLACKLIST_BUTTON: 'mv-x-hide', // hides blacklist button during animation
   HIDE_FAKEBOX_AND_LOGO: 'hide-fakebox-logo',
   HIDE_NOTIFICATION: 'mv-notice-hide',
   // Vertically centers the most visited section for a non-Google provided page.
   NON_GOOGLE_PAGE: 'non-google-page',
-  PAGE: 'mv-page', // page tiles
-  PAGE_READY: 'mv-page-ready',  // page tile when ready
-  RTL: 'rtl',  // Right-to-left language text.
-  THUMBNAIL: 'mv-thumb',
-  THUMBNAIL_FALLBACK: 'mv-thumb-fallback',
-  THUMBNAIL_MASK: 'mv-mask',
-  TILE: 'mv-tile',
-  TILE_INNER: 'mv-tile-inner',
-  TITLE: 'mv-title'
+  RTL: 'rtl'  // Right-to-left language text.
 };
 
 
@@ -103,21 +86,6 @@ var NTP_DISPOSE_STATE = {
 
 
 /**
- * The JavaScript button event value for a middle click.
- * @type {number}
- * @const
- */
-var MIDDLE_MOUSE_BUTTON = 1;
-
-
-/**
- * The container for the tile elements.
- * @type {Element}
- */
-var tilesContainer;
-
-
-/**
  * The notification displayed when a page is blacklisted.
  * @type {Element}
  */
@@ -147,35 +115,14 @@ var ntpContents;
 
 
 /**
- * The array of rendered tiles, ordered by appearance.
- * @type {!Array<Tile>}
- */
-var tiles = [];
-
-
-/**
- * The last blacklisted tile if any, which by definition should not be filler.
- * @type {?Tile}
+ * The last blacklisted tile rid if any, which by definition should not be
+ * filler.
+ * @type {?number}
  */
 var lastBlacklistedTile = null;
 
 
 /**
- * The iframe element which is currently keyboard focused, or null.
- * @type {?Element}
- */
-var focusedIframe = null;
-
-
-/**
- * True if a page has been blacklisted and we're waiting on the
- * onmostvisitedchange callback. See renderAllTiles() for how this is used.
- * @type {boolean}
- */
-var isBlacklisting = false;
-
-
-/**
  * Current number of tiles columns shown based on the window width, including
  * those that just contain filler.
  * @type {number}
@@ -184,14 +131,6 @@ var numColumnsShown = 0;
 
 
 /**
- * A flag to indicate Most Visited changed caused by user action. If true, then
- * in renderAllTiles() tiles remain visible so no flickering occurs.
- * @type {boolean}
- */
-var userInitiatedMostVisitedChange = false;
-
-
-/**
  * The browser embeddedSearch.newTabPage object.
  * @type {Object}
  */
@@ -245,22 +184,6 @@ var MIN_TOTAL_HORIZONTAL_PADDING = 200;
 
 
 /**
- * The filename for a most visited iframe src which shows a page title.
- * @type {string}
- * @const
- */
-var MOST_VISITED_TITLE_IFRAME = 'title.html';
-
-
-/**
- * The filename for a most visited iframe src which shows a thumbnail image.
- * @type {string}
- * @const
- */
-var MOST_VISITED_THUMBNAIL_IFRAME = 'thumbnail.html';
-
-
-/**
  * The color of the title in RRGGBBAA format.
  * @type {?string}
  */
@@ -268,44 +191,6 @@ var titleColor = null;
 
 
 /**
- * Hide most visited tiles for at most this many milliseconds while painting.
- * @type {number}
- * @const
- */
-var MOST_VISITED_PAINT_TIMEOUT_MSEC = 500;
-
-
-/**
- * A Tile is either a rendering of a Most Visited page or "filler" used to
- * pad out the section when not enough pages exist.
- *
- * @param {Element} elem The element for rendering the tile.
- * @param {Element=} opt_innerElem The element for contents of tile.
- * @param {Element=} opt_titleElem The element for rendering the title.
- * @param {Element=} opt_thumbnailElem The element for rendering the thumbnail.
- * @param {number=} opt_rid The RID for the corresponding Most Visited page.
- *     Should only be left unspecified when creating a filler tile.
- * @constructor
- */
-function Tile(elem, opt_innerElem, opt_titleElem, opt_thumbnailElem, opt_rid) {
-  /** @type {Element} */
-  this.elem = elem;
-
-  /** @type {Element|undefined} */
-  this.innerElem = opt_innerElem;
-
-  /** @type {Element|undefined} */
-  this.titleElem = opt_titleElem;
-
-  /** @type {Element|undefined} */
-  this.thumbnailElem = opt_thumbnailElem;
-
-  /** @type {number|undefined} */
-  this.rid = opt_rid;
-}
-
-
-/**
  * Heuristic to determine whether a theme should be considered to be dark, so
  * the colors of various UI elements can be adjusted.
  * @param {ThemeBackgroundInfo|undefined} info Theme background information.
@@ -370,8 +255,6 @@ function renderTheme() {
  */
 function onThemeChange() {
   renderTheme();
-  tilesContainer.innerHTML = '';
-  renderAllTiles();
 }
 
 
@@ -489,301 +372,22 @@ function convertToRGBAColor(color) {
  * Called when page data change.
  */
 function onMostVisitedChange() {
-  renderAllTiles();
-}
-
-
-/**
- * Rerenders all tiles based on Most Visited page data.
- */
-function renderAllTiles() {
-  if (isBlacklisting) {
-    // Trigger the blacklist animation, which then triggers reloadAllTiles().
-    var lastBlacklistedTileElem = lastBlacklistedTile.elem;
-    lastBlacklistedTileElem.addEventListener(
-        'webkitTransitionEnd', blacklistAnimationDone);
-    lastBlacklistedTileElem.classList.add(CLASSES.BLACKLIST);
-  } else {
-    reloadAllTiles();
-  }
-}
-
-
-/**
- * Handles the end of the blacklist animation by showing the notification and
- * re-rendering the new set of tiles.
- */
-function blacklistAnimationDone() {
-  showNotification();
-  isBlacklisting = false;
-  tilesContainer.classList.remove(CLASSES.HIDE_BLACKLIST_BUTTON);
-  lastBlacklistedTile.elem.removeEventListener(
-      'webkitTransitionEnd', blacklistAnimationDone);
-  // Need to call explicitly to re-render the tiles, since the initial
-  // renderAllTiles() issued by the blacklist function only triggered the
-  // animation.
-  reloadAllTiles();
+  reloadTiles();
 }
 
 
 /**
  * Fetches new data, creates, and renders tiles.
  */
-function reloadAllTiles() {
+function reloadTiles() {
   var pages = ntpApiHandle.mostVisited;
+  var iframe = $('mv-single').contentWindow;
 
   tiles = [];
-  for (var i = 0; i < MAX_NUM_TILES_TO_SHOW; ++i)
-    tiles.push(createTile(pages[i], i));
-
-  tilesContainer.innerHTML = '';
-  renderAndShowTiles();
-}
-
-
-/**
- * Binds onload events for a tile's internal iframe elements.
- * @param {Tile} tile The main tile to bind events to.
- * @param {Barrier} tileVisibilityBarrier A barrier to make all tiles visible
- *   the moment all tiles are loaded.
- */
-function bindTileOnloadEvents(tile, tileVisibilityBarrier) {
-  if (tile.titleElem) {
-    tileVisibilityBarrier.add();
-    tile.titleElem.onload = function() {
-      tileVisibilityBarrier.remove();
-    };
+  for (var i = 0; i < Math.min(MAX_NUM_TILES_TO_SHOW, pages.length); ++i) {
+    iframe.postMessage({cmd: 'tile', rid: pages[i].rid}, '*');
   }
-  if (tile.thumbnailElem) {
-    tileVisibilityBarrier.add();
-    tile.thumbnailElem.onload = function() {
-      tile.elem.classList.add(CLASSES.PAGE_READY);
-      tileVisibilityBarrier.remove();
-    };
-  }
-}
-
-
-/**
- * Renders the current list of visible tiles to DOM, and hides tiles that are
- * already in the DOM but should not be seen.
- */
-function renderAndShowTiles() {
-  var numExisting = tilesContainer.querySelectorAll('.' + CLASSES.TILE).length;
-  // Only add visible tiles to the DOM, to avoid creating invisible tiles that
-  // produce meaningless impression metrics. However, if a tile becomes
-  // invisible then we leave it in DOM to prevent reload if it's shown again.
-  var numDesired = Math.min(tiles.length, numColumnsShown * NUM_ROWS);
-
-  // If we need to render new tiles, manage the visibility to hide intermediate
-  // load states of the iframes.
-  if (numExisting < numDesired) {
-    var showAll = function() {
-      for (var i = 0; i < numDesired; ++i) {
-        if (tiles[i].titleElem || tiles[i].thumbnailElem)
-          tiles[i].elem.classList.add(CLASSES.PAGE_READY);
-      }
-    };
-    var tileVisibilityBarrier = new Barrier(showAll);
-
-    if (!userInitiatedMostVisitedChange) {
-      // Make titleContainer invisible, but still taking up space.
-      // titleContainer becomes visible again (1) on timeout, or (2) when all
-      // tiles finish loading (using tileVisibilityBarrier).
-      window.setTimeout(function() {
-        tileVisibilityBarrier.cancel();
-        showAll();
-      }, MOST_VISITED_PAINT_TIMEOUT_MSEC);
-    }
-    userInitiatedMostVisitedChange = false;
-
-    for (var i = numExisting; i < numDesired; ++i) {
-      bindTileOnloadEvents(tiles[i], tileVisibilityBarrier);
-      tilesContainer.appendChild(tiles[i].elem);
-    }
-  }
-
-  // Show only the desired tiles. Note that .hidden does not work for
-  // inline-block elements like tiles[i].elem.
-  for (var i = 0; i < numDesired; ++i)
-    tiles[i].elem.style.display = 'inline-block';
-  // If |numDesired| < |numExisting| then hide extra tiles (e.g., this occurs
-  // when window is downsized).
-  for (; i < numExisting; ++i)
-    tiles[i].elem.style.display = 'none';
-}
-
-
-/**
- * Builds a URL to display a most visited tile title in an iframe.
- * @param {number} rid The restricted ID.
- * @param {number} position The position of the iframe in the UI.
- * @return {string} An URL to display the most visited title in an iframe.
- */
-function getMostVisitedTitleIframeUrl(rid, position) {
-  var url = 'chrome-search://most-visited/' +
-      encodeURIComponent(MOST_VISITED_TITLE_IFRAME);
-  var params = [
-      'rid=' + encodeURIComponent(rid),
-      'f=' + encodeURIComponent(NTP_DESIGN.fontFamily),
-      'fs=' + encodeURIComponent(NTP_DESIGN.fontSize),
-      'c=' + encodeURIComponent(titleColor),
-      'pos=' + encodeURIComponent(position)];
-  if (NTP_DESIGN.titleTextAlign)
-    params.push('ta=' + encodeURIComponent(NTP_DESIGN.titleTextAlign));
-  if (NTP_DESIGN.titleTextFade)
-    params.push('tf=' + encodeURIComponent(NTP_DESIGN.titleTextFade));
-  return url + '?' + params.join('&');
-}
-
-
-/**
- * Builds a URL to display a most visited tile thumbnail in an iframe.
- * @param {number} rid The restricted ID.
- * @param {number} position The position of the iframe in the UI.
- * @return {string} An URL to display the most visited thumbnail in an iframe.
- */
-function getMostVisitedThumbnailIframeUrl(rid, position) {
-  var url = 'chrome-search://most-visited/' +
-      encodeURIComponent(MOST_VISITED_THUMBNAIL_IFRAME);
-  var params = [
-      'rid=' + encodeURIComponent(rid),
-      'f=' + encodeURIComponent(NTP_DESIGN.fontFamily),
-      'fs=' + encodeURIComponent(NTP_DESIGN.fontSize),
-      'c=' + encodeURIComponent(NTP_DESIGN.thumbnailTextColor),
-      'pos=' + encodeURIComponent(position)];
-  if (NTP_DESIGN.thumbnailFallback)
-    params.push('etfb=1');
-  return url + '?' + params.join('&');
-}
-
-
-/**
- * Creates a Tile with the specified page data. If no data is provided, a
- * filler Tile is created.
- * @param {?Object} page The page data.
- * @param {number} position The position of the tile.
- * @return {Tile} The new Tile.
- */
-function createTile(page, position) {
-  var tileElem = document.createElement('div');
-  tileElem.classList.add(CLASSES.TILE);
-  // Prevent tile from being selected (and highlighted) when areas outside the
-  // iframes are clicked.
-  tileElem.addEventListener('mousedown', function(e) {
-    e.preventDefault();
-  });
-
-  if (!page) {
-    return new Tile(tileElem);
-  }
-
-  var rid = page.rid;
-  tileElem.classList.add(CLASSES.PAGE);
-
-  var navigateFunction = function(e) {
-    e.preventDefault();
-    ntpApiHandle.navigateContentWindow(rid, getDispositionFromEvent(e));
-  };
-
-  // The click handler for navigating to the page identified by the RID.
-  tileElem.addEventListener('click', navigateFunction);
-
-  // Container of tile contents.
-  var innerElem = createAndAppendElement(tileElem, 'div', CLASSES.TILE_INNER);
-
-  // The iframe which renders the page title.
-  var titleElem = document.createElement('iframe');
-  // Enable tab navigation on the iframe, which will move the selection to the
-  // link element (which also has a tabindex).
-  titleElem.tabIndex = '0';
-
-  // Make the iframe presentational for accessibility so screen readers perceive
-  // the iframe content as just part of the same page.
-  titleElem.setAttribute('role', 'presentation');
-
-  // Why iframes have IDs:
-  //
-  // On navigating back to the NTP we see several onmostvisitedchange() events
-  // in series with incrementing RIDs. After the first event, a set of iframes
-  // begins loading RIDs n, n+1, ..., n+k-1; after the second event, these get
-  // destroyed and a new set begins loading RIDs n+k, n+k+1, ..., n+2k-1.
-  // Now due to crbug.com/68841, Chrome incorrectly loads the content for the
-  // first set of iframes into the most recent set of iframes.
-  //
-  // Giving iframes distinct ids seems to cause some invalidation and prevent
-  // associating the incorrect data.
-  //
-  // TODO(jered): Find and fix the root (probably Blink) bug.
-
-  // Keep this ID here. See comment above.
-  titleElem.id = 'title-' + rid;
-  titleElem.className = CLASSES.TITLE;
-  titleElem.src = getMostVisitedTitleIframeUrl(rid, position);
-  innerElem.appendChild(titleElem);
-
-  // A fallback element for missing thumbnails.
-  if (NTP_DESIGN.thumbnailFallback) {
-    var fallbackElem = createAndAppendElement(
-        innerElem, 'div', CLASSES.THUMBNAIL_FALLBACK);
-    if (NTP_DESIGN.thumbnailFallback === THUMBNAIL_FALLBACK.DOT)
-      createAndAppendElement(fallbackElem, 'div', CLASSES.DOT);
-  }
-
-  // The iframe which renders either a thumbnail or domain element.
-  var thumbnailElem = document.createElement('iframe');
-  thumbnailElem.tabIndex = '-1';
-  thumbnailElem.setAttribute('aria-hidden', 'true');
-  // Keep this ID here. See comment above.
-  thumbnailElem.id = 'thumb-' + rid;
-  thumbnailElem.className = CLASSES.THUMBNAIL;
-  thumbnailElem.src = getMostVisitedThumbnailIframeUrl(rid, position);
-  innerElem.appendChild(thumbnailElem);
-
-  // The button used to blacklist this page.
-  var blacklistButton = createAndAppendElement(
-      innerElem, 'div', CLASSES.BLACKLIST_BUTTON);
-  createAndAppendElement(
-      blacklistButton, 'div', CLASSES.BLACKLIST_BUTTON_INNER);
-  var blacklistFunction = generateBlacklistFunction(rid);
-  blacklistButton.addEventListener('click', blacklistFunction);
-  blacklistButton.title = configData.translatedStrings.removeThumbnailTooltip;
-
-  // A helper mask on top of the tile that is used to create hover border
-  // and/or to darken the thumbnail on focus.
-  var maskElement = createAndAppendElement(
-      innerElem, 'div', CLASSES.THUMBNAIL_MASK);
-
-  // The page favicon, or a fallback.
-  var favicon = createAndAppendElement(innerElem, 'div', CLASSES.FAVICON);
-  if (page.faviconUrl) {
-    favicon.style.backgroundImage = 'url(' + page.faviconUrl + ')';
-  } else {
-    favicon.classList.add(CLASSES.FAVICON_FALLBACK);
-  }
-  return new Tile(tileElem, innerElem, titleElem, thumbnailElem, rid);
-}
-
-
-/**
- * Generates a function to be called when the page with the corresponding RID
- * is blacklisted.
- * @param {number} rid The RID of the page being blacklisted.
- * @return {function(Event=)} A function which handles the blacklisting of the
- *     page by updating state variables and notifying Chrome.
- */
-function generateBlacklistFunction(rid) {
-  return function(e) {
-    // Prevent navigation when the page is being blacklisted.
-    if (e)
-      e.stopPropagation();
-
-    userInitiatedMostVisitedChange = true;
-    isBlacklisting = true;
-    tilesContainer.classList.add(CLASSES.HIDE_BLACKLIST_BUTTON);
-    lastBlacklistedTile = getTileByRid(rid);
-    ntpApiHandle.deleteMostVisitedItem(rid);
-  };
+  iframe.postMessage({cmd: 'show'}, '*');
 }
 
 
@@ -812,11 +416,10 @@ function hideNotification() {
  * informing Chrome.
  */
 function onUndo() {
-  userInitiatedMostVisitedChange = true;
   hideNotification();
-  var lastBlacklistedRID = lastBlacklistedTile.rid;
-  if (typeof lastBlacklistedRID != 'undefined')
-    ntpApiHandle.undoMostVisitedDeletion(lastBlacklistedRID);
+  if (lastBlacklistedTile != null) {
+    ntpApiHandle.undoMostVisitedDeletion(lastBlacklistedTile);
+  }
 }
 
 
@@ -825,7 +428,6 @@ function onUndo() {
  * notification and informing Chrome.
  */
 function onRestoreAll() {
-  userInitiatedMostVisitedChange = true;
   hideNotification();
   ntpApiHandle.undoAllMostVisitedDeletions();
 }
@@ -856,7 +458,7 @@ function updateContentWidth() {
 
   numColumnsShown = newNumColumns;
   var tilesContainerWidth = numColumnsShown * tileRequiredWidth;
-  tilesContainer.style.width = tilesContainerWidth + 'px';
+  $(IDS.TILES).style.width = tilesContainerWidth + 'px';
   if (fakebox) {
     // -2 to account for border.
     var fakeboxWidth = (tilesContainerWidth - NTP_DESIGN.tileMargin - 2);
@@ -872,25 +474,7 @@ function updateContentWidth() {
  * new width of the page.
  */
 function onResize() {
-  if (updateContentWidth()) {
-    // Render without clearing tiles.
-    renderAndShowTiles();
-  }
-}
-
-
-/**
- * Returns the tile corresponding to the specified page RID.
- * @param {number} rid The page RID being looked up.
- * @return {Tile} The corresponding tile.
- */
-function getTileByRid(rid) {
-  for (var i = 0, length = tiles.length; i < length; ++i) {
-    var tile = tiles[i];
-    if (tile.rid == rid)
-      return tile;
-  }
-  return null;
+  updateContentWidth();
 }
 
 
@@ -1008,15 +592,6 @@ function createAndAppendElement(parent, name, opt_class) {
 
 
 /**
- * Removes a node from its parent.
- * @param {Node} node The node to remove.
- */
-function removeNode(node) {
-  node.parentNode.removeChild(node);
-}
-
-
-/**
  * @param {!Element} element The element to register the handler for.
  * @param {number} keycode The keycode of the key to register.
  * @param {!Function} handler The key handler to register.
@@ -1047,23 +622,13 @@ function getEmbeddedSearchApiHandle() {
  * @param {Event} event Event received.
  */
 function handlePostMessage(event) {
-  if (event.origin !== 'chrome-search://most-visited')
-    return;
+  var cmd = event.data.cmd;
+  var args = event.data;
+  if (cmd == 'tileBlacklisted') {
+    showNotification();
+    lastBlacklistedTile = args.rid;
 
-  if (event.data === 'linkFocused') {
-    var activeElement = document.activeElement;
-    if (activeElement.classList.contains(CLASSES.TITLE)) {
-      activeElement.classList.add(CLASSES.FOCUSED);
-      focusedIframe = activeElement;
-    }
-  } else if (event.data === 'linkBlurred') {
-    if (focusedIframe)
-      focusedIframe.classList.remove(CLASSES.FOCUSED);
-    focusedIframe = null;
-  } else if (event.data.indexOf('tileBlacklisted') === 0) {
-    var tilePosition = event.data.split(',')[1];
-    if (tilePosition)
-      generateBlacklistFunction(tiles[parseInt(tilePosition, 10)].rid)();
+    ntpApiHandle.deleteMostVisitedItem(args.rid);
   }
 }
 
@@ -1074,7 +639,6 @@ function handlePostMessage(event) {
  * Google-provided page.
  */
 function init() {
-  tilesContainer = $(IDS.TILES);
   notification = $(IDS.NOTIFICATION);
   attribution = $(IDS.ATTRIBUTION);
   ntpContents = $(IDS.NTP_CONTENTS);
@@ -1141,7 +705,6 @@ function init() {
     onInputStart();
 
   renderTheme();
-  renderAllTiles();
 
   searchboxApiHandle = topLevelHandle.searchBox;
 
@@ -1190,9 +753,23 @@ function init() {
     document.documentElement.setAttribute('dir', 'rtl');
     // Add class for setting alignments based on language directionality.
     document.documentElement.classList.add(CLASSES.RTL);
-    $(IDS.TILES).dir = 'rtl';
   }
 
+  var iframe = document.createElement('iframe');
+  iframe.id = 'mv-single';
+  var args = [];
+
+  if (searchboxApiHandle.rtl) {
+    args.push('rtl=1');
+  }
+
+  iframe.src = '//most-visited/single.html?' + args.join('&');
+  $(IDS.TILES).appendChild(iframe);
+
+  iframe.onload = function() {
+    reloadTiles();
+  };
+
   window.addEventListener('message', handlePostMessage);
 }