Refactor parts of the NTP to split things into more managable chunks....

chrome/browser/resources/new_new_tab.js

Index: chrome/browser/resources/new_new_tab.js
===================================================================
--- chrome/browser/resources/new_new_tab.js	(revision 45471)
+++ chrome/browser/resources/new_new_tab.js	(working copy)
@@ -1,3 +1,6 @@
+// Copyright (c) 2010 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.
 
 // Helpers
 
@@ -47,33 +50,7 @@
 const IS_MAC = /$Mac/.test(navigator.platform);
 
 var loading = true;
-var mostVisitedData = [];
-var gotMostVisited = false;
 
-function mostVisitedPages(data, firstRun) {
-  logEvent('received most visited pages');
-
-  // We append the class name with the "filler" so that we can style fillers
-  // differently.
-  var maxItems = 8;
-  data.length = Math.min(maxItems, data.length);
-  var len = data.length;
-  for (var i = len; i < maxItems; i++) {
-    data[i] = {filler: true};
-  }
-
-  mostVisitedData = data;
-  renderMostVisited(data);
-
-  gotMostVisited = true;
-  onDataLoaded();
-
-  // Only show the first run notification if first run.
-  if (firstRun) {
-    showFirstRunNotification();
-  }
-}
-
 function getAppsCallback(data) {
   var appsSection = $('apps-section');
   appsSection.innerHTML = '';
@@ -220,12 +197,6 @@
   chrome.send('setShownSections', [String(shownSections)]);
 }
 
-function getThumbnailClassName(data) {
-  return 'thumbnail-container' +
-      (data.pinned ? ' pinned' : '') +
-      (data.filler ? ' filler' : '');
-}
-
 function url(s) {
   // http://www.w3.org/TR/css3-values/#uris
   // Parentheses, commas, whitespace characters, single quotes (') and double
@@ -240,50 +211,6 @@
   return 'url("' + s2 + '")';
 }
 
-function renderMostVisited(data) {
-  var parent = $('most-visited');
-  var children = parent.children;
-  for (var i = 0; i < data.length; i++) {
-    var d = data[i];
-    var t = children[i];
-
-    // If we have a filler continue
-    var oldClassName = t.className;
-    var newClassName = getThumbnailClassName(d);
-    if (oldClassName != newClassName) {
-      t.className = newClassName;
-    }
-
-    // No need to continue if this is a filler.
-    if (newClassName == 'thumbnail-container filler') {
-      // Make sure the user cannot tab to the filler.
-      t.tabIndex = -1;
-      continue;
-    }
-    // Allow focus.
-    t.tabIndex = 1;
-
-    t.href = d.url;
-    t.querySelector('.pin').title = localStrings.getString(d.pinned ?
-        'unpinthumbnailtooltip' : 'pinthumbnailtooltip');
-    t.querySelector('.remove').title =
-        localStrings.getString('removethumbnailtooltip');
-
-    // There was some concern that a malformed malicious URL could cause an XSS
-    // attack but setting style.backgroundImage = 'url(javascript:...)' does
-    // not execute the JavaScript in WebKit.
-
-    var thumbnailUrl = d.thumbnailUrl || 'chrome://thumb/' + d.url;
-    t.querySelector('.thumbnail-wrapper').style.backgroundImage =
-        url(thumbnailUrl);
-    var titleDiv = t.querySelector('.title > div');
-    titleDiv.xtitle = titleDiv.textContent = d.title;
-    var faviconUrl = d.faviconUrl || 'chrome://favicon/' + d.url;
-    titleDiv.style.backgroundImage = url(faviconUrl);
-    titleDiv.dir = d.direction;
-  }
-}
-
 /**
  * Calls chrome.send with a callback and restores the original afterwards.
  */
@@ -362,194 +289,6 @@
   }
 }
 
-var mostVisited = {
-  addPinnedUrl_: function(data, index) {
-    chrome.send('addPinnedURL', [data.url, data.title, data.faviconUrl || '',
-                                 data.thumbnailUrl || '', String(index)]);
-  },
-  getItem: function(el) {
-    return findAncestorByClass(el, 'thumbnail-container');
-  },
-
-  getHref: function(el) {
-    return el.href;
-  },
-
-  togglePinned: function(el) {
-    var index = this.getThumbnailIndex(el);
-    var data = mostVisitedData[index];
-    data.pinned = !data.pinned;
-    if (data.pinned) {
-      this.addPinnedUrl_(data, index);
-    } else {
-      chrome.send('removePinnedURL', [data.url]);
-    }
-    this.updatePinnedDom_(el, data.pinned);
-  },
-
-  updatePinnedDom_: function(el, pinned) {
-    el.querySelector('.pin').title = localStrings.getString(pinned ?
-        'unpinthumbnailtooltip' : 'pinthumbnailtooltip');
-    if (pinned) {
-      addClass(el, 'pinned');
-    } else {
-      removeClass(el, 'pinned');
-    }
-  },
-
-  getThumbnailIndex: function(el) {
-    var nodes = el.parentNode.querySelectorAll('.thumbnail-container');
-    return Array.prototype.indexOf.call(nodes, el);
-  },
-
-  swapPosition: function(source, destination) {
-    var nodes = source.parentNode.querySelectorAll('.thumbnail-container');
-    var sourceIndex = this.getThumbnailIndex(source);
-    var destinationIndex = this.getThumbnailIndex(destination);
-    swapDomNodes(source, destination);
-
-    var sourceData = mostVisitedData[sourceIndex];
-    this.addPinnedUrl_(sourceData, destinationIndex);
-    sourceData.pinned = true;
-    this.updatePinnedDom_(source, true);
-
-    var destinationData = mostVisitedData[destinationIndex];
-    // Only update the destination if it was pinned before.
-    if (destinationData.pinned) {
-      this.addPinnedUrl_(destinationData, sourceIndex);
-    }
-    mostVisitedData[destinationIndex] = sourceData;
-    mostVisitedData[sourceIndex] = destinationData;
-  },
-
-  blacklist: function(el) {
-    var self = this;
-    var url = this.getHref(el);
-    chrome.send('blacklistURLFromMostVisited', [url]);
-
-    addClass(el, 'hide');
-
-    // Find the old item.
-    var oldUrls = {};
-    var oldIndex = -1;
-    var oldItem;
-    for (var i = 0; i < mostVisitedData.length; i++) {
-      if (mostVisitedData[i].url == url) {
-        oldItem = mostVisitedData[i];
-        oldIndex = i;
-      }
-      oldUrls[mostVisitedData[i].url] = true;
-    }
-
-    // Send 'getMostVisitedPages' with a callback since we want to find the new
-    // page and add that in the place of the removed page.
-    chromeSend('getMostVisited', [], 'mostVisitedPages', function(data) {
-      // Find new item.
-      var newItem;
-      for (var i = 0; i < data.length; i++) {
-        if (!(data[i].url in oldUrls)) {
-          newItem = data[i];
-          break;
-        }
-      }
-
-      if (!newItem) {
-        // If no other page is available to replace the blacklisted item,
-        // we need to reorder items s.t. all filler items are in the rightmost
-        // indices.
-        mostVisitedPages(data);
-
-      // Replace old item with new item in the mostVisitedData array.
-      } else if (oldIndex != -1) {
-        mostVisitedData.splice(oldIndex, 1, newItem);
-        mostVisitedPages(mostVisitedData);
-        addClass(el, 'fade-in');
-      }
-
-      // We wrap the title in a <span class=blacklisted-title>. We pass an empty
-      // string to the notifier function and use DOM to insert the real string.
-      var actionText = localStrings.getString('undothumbnailremove');
-
-      // Show notification and add undo callback function.
-      var wasPinned = oldItem.pinned;
-      showNotification('', actionText, function() {
-        self.removeFromBlackList(url);
-        if (wasPinned) {
-          self.addPinnedUrl_(oldItem, oldIndex);
-        }
-        chrome.send('getMostVisited');
-      });
-
-      // Now change the DOM.
-      var removeText = localStrings.getString('thumbnailremovednotification');
-      var notifySpan = document.querySelector('#notification > span');
-      notifySpan.textContent = removeText;
-
-      // Focus the undo link.
-      var undoLink = document.querySelector(
-          '#notification > .link > [tabindex]');
-      undoLink.focus();
-    });
-  },
-
-  removeFromBlackList: function(url) {
-    chrome.send('removeURLsFromMostVisitedBlacklist', [url]);
-  },
-
-  clearAllBlacklisted: function() {
-    chrome.send('clearMostVisitedURLsBlacklist', []);
-    hideNotification();
-  },
-
-  updateDisplayMode: function() {
-    if (!this.dirty_) {
-      return;
-    }
-    updateSimpleSection('most-visited-section', Section.THUMB);
-  },
-
-  dirty_: false,
-
-  invalidate: function() {
-    this.dirty_ = true;
-  },
-
-  layout: function() {
-    if (!this.dirty_) {
-      return;
-    }
-    var d0 = Date.now();
-
-    var mostVisitedElement = $('most-visited');
-    var thumbnails = mostVisitedElement.children;
-    var hidden = !(shownSections & Section.THUMB);
-
-
-    // We set overflow to hidden so that the most visited element does not
-    // "leak" when we hide and show it.
-    if (hidden) {
-      mostVisitedElement.style.overflow = 'hidden';
-    }
-
-    applyMostVisitedRects();
-
-    // Only set overflow to visible if the element is shown.
-    if (!hidden) {
-      afterTransition(function() {
-        mostVisitedElement.style.overflow = '';
-      });
-    }
-
-    this.dirty_ = false;
-
-    logEvent('mostVisited.layout: ' + (Date.now() - d0));
-  },
-
-  getRectByIndex: function(index) {
-    return getMostVisitedLayoutRects()[index];
-  }
-};
-
 // Recently closed
 
 function layoutRecentlyClosed() {
@@ -829,7 +568,6 @@
   addClass(notification, 'first-run');
 }
 
-
 /**
  * This handles the option menu.
  * @param {Element} button The button element.
@@ -1028,25 +766,6 @@
   }
 };
 
-$('most-visited').addEventListener('click', function(e) {
-  var target = e.target;
-  if (hasClass(target, 'pin')) {
-    mostVisited.togglePinned(mostVisited.getItem(target));
-    e.preventDefault();
-  } else if (hasClass(target, 'remove')) {
-    mostVisited.blacklist(mostVisited.getItem(target));
-    e.preventDefault();
-  }
-});
-
-// Allow blacklisting most visited site using the keyboard.
-$('most-visited').addEventListener('keydown', function(e) {
-  if (!IS_MAC && e.keyCode == 46 || // Del
-      IS_MAC && e.metaKey && e.keyCode == 8) { // Cmd + Backspace
-    mostVisited.blacklist(e.target);
-  }
-});
-
 $('main').addEventListener('click', function(e) {
   if (e.target.tagName == 'H2') {
     var p = e.target.parentNode;
@@ -1240,14 +959,6 @@
 // Set up links and text-decoration for promotional message.
 document.addEventListener('DOMContentLoaded', setUpPromoMessage);
 
-// Work around for http://crbug.com/25329
-function ensureSmallGridCorrect() {
-  if (wasSmallGrid != useSmallGrid()) {
-    applyMostVisitedRects();
-  }
-}
-document.addEventListener('DOMContentLoaded', ensureSmallGridCorrect);
-
 /**
  * The sync code is not yet built by default on all platforms so we have to
  * make sure we don't send the initial sync message to the backend unless the
@@ -1301,280 +1012,7 @@
   }
 });
 
-// DnD
-
-var dnd = {
-  currentOverItem_: null,
-  get currentOverItem() {
-    return this.currentOverItem_;
-  },
-  set currentOverItem(item) {
-    var style;
-    if (item != this.currentOverItem_) {
-      if (this.currentOverItem_) {
-        style = this.currentOverItem_.firstElementChild.style;
-        style.left = style.top = '';
-      }
-      this.currentOverItem_ = item;
-
-      if (item) {
-        // Make the drag over item move 15px towards the source. The movement is
-        // done by only moving the edit-mode-border (as in the mocks) and it is
-        // done with relative positioning so that the movement does not change
-        // the drop target.
-        var dragIndex = mostVisited.getThumbnailIndex(this.dragItem);
-        var overIndex = mostVisited.getThumbnailIndex(item);
-        if (dragIndex == -1 || overIndex == -1) {
-          return;
-        }
-
-        var dragRect = mostVisited.getRectByIndex(dragIndex);
-        var overRect = mostVisited.getRectByIndex(overIndex);
-
-        var x = dragRect.left - overRect.left;
-        var y = dragRect.top - overRect.top;
-        var z = Math.sqrt(x * x + y * y);
-        var z2 = 15;
-        var x2 = x * z2 / z;
-        var y2 = y * z2 / z;
-
-        style = this.currentOverItem_.firstElementChild.style;
-        style.left = x2 + 'px';
-        style.top = y2 + 'px';
-      }
-    }
-  },
-  dragItem: null,
-  startX: 0,
-  startY: 0,
-  startScreenX: 0,
-  startScreenY: 0,
-  dragEndTimer: null,
-
-  handleDragStart: function(e) {
-    var thumbnail = mostVisited.getItem(e.target);
-    if (thumbnail) {
-      // Don't set data since HTML5 does not allow setting the name for
-      // url-list. Instead, we just rely on the dragging of link behavior.
-      this.dragItem = thumbnail;
-      addClass(this.dragItem, 'dragging');
-      this.dragItem.style.zIndex = 2;
-      e.dataTransfer.effectAllowed = 'copyLinkMove';
-    }
-  },
-
-  handleDragEnter: function(e) {
-    if (this.canDropOnElement(this.currentOverItem)) {
-      e.preventDefault();
-    }
-  },
-
-  handleDragOver: function(e) {
-    var item = mostVisited.getItem(e.target);
-    this.currentOverItem = item;
-    if (this.canDropOnElement(item)) {
-      e.preventDefault();
-      e.dataTransfer.dropEffect = 'move';
-    }
-  },
-
-  handleDragLeave: function(e) {
-    var item = mostVisited.getItem(e.target);
-    if (item) {
-      e.preventDefault();
-    }
-
-    this.currentOverItem = null;
-  },
-
-  handleDrop: function(e) {
-    var dropTarget = mostVisited.getItem(e.target);
-    if (this.canDropOnElement(dropTarget)) {
-      dropTarget.style.zIndex = 1;
-      mostVisited.swapPosition(this.dragItem, dropTarget);
-      // The timeout below is to allow WebKit to see that we turned off
-      // pointer-event before moving the thumbnails so that we can get out of
-      // hover mode.
-      window.setTimeout(function() {
-        mostVisited.invalidate();
-        mostVisited.layout();
-      }, 10);
-      e.preventDefault();
-      if (this.dragEndTimer) {
-        window.clearTimeout(this.dragEndTimer);
-        this.dragEndTimer = null;
-      }
-      afterTransition(function() {
-        dropTarget.style.zIndex = '';
-      });
-    }
-  },
-
-  handleDragEnd: function(e) {
-    var dragItem = this.dragItem;
-    if (dragItem) {
-      dragItem.style.pointerEvents = '';
-      removeClass(dragItem, 'dragging');
-
-      afterTransition(function() {
-        // Delay resetting zIndex to let the animation finish.
-        dragItem.style.zIndex = '';
-        // Same for overflow.
-        dragItem.parentNode.style.overflow = '';
-      });
-
-      mostVisited.invalidate();
-      mostVisited.layout();
-      this.dragItem = null;
-    }
-  },
-
-  handleDrag: function(e) {
-    // Moves the drag item making sure that it is not displayed outside the
-    // browser viewport.
-    var item = mostVisited.getItem(e.target);
-    var rect = document.querySelector('#most-visited').getBoundingClientRect();
-    item.style.pointerEvents = 'none';
-
-    var x = this.startX + e.screenX - this.startScreenX;
-    var y = this.startY + e.screenY - this.startScreenY;
-
-    // The position of the item is relative to #most-visited so we need to
-    // subtract that when calculating the allowed position.
-    x = Math.max(x, -rect.left);
-    x = Math.min(x, document.body.clientWidth - rect.left - item.offsetWidth -
-                 2);
-    // The shadow is 2px
-    y = Math.max(-rect.top, y);
-    y = Math.min(y, document.body.clientHeight - rect.top - item.offsetHeight -
-                 2);
-
-    // Override right in case of RTL.
-    item.style.right = 'auto';
-    item.style.left = x + 'px';
-    item.style.top = y + 'px';
-    item.style.zIndex = 2;
-  },
-
-  // We listen to mousedown to get the relative position of the cursor for dnd.
-  handleMouseDown: function(e) {
-    var item = mostVisited.getItem(e.target);
-    if (item) {
-      this.startX = item.offsetLeft;
-      this.startY = item.offsetTop;
-      this.startScreenX = e.screenX;
-      this.startScreenY = e.screenY;
-
-      // We don't want to focus the item on mousedown. However, to prevent focus
-      // one has to call preventDefault but this also prevents the drag and drop
-      // (sigh) so we only prevent it when the user is not doing a left mouse
-      // button drag.
-      if (e.button != 0) // LEFT
-        e.preventDefault();
-    }
-  },
-
-  canDropOnElement: function(el) {
-    return this.dragItem && el && hasClass(el, 'thumbnail-container') &&
-        !hasClass(el, 'filler');
-  },
-
-  init: function() {
-    var el = $('most-visited');
-    el.addEventListener('dragstart', bind(this.handleDragStart, this));
-    el.addEventListener('dragenter', bind(this.handleDragEnter, this));
-    el.addEventListener('dragover', bind(this.handleDragOver, this));
-    el.addEventListener('dragleave', bind(this.handleDragLeave, this));
-    el.addEventListener('drop', bind(this.handleDrop, this));
-    el.addEventListener('dragend', bind(this.handleDragEnd, this));
-    el.addEventListener('drag', bind(this.handleDrag, this));
-    el.addEventListener('mousedown', bind(this.handleMouseDown, this));
-  }
-};
-
-dnd.init();
-
 /**
- * Whitelist of tag names allowed in parseHtmlSubset.
- * @type {[string]}
- */
-var allowedTags = ['A', 'B', 'STRONG'];
-
-/**
- * Parse a very small subset of HTML.
- * @param {string} s The string to parse.
- * @throws {Error} In case of non supported markup.
- * @return {DocumentFragment} A document fragment containing the DOM tree.
- */
-var allowedAttributes = {
-  'href': function(node, value) {
-    // Only allow a[href] starting with http:// and https://
-    return node.tagName == 'A' && (value.indexOf('http://') == 0 ||
-        value.indexOf('https://') == 0);
-  },
-  'target': function(node, value) {
-    // Allow a[target] but reset the value to "".
-    if (node.tagName != 'A')
-      return false;
-    node.setAttribute('target', '');
-    return true;
-  }
-}
-
-/**
- * Parse a very small subset of HTML.  This ensures that insecure HTML /
- * javascript cannot be injected into the new tab page.
- * @param {string} s The string to parse.
- * @throws {Error} In case of non supported markup.
- * @return {DocumentFragment} A document fragment containing the DOM tree.
- */
-function parseHtmlSubset(s) {
-  function walk(n, f) {
-    f(n);
-    for (var i = 0; i < n.childNodes.length; i++) {
-      walk(n.childNodes[i], f);
-    }
-  }
-
-  function assertElement(node) {
-    if (allowedTags.indexOf(node.tagName) == -1)
-      throw Error(node.tagName + ' is not supported');
-  }
-
-  function assertAttribute(attrNode, node) {
-    var n = attrNode.nodeName;
-    var v = attrNode.nodeValue;
-    if (!allowedAttributes.hasOwnProperty(n) || !allowedAttributes[n](node, v))
-      throw Error(node.tagName + '[' + n + '="' + v + '"] is not supported');
-  }
-
-  var r = document.createRange();
-  r.selectNode(document.body);
-  // This does not execute any scripts.
-  var df = r.createContextualFragment(s);
-  walk(df, function(node) {
-    switch (node.nodeType) {
-      case Node.ELEMENT_NODE:
-        assertElement(node);
-        var attrs = node.attributes;
-        for (var i = 0; i < attrs.length; i++) {
-          assertAttribute(attrs[i], node);
-        }
-        break;
-
-      case Node.COMMENT_NODE:
-      case Node.DOCUMENT_FRAGMENT_NODE:
-      case Node.TEXT_NODE:
-        break;
-
-      default:
-        throw Error('Node type ' + node.nodeType + ' is not supported');
-    }
-  });
-  return df;
-}
-
-/**
  * Makes links and buttons support a different underline color.
  * @param {Node} node The node to search for links and buttons in.
  */