Add m-esr52 at 52.6.0

1 files changed, 1536 insertions, 0 deletions

diff --git a/devtools/server/css-logic.js b/devtools/server/css-logic.js
new file mode 100644
index 000000000..f632871e1
--- /dev/null
+++ b/devtools/server/css-logic.js
@@ -0,0 +1,1536 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * About the objects defined in this file:
+ * - CssLogic contains style information about a view context. It provides
+ *   access to 2 sets of objects: Css[Sheet|Rule|Selector] provide access to
+ *   information that does not change when the selected element changes while
+ *   Css[Property|Selector]Info provide information that is dependent on the
+ *   selected element.
+ *   Its key methods are highlight(), getPropertyInfo() and forEachSheet(), etc
+ *
+ * - CssSheet provides a more useful API to a DOM CSSSheet for our purposes,
+ *   including shortSource and href.
+ * - CssRule a more useful API to a nsIDOMCSSRule including access to the group
+ *   of CssSelectors that the rule provides properties for
+ * - CssSelector A single selector - i.e. not a selector group. In other words
+ *   a CssSelector does not contain ','. This terminology is different from the
+ *   standard DOM API, but more inline with the definition in the spec.
+ *
+ * - CssPropertyInfo contains style information for a single property for the
+ *   highlighted element.
+ * - CssSelectorInfo is a wrapper around CssSelector, which adds sorting with
+ *   reference to the selected element.
+ */
+
+"use strict";
+
+const { Cc, Ci, Cu } = require("chrome");
+const DevToolsUtils = require("devtools/shared/DevToolsUtils");
+const { getRootBindingParent } = require("devtools/shared/layout/utils");
+const nodeConstants = require("devtools/shared/dom-node-constants");
+const {l10n, isContentStylesheet, shortSource, FILTER, STATUS} = require("devtools/shared/inspector/css-logic");
+
+loader.lazyRequireGetter(this, "CSSLexer", "devtools/shared/css/lexer");
+
+/**
+ * @param {function} isInherited A function that determines if the CSS property
+ *                   is inherited.
+ */
+function CssLogic(isInherited) {
+  // The cache of examined CSS properties.
+  this._isInherited = isInherited;
+  this._propertyInfos = {};
+}
+
+exports.CssLogic = CssLogic;
+
+CssLogic.prototype = {
+  // Both setup by highlight().
+  viewedElement: null,
+  viewedDocument: null,
+
+  // The cache of the known sheets.
+  _sheets: null,
+
+  // Have the sheets been cached?
+  _sheetsCached: false,
+
+  // The total number of rules, in all stylesheets, after filtering.
+  _ruleCount: 0,
+
+  // The computed styles for the viewedElement.
+  _computedStyle: null,
+
+  // Source filter. Only display properties coming from the given source
+  _sourceFilter: FILTER.USER,
+
+  // Used for tracking unique CssSheet/CssRule/CssSelector objects, in a run of
+  // processMatchedSelectors().
+  _passId: 0,
+
+  // Used for tracking matched CssSelector objects.
+  _matchId: 0,
+
+  _matchedRules: null,
+  _matchedSelectors: null,
+
+  // Cached keyframes rules in all stylesheets
+  _keyframesRules: null,
+
+  /**
+   * Reset various properties
+   */
+  reset: function () {
+    this._propertyInfos = {};
+    this._ruleCount = 0;
+    this._sheetIndex = 0;
+    this._sheets = {};
+    this._sheetsCached = false;
+    this._matchedRules = null;
+    this._matchedSelectors = null;
+    this._keyframesRules = [];
+  },
+
+  /**
+   * Focus on a new element - remove the style caches.
+   *
+   * @param {nsIDOMElement} aViewedElement the element the user has highlighted
+   * in the Inspector.
+   */
+  highlight: function (viewedElement) {
+    if (!viewedElement) {
+      this.viewedElement = null;
+      this.viewedDocument = null;
+      this._computedStyle = null;
+      this.reset();
+      return;
+    }
+
+    if (viewedElement === this.viewedElement) {
+      return;
+    }
+
+    this.viewedElement = viewedElement;
+
+    let doc = this.viewedElement.ownerDocument;
+    if (doc != this.viewedDocument) {
+      // New document: clear/rebuild the cache.
+      this.viewedDocument = doc;
+
+      // Hunt down top level stylesheets, and cache them.
+      this._cacheSheets();
+    } else {
+      // Clear cached data in the CssPropertyInfo objects.
+      this._propertyInfos = {};
+    }
+
+    this._matchedRules = null;
+    this._matchedSelectors = null;
+    this._computedStyle = CssLogic.getComputedStyle(this.viewedElement);
+  },
+
+  /**
+   * Get the values of all the computed CSS properties for the highlighted
+   * element.
+   * @returns {object} The computed CSS properties for a selected element
+   */
+  get computedStyle() {
+    return this._computedStyle;
+  },
+
+  /**
+   * Get the source filter.
+   * @returns {string} The source filter being used.
+   */
+  get sourceFilter() {
+    return this._sourceFilter;
+  },
+
+  /**
+   * Source filter. Only display properties coming from the given source (web
+   * address). Note that in order to avoid information overload we DO NOT show
+   * unmatched system rules.
+   * @see FILTER.*
+   */
+  set sourceFilter(value) {
+    let oldValue = this._sourceFilter;
+    this._sourceFilter = value;
+
+    let ruleCount = 0;
+
+    // Update the CssSheet objects.
+    this.forEachSheet(function (sheet) {
+      sheet._sheetAllowed = -1;
+      if (sheet.contentSheet && sheet.sheetAllowed) {
+        ruleCount += sheet.ruleCount;
+      }
+    }, this);
+
+    this._ruleCount = ruleCount;
+
+    // Full update is needed because the this.processMatchedSelectors() method
+    // skips UA stylesheets if the filter does not allow such sheets.
+    let needFullUpdate = (oldValue == FILTER.UA || value == FILTER.UA);
+
+    if (needFullUpdate) {
+      this._matchedRules = null;
+      this._matchedSelectors = null;
+      this._propertyInfos = {};
+    } else {
+      // Update the CssPropertyInfo objects.
+      for (let property in this._propertyInfos) {
+        this._propertyInfos[property].needRefilter = true;
+      }
+    }
+  },
+
+  /**
+   * Return a CssPropertyInfo data structure for the currently viewed element
+   * and the specified CSS property. If there is no currently viewed element we
+   * return an empty object.
+   *
+   * @param {string} property The CSS property to look for.
+   * @return {CssPropertyInfo} a CssPropertyInfo structure for the given
+   * property.
+   */
+  getPropertyInfo: function (property) {
+    if (!this.viewedElement) {
+      return {};
+    }
+
+    let info = this._propertyInfos[property];
+    if (!info) {
+      info = new CssPropertyInfo(this, property, this._isInherited);
+      this._propertyInfos[property] = info;
+    }
+
+    return info;
+  },
+
+  /**
+   * Cache all the stylesheets in the inspected document
+   * @private
+   */
+  _cacheSheets: function () {
+    this._passId++;
+    this.reset();
+
+    // styleSheets isn't an array, but forEach can work on it anyway
+    Array.prototype.forEach.call(this.viewedDocument.styleSheets,
+        this._cacheSheet, this);
+
+    this._sheetsCached = true;
+  },
+
+  /**
+   * Cache a stylesheet if it falls within the requirements: if it's enabled,
+   * and if the @media is allowed. This method also walks through the stylesheet
+   * cssRules to find @imported rules, to cache the stylesheets of those rules
+   * as well. In addition, the @keyframes rules in the stylesheet are cached.
+   *
+   * @private
+   * @param {CSSStyleSheet} domSheet the CSSStyleSheet object to cache.
+   */
+  _cacheSheet: function (domSheet) {
+    if (domSheet.disabled) {
+      return;
+    }
+
+    // Only work with stylesheets that have their media allowed.
+    if (!this.mediaMatches(domSheet)) {
+      return;
+    }
+
+    // Cache the sheet.
+    let cssSheet = this.getSheet(domSheet, this._sheetIndex++);
+    if (cssSheet._passId != this._passId) {
+      cssSheet._passId = this._passId;
+
+      // Find import and keyframes rules.
+      for (let aDomRule of domSheet.cssRules) {
+        if (aDomRule.type == CSSRule.IMPORT_RULE &&
+            aDomRule.styleSheet &&
+            this.mediaMatches(aDomRule)) {
+          this._cacheSheet(aDomRule.styleSheet);
+        } else if (aDomRule.type == CSSRule.KEYFRAMES_RULE) {
+          this._keyframesRules.push(aDomRule);
+        }
+      }
+    }
+  },
+
+  /**
+   * Retrieve the list of stylesheets in the document.
+   *
+   * @return {array} the list of stylesheets in the document.
+   */
+  get sheets() {
+    if (!this._sheetsCached) {
+      this._cacheSheets();
+    }
+
+    let sheets = [];
+    this.forEachSheet(function (sheet) {
+      if (sheet.contentSheet) {
+        sheets.push(sheet);
+      }
+    }, this);
+
+    return sheets;
+  },
+
+  /**
+   * Retrieve the list of keyframes rules in the document.
+   *
+   * @ return {array} the list of keyframes rules in the document.
+   */
+  get keyframesRules() {
+    if (!this._sheetsCached) {
+      this._cacheSheets();
+    }
+    return this._keyframesRules;
+  },
+
+  /**
+   * Retrieve a CssSheet object for a given a CSSStyleSheet object. If the
+   * stylesheet is already cached, you get the existing CssSheet object,
+   * otherwise the new CSSStyleSheet object is cached.
+   *
+   * @param {CSSStyleSheet} domSheet the CSSStyleSheet object you want.
+   * @param {number} index the index, within the document, of the stylesheet.
+   *
+   * @return {CssSheet} the CssSheet object for the given CSSStyleSheet object.
+   */
+  getSheet: function (domSheet, index) {
+    let cacheId = "";
+
+    if (domSheet.href) {
+      cacheId = domSheet.href;
+    } else if (domSheet.ownerNode && domSheet.ownerNode.ownerDocument) {
+      cacheId = domSheet.ownerNode.ownerDocument.location;
+    }
+
+    let sheet = null;
+    let sheetFound = false;
+
+    if (cacheId in this._sheets) {
+      for (let i = 0, numSheets = this._sheets[cacheId].length;
+           i < numSheets;
+           i++) {
+        sheet = this._sheets[cacheId][i];
+        if (sheet.domSheet === domSheet) {
+          if (index != -1) {
+            sheet.index = index;
+          }
+          sheetFound = true;
+          break;
+        }
+      }
+    }
+
+    if (!sheetFound) {
+      if (!(cacheId in this._sheets)) {
+        this._sheets[cacheId] = [];
+      }
+
+      sheet = new CssSheet(this, domSheet, index);
+      if (sheet.sheetAllowed && sheet.contentSheet) {
+        this._ruleCount += sheet.ruleCount;
+      }
+
+      this._sheets[cacheId].push(sheet);
+    }
+
+    return sheet;
+  },
+
+  /**
+   * Process each cached stylesheet in the document using your callback.
+   *
+   * @param {function} callback the function you want executed for each of the
+   * CssSheet objects cached.
+   * @param {object} scope the scope you want for the callback function. scope
+   * will be the this object when callback executes.
+   */
+  forEachSheet: function (callback, scope) {
+    for (let cacheId in this._sheets) {
+      let sheets = this._sheets[cacheId];
+      for (let i = 0; i < sheets.length; i++) {
+        // We take this as an opportunity to clean dead sheets
+        try {
+          let sheet = sheets[i];
+          // If accessing domSheet raises an exception, then the style
+          // sheet is a dead object.
+          sheet.domSheet;
+          callback.call(scope, sheet, i, sheets);
+        } catch (e) {
+          sheets.splice(i, 1);
+          i--;
+        }
+      }
+    }
+  },
+
+  /**
+
+  /**
+   * Get the number nsIDOMCSSRule objects in the document, counted from all of
+   * the stylesheets. System sheets are excluded. If a filter is active, this
+   * tells only the number of nsIDOMCSSRule objects inside the selected
+   * CSSStyleSheet.
+   *
+   * WARNING: This only provides an estimate of the rule count, and the results
+   * could change at a later date. Todo remove this
+   *
+   * @return {number} the number of nsIDOMCSSRule (all rules).
+   */
+  get ruleCount() {
+    if (!this._sheetsCached) {
+      this._cacheSheets();
+    }
+
+    return this._ruleCount;
+  },
+
+  /**
+   * Process the CssSelector objects that match the highlighted element and its
+   * parent elements. scope.callback() is executed for each CssSelector
+   * object, being passed the CssSelector object and the match status.
+   *
+   * This method also includes all of the element.style properties, for each
+   * highlighted element parent and for the highlighted element itself.
+   *
+   * Note that the matched selectors are cached, such that next time your
+   * callback is invoked for the cached list of CssSelector objects.
+   *
+   * @param {function} callback the function you want to execute for each of
+   * the matched selectors.
+   * @param {object} scope the scope you want for the callback function. scope
+   * will be the this object when callback executes.
+   */
+  processMatchedSelectors: function (callback, scope) {
+    if (this._matchedSelectors) {
+      if (callback) {
+        this._passId++;
+        this._matchedSelectors.forEach(function (value) {
+          callback.call(scope, value[0], value[1]);
+          value[0].cssRule._passId = this._passId;
+        }, this);
+      }
+      return;
+    }
+
+    if (!this._matchedRules) {
+      this._buildMatchedRules();
+    }
+
+    this._matchedSelectors = [];
+    this._passId++;
+
+    for (let i = 0; i < this._matchedRules.length; i++) {
+      let rule = this._matchedRules[i][0];
+      let status = this._matchedRules[i][1];
+
+      rule.selectors.forEach(function (selector) {
+        if (selector._matchId !== this._matchId &&
+           (selector.elementStyle ||
+            this.selectorMatchesElement(rule.domRule,
+                                        selector.selectorIndex))) {
+          selector._matchId = this._matchId;
+          this._matchedSelectors.push([ selector, status ]);
+          if (callback) {
+            callback.call(scope, selector, status);
+          }
+        }
+      }, this);
+
+      rule._passId = this._passId;
+    }
+  },
+
+  /**
+   * Check if the given selector matches the highlighted element or any of its
+   * parents.
+   *
+   * @private
+   * @param {DOMRule} domRule
+   *        The DOM Rule containing the selector.
+   * @param {Number} idx
+   *        The index of the selector within the DOMRule.
+   * @return {boolean}
+   *         true if the given selector matches the highlighted element or any
+   *         of its parents, otherwise false is returned.
+   */
+  selectorMatchesElement: function (domRule, idx) {
+    let element = this.viewedElement;
+    do {
+      if (domUtils.selectorMatchesElement(element, domRule, idx)) {
+        return true;
+      }
+    } while ((element = element.parentNode) &&
+             element.nodeType === nodeConstants.ELEMENT_NODE);
+
+    return false;
+  },
+
+  /**
+   * Check if the highlighted element or it's parents have matched selectors.
+   *
+   * @param {array} aProperties The list of properties you want to check if they
+   * have matched selectors or not.
+   * @return {object} An object that tells for each property if it has matched
+   * selectors or not. Object keys are property names and values are booleans.
+   */
+  hasMatchedSelectors: function (properties) {
+    if (!this._matchedRules) {
+      this._buildMatchedRules();
+    }
+
+    let result = {};
+
+    this._matchedRules.some(function (value) {
+      let rule = value[0];
+      let status = value[1];
+      properties = properties.filter((property) => {
+        // We just need to find if a rule has this property while it matches
+        // the viewedElement (or its parents).
+        if (rule.getPropertyValue(property) &&
+            (status == STATUS.MATCHED ||
+             (status == STATUS.PARENT_MATCH &&
+              this._isInherited(property)))) {
+          result[property] = true;
+          return false;
+        }
+        // Keep the property for the next rule.
+        return true;
+      });
+      return properties.length == 0;
+    }, this);
+
+    return result;
+  },
+
+  /**
+   * Build the array of matched rules for the currently highlighted element.
+   * The array will hold rules that match the viewedElement and its parents.
+   *
+   * @private
+   */
+  _buildMatchedRules: function () {
+    let domRules;
+    let element = this.viewedElement;
+    let filter = this.sourceFilter;
+    let sheetIndex = 0;
+
+    this._matchId++;
+    this._passId++;
+    this._matchedRules = [];
+
+    if (!element) {
+      return;
+    }
+
+    do {
+      let status = this.viewedElement === element ?
+                   STATUS.MATCHED : STATUS.PARENT_MATCH;
+
+      try {
+        // Handle finding rules on pseudo by reading style rules
+        // on the parent node with proper pseudo arg to getCSSStyleRules.
+        let {bindingElement, pseudo} =
+            CssLogic.getBindingElementAndPseudo(element);
+        domRules = domUtils.getCSSStyleRules(bindingElement, pseudo);
+      } catch (ex) {
+        console.log("CL__buildMatchedRules error: " + ex);
+        continue;
+      }
+
+      // getCSSStyleRules can return null with a shadow DOM element.
+      let numDomRules = domRules ? domRules.Count() : 0;
+      for (let i = 0; i < numDomRules; i++) {
+        let domRule = domRules.GetElementAt(i);
+        if (domRule.type !== CSSRule.STYLE_RULE) {
+          continue;
+        }
+
+        let sheet = this.getSheet(domRule.parentStyleSheet, -1);
+        if (sheet._passId !== this._passId) {
+          sheet.index = sheetIndex++;
+          sheet._passId = this._passId;
+        }
+
+        if (filter === FILTER.USER && !sheet.contentSheet) {
+          continue;
+        }
+
+        let rule = sheet.getRule(domRule);
+        if (rule._passId === this._passId) {
+          continue;
+        }
+
+        rule._matchId = this._matchId;
+        rule._passId = this._passId;
+        this._matchedRules.push([rule, status]);
+      }
+
+      // Add element.style information.
+      if (element.style && element.style.length > 0) {
+        let rule = new CssRule(null, { style: element.style }, element);
+        rule._matchId = this._matchId;
+        rule._passId = this._passId;
+        this._matchedRules.push([rule, status]);
+      }
+    } while ((element = element.parentNode) &&
+              element.nodeType === nodeConstants.ELEMENT_NODE);
+  },
+
+  /**
+   * Tells if the given DOM CSS object matches the current view media.
+   *
+   * @param {object} domObject The DOM CSS object to check.
+   * @return {boolean} True if the DOM CSS object matches the current view
+   * media, or false otherwise.
+   */
+  mediaMatches: function (domObject) {
+    let mediaText = domObject.media.mediaText;
+    return !mediaText ||
+      this.viewedDocument.defaultView.matchMedia(mediaText).matches;
+  },
+};
+
+/**
+ * If the element has an id, return '#id'. Otherwise return 'tagname[n]' where
+ * n is the index of this element in its siblings.
+ * <p>A technically more 'correct' output from the no-id case might be:
+ * 'tagname:nth-of-type(n)' however this is unlikely to be more understood
+ * and it is longer.
+ *
+ * @param {nsIDOMElement} element the element for which you want the short name.
+ * @return {string} the string to be displayed for element.
+ */
+CssLogic.getShortName = function (element) {
+  if (!element) {
+    return "null";
+  }
+  if (element.id) {
+    return "#" + element.id;
+  }
+  let priorSiblings = 0;
+  let temp = element;
+  while ((temp = temp.previousElementSibling)) {
+    priorSiblings++;
+  }
+  return element.tagName + "[" + priorSiblings + "]";
+};
+
+/**
+ * Get a string list of selectors for a given DOMRule.
+ *
+ * @param {DOMRule} domRule
+ *        The DOMRule to parse.
+ * @return {Array}
+ *         An array of string selectors.
+ */
+CssLogic.getSelectors = function (domRule) {
+  let selectors = [];
+
+  let len = domUtils.getSelectorCount(domRule);
+  for (let i = 0; i < len; i++) {
+    let text = domUtils.getSelectorText(domRule, i);
+    selectors.push(text);
+  }
+  return selectors;
+};
+
+/**
+ * Given a node, check to see if it is a ::before or ::after element.
+ * If so, return the node that is accessible from within the document
+ * (the parent of the anonymous node), along with which pseudo element
+ * it was.  Otherwise, return the node itself.
+ *
+ * @returns {Object}
+ *            - {DOMNode} node The non-anonymous node
+ *            - {string} pseudo One of ':before', ':after', or null.
+ */
+CssLogic.getBindingElementAndPseudo = function (node) {
+  let bindingElement = node;
+  let pseudo = null;
+  if (node.nodeName == "_moz_generated_content_before") {
+    bindingElement = node.parentNode;
+    pseudo = ":before";
+  } else if (node.nodeName == "_moz_generated_content_after") {
+    bindingElement = node.parentNode;
+    pseudo = ":after";
+  }
+  return {
+    bindingElement: bindingElement,
+    pseudo: pseudo
+  };
+};
+
+/**
+ * Get the computed style on a node.  Automatically handles reading
+ * computed styles on a ::before/::after element by reading on the
+ * parent node with the proper pseudo argument.
+ *
+ * @param {Node}
+ * @returns {CSSStyleDeclaration}
+ */
+CssLogic.getComputedStyle = function (node) {
+  if (!node ||
+      Cu.isDeadWrapper(node) ||
+      node.nodeType !== nodeConstants.ELEMENT_NODE ||
+      !node.ownerDocument ||
+      !node.ownerDocument.defaultView) {
+    return null;
+  }
+
+  let {bindingElement, pseudo} = CssLogic.getBindingElementAndPseudo(node);
+  return node.ownerDocument.defaultView.getComputedStyle(bindingElement,
+                                                         pseudo);
+};
+
+/**
+ * Get a source for a stylesheet, taking into account embedded stylesheets
+ * for which we need to use document.defaultView.location.href rather than
+ * sheet.href
+ *
+ * @param {CSSStyleSheet} sheet the DOM object for the style sheet.
+ * @return {string} the address of the stylesheet.
+ */
+CssLogic.href = function (sheet) {
+  let href = sheet.href;
+  if (!href) {
+    href = sheet.ownerNode.ownerDocument.location;
+  }
+
+  return href;
+};
+
+/**
+ * Find the position of [element] in [nodeList].
+ * @returns an index of the match, or -1 if there is no match
+ */
+function positionInNodeList(element, nodeList) {
+  for (let i = 0; i < nodeList.length; i++) {
+    if (element === nodeList[i]) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+/**
+ * Find a unique CSS selector for a given element
+ * @returns a string such that ele.ownerDocument.querySelector(reply) === ele
+ * and ele.ownerDocument.querySelectorAll(reply).length === 1
+ */
+CssLogic.findCssSelector = function (ele) {
+  ele = getRootBindingParent(ele);
+  let document = ele.ownerDocument;
+  if (!document || !document.contains(ele)) {
+    throw new Error("findCssSelector received element not inside document");
+  }
+
+  // document.querySelectorAll("#id") returns multiple if elements share an ID
+  if (ele.id &&
+      document.querySelectorAll("#" + CSS.escape(ele.id)).length === 1) {
+    return "#" + CSS.escape(ele.id);
+  }
+
+  // Inherently unique by tag name
+  let tagName = ele.localName;
+  if (tagName === "html") {
+    return "html";
+  }
+  if (tagName === "head") {
+    return "head";
+  }
+  if (tagName === "body") {
+    return "body";
+  }
+
+  // We might be able to find a unique class name
+  let selector, index, matches;
+  if (ele.classList.length > 0) {
+    for (let i = 0; i < ele.classList.length; i++) {
+      // Is this className unique by itself?
+      selector = "." + CSS.escape(ele.classList.item(i));
+      matches = document.querySelectorAll(selector);
+      if (matches.length === 1) {
+        return selector;
+      }
+      // Maybe it's unique with a tag name?
+      selector = tagName + selector;
+      matches = document.querySelectorAll(selector);
+      if (matches.length === 1) {
+        return selector;
+      }
+      // Maybe it's unique using a tag name and nth-child
+      index = positionInNodeList(ele, ele.parentNode.children) + 1;
+      selector = selector + ":nth-child(" + index + ")";
+      matches = document.querySelectorAll(selector);
+      if (matches.length === 1) {
+        return selector;
+      }
+    }
+  }
+
+  // Not unique enough yet.  As long as it's not a child of the document,
+  // continue recursing up until it is unique enough.
+  if (ele.parentNode !== document) {
+    index = positionInNodeList(ele, ele.parentNode.children) + 1;
+    selector = CssLogic.findCssSelector(ele.parentNode) + " > " +
+      tagName + ":nth-child(" + index + ")";
+  }
+
+  return selector;
+};
+
+/**
+ * A safe way to access cached bits of information about a stylesheet.
+ *
+ * @constructor
+ * @param {CssLogic} cssLogic pointer to the CssLogic instance working with
+ * this CssSheet object.
+ * @param {CSSStyleSheet} domSheet reference to a DOM CSSStyleSheet object.
+ * @param {number} index tells the index/position of the stylesheet within the
+ * main document.
+ */
+function CssSheet(cssLogic, domSheet, index) {
+  this._cssLogic = cssLogic;
+  this.domSheet = domSheet;
+  this.index = this.contentSheet ? index : -100 * index;
+
+  // Cache of the sheets href. Cached by the getter.
+  this._href = null;
+  // Short version of href for use in select boxes etc. Cached by getter.
+  this._shortSource = null;
+
+  // null for uncached.
+  this._sheetAllowed = null;
+
+  // Cached CssRules from the given stylesheet.
+  this._rules = {};
+
+  this._ruleCount = -1;
+}
+
+CssSheet.prototype = {
+  _passId: null,
+  _contentSheet: null,
+
+  /**
+   * Tells if the stylesheet is provided by the browser or not.
+   *
+   * @return {boolean} false if this is a browser-provided stylesheet, or true
+   * otherwise.
+   */
+  get contentSheet() {
+    if (this._contentSheet === null) {
+      this._contentSheet = isContentStylesheet(this.domSheet);
+    }
+    return this._contentSheet;
+  },
+
+  /**
+   * Tells if the stylesheet is disabled or not.
+   * @return {boolean} true if this stylesheet is disabled, or false otherwise.
+   */
+  get disabled() {
+    return this.domSheet.disabled;
+  },
+
+  /**
+   * Get a source for a stylesheet, using CssLogic.href
+   *
+   * @return {string} the address of the stylesheet.
+   */
+  get href() {
+    if (this._href) {
+      return this._href;
+    }
+
+    this._href = CssLogic.href(this.domSheet);
+    return this._href;
+  },
+
+  /**
+   * Create a shorthand version of the href of a stylesheet.
+   *
+   * @return {string} the shorthand source of the stylesheet.
+   */
+  get shortSource() {
+    if (this._shortSource) {
+      return this._shortSource;
+    }
+
+    this._shortSource = shortSource(this.domSheet);
+    return this._shortSource;
+  },
+
+  /**
+   * Tells if the sheet is allowed or not by the current CssLogic.sourceFilter.
+   *
+   * @return {boolean} true if the stylesheet is allowed by the sourceFilter, or
+   * false otherwise.
+   */
+  get sheetAllowed() {
+    if (this._sheetAllowed !== null) {
+      return this._sheetAllowed;
+    }
+
+    this._sheetAllowed = true;
+
+    let filter = this._cssLogic.sourceFilter;
+    if (filter === FILTER.USER && !this.contentSheet) {
+      this._sheetAllowed = false;
+    }
+    if (filter !== FILTER.USER && filter !== FILTER.UA) {
+      this._sheetAllowed = (filter === this.href);
+    }
+
+    return this._sheetAllowed;
+  },
+
+  /**
+   * Retrieve the number of rules in this stylesheet.
+   *
+   * @return {number} the number of nsIDOMCSSRule objects in this stylesheet.
+   */
+  get ruleCount() {
+    return this._ruleCount > -1 ?
+      this._ruleCount :
+      this.domSheet.cssRules.length;
+  },
+
+  /**
+   * Retrieve a CssRule object for the given CSSStyleRule. The CssRule object is
+   * cached, such that subsequent retrievals return the same CssRule object for
+   * the same CSSStyleRule object.
+   *
+   * @param {CSSStyleRule} aDomRule the CSSStyleRule object for which you want a
+   * CssRule object.
+   * @return {CssRule} the cached CssRule object for the given CSSStyleRule
+   * object.
+   */
+  getRule: function (domRule) {
+    let cacheId = domRule.type + domRule.selectorText;
+
+    let rule = null;
+    let ruleFound = false;
+
+    if (cacheId in this._rules) {
+      for (let i = 0, rulesLen = this._rules[cacheId].length;
+           i < rulesLen;
+           i++) {
+        rule = this._rules[cacheId][i];
+        if (rule.domRule === domRule) {
+          ruleFound = true;
+          break;
+        }
+      }
+    }
+
+    if (!ruleFound) {
+      if (!(cacheId in this._rules)) {
+        this._rules[cacheId] = [];
+      }
+
+      rule = new CssRule(this, domRule);
+      this._rules[cacheId].push(rule);
+    }
+
+    return rule;
+  },
+
+  toString: function () {
+    return "CssSheet[" + this.shortSource + "]";
+  }
+};
+
+/**
+ * Information about a single CSSStyleRule.
+ *
+ * @param {CSSSheet|null} cssSheet the CssSheet object of the stylesheet that
+ * holds the CSSStyleRule. If the rule comes from element.style, set this
+ * argument to null.
+ * @param {CSSStyleRule|object} domRule the DOM CSSStyleRule for which you want
+ * to cache data. If the rule comes from element.style, then provide
+ * an object of the form: {style: element.style}.
+ * @param {Element} [element] If the rule comes from element.style, then this
+ * argument must point to the element.
+ * @constructor
+ */
+function CssRule(cssSheet, domRule, element) {
+  this._cssSheet = cssSheet;
+  this.domRule = domRule;
+
+  let parentRule = domRule.parentRule;
+  if (parentRule && parentRule.type == CSSRule.MEDIA_RULE) {
+    this.mediaText = parentRule.media.mediaText;
+  }
+
+  if (this._cssSheet) {
+    // parse domRule.selectorText on call to this.selectors
+    this._selectors = null;
+    this.line = domUtils.getRuleLine(this.domRule);
+    this.source = this._cssSheet.shortSource + ":" + this.line;
+    if (this.mediaText) {
+      this.source += " @media " + this.mediaText;
+    }
+    this.href = this._cssSheet.href;
+    this.contentRule = this._cssSheet.contentSheet;
+  } else if (element) {
+    this._selectors = [ new CssSelector(this, "@element.style", 0) ];
+    this.line = -1;
+    this.source = l10n("rule.sourceElement");
+    this.href = "#";
+    this.contentRule = true;
+    this.sourceElement = element;
+  }
+}
+
+CssRule.prototype = {
+  _passId: null,
+
+  mediaText: "",
+
+  get isMediaRule() {
+    return !!this.mediaText;
+  },
+
+  /**
+   * Check if the parent stylesheet is allowed by the CssLogic.sourceFilter.
+   *
+   * @return {boolean} true if the parent stylesheet is allowed by the current
+   * sourceFilter, or false otherwise.
+   */
+  get sheetAllowed() {
+    return this._cssSheet ? this._cssSheet.sheetAllowed : true;
+  },
+
+  /**
+   * Retrieve the parent stylesheet index/position in the viewed document.
+   *
+   * @return {number} the parent stylesheet index/position in the viewed
+   * document.
+   */
+  get sheetIndex() {
+    return this._cssSheet ? this._cssSheet.index : 0;
+  },
+
+  /**
+   * Retrieve the style property value from the current CSSStyleRule.
+   *
+   * @param {string} property the CSS property name for which you want the
+   * value.
+   * @return {string} the property value.
+   */
+  getPropertyValue: function (property) {
+    return this.domRule.style.getPropertyValue(property);
+  },
+
+  /**
+   * Retrieve the style property priority from the current CSSStyleRule.
+   *
+   * @param {string} property the CSS property name for which you want the
+   * priority.
+   * @return {string} the property priority.
+   */
+  getPropertyPriority: function (property) {
+    return this.domRule.style.getPropertyPriority(property);
+  },
+
+  /**
+   * Retrieve the list of CssSelector objects for each of the parsed selectors
+   * of the current CSSStyleRule.
+   *
+   * @return {array} the array hold the CssSelector objects.
+   */
+  get selectors() {
+    if (this._selectors) {
+      return this._selectors;
+    }
+
+    // Parse the CSSStyleRule.selectorText string.
+    this._selectors = [];
+
+    if (!this.domRule.selectorText) {
+      return this._selectors;
+    }
+
+    let selectors = CssLogic.getSelectors(this.domRule);
+
+    for (let i = 0, len = selectors.length; i < len; i++) {
+      this._selectors.push(new CssSelector(this, selectors[i], i));
+    }
+
+    return this._selectors;
+  },
+
+  toString: function () {
+    return "[CssRule " + this.domRule.selectorText + "]";
+  },
+};
+
+/**
+ * The CSS selector class allows us to document the ranking of various CSS
+ * selectors.
+ *
+ * @constructor
+ * @param {CssRule} cssRule the CssRule instance from where the selector comes.
+ * @param {string} selector The selector that we wish to investigate.
+ * @param {Number} index The index of the selector within it's rule.
+ */
+function CssSelector(cssRule, selector, index) {
+  this.cssRule = cssRule;
+  this.text = selector;
+  this.elementStyle = this.text == "@element.style";
+  this._specificity = null;
+  this.selectorIndex = index;
+}
+
+exports.CssSelector = CssSelector;
+
+CssSelector.prototype = {
+  _matchId: null,
+
+  /**
+   * Retrieve the CssSelector source, which is the source of the CssSheet owning
+   * the selector.
+   *
+   * @return {string} the selector source.
+   */
+  get source() {
+    return this.cssRule.source;
+  },
+
+  /**
+   * Retrieve the CssSelector source element, which is the source of the CssRule
+   * owning the selector. This is only available when the CssSelector comes from
+   * an element.style.
+   *
+   * @return {string} the source element selector.
+   */
+  get sourceElement() {
+    return this.cssRule.sourceElement;
+  },
+
+  /**
+   * Retrieve the address of the CssSelector. This points to the address of the
+   * CssSheet owning this selector.
+   *
+   * @return {string} the address of the CssSelector.
+   */
+  get href() {
+    return this.cssRule.href;
+  },
+
+  /**
+   * Check if the selector comes from a browser-provided stylesheet.
+   *
+   * @return {boolean} true if the selector comes from a content-provided
+   * stylesheet, or false otherwise.
+   */
+  get contentRule() {
+    return this.cssRule.contentRule;
+  },
+
+  /**
+   * Check if the parent stylesheet is allowed by the CssLogic.sourceFilter.
+   *
+   * @return {boolean} true if the parent stylesheet is allowed by the current
+   * sourceFilter, or false otherwise.
+   */
+  get sheetAllowed() {
+    return this.cssRule.sheetAllowed;
+  },
+
+  /**
+   * Retrieve the parent stylesheet index/position in the viewed document.
+   *
+   * @return {number} the parent stylesheet index/position in the viewed
+   * document.
+   */
+  get sheetIndex() {
+    return this.cssRule.sheetIndex;
+  },
+
+  /**
+   * Retrieve the line of the parent CSSStyleRule in the parent CSSStyleSheet.
+   *
+   * @return {number} the line of the parent CSSStyleRule in the parent
+   * stylesheet.
+   */
+  get ruleLine() {
+    return this.cssRule.line;
+  },
+
+  /**
+   * Retrieve specificity information for the current selector.
+   *
+   * @see http://www.w3.org/TR/css3-selectors/#specificity
+   * @see http://www.w3.org/TR/CSS2/selector.html
+   *
+   * @return {Number} The selector's specificity.
+   */
+  get specificity() {
+    if (this.elementStyle) {
+      // We can't ask specificity from DOMUtils as element styles don't provide
+      // CSSStyleRule interface DOMUtils expect. However, specificity of element
+      // style is constant, 1,0,0,0 or 0x01000000, just return the constant
+      // directly. @see http://www.w3.org/TR/CSS2/cascade.html#specificity
+      return 0x01000000;
+    }
+
+    if (this._specificity) {
+      return this._specificity;
+    }
+
+    this._specificity = domUtils.getSpecificity(this.cssRule.domRule,
+                                                this.selectorIndex);
+
+    return this._specificity;
+  },
+
+  toString: function () {
+    return this.text;
+  },
+};
+
+/**
+ * A cache of information about the matched rules, selectors and values attached
+ * to a CSS property, for the highlighted element.
+ *
+ * The heart of the CssPropertyInfo object is the _findMatchedSelectors()
+ * method. This are invoked when the PropertyView tries to access the
+ * .matchedSelectors array.
+ * Results are cached, for later reuse.
+ *
+ * @param {CssLogic} cssLogic Reference to the parent CssLogic instance
+ * @param {string} property The CSS property we are gathering information for
+ * @param {function} isInherited A function that determines if the CSS property
+ *                   is inherited.
+ * @constructor
+ */
+function CssPropertyInfo(cssLogic, property, isInherited) {
+  this._cssLogic = cssLogic;
+  this.property = property;
+  this._value = "";
+  this._isInherited = isInherited;
+
+  // An array holding CssSelectorInfo objects for each of the matched selectors
+  // that are inside a CSS rule. Only rules that hold the this.property are
+  // counted. This includes rules that come from filtered stylesheets (those
+  // that have sheetAllowed = false).
+  this._matchedSelectors = null;
+}
+
+CssPropertyInfo.prototype = {
+  /**
+   * Retrieve the computed style value for the current property, for the
+   * highlighted element.
+   *
+   * @return {string} the computed style value for the current property, for the
+   * highlighted element.
+   */
+  get value() {
+    if (!this._value && this._cssLogic.computedStyle) {
+      try {
+        this._value =
+          this._cssLogic.computedStyle.getPropertyValue(this.property);
+      } catch (ex) {
+        console.log("Error reading computed style for " + this.property);
+        console.log(ex);
+      }
+    }
+    return this._value;
+  },
+
+  /**
+   * Retrieve the array holding CssSelectorInfo objects for each of the matched
+   * selectors, from each of the matched rules. Only selectors coming from
+   * allowed stylesheets are included in the array.
+   *
+   * @return {array} the list of CssSelectorInfo objects of selectors that match
+   * the highlighted element and its parents.
+   */
+  get matchedSelectors() {
+    if (!this._matchedSelectors) {
+      this._findMatchedSelectors();
+    } else if (this.needRefilter) {
+      this._refilterSelectors();
+    }
+
+    return this._matchedSelectors;
+  },
+
+  /**
+   * Find the selectors that match the highlighted element and its parents.
+   * Uses CssLogic.processMatchedSelectors() to find the matched selectors,
+   * passing in a reference to CssPropertyInfo._processMatchedSelector() to
+   * create CssSelectorInfo objects, which we then sort
+   * @private
+   */
+  _findMatchedSelectors: function () {
+    this._matchedSelectors = [];
+    this.needRefilter = false;
+
+    this._cssLogic.processMatchedSelectors(this._processMatchedSelector, this);
+
+    // Sort the selectors by how well they match the given element.
+    this._matchedSelectors.sort(function (selectorInfo1, selectorInfo2) {
+      if (selectorInfo1.status > selectorInfo2.status) {
+        return -1;
+      } else if (selectorInfo2.status > selectorInfo1.status) {
+        return 1;
+      }
+      return selectorInfo1.compareTo(selectorInfo2);
+    });
+
+    // Now we know which of the matches is best, we can mark it BEST_MATCH.
+    if (this._matchedSelectors.length > 0 &&
+        this._matchedSelectors[0].status > STATUS.UNMATCHED) {
+      this._matchedSelectors[0].status = STATUS.BEST;
+    }
+  },
+
+  /**
+   * Process a matched CssSelector object.
+   *
+   * @private
+   * @param {CssSelector} selector the matched CssSelector object.
+   * @param {STATUS} status the CssSelector match status.
+   */
+  _processMatchedSelector: function (selector, status) {
+    let cssRule = selector.cssRule;
+    let value = cssRule.getPropertyValue(this.property);
+    if (value &&
+        (status == STATUS.MATCHED ||
+         (status == STATUS.PARENT_MATCH &&
+          this._isInherited(this.property)))) {
+      let selectorInfo = new CssSelectorInfo(selector, this.property, value,
+          status);
+      this._matchedSelectors.push(selectorInfo);
+    }
+  },
+
+  /**
+   * Refilter the matched selectors array when the CssLogic.sourceFilter
+   * changes. This allows for quick filter changes.
+   * @private
+   */
+  _refilterSelectors: function () {
+    let passId = ++this._cssLogic._passId;
+
+    let iterator = function (selectorInfo) {
+      let cssRule = selectorInfo.selector.cssRule;
+      if (cssRule._passId != passId) {
+        cssRule._passId = passId;
+      }
+    };
+
+    if (this._matchedSelectors) {
+      this._matchedSelectors.forEach(iterator);
+    }
+
+    this.needRefilter = false;
+  },
+
+  toString: function () {
+    return "CssPropertyInfo[" + this.property + "]";
+  },
+};
+
+/**
+ * A class that holds information about a given CssSelector object.
+ *
+ * Instances of this class are given to CssHtmlTree in the array of matched
+ * selectors. Each such object represents a displayable row in the PropertyView
+ * objects. The information given by this object blends data coming from the
+ * CssSheet, CssRule and from the CssSelector that own this object.
+ *
+ * @param {CssSelector} selector The CssSelector object for which to
+ *        present information.
+ * @param {string} property The property for which information should
+ *        be retrieved.
+ * @param {string} value The property value from the CssRule that owns
+ *        the selector.
+ * @param {STATUS} status The selector match status.
+ * @constructor
+ */
+function CssSelectorInfo(selector, property, value, status) {
+  this.selector = selector;
+  this.property = property;
+  this.status = status;
+  this.value = value;
+  let priority = this.selector.cssRule.getPropertyPriority(this.property);
+  this.important = (priority === "important");
+}
+
+CssSelectorInfo.prototype = {
+  /**
+   * Retrieve the CssSelector source, which is the source of the CssSheet owning
+   * the selector.
+   *
+   * @return {string} the selector source.
+   */
+  get source() {
+    return this.selector.source;
+  },
+
+  /**
+   * Retrieve the CssSelector source element, which is the source of the CssRule
+   * owning the selector. This is only available when the CssSelector comes from
+   * an element.style.
+   *
+   * @return {string} the source element selector.
+   */
+  get sourceElement() {
+    return this.selector.sourceElement;
+  },
+
+  /**
+   * Retrieve the address of the CssSelector. This points to the address of the
+   * CssSheet owning this selector.
+   *
+   * @return {string} the address of the CssSelector.
+   */
+  get href() {
+    return this.selector.href;
+  },
+
+  /**
+   * Check if the CssSelector comes from element.style or not.
+   *
+   * @return {boolean} true if the CssSelector comes from element.style, or
+   * false otherwise.
+   */
+  get elementStyle() {
+    return this.selector.elementStyle;
+  },
+
+  /**
+   * Retrieve specificity information for the current selector.
+   *
+   * @return {object} an object holding specificity information for the current
+   * selector.
+   */
+  get specificity() {
+    return this.selector.specificity;
+  },
+
+  /**
+   * Retrieve the parent stylesheet index/position in the viewed document.
+   *
+   * @return {number} the parent stylesheet index/position in the viewed
+   * document.
+   */
+  get sheetIndex() {
+    return this.selector.sheetIndex;
+  },
+
+  /**
+   * Check if the parent stylesheet is allowed by the CssLogic.sourceFilter.
+   *
+   * @return {boolean} true if the parent stylesheet is allowed by the current
+   * sourceFilter, or false otherwise.
+   */
+  get sheetAllowed() {
+    return this.selector.sheetAllowed;
+  },
+
+  /**
+   * Retrieve the line of the parent CSSStyleRule in the parent CSSStyleSheet.
+   *
+   * @return {number} the line of the parent CSSStyleRule in the parent
+   * stylesheet.
+   */
+  get ruleLine() {
+    return this.selector.ruleLine;
+  },
+
+  /**
+   * Check if the selector comes from a browser-provided stylesheet.
+   *
+   * @return {boolean} true if the selector comes from a browser-provided
+   * stylesheet, or false otherwise.
+   */
+  get contentRule() {
+    return this.selector.contentRule;
+  },
+
+  /**
+   * Compare the current CssSelectorInfo instance to another instance, based on
+   * specificity information.
+   *
+   * @param {CssSelectorInfo} that The instance to compare ourselves against.
+   * @return number -1, 0, 1 depending on how that compares with this.
+   */
+  compareTo: function (that) {
+    if (!this.contentRule && that.contentRule) {
+      return 1;
+    }
+    if (this.contentRule && !that.contentRule) {
+      return -1;
+    }
+
+    if (this.elementStyle && !that.elementStyle) {
+      if (!this.important && that.important) {
+        return 1;
+      }
+      return -1;
+    }
+
+    if (!this.elementStyle && that.elementStyle) {
+      if (this.important && !that.important) {
+        return -1;
+      }
+      return 1;
+    }
+
+    if (this.important && !that.important) {
+      return -1;
+    }
+    if (that.important && !this.important) {
+      return 1;
+    }
+
+    if (this.specificity > that.specificity) {
+      return -1;
+    }
+    if (that.specificity > this.specificity) {
+      return 1;
+    }
+
+    if (this.sheetIndex > that.sheetIndex) {
+      return -1;
+    }
+    if (that.sheetIndex > this.sheetIndex) {
+      return 1;
+    }
+
+    if (this.ruleLine > that.ruleLine) {
+      return -1;
+    }
+    if (that.ruleLine > this.ruleLine) {
+      return 1;
+    }
+
+    return 0;
+  },
+
+  toString: function () {
+    return this.selector + " -> " + this.value;
+  },
+};
+
+DevToolsUtils.defineLazyGetter(this, "domUtils", function () {
+  return Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
+});