Issue 2595 - Use the core code from adblockpluscore

lib/elemHide.js

-/*
- * This file is part of Adblock Plus <https://adblockplus.org/>,
- * Copyright (C) 2006-2016 Eyeo GmbH
- *
- * Adblock Plus is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 3 as
- * published by the Free Software Foundation.
- *
- * Adblock Plus is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/**
- * @fileOverview Element hiding implementation.
- */
-
-Cu.import("resource://gre/modules/Services.jsm");
-
-var {Utils} = require("utils");
-var {IO} = require("io");
-var {Prefs} = require("prefs");
-var {ElemHideException} = require("filterClasses");
-var {FilterNotifier} = require("filterNotifier");
-
-/**
- * Lookup table, filters by their associated key
- * @type Object
- */
-var filterByKey = Object.create(null);
-
-/**
- * Lookup table, keys of the filters by filter text
- * @type Object
- */
-var keyByFilter = Object.create(null);
-
-/**
- * Lookup table, keys are known element hiding exceptions
- * @type Object
- */
-var knownExceptions = Object.create(null);
-
-/**
- * Lookup table, lists of element hiding exceptions by selector
- * @type Object
- */
-var exceptions = Object.create(null);
-
-/**
- * Currently applied stylesheet URL
- * @type nsIURI
- */
-var styleURL = null;
-
-/**
- * Element hiding component
- * @class
- */
-var ElemHide = exports.ElemHide =
-{
-  /**
-   * Indicates whether filters have been added or removed since the last apply() call.
-   * @type Boolean
-   */
-  isDirty: false,
-
-  /**
-   * Inidicates whether the element hiding stylesheet is currently applied.
-   * @type Boolean
-   */
-  applied: false,
-
-  /**
-   * Called on module startup.
-   */
-  init: function()
-  {
-    Prefs.addListener(function(name)
-    {
-      if (name == "enabled")
-        ElemHide.apply();
-    });
-    onShutdown.add(() => ElemHide.unapply());
-
-    let styleFile = IO.resolveFilePath(Prefs.data_directory);
-    styleFile.append("elemhide.css");
-    styleURL = Services.io.newFileURI(styleFile).QueryInterface(Ci.nsIFileURL);
-  },
-
-  /**
-   * Removes all known filters
-   */
-  clear: function()
-  {
-    filterByKey = Object.create(null);
-    keyByFilter = Object.create(null);
-    knownExceptions = Object.create(null);
-    exceptions = Object.create(null);
-    ElemHide.isDirty = false;
-    ElemHide.unapply();
-  },
-
-  /**
-   * Add a new element hiding filter
-   * @param {ElemHideFilter} filter
-   */
-  add: function(filter)
-  {
-    if (filter instanceof ElemHideException)
-    {
-      if (filter.text in knownExceptions)
-        return;
-
-      let selector = filter.selector;
-      if (!(selector in exceptions))
-        exceptions[selector] = [];
-      exceptions[selector].push(filter);
-      knownExceptions[filter.text] = true;
-    }
-    else
-    {
-      if (filter.text in keyByFilter)
-        return;
-
-      let key;
-      do {
-        key = Math.random().toFixed(15).substr(5);
-      } while (key in filterByKey);
-
-      filterByKey[key] = filter;
-      keyByFilter[filter.text] = key;
-      ElemHide.isDirty = true;
-    }
-  },
-
-  /**
-   * Removes an element hiding filter
-   * @param {ElemHideFilter} filter
-   */
-  remove: function(filter)
-  {
-    if (filter instanceof ElemHideException)
-    {
-      if (!(filter.text in knownExceptions))
-        return;
-
-      let list = exceptions[filter.selector];
-      let index = list.indexOf(filter);
-      if (index >= 0)
-        list.splice(index, 1);
-      delete knownExceptions[filter.text];
-    }
-    else
-    {
-      if (!(filter.text in keyByFilter))
-        return;
-
-      let key = keyByFilter[filter.text];
-      delete filterByKey[key];
-      delete keyByFilter[filter.text];
-      ElemHide.isDirty = true;
-    }
-  },
-
-  /**
-   * Checks whether an exception rule is registered for a filter on a particular
-   * domain.
-   */
-  getException: function(/**Filter*/ filter, /**String*/ docDomain) /**ElemHideException*/
-  {
-    if (!(filter.selector in exceptions))
-      return null;
-
-    let list = exceptions[filter.selector];
-    for (let i = list.length - 1; i >= 0; i--)
-      if (list[i].isActiveOnDomain(docDomain))
-        return list[i];
-
-    return null;
-  },
-
-  /**
-   * Will be set to true if apply() is running (reentrance protection).
-   * @type Boolean
-   */
-  _applying: false,
-
-  /**
-   * Will be set to true if an apply() call arrives while apply() is already
-   * running (delayed execution).
-   * @type Boolean
-   */
-  _needsApply: false,
-
-  /**
-   * Generates stylesheet URL and applies it globally
-   */
-  apply: function()
-  {
-    if (this._applying)
-    {
-      this._needsApply = true;
-      return;
-    }
-
-    if (!ElemHide.isDirty || !Prefs.enabled)
-    {
-      // Nothing changed, looks like we merely got enabled/disabled
-      if (Prefs.enabled && !ElemHide.applied)
-      {
-        try
-        {
-          Utils.styleService.loadAndRegisterSheet(styleURL, Ci.nsIStyleSheetService.USER_SHEET);
-          ElemHide.applied = true;
-        }
-        catch (e)
-        {
-          Cu.reportError(e);
-        }
-      }
-      else if (!Prefs.enabled && ElemHide.applied)
-      {
-        ElemHide.unapply();
-      }
-
-      return;
-    }
-
-    IO.writeToFile(styleURL.file, this._generateCSSContent(), function(e)
-    {
-      this._applying = false;
-
-      // _generateCSSContent is throwing NS_ERROR_NOT_AVAILABLE to indicate that
-      // there are no filters. If that exception is passed through XPCOM we will
-      // see a proper exception here, otherwise a number.
-      let noFilters = (e == Cr.NS_ERROR_NOT_AVAILABLE || (e && e.result == Cr.NS_ERROR_NOT_AVAILABLE));
-      if (noFilters)
-      {
-        e = null;
-        IO.removeFile(styleURL.file, function(e) {});
-      }
-      else if (e)
-        Cu.reportError(e);
-
-      if (this._needsApply)
-      {
-        this._needsApply = false;
-        this.apply();
-      }
-      else if (!e)
-      {
-        ElemHide.isDirty = false;
-
-        ElemHide.unapply();
-
-        if (!noFilters)
-        {
-          try
-          {
-            Utils.styleService.loadAndRegisterSheet(styleURL, Ci.nsIStyleSheetService.USER_SHEET);
-            ElemHide.applied = true;
-          }
-          catch (e)
-          {
-            Cu.reportError(e);
-          }
-        }
-
-        FilterNotifier.triggerListeners("elemhideupdate");
-      }
-    }.bind(this));
-
-    this._applying = true;
-  },
-
-  _generateCSSContent: function*()
-  {
-    // Grouping selectors by domains
-    let domains = Object.create(null);
-    let hasFilters = false;
-    for (let key in filterByKey)
-    {
-      let filter = filterByKey[key];
-      let domain = filter.selectorDomain || "";
-
-      let list;
-      if (domain in domains)
-        list = domains[domain];
-      else
-      {
-        list = Object.create(null);
-        domains[domain] = list;
-      }
-      list[filter.selector] = key;
-      hasFilters = true;
-    }
-
-    if (!hasFilters)
-      throw Cr.NS_ERROR_NOT_AVAILABLE;
-
-    function escapeChar(match)
-    {
-      return "\\" + match.charCodeAt(0).toString(16) + " ";
-    }
-
-    // Return CSS data
-    let cssTemplate = "-moz-binding: url(about:abp-elemhidehit?%ID%#dummy) !important;";
-    for (let domain in domains)
-    {
-      let rules = [];
-      let list = domains[domain];
-
-      if (domain)
-        yield ('@-moz-document domain("' + domain.split(",").join('"),domain("') + '"){').replace(/[^\x01-\x7F]/g, escapeChar);
-      else
-      {
-        // Only allow unqualified rules on a few protocols to prevent them from blocking chrome
-        yield '@-moz-document url-prefix("http://"),url-prefix("https://"),'
-                  + 'url-prefix("mailbox://"),url-prefix("imap://"),'
-                  + 'url-prefix("news://"),url-prefix("snews://"){';
-      }
-
-      for (let selector in list)
-        yield selector.replace(/[^\x01-\x7F]/g, escapeChar) + "{" + cssTemplate.replace("%ID%", list[selector]) + "}";
-      yield '}';
-    }
-  },
-
-  /**
-   * Unapplies current stylesheet URL
-   */
-  unapply: function()
-  {
-    if (ElemHide.applied)
-    {
-      try
-      {
-        Utils.styleService.unregisterSheet(styleURL, Ci.nsIStyleSheetService.USER_SHEET);
-      }
-      catch (e)
-      {
-        Cu.reportError(e);
-      }
-      ElemHide.applied = false;
-    }
-  },
-
-  /**
-   * Retrieves the currently applied stylesheet URL
-   * @type String
-   */
-  get styleURL()
-  {
-    return ElemHide.applied ? styleURL.spec : null;
-  },
-
-  /**
-   * Retrieves an element hiding filter by the corresponding protocol key
-   */
-  getFilterByKey: function(/**String*/ key) /**Filter*/
-  {
-    return (key in filterByKey ? filterByKey[key] : null);
-  },
-
-  /**
-   * Returns a list of all selectors active on a particular domain (currently
-   * used only in Chrome, Opera and Safari).
-   */
-  getSelectorsForDomain: function(/**String*/ domain, /**Boolean*/ specificOnly)
-  {
-    let result = [];
-    let keys = Object.getOwnPropertyNames(filterByKey);
-    for (let key of keys)
-    {
-      let filter = filterByKey[key];
-      if (specificOnly && (!filter.domains || filter.domains[""]))
-        continue;
-
-      if (filter.isActiveOnDomain(domain) && !this.getException(filter, domain))
-        result.push(filter.selector);
-    }
-    return result;
-  }
-};