/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   L. David Baron <dbaron@dbaron.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * the provisions above, a recipient may use your version of this file under
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 *
 * ***** END LICENSE BLOCK ***** */

/*
 * style rule processor for CSS style sheets, responsible for selector
 * matching and cascading
 */

#ifndef nsCSSRuleProcessor_h_
#define nsCSSRuleProcessor_h_

#include "nsIStyleRuleProcessor.h"
#include "nsCSSStyleSheet.h"

struct RuleCascadeData;
struct nsCSSSelectorList;

/**
 * The CSS style rule processor provides a mechanism for sibling style
 * sheets to combine their rule processing in order to allow proper
 * cascading to happen.
 *
 * CSS style rule processors keep a live reference on all style sheets
 * bound to them.  The CSS style sheets keep a weak reference to all the
 * processors that they are bound to (many to many).  The CSS style sheet
 * is told when the rule processor is going away (via DropRuleProcessor).
 */

class nsCSSRuleProcessor: public nsIStyleRuleProcessor {
public:
  nsCSSRuleProcessor(const nsCOMArray<nsICSSStyleSheet>& aSheets);
  virtual ~nsCSSRuleProcessor();

  NS_DECL_ISUPPORTS

public:
  nsresult ClearRuleCascades();

  static void Shutdown();

  /*
   * Returns true if the given RuleProcessorData matches one of the
   * selectors in aSelectorList.  Note that this method will assume
   * the matching is not for styling purposes.
   */
  static PRBool SelectorListMatches(RuleProcessorData& aData,
                                    nsCSSSelectorList* aSelectorList);

  // nsIStyleRuleProcessor
  NS_IMETHOD RulesMatching(ElementRuleProcessorData* aData);

  NS_IMETHOD RulesMatching(PseudoRuleProcessorData* aData);

  NS_IMETHOD HasStateDependentStyle(StateRuleProcessorData* aData,
                                    nsReStyleHint* aResult);

  NS_IMETHOD HasAttributeDependentStyle(AttributeRuleProcessorData* aData,
                                        nsReStyleHint* aResult);

protected:
  RuleCascadeData* GetRuleCascade(nsPresContext* aPresContext);

  // The sheet order here is the same as in nsStyleSet::mSheets
  nsCOMArray<nsICSSStyleSheet> mSheets;

  RuleCascadeData* mRuleCascades;
};

#endif /* nsCSSRuleProcessor_h_ */