layout/style/nsCSSRuleProcessor.h

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   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
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   9  * http://www.mozilla.org/MPL/
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  16  * The Original Code is mozilla.org code.
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  20  * Portions created by the Initial Developer are Copyright (C) 1998
  21  * the Initial Developer. All Rights Reserved.
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  23  * Contributor(s):
  24  *   L. David Baron <dbaron@dbaron.org>
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  38  * ***** END LICENSE BLOCK ***** */
  39
  40 /*
  41  * style rule processor for CSS style sheets, responsible for selector
  42  * matching and cascading
  43  */
  44
  45 #ifndef nsCSSRuleProcessor_h_
  46 #define nsCSSRuleProcessor_h_
  47
  48 #include "nsIStyleRuleProcessor.h"
  49 #include "nsCSSStyleSheet.h"
  50
  51 struct RuleCascadeData;
  52 struct nsCSSSelectorList;
  53
  54 /**
  55  * The CSS style rule processor provides a mechanism for sibling style
  56  * sheets to combine their rule processing in order to allow proper
  57  * cascading to happen.
  58  *
  59  * CSS style rule processors keep a live reference on all style sheets
  60  * bound to them.  The CSS style sheets keep a weak reference to all the
  61  * processors that they are bound to (many to many).  The CSS style sheet
  62  * is told when the rule processor is going away (via DropRuleProcessor).
  63  */
  64
  65 class nsCSSRuleProcessor: public nsIStyleRuleProcessor {
  66 public:
  67   nsCSSRuleProcessor(const nsCOMArray<nsICSSStyleSheet>& aSheets);
  68   virtual ~nsCSSRuleProcessor();
  69
  70   NS_DECL_ISUPPORTS
  71
  72 public:
  73   nsresult ClearRuleCascades();
  74
  75   static void Startup();
  76   static void FreeSystemMetrics();
  77
  78   /*
  79    * Returns true if the given RuleProcessorData matches one of the
  80    * selectors in aSelectorList.  Note that this method will assume
  81    * the matching is not for styling purposes.
  82    */
  83   static PRBool SelectorListMatches(RuleProcessorData& aData,
  84                                     nsCSSSelectorList* aSelectorList);
  85
  86   // nsIStyleRuleProcessor
  87   NS_IMETHOD RulesMatching(ElementRuleProcessorData* aData);
  88
  89   NS_IMETHOD RulesMatching(PseudoRuleProcessorData* aData);
  90
  91   NS_IMETHOD HasStateDependentStyle(StateRuleProcessorData* aData,
  92                                     nsReStyleHint* aResult);
  93
  94   NS_IMETHOD HasAttributeDependentStyle(AttributeRuleProcessorData* aData,
  95                                         nsReStyleHint* aResult);
  96
  97   NS_IMETHOD MediumFeaturesChanged(nsPresContext* aPresContext,
  98                                    PRBool* aRulesChanged);
  99
 100 #ifdef DEBUG
 101   void AssertQuirksChangeOK() {
 102     NS_ASSERTION(!mRuleCascades, "too late to set quirks style sheet");
 103   }
 104 #endif
 105
 106 private:
 107   static PRBool CascadeSheetRulesInto(nsICSSStyleSheet* aSheet, void* aData);
 108
 109   RuleCascadeData* GetRuleCascade(nsPresContext* aPresContext);
 110   void RefreshRuleCascade(nsPresContext* aPresContext);
 111
 112   // The sheet order here is the same as in nsStyleSet::mSheets
 113   nsCOMArray<nsICSSStyleSheet> mSheets;
 114
 115   // active first, then cached (most recent first)
 116   RuleCascadeData* mRuleCascades;
 117
 118   // The last pres context for which GetRuleCascades was called.
 119   nsPresContext *mLastPresContext;
 120 };
 121
 122 #endif /* nsCSSRuleProcessor_h_ */