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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* 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/. */

 /*

  * internal abstract interface for containers (roughly origins within

  * the CSS cascade) that provide style rules matching an element or

  * pseudo-element

  */

 #ifndef nsIStyleRuleProcessor_h___

 #define nsIStyleRuleProcessor_h___

 #include "mozilla/MemoryReporting.h"

 #include "nsISupports.h"

 #include "nsChangeHint.h"

 struct RuleProcessorData;

 struct ElementDependentRuleProcessorData;

 struct ElementRuleProcessorData;

 struct PseudoElementRuleProcessorData;

 struct AnonBoxRuleProcessorData;

 #ifdef MOZ_XUL

 struct XULTreeRuleProcessorData;

 #endif

 struct StateRuleProcessorData;

 struct PseudoElementStateRuleProcessorData;

 struct AttributeRuleProcessorData;

 class nsPresContext;

 // IID for the nsIStyleRuleProcessor interface

 // {c1d6001e-4fcb-4c40-bce1-5eba80bfd8f3}

 #define NS_ISTYLE_RULE_PROCESSOR_IID     \

 { 0xc1d6001e, 0x4fcb, 0x4c40, \

   {0xbc, 0xe1, 0x5e, 0xba, 0x80, 0xbf, 0xd8, 0xf3} }

 /* The style rule processor interface is a mechanism to separate the matching

  * of style rules from style sheet instances.

  * Simple style sheets can and will act as their own processor. 

  * Sheets where rule ordering interlaces between multiple sheets, will need to 

  * share a single rule processor between them (CSS sheets do this for cascading order)

  *

  * @see nsIStyleRule (for significantly more detailed comments)

  */

 class nsIStyleRuleProcessor : public nsISupports {

 public:

   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISTYLE_RULE_PROCESSOR_IID)

   // Shorthand for:

   //  nsCOMArray<nsIStyleRuleProcessor>::nsCOMArrayEnumFunc

   typedef bool (* EnumFunc)(nsIStyleRuleProcessor*, void*);

   /**

    * Find the |nsIStyleRule|s matching the given content node and

    * position the given |nsRuleWalker| at the |nsRuleNode| in the rule

    * tree representing that ordered list of rules (with higher

    * precedence being farther from the root of the lexicographic tree).

    */

   virtual void RulesMatching(ElementRuleProcessorData* aData) = 0;

   /**

    * Just like the previous |RulesMatching|, except for a given content

    * node <em>and pseudo-element</em>.

    */

   virtual void RulesMatching(PseudoElementRuleProcessorData* aData) = 0;

   /**

    * Just like the previous |RulesMatching|, except for a given anonymous box.

    */

   virtual void RulesMatching(AnonBoxRuleProcessorData* aData) = 0;

 #ifdef MOZ_XUL

   /**

    * Just like the previous |RulesMatching|, except for a given content

    * node <em>and tree pseudo</em>.

    */

   virtual void RulesMatching(XULTreeRuleProcessorData* aData) = 0;

 #endif

   /**

    * Return whether style can depend on a change of the given document state.

    *

    * Document states are defined in nsIDocument.h.

    */

   virtual bool

     HasDocumentStateDependentStyle(StateRuleProcessorData* aData) = 0;

   /**

    * Return how (as described by nsRestyleHint) style can depend on a

    * change of the given content state on the given content node.  This

    * test is used for optimization only, and may err on the side of

    * reporting more dependencies than really exist.

    *

    * Event states are defined in mozilla/EventStates.h.

    */

   virtual nsRestyleHint

     HasStateDependentStyle(StateRuleProcessorData* aData) = 0;

   virtual nsRestyleHint

     HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData) = 0;

   /**

    * This method will be called twice for every attribute change.

    * During the first call, aData->mAttrHasChanged will be false and

    * the attribute change will not have happened yet.  During the

    * second call, aData->mAttrHasChanged will be true and the

    * change will have already happened.  The bitwise OR of the two

    * return values must describe the style changes that are needed due

    * to the attribute change.  It's up to the rule processor

    * implementation to decide how to split the bits up amongst the two

    * return values.  For example, it could return the bits needed by

    * rules that might stop matching the node from the first call and

    * the bits needed by rules that might have started matching the

    * node from the second call.  This test is used for optimization

    * only, and may err on the side of reporting more dependencies than

    * really exist.

    */

   virtual nsRestyleHint

     HasAttributeDependentStyle(AttributeRuleProcessorData* aData) = 0;

   /**

    * Do any processing that needs to happen as a result of a change in

    * the characteristics of the medium, and return whether this rule

    * processor's rules have changed (e.g., because of media queries).

    */

   virtual bool MediumFeaturesChanged(nsPresContext* aPresContext) = 0;

   /**

    * Report the size of this style rule processor to about:memory.  A

    * processor may return 0.

    */

   virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const = 0;

   virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const = 0;

 };

 NS_DEFINE_STATIC_IID_ACCESSOR(nsIStyleRuleProcessor,

                               NS_ISTYLE_RULE_PROCESSOR_IID)

 #endif /* nsIStyleRuleProcessor_h___ */