michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * internal abstract interface for containers (roughly origins within
michael@0:  * the CSS cascade) that provide style rules matching an element or
michael@0:  * pseudo-element
michael@0:  */
michael@0: 
michael@0: #ifndef nsIStyleRuleProcessor_h___
michael@0: #define nsIStyleRuleProcessor_h___
michael@0: 
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: #include "nsISupports.h"
michael@0: #include "nsChangeHint.h"
michael@0: 
michael@0: struct RuleProcessorData;
michael@0: struct ElementDependentRuleProcessorData;
michael@0: struct ElementRuleProcessorData;
michael@0: struct PseudoElementRuleProcessorData;
michael@0: struct AnonBoxRuleProcessorData;
michael@0: #ifdef MOZ_XUL
michael@0: struct XULTreeRuleProcessorData;
michael@0: #endif
michael@0: struct StateRuleProcessorData;
michael@0: struct PseudoElementStateRuleProcessorData;
michael@0: struct AttributeRuleProcessorData;
michael@0: class nsPresContext;
michael@0: 
michael@0: // IID for the nsIStyleRuleProcessor interface
michael@0: // {c1d6001e-4fcb-4c40-bce1-5eba80bfd8f3}
michael@0: #define NS_ISTYLE_RULE_PROCESSOR_IID     \
michael@0: { 0xc1d6001e, 0x4fcb, 0x4c40, \
michael@0:   {0xbc, 0xe1, 0x5e, 0xba, 0x80, 0xbf, 0xd8, 0xf3} }
michael@0: 
michael@0: 
michael@0: /* The style rule processor interface is a mechanism to separate the matching
michael@0:  * of style rules from style sheet instances.
michael@0:  * Simple style sheets can and will act as their own processor. 
michael@0:  * Sheets where rule ordering interlaces between multiple sheets, will need to 
michael@0:  * share a single rule processor between them (CSS sheets do this for cascading order)
michael@0:  *
michael@0:  * @see nsIStyleRule (for significantly more detailed comments)
michael@0:  */
michael@0: class nsIStyleRuleProcessor : public nsISupports {
michael@0: public:
michael@0:   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISTYLE_RULE_PROCESSOR_IID)
michael@0: 
michael@0:   // Shorthand for:
michael@0:   //  nsCOMArray<nsIStyleRuleProcessor>::nsCOMArrayEnumFunc
michael@0:   typedef bool (* EnumFunc)(nsIStyleRuleProcessor*, void*);
michael@0: 
michael@0:   /**
michael@0:    * Find the |nsIStyleRule|s matching the given content node and
michael@0:    * position the given |nsRuleWalker| at the |nsRuleNode| in the rule
michael@0:    * tree representing that ordered list of rules (with higher
michael@0:    * precedence being farther from the root of the lexicographic tree).
michael@0:    */
michael@0:   virtual void RulesMatching(ElementRuleProcessorData* aData) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Just like the previous |RulesMatching|, except for a given content
michael@0:    * node <em>and pseudo-element</em>.
michael@0:    */
michael@0:   virtual void RulesMatching(PseudoElementRuleProcessorData* aData) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Just like the previous |RulesMatching|, except for a given anonymous box.
michael@0:    */
michael@0:   virtual void RulesMatching(AnonBoxRuleProcessorData* aData) = 0;
michael@0: 
michael@0: #ifdef MOZ_XUL
michael@0:   /**
michael@0:    * Just like the previous |RulesMatching|, except for a given content
michael@0:    * node <em>and tree pseudo</em>.
michael@0:    */
michael@0:   virtual void RulesMatching(XULTreeRuleProcessorData* aData) = 0;
michael@0: #endif
michael@0: 
michael@0:   /**
michael@0:    * Return whether style can depend on a change of the given document state.
michael@0:    *
michael@0:    * Document states are defined in nsIDocument.h.
michael@0:    */
michael@0:   virtual bool
michael@0:     HasDocumentStateDependentStyle(StateRuleProcessorData* aData) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Return how (as described by nsRestyleHint) style can depend on a
michael@0:    * change of the given content state on the given content node.  This
michael@0:    * test is used for optimization only, and may err on the side of
michael@0:    * reporting more dependencies than really exist.
michael@0:    *
michael@0:    * Event states are defined in mozilla/EventStates.h.
michael@0:    */
michael@0:   virtual nsRestyleHint
michael@0:     HasStateDependentStyle(StateRuleProcessorData* aData) = 0;
michael@0:   virtual nsRestyleHint
michael@0:     HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData) = 0;
michael@0: 
michael@0:   /**
michael@0:    * This method will be called twice for every attribute change.
michael@0:    * During the first call, aData->mAttrHasChanged will be false and
michael@0:    * the attribute change will not have happened yet.  During the
michael@0:    * second call, aData->mAttrHasChanged will be true and the
michael@0:    * change will have already happened.  The bitwise OR of the two
michael@0:    * return values must describe the style changes that are needed due
michael@0:    * to the attribute change.  It's up to the rule processor
michael@0:    * implementation to decide how to split the bits up amongst the two
michael@0:    * return values.  For example, it could return the bits needed by
michael@0:    * rules that might stop matching the node from the first call and
michael@0:    * the bits needed by rules that might have started matching the
michael@0:    * node from the second call.  This test is used for optimization
michael@0:    * only, and may err on the side of reporting more dependencies than
michael@0:    * really exist.
michael@0:    */
michael@0:   virtual nsRestyleHint
michael@0:     HasAttributeDependentStyle(AttributeRuleProcessorData* aData) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Do any processing that needs to happen as a result of a change in
michael@0:    * the characteristics of the medium, and return whether this rule
michael@0:    * processor's rules have changed (e.g., because of media queries).
michael@0:    */
michael@0:   virtual bool MediumFeaturesChanged(nsPresContext* aPresContext) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Report the size of this style rule processor to about:memory.  A
michael@0:    * processor may return 0.
michael@0:    */
michael@0:   virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const = 0;
michael@0:   virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const = 0;
michael@0: };
michael@0: 
michael@0: NS_DEFINE_STATIC_IID_ACCESSOR(nsIStyleRuleProcessor,
michael@0:                               NS_ISTYLE_RULE_PROCESSOR_IID)
michael@0: 
michael@0: #endif /* nsIStyleRuleProcessor_h___ */