gecko-dev/layout/style/nsIStyleRuleProcessor.h
2011-04-21 19:35:52 +02:00

163 lines
6.2 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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>, Mozilla Corporation
*
* 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
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* 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 "nsISupports.h"
#include "nsChangeHint.h"
#include "nsIContent.h"
struct RuleProcessorData;
struct ElementRuleProcessorData;
struct PseudoElementRuleProcessorData;
struct AnonBoxRuleProcessorData;
#ifdef MOZ_XUL
struct XULTreeRuleProcessorData;
#endif
struct StateRuleProcessorData;
struct AttributeRuleProcessorData;
class nsPresContext;
// IID for the nsIStyleRuleProcessor interface
// {b8e44bbe-aaac-4125-8ab2-0f42802e14ad}
#define NS_ISTYLE_RULE_PROCESSOR_IID \
{ 0xb8e44bbe, 0xaaac, 0x4125, \
{ 0x8a, 0xb2, 0x0f, 0x42, 0x80, 0x2e, 0x14, 0xad } }
/* 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 PRBool (* 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 PRBool
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 nsEventStates.h.
*/
virtual nsRestyleHint
HasStateDependentStyle(StateRuleProcessorData* 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 PRBool MediumFeaturesChanged(nsPresContext* aPresContext) = 0;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsIStyleRuleProcessor,
NS_ISTYLE_RULE_PROCESSOR_IID)
#endif /* nsIStyleRuleProcessor_h___ */