зеркало из https://github.com/mozilla/pjs.git
115 строки
4.5 KiB
C++
115 строки
4.5 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):
|
|
*
|
|
* 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 objects providing immutable style
|
|
* information
|
|
*/
|
|
|
|
#ifndef nsIStyleRule_h___
|
|
#define nsIStyleRule_h___
|
|
|
|
#include <stdio.h>
|
|
|
|
#include "nsISupports.h"
|
|
|
|
class nsIStyleSheet;
|
|
class nsPresContext;
|
|
class nsIContent;
|
|
struct nsRuleData;
|
|
|
|
// IID for the nsIStyleRule interface {40ae5c90-ad6a-11d1-8031-006008159b5a}
|
|
#define NS_ISTYLE_RULE_IID \
|
|
{0x40ae5c90, 0xad6a, 0x11d1, {0x80, 0x31, 0x00, 0x60, 0x08, 0x15, 0x9b, 0x5a}}
|
|
|
|
/**
|
|
* An object implementing |nsIStyleRule| (henceforth, a rule) represents
|
|
* immutable stylistic information that either applies or does not apply
|
|
* to a given element. It belongs to an object or group of objects that
|
|
* implement |nsIStyleSheet| and |nsIStyleRuleProcessor| (henceforth, a
|
|
* sheet).
|
|
*
|
|
* A rule becomes relevant to the computation of style data when
|
|
* |nsIStyleRuleProcessor::RulesMatching| creates a rule node that
|
|
* points to the rule. (A rule node, |nsRuleNode|, is a node in the
|
|
* rule tree, which is a lexicographic tree indexed by rules. The path
|
|
* from the root of the rule tree to the |nsRuleNode| for a given
|
|
* |nsStyleContext| contains exactly the rules that match the element
|
|
* that the style context is for, in priority (weight, origin,
|
|
* specificity) order.)
|
|
*
|
|
* The computation of style data uses the rule tree, which calls
|
|
* |nsIStyleRule::MapRuleInfoInto| below.
|
|
*
|
|
* It is worth emphasizing that the data represented by a rule
|
|
* implementation are immutable. When the data need to be changed, a
|
|
* new rule object must be created. Failing to do this will lead to
|
|
* bugs in the handling of dynamic style changes, since the rule tree
|
|
* caches the results of |MapRuleInfoInto|.
|
|
*
|
|
* |nsIStyleRule| objects are owned by |nsRuleNode| objects (in addition
|
|
* to typically being owned by their sheet), which are in turn garbage
|
|
* collected (with the garbage collection roots being style contexts).
|
|
*/
|
|
|
|
|
|
class nsIStyleRule : public nsISupports {
|
|
public:
|
|
NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISTYLE_RULE_IID)
|
|
|
|
/**
|
|
* |nsIStyleRule::MapRuleInfoInto| is a request to copy all stylistic
|
|
* data represented by the rule that:
|
|
* + are relevant for |aRuleData->mSID| (the style struct ID)
|
|
* + are not already filled into the data struct
|
|
* into the appropriate data struct in |aRuleData|. It is important
|
|
* that only empty data are filled in, since the rule tree is walked
|
|
* from highest priority rule to least, so that the walk can stop if
|
|
* all needed data are found. Thus overwriting non-empty data will
|
|
* break CSS cascading rules.
|
|
*/
|
|
NS_IMETHOD MapRuleInfoInto(nsRuleData* aRuleData)=0;
|
|
|
|
#ifdef DEBUG
|
|
NS_IMETHOD List(FILE* out = stdout, PRInt32 aIndent = 0) const = 0;
|
|
#endif
|
|
};
|
|
|
|
NS_DEFINE_STATIC_IID_ACCESSOR(nsIStyleRule, NS_ISTYLE_RULE_IID)
|
|
|
|
#endif /* nsIStyleRule_h___ */
|