gecko-dev/layout/style/nsCSSDeclaration.h

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/* -*- 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):
* Daniel Glazman <glazman@netscape.com>
*
* 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 ***** */
/*
* representation of a declaration block (or style attribute) in a CSS
* stylesheet
*/
#ifndef nsCSSDeclaration_h___
#define nsCSSDeclaration_h___
#include "nsISupports.h"
#include "nsColor.h"
#include <stdio.h>
#include "nsString.h"
#include "nsCoord.h"
#include "nsCSSValue.h"
#include "nsCSSProps.h"
#include "nsTArray.h"
#include "nsCSSDataBlock.h"
#include "nsCSSStruct.h"
class nsCSSDeclaration {
public:
/**
* Construct an |nsCSSDeclaration| that is in an invalid state (null
* |mData|) and cannot be used until its |CompressFrom| method or
* |InitializeEmpty| method is called.
*/
nsCSSDeclaration();
nsCSSDeclaration(const nsCSSDeclaration& aCopy);
/**
* |ValueAppended| must be called to maintain this declaration's
* |mOrder| whenever a property is parsed into an expanded data block
* for this declaration. aProperty must not be a shorthand.
*/
nsresult ValueAppended(nsCSSProperty aProperty);
nsresult RemoveProperty(nsCSSProperty aProperty);
nsresult GetValue(nsCSSProperty aProperty, nsAString& aValue) const;
PRBool HasImportantData() const { return mImportantData != nsnull; }
PRBool GetValueIsImportant(nsCSSProperty aProperty) const;
PRBool GetValueIsImportant(const nsAString& aProperty) const;
PRUint32 Count() const {
return mOrder.Length();
}
nsresult GetNthProperty(PRUint32 aIndex, nsAString& aReturn) const;
nsresult ToString(nsAString& aString) const;
nsCSSDeclaration* Clone() const;
nsCSSCompressedDataBlock* GetNormalBlock() const { return mData; }
nsCSSCompressedDataBlock* GetImportantBlock() const { return mImportantData; }
/**
* Initialize this declaration as holding no data. Return false on
* out-of-memory.
*/
PRBool InitializeEmpty();
/**
* Transfer all of the state from |aExpandedData| into this declaration.
* After calling, |aExpandedData| should be in its initial state.
*/
void CompressFrom(nsCSSExpandedDataBlock *aExpandedData) {
NS_ASSERTION(!mData, "oops");
NS_ASSERTION(!mImportantData, "oops");
aExpandedData->Compress(getter_AddRefs(mData),
getter_AddRefs(mImportantData));
aExpandedData->AssertInitialState();
}
/**
* Transfer all of the state from this declaration into
* |aExpandedData| and put this declaration temporarily into an
* invalid state (ended by |CompressFrom| or |InitializeEmpty|) that
* should last only during parsing. During this time only
* |ValueAppended| should be called.
*/
void ExpandTo(nsCSSExpandedDataBlock *aExpandedData) {
aExpandedData->AssertInitialState();
NS_ASSERTION(mData, "oops");
aExpandedData->Expand(&mData, &mImportantData);
NS_ASSERTION(!mData && !mImportantData,
"Expand didn't null things out");
}
/**
* Return a pointer to our current value for this property. This only
* returns non-null if the property is set and it not !important. This
* should only be called when not expanded. Always returns null for
* shorthand properties.
*
* The caller must call EnsureMutable first.
*/
void* SlotForValue(nsCSSProperty aProperty) {
NS_PRECONDITION(mData, "How did that happen?");
if (nsCSSProps::IsShorthand(aProperty)) {
return nsnull;
}
void* slot = mData->SlotForValue(aProperty);
NS_ASSERTION(!slot || !mImportantData ||
!mImportantData->StorageFor(aProperty),
"Property both important and not?");
return slot;
}
PRBool HasNonImportantValueFor(nsCSSProperty aProperty) const {
NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty), "must be longhand");
return !!mData->StorageFor(aProperty);
}
/**
* Ensures that IsMutable on both data blocks will return true by
* cloning data blocks if needed. Returns false on out-of-memory
* (which means IsMutable won't return true).
*/
PRBool EnsureMutable();
/**
* Clear the data, in preparation for its replacement with entirely
* new data by a call to |CompressFrom|.
*/
void ClearData() {
mData = nsnull;
mImportantData = nsnull;
mOrder.Clear();
}
#ifdef DEBUG
void List(FILE* out = stdout, PRInt32 aIndent = 0) const;
#endif
// return whether there was a value in |aValue| (i.e., it had a non-null unit)
static PRBool AppendCSSValueToString(nsCSSProperty aProperty,
const nsCSSValue& aValue,
nsAString& aResult);
// return whether there was a value in |aStorage| (i.e., it was non-null)
static PRBool AppendStorageToString(nsCSSProperty aProperty,
const void* aStorage,
nsAString& aResult);
private:
// Not implemented, and not supported.
nsCSSDeclaration& operator=(const nsCSSDeclaration& aCopy);
PRBool operator==(const nsCSSDeclaration& aCopy) const;
static void AppendImportanceToString(PRBool aIsImportant, nsAString& aString);
// return whether there was a value in |aValue| (i.e., it had a non-null unit)
PRBool AppendValueToString(nsCSSProperty aProperty, nsAString& aResult) const;
// Helper for ToString with strange semantics regarding aValue.
void AppendPropertyAndValueToString(nsCSSProperty aProperty,
nsAutoString& aValue,
nsAString& aResult) const;
private:
//
// Specialized ref counting.
// We do not want everyone to ref count us, only the rules which hold
// onto us (our well defined lifetime is when the last rule releases
// us).
// It's worth a comment here that the main nsCSSDeclaration is refcounted,
// but it's |mImportant| is not refcounted, but just owned by the
// non-important declaration.
//
friend class CSSStyleRuleImpl;
void AddRef(void) {
if (mRefCnt == PR_UINT32_MAX) {
NS_WARNING("refcount overflow, leaking object");
return;
}
++mRefCnt;
}
void Release(void) {
if (mRefCnt == PR_UINT32_MAX) {
NS_WARNING("refcount overflow, leaking object");
return;
}
NS_ASSERTION(0 < mRefCnt, "bad Release");
if (0 == --mRefCnt) {
delete this;
}
}
public:
void RuleAbort(void) {
NS_ASSERTION(0 == mRefCnt, "bad RuleAbort");
delete this;
}
private:
// Block everyone, except us or a derivative, from deleting us.
~nsCSSDeclaration(void);
nsCSSProperty OrderValueAt(PRUint32 aValue) const {
return nsCSSProperty(mOrder.ElementAt(aValue));
}
private:
nsAutoTArray<PRUint8, 8> mOrder;
nsAutoRefCnt mRefCnt;
// never null, except while expanded
nsRefPtr<nsCSSCompressedDataBlock> mData;
// may be null
nsRefPtr<nsCSSCompressedDataBlock> mImportantData;
};
#endif /* nsCSSDeclaration_h___ */