gecko-dev/layout/base/nsStyleChangeList.cpp

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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):
*
* 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 ***** */
/*
* a list of the recomputation that needs to be done in response to a
* style change
*/
#include "nsStyleChangeList.h"
#include "nsStyleConsts.h"
#include "nsIFrame.h"
#include "nsIContent.h"
#include "nsCRT.h"
static const PRUint32 kGrowArrayBy = 10;
nsStyleChangeList::nsStyleChangeList()
: mArray(mBuffer),
mArraySize(kStyleChangeBufferSize),
mCount(0)
{
MOZ_COUNT_CTOR(nsStyleChangeList);
}
nsStyleChangeList::~nsStyleChangeList()
{
MOZ_COUNT_DTOR(nsStyleChangeList);
Clear();
}
nsresult
nsStyleChangeList::ChangeAt(PRInt32 aIndex, nsIFrame*& aFrame, nsIContent*& aContent,
nsChangeHint& aHint) const
{
if ((0 <= aIndex) && (aIndex < mCount)) {
aFrame = mArray[aIndex].mFrame;
aContent = mArray[aIndex].mContent;
aHint = mArray[aIndex].mHint;
return NS_OK;
}
return NS_ERROR_ILLEGAL_VALUE;
}
nsresult
nsStyleChangeList::ChangeAt(PRInt32 aIndex, const nsStyleChangeData** aChangeData) const
{
if ((0 <= aIndex) && (aIndex < mCount)) {
*aChangeData = &mArray[aIndex];
return NS_OK;
}
return NS_ERROR_ILLEGAL_VALUE;
}
nsresult
nsStyleChangeList::AppendChange(nsIFrame* aFrame, nsIContent* aContent, nsChangeHint aHint)
{
NS_ASSERTION(aFrame || (aHint & nsChangeHint_ReconstructFrame),
"must have frame");
NS_ASSERTION(aContent || !(aHint & nsChangeHint_ReconstructFrame),
"must have content");
NS_ASSERTION(!aContent || aContent->IsNodeOfType(nsINode::eELEMENT),
"Shouldn't be trying to restyle non-elements directly");
NS_ASSERTION(!(aHint & nsChangeHint_ReflowFrame) ||
(aHint & nsChangeHint_NeedReflow),
"Reflow hint bits set without actually asking for a reflow");
if ((0 < mCount) && (aHint & nsChangeHint_ReconstructFrame)) { // filter out all other changes for same content
if (aContent) {
for (PRInt32 index = mCount - 1; index >= 0; --index) {
if (aContent == mArray[index].mContent) { // remove this change
aContent->Release();
mCount--;
if (index < mCount) { // move later changes down
::memmove(&mArray[index], &mArray[index + 1],
(mCount - index) * sizeof(nsStyleChangeData));
}
}
}
}
}
PRInt32 last = mCount - 1;
if ((0 < mCount) && aFrame && (aFrame == mArray[last].mFrame)) { // same as last frame
NS_UpdateHint(mArray[last].mHint, aHint);
}
else {
if (mCount == mArraySize) {
PRInt32 newSize = mArraySize + kGrowArrayBy;
nsStyleChangeData* newArray = new nsStyleChangeData[newSize];
if (newArray) {
memcpy(newArray, mArray, mCount * sizeof(nsStyleChangeData));
if (mArray != mBuffer) {
delete [] mArray;
}
mArray = newArray;
mArraySize = newSize;
}
else {
return NS_ERROR_OUT_OF_MEMORY;
}
}
mArray[mCount].mFrame = aFrame;
mArray[mCount].mContent = aContent;
if (aContent) {
aContent->AddRef();
}
mArray[mCount].mHint = aHint;
mCount++;
}
return NS_OK;
}
void
nsStyleChangeList::Clear()
{
for (PRInt32 index = mCount - 1; index >= 0; --index) {
nsIContent* content = mArray[index].mContent;
if (content) {
content->Release();
}
}
if (mArray != mBuffer) {
delete [] mArray;
mArray = mBuffer;
mArraySize = kStyleChangeBufferSize;
}
mCount = 0;
}