gecko/layout/base/nsChildIterator.h
Michael Wu d8e503c38b Bug 675553 - Switch from PRBool to bool on a CLOSED TREE , r=bsmedberg,khuey,bz,cjones
--HG--
rename : tools/trace-malloc/bloatblame.c => tools/trace-malloc/bloatblame.cpp
2011-09-28 23:19:26 -07:00

194 lines
5.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=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
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* 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 ***** */
/*
* used by nsCSSFrameConstructor to determine and iterate the child list
* used to construct frames (normal children or something from XBL)
*/
#include "nsCOMPtr.h"
#include "nsIContent.h"
#include "nsINodeList.h"
/**
* Helper class for iterating children during frame construction.
* This class should always be used in lieu of the straight content
* node APIs, since it handles XBL-generated anonymous content as
* well.
*/
class NS_STACK_CLASS ChildIterator
{
protected:
nsIContent* mContent;
// If mNodes is non-null (so XBLInvolved() is true), mIndex is the
// index into mNodes for our current position. Otherwise, mChild is
// our current child (which might be null if we're done iterating).
union {
PRUint32 mIndex;
nsIContent* mChild;
};
nsINodeList* mNodes;
public:
ChildIterator()
: mContent(nsnull), mChild(0), mNodes(nsnull) {}
ChildIterator(const ChildIterator& aOther)
: mContent(aOther.mContent),
mNodes(aOther.mNodes) {
if (XBLInvolved()) {
mIndex = aOther.mIndex;
} else {
mChild = aOther.mChild;
}
}
ChildIterator& operator=(const ChildIterator& aOther) {
mContent = aOther.mContent;
mNodes = aOther.mNodes;
if (XBLInvolved()) {
mIndex = aOther.mIndex;
} else {
mChild = aOther.mChild;
}
return *this;
}
ChildIterator& operator++() {
if (XBLInvolved()) {
++mIndex;
} else {
NS_ASSERTION(mChild, "Walking off end of list?");
mChild = mChild->GetNextSibling();
}
return *this;
}
ChildIterator operator++(int) {
ChildIterator result(*this);
++(*this);
return result;
}
ChildIterator& operator--() {
if (XBLInvolved()) {
--mIndex;
} else if (mChild) {
mChild = mChild->GetPreviousSibling();
NS_ASSERTION(mChild, "Walking off beginning of list");
} else {
mChild = mContent->GetLastChild();
}
return *this;
}
ChildIterator operator--(int) {
ChildIterator result(*this);
--(*this);
return result;
}
nsIContent* get() const {
if (XBLInvolved()) {
return mNodes->GetNodeAt(mIndex);
}
return mChild;
}
nsIContent* operator*() const { return get(); }
bool operator==(const ChildIterator& aOther) const {
if (XBLInvolved()) {
return mContent == aOther.mContent && mIndex == aOther.mIndex;
}
return mContent == aOther.mContent && mChild == aOther.mChild;
}
bool operator!=(const ChildIterator& aOther) const {
return !aOther.operator==(*this);
}
void seek(nsIContent* aContent) {
if (XBLInvolved()) {
PRInt32 index = mNodes->IndexOf(aContent);
// XXXbz I wish we could assert that index != -1, but it seems to not be
// the case in some XBL cases with filtered insertion points and no
// default insertion point. I will now claim that XBL's management of
// its insertion points is broken in those cases, since it's returning an
// insertion parent for a node that doesn't actually have the node in its
// child list according to ChildIterator. See bug 474324.
if (index != -1) {
mIndex = index;
} else {
// If aContent isn't going to get hit by this iterator, just seek to the
// end of the list for lack of anything better to do.
mIndex = length();
}
} else if (aContent->GetParent() == mContent) {
mChild = aContent;
} else {
// XXXbz I wish we could assert this doesn't happen, but I think that's
// not necessarily the case when called from ContentInserted if
// first-letter frames are about.
mChild = nsnull;
}
}
bool XBLInvolved() const { return mNodes != nsnull; }
/**
* Create a pair of ChildIterators for a content node. aFirst will
* point to the first child of aContent; aLast will point one past
* the last child of aContent.
*/
static nsresult Init(nsIContent* aContent,
ChildIterator* aFirst,
ChildIterator* aLast);
private:
PRUint32 length() {
NS_PRECONDITION(XBLInvolved(), "Don't call me");
PRUint32 l;
mNodes->GetLength(&l);
return l;
}
};