gecko-dev/embedding/browser/webBrowser/nsDOMWalker.cpp

120 lines
3.5 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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 the Mozilla browser.
*
* The Initial Developer of the Original Code is Netscape
* Communications, Inc. Portions created by Netscape are
* Copyright (C) 1999, Mozilla. All Rights Reserved.
*
* Contributor(s):
* Adam Lock <adamlock@netscape.com>
*/
#include "nsVoidArray.h"
#include "nsCOMPtr.h"
#include "nsDOMWalker.h"
struct DOMTreePos
{
nsCOMPtr<nsIDOMNode> current;
};
nsresult nsDOMWalker::WalkDOM(nsIDOMNode *aRootNode, nsDOMWalkerCallback *aCallback)
{
NS_ENSURE_ARG_POINTER(aRootNode);
NS_ENSURE_ARG_POINTER(aCallback);
nsVoidArray stack;
nsresult rv = NS_OK;
// Push the top most node onto the stack
DOMTreePos *rootPos = new DOMTreePos;
if (rootPos == nsnull)
{
return NS_ERROR_OUT_OF_MEMORY;
}
rootPos->current = aRootNode;
stack.AppendElement(rootPos);
while (stack.Count() > 0)
{
nsCOMPtr<nsIDOMNode> current;
nsCOMPtr<nsIDOMNode> next;
// Pop the last position off the stack
DOMTreePos *pos = (DOMTreePos *) stack.ElementAt(stack.Count() - 1);
stack.RemoveElementAt(stack.Count() - 1);
current = do_QueryInterface(pos->current);
delete pos;
// Iterate through each sibling
while (current)
{
PRBool hasChildNodes = PR_FALSE;
current->GetNextSibling(getter_AddRefs(next));
current->HasChildNodes(&hasChildNodes);
// Call the callback to let them do what they want to do
if (aCallback)
{
PRBool abort = PR_FALSE;
aCallback->OnWalkDOMNode(current, &abort);
if (abort)
{
goto cleanup;
}
}
if (hasChildNodes)
{
// Push the current node back onto the stack
if (next)
{
DOMTreePos *nextPos = new DOMTreePos;
if (nextPos == nsnull)
{
rv = NS_ERROR_OUT_OF_MEMORY;
goto cleanup;
}
nextPos->current = next;
stack.AppendElement(nextPos);
}
// Push the first child onto the stack
DOMTreePos *childPos = new DOMTreePos;
if (childPos == nsnull)
{
rv = NS_ERROR_OUT_OF_MEMORY;
goto cleanup;
}
current->GetFirstChild(getter_AddRefs(childPos->current));
stack.AppendElement(childPos);
break;
}
current = next;
}
}
cleanup:
// Clean the tree in case we came out early
PRInt32 i;
for (i = 0; i < stack.Count(); i++)
{
DOMTreePos *pos = (DOMTreePos *) stack.ElementAt(i);
delete pos;
}
stack.Clear();
return rv;
}