gecko-dev/dom/xul/templates/nsXULTemplateResultSetRDF.cpp

83 lines
2.3 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsXULTemplateResultSetRDF.h"
#include "nsXULTemplateQueryProcessorRDF.h"
NS_IMPL_ISUPPORTS(nsXULTemplateResultSetRDF, nsISimpleEnumerator)
NS_IMETHODIMP
nsXULTemplateResultSetRDF::HasMoreElements(bool *aResult)
{
*aResult = true;
nsCOMPtr<nsIRDFNode> node;
if (! mInstantiations || ! mQuery) {
*aResult = false;
return NS_OK;
}
if (mCheckedNext) {
if (!mCurrent || mCurrent == &(mInstantiations->mHead))
*aResult = false;
return NS_OK;
}
mCheckedNext = true;
do {
if (mCurrent) {
mCurrent = mCurrent->mNext;
if (mCurrent == &(mInstantiations->mHead)) {
*aResult = false;
return NS_OK;
}
}
else {
*aResult = ! mInstantiations->Empty();
if (*aResult)
mCurrent = mInstantiations->mHead.mNext;
}
// get the value of the member variable. If it is not set, skip
// the result and move on to the next result
if (mCurrent) {
mCurrent->mInstantiation.mAssignments.
GetAssignmentFor(mQuery->mMemberVariable, getter_AddRefs(node));
}
// only resources may be used as results
mResource = do_QueryInterface(node);
} while (! mResource);
return NS_OK;
}
NS_IMETHODIMP
nsXULTemplateResultSetRDF::GetNext(nsISupports **aResult)
{
if (!aResult)
return NS_ERROR_NULL_POINTER;
if (!mCurrent || !mCheckedNext)
return NS_ERROR_FAILURE;
nsRefPtr<nsXULTemplateResultRDF> nextresult =
new nsXULTemplateResultRDF(mQuery, mCurrent->mInstantiation, mResource);
if (!nextresult)
return NS_ERROR_OUT_OF_MEMORY;
// add the supporting memory elements to the processor's map. These are
// used to remove the results when an assertion is removed from the graph
mProcessor->AddMemoryElements(mCurrent->mInstantiation, nextresult);
mCheckedNext = false;
nextresult.forget(aResult);
return NS_OK;
}