michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsSupportsArrayEnumerator.h"
michael@0: #include "nsISupportsArray.h"
michael@0: 
michael@0: nsSupportsArrayEnumerator::nsSupportsArrayEnumerator(nsISupportsArray* array)
michael@0:   : mArray(array), mCursor(0)
michael@0: {
michael@0:   NS_ASSERTION(array, "null array");
michael@0:   NS_ADDREF(mArray);
michael@0: }
michael@0: 
michael@0: nsSupportsArrayEnumerator::~nsSupportsArrayEnumerator()
michael@0: {
michael@0:   NS_RELEASE(mArray);
michael@0: }
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsSupportsArrayEnumerator, nsIBidirectionalEnumerator, nsIEnumerator)
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::First()
michael@0: {
michael@0:   mCursor = 0;
michael@0:   uint32_t cnt;
michael@0:   nsresult rv = mArray->Count(&cnt);
michael@0:   if (NS_FAILED(rv)) return rv;
michael@0:   int32_t end = (int32_t)cnt;
michael@0:   if (mCursor < end)
michael@0:     return NS_OK;
michael@0:   else
michael@0:     return NS_ERROR_FAILURE;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::Next()
michael@0: {
michael@0:   uint32_t cnt;
michael@0:   nsresult rv = mArray->Count(&cnt);
michael@0:   if (NS_FAILED(rv)) return rv;
michael@0:   int32_t end = (int32_t)cnt;
michael@0:   if (mCursor < end)   // don't count upward forever
michael@0:     mCursor++;
michael@0:   if (mCursor < end)
michael@0:     return NS_OK;
michael@0:   else
michael@0:     return NS_ERROR_FAILURE;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::CurrentItem(nsISupports **aItem)
michael@0: {
michael@0:   NS_ASSERTION(aItem, "null out parameter");
michael@0:   uint32_t cnt;
michael@0:   nsresult rv = mArray->Count(&cnt);
michael@0:   if (NS_FAILED(rv)) return rv;
michael@0:   if (mCursor >= 0 && mCursor < (int32_t)cnt) {
michael@0:     return mArray->GetElementAt(mCursor, aItem);
michael@0:   }
michael@0:   return NS_ERROR_FAILURE;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::IsDone()
michael@0: {
michael@0:   uint32_t cnt;
michael@0:   nsresult rv = mArray->Count(&cnt);
michael@0:   if (NS_FAILED(rv)) return rv;
michael@0:   // XXX This is completely incompatible with the meaning of nsresult.
michael@0:   // NS_ENUMERATOR_FALSE is defined to be 1.  (bug 778111)
michael@0:   return (mCursor >= 0 && mCursor < (int32_t)cnt)
michael@0:     ? (nsresult)NS_ENUMERATOR_FALSE : NS_OK;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::Last()
michael@0: {
michael@0:   uint32_t cnt;
michael@0:   nsresult rv = mArray->Count(&cnt);
michael@0:   if (NS_FAILED(rv)) return rv;
michael@0:   mCursor = cnt - 1;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSupportsArrayEnumerator::Prev()
michael@0: {
michael@0:   if (mCursor >= 0)
michael@0:     --mCursor;
michael@0:   if (mCursor >= 0)
michael@0:     return NS_OK;
michael@0:   else
michael@0:     return NS_ERROR_FAILURE;
michael@0: }
michael@0: