Added nsISimpleEnumerator as Phase I of the great enumerator unification. Added misc files for XPConnect. Details in RDF_19990422_BRANCH.

This file was copied in CVS from the following location:
mozilla/xpcom/ds/nsEnumeratorUtils.cpp
Original committer: waterson%netscape.com
Original revision: 3.1
Original date: 1999/04/24 02:38:54

xpcom/glue/nsEnumeratorUtils.cpp

@@ -0,0 +1,186 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+#include "nsEnumeratorUtils.h"
+
+
+nsArrayEnumerator::nsArrayEnumerator(nsISupportsArray* aValueArray)
+    : mValueArray(aValueArray),
+      mIndex(0)
+{
+    NS_INIT_REFCNT();
+    NS_IF_ADDREF(mValueArray);
+}
+
+nsArrayEnumerator::~nsArrayEnumerator(void)
+{
+    NS_IF_RELEASE(mValueArray);
+}
+
+NS_IMPL_ISUPPORTS(nsArrayEnumerator, nsISimpleEnumerator::GetIID());
+
+NS_IMETHODIMP
+nsArrayEnumerator::HasMoreElements(PRBool* aResult)
+{
+    NS_PRECONDITION(aResult != 0, "null ptr");
+    if (! aResult)
+        return NS_ERROR_NULL_POINTER;
+
+    *aResult = (mIndex < (PRInt32) mValueArray->Count());
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsArrayEnumerator::GetNext(nsISupports** aResult)
+{
+    NS_PRECONDITION(aResult != 0, "null ptr");
+    if (! aResult)
+        return NS_ERROR_NULL_POINTER;
+
+    if (mIndex >= (PRInt32) mValueArray->Count())
+        return NS_ERROR_UNEXPECTED;
+
+    *aResult = mValueArray->ElementAt(mIndex++);
+    return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+nsSingletonEnumerator::nsSingletonEnumerator(nsISupports* aValue)
+    : mValue(aValue)
+{
+    NS_INIT_REFCNT();
+    NS_IF_ADDREF(mValue);
+    mConsumed = (mValue ? PR_FALSE : PR_TRUE);
+}
+
+nsSingletonEnumerator::~nsSingletonEnumerator()
+{
+    NS_IF_RELEASE(mValue);
+}
+
+NS_IMPL_ISUPPORTS(nsSingletonEnumerator, nsISimpleEnumerator::GetIID());
+
+NS_IMETHODIMP
+nsSingletonEnumerator::HasMoreElements(PRBool* aResult)
+{
+    NS_PRECONDITION(aResult != 0, "null ptr");
+    if (! aResult)
+        return NS_ERROR_NULL_POINTER;
+
+    *aResult = !mConsumed;
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsSingletonEnumerator::GetNext(nsISupports** aResult)
+{
+    NS_PRECONDITION(aResult != 0, "null ptr");
+    if (! aResult)
+        return NS_ERROR_NULL_POINTER;
+
+    if (mConsumed)
+        return NS_ERROR_UNEXPECTED;
+
+    mConsumed = PR_TRUE;
+
+    NS_ADDREF(mValue);
+    *aResult = mValue;
+    return NS_OK;
+}
+
+
+////////////////////////////////////////////////////////////////////////
+
+
+nsAdapterEnumerator::nsAdapterEnumerator(nsIEnumerator* aEnum)
+    : mEnum(aEnum), mCurrent(0), mStarted(PR_FALSE)
+{
+    NS_INIT_REFCNT();
+    NS_ADDREF(mEnum);
+}
+
+
+nsAdapterEnumerator::~nsAdapterEnumerator()
+{
+    NS_RELEASE(mEnum);
+    NS_IF_RELEASE(mCurrent);
+}
+
+
+NS_IMPL_ISUPPORTS(nsAdapterEnumerator, nsISimpleEnumerator::GetIID());
+
+
+NS_IMETHODIMP
+nsAdapterEnumerator::HasMoreElements(PRBool* aResult)
+{
+    nsresult rv;
+
+    if (mCurrent) {
+        *aResult = PR_TRUE;
+        return NS_OK;
+    }
+
+    if (! mStarted) {
+        mStarted = PR_TRUE;
+        rv = mEnum->First();
+        if (rv == NS_OK) {
+            mEnum->CurrentItem(&mCurrent);
+            *aResult = PR_TRUE;
+        }
+        else {
+            *aResult = PR_FALSE;
+        }
+    }
+    else {
+        *aResult = PR_FALSE;
+
+        rv = mEnum->IsDone();
+        if (rv != NS_OK) {
+            // We're not done. Advance to the next one.
+            rv = mEnum->Next();
+            if (rv == NS_OK) {
+                mEnum->CurrentItem(&mCurrent);
+                *aResult = PR_TRUE;
+            }
+        }
+    }
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsAdapterEnumerator::GetNext(nsISupports** aResult)
+{
+    nsresult rv;
+
+    PRBool hasMore;
+    rv = HasMoreElements(&hasMore);
+    if (NS_FAILED(rv)) return rv;
+
+    if (! hasMore)
+        return NS_ERROR_UNEXPECTED;
+
+    // No need to addref, we "transfer" the ownership to the caller.
+    *aResult = mCurrent;
+    mCurrent = 0;
+    return NS_OK;
+}
+
+