prelanding of minimo. adding nsAdapterEnumerator to this directory. not part of build yet. r=doug/alec.

git-svn-id: svn://10.0.0.236/trunk@139355 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/mailnews/base/util/nsAdapterEnumerator.cpp

@@ -0,0 +1,114 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape 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/NPL/
+ *
+ * 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 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
+ * use your version of this file under the terms of the NPL, indicate your
+ * 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 NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsAdapterEnumerator.h"
+
+////////////////////////////////////////////////////////////////////////
+
+
+nsAdapterEnumerator::nsAdapterEnumerator(nsIEnumerator* aEnum)
+    : mEnum(aEnum), mCurrent(0), mStarted(PR_FALSE)
+{
+    NS_ADDREF(mEnum);
+}
+
+
+nsAdapterEnumerator::~nsAdapterEnumerator()
+{
+    NS_RELEASE(mEnum);
+    NS_IF_RELEASE(mCurrent);
+}
+
+
+NS_IMPL_ISUPPORTS1(nsAdapterEnumerator, nsISimpleEnumerator)
+
+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;
+}
+

mozilla/mailnews/base/util/nsAdapterEnumerator.h

@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape 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/NPL/
+ *
+ * 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 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
+ * use your version of this file under the terms of the NPL, indicate your
+ * 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 NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsAdapterEnumerator_h__
+#define nsAdapterEnumerator_h__
+
+#include "msgCore.h"
+
+#include "nsISimpleEnumerator.h"
+#include "nsIEnumerator.h"
+
+class NS_MSG_BASE nsAdapterEnumerator : public nsISimpleEnumerator
+{
+public:
+    NS_DECL_ISUPPORTS
+
+    // nsISimpleEnumerator methods
+    NS_IMETHOD HasMoreElements(PRBool* aResult);
+    NS_IMETHOD GetNext(nsISupports** aResult);
+
+    nsAdapterEnumerator(nsIEnumerator* aEnum);
+    virtual ~nsAdapterEnumerator();
+
+protected:
+    nsIEnumerator* mEnum;
+    nsISupports*   mCurrent;
+    PRBool mStarted;
+};
+
+#endif