--- /dev/null
+/*
+ * Copyright (C) 2007-2012 Argeo GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.argeo.eclipse.ui.jcr.utils;
+
+import javax.jcr.Node;
+import javax.jcr.RepositoryException;
+
+import org.argeo.ArgeoException;
+import org.eclipse.jface.viewers.IElementComparer;
+
+/** Compare JCR nodes based on their JCR identifiers, for use in JFace viewers. */
+public class NodeViewerComparer implements IElementComparer {
+
+ // force comparison on Node IDs only.
+ public boolean equals(Object elementA, Object elementB) {
+ if (!(elementA instanceof Node) || !(elementB instanceof Node)) {
+ return elementA == null ? elementB == null : elementA
+ .equals(elementB);
+ } else {
+
+ boolean result = false;
+ try {
+ String idA = ((Node) elementA).getIdentifier();
+ String idB = ((Node) elementB).getIdentifier();
+ result = idA == null ? idB == null : idA.equals(idB);
+ } catch (RepositoryException re) {
+ throw new ArgeoException("cannot compare nodes", re);
+ }
+
+ return result;
+ }
+ }
+
+ public int hashCode(Object element) {
+ // TODO enhanced this method.
+ return element.getClass().toString().hashCode();
+ }
+}
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