1 files changed, 52 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/ui/table/cell/DefaultCellComparator.java b/framework/src/onos/core/api/src/main/java/org/onosproject/ui/table/cell/DefaultCellComparator.java
new file mode 100644
index 00000000..093a20d3
--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/ui/table/cell/DefaultCellComparator.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.onosproject.ui.table.cell;
+
+import org.onosproject.ui.table.CellComparator;
+
+/**
+ * A default cell comparator.
+ * <p>
+ * Verifies that the objects being compared are the same class.
+ * Looks to see if the objects being compared implement comparable and, if so,
+ * delegates to that; otherwise, implements a lexicographical compare function
+ * (i.e. string sorting). Uses the objects' toString() method and then
+ * compares the resulting strings. Note that null values are acceptable and
+ * are considered "smaller" than any non-null value.
+ */
+public final class DefaultCellComparator extends AbstractCellComparator {
+
+    // non-instantiable
+    private DefaultCellComparator() { }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    protected int nonNullCompare(Object o1, Object o2) {
+        if (o1 instanceof Comparable) {
+            // if o2 is not the same class as o1, then compareTo will
+            // throw ClassCastException for us
+            return ((Comparable) o1).compareTo(o2);
+        }
+        return o1.toString().compareTo(o2.toString());
+    }
+
+    /**
+     * An instance of this class.
+     */
+    public static final CellComparator INSTANCE = new DefaultCellComparator();
+}