GUI -- Implemented table sorting in our simple table/row/cell model
- Introduced CellComparator (with default implementation)

Change-Id: I125f52c2c1ca219746b0e506e8837e24fb149038
diff --git a/core/api/src/test/java/org/onosproject/ui/table/DefaultCellComparatorTest.java b/core/api/src/test/java/org/onosproject/ui/table/DefaultCellComparatorTest.java
new file mode 100644
index 0000000..86add93
--- /dev/null
+++ b/core/api/src/test/java/org/onosproject/ui/table/DefaultCellComparatorTest.java
@@ -0,0 +1,83 @@
+/*
+ * 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;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Unit tests for {@link DefaultCellComparator}.
+ */
+public class DefaultCellComparatorTest {
+
+    private static class TestClass {
+        @Override
+        public String toString() {
+            return SOME;
+        }
+    }
+
+    private static final String SOME = "SoMeStRiNg";
+    private static final String OTHER = "OtherSTRING";
+    private static final int NUMBER = 42;
+    private static final TestClass OBJECT = new TestClass();
+
+    private CellComparator cmp = new DefaultCellComparator();
+
+    @Test
+    public void sameString() {
+        assertTrue("same string", cmp.compare(SOME, SOME) == 0);
+    }
+
+    @Test
+    public void someVsOther() {
+        assertTrue("some vs other", cmp.compare(SOME, OTHER) > 0);
+    }
+
+    @Test
+    public void otherVsSome() {
+        assertTrue("other vs some", cmp.compare(OTHER, SOME) < 0);
+    }
+
+    @Test
+    public void someVsObject() {
+        assertTrue("some vs object", cmp.compare(SOME, OBJECT) == 0);
+    }
+
+    @Test
+    public void otherVsObject() {
+        assertTrue("other vs object", cmp.compare(OTHER, OBJECT) < 0);
+    }
+
+    @Test
+    public void otherVsNumber() {
+        assertTrue("other vs 42", cmp.compare(OTHER, NUMBER) > 0);
+    }
+
+    @Test
+    public void someVsNull() {
+        assertTrue("some vs null", cmp.compare(SOME, null) > 0);
+    }
+
+    @Test
+    public void nullVsSome() {
+        assertTrue("null vs some", cmp.compare(null, SOME) < 0);
+    }
+
+}