| /* |
| * Copyright 2015-present 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; |
| |
| /** |
| * Base implementation of a {@link CellComparator}. This class takes care |
| * of dealing with null inputs; subclasses should implement their comparison |
| * knowing that both inputs are guaranteed to be non-null. |
| */ |
| public abstract class AbstractCellComparator implements CellComparator { |
| |
| @Override |
| public int compare(Object o1, Object o2) { |
| if (o1 == null && o2 == null) { |
| return 0; // o1 == o2 |
| } |
| if (o1 == null) { |
| return -1; // o1 < o2 |
| } |
| if (o2 == null) { |
| return 1; // o1 > o2 |
| } |
| return nonNullCompare(o1, o2); |
| } |
| |
| /** |
| * Compares its two arguments for order. Returns a negative integer, |
| * zero, or a positive integer as the first argument is less than, equal |
| * to, or greater than the second. |
| * <p> |
| * Note that both objects are guaranteed to be non-null. |
| * |
| * @see java.util.Comparator#compare(Object, Object) |
| * |
| * @param o1 the first object to be compared |
| * @param o2 the second object to be compared |
| * @return an integer representing relative ordering |
| * @throws ClassCastException if the arguments' types prevent them from |
| * being compared by this comparator |
| */ |
| protected abstract int nonNullCompare(Object o1, Object o2); |
| } |