1 /*
2 * #%L
3 * settings4j
4 * ===============================================================
5 * Copyright (C) 2008 - 2015 Brabenetz Harald, Austria
6 * ===============================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package org.settings4j;
21
22 import java.util.List;
23
24 /**
25 * Interface to show on which position a Connector should be added with {@link List#add(int, Object)}.
26 * <h3>Default Implementations</h3>
27 * <p>
28 * The easiest way to get an instance of a ConnectorPosition implementation is to use the Factory Methods from {@link ConnectorPositions}:
29 * </p>
30 *
31 * <pre>
32 * // get the ConnectorPosition instance for the postion after the last
33 * // {@link org.settings4j.connector.SystemPropertyConnector}
34 * ConnectorPositions.afterLast(SystemPropertyConnector.class);
35 * </pre>
36 *
37 * @author brabenetz
38 */
39 public interface ConnectorPosition {
40
41 /**
42 * the position value it the position cannot be determined.
43 */
44 int UNKNOWN_POSITION = -1;
45
46 /**
47 * @param connectors the existing list of connectors.
48 * @return the position where the new Connector should be added.
49 */
50 int getPosition(List<Connector> connectors);
51 }