1 /* ***************************************************************************
2 * Copyright (c) 2012 Brabenetz Harald, Austria.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 *****************************************************************************/
17
18 package org.settings4j;
19
20 import java.util.List;
21
22 /**
23 * Interface to show on which position a Connector should be added with {@link List#add(int, Object)}.
24 * <p>
25 * <h3>Default Implementations</h3> <br />
26 * The easiest way to get an instance of a ConnectorPosition implementation is to use the Factory Methods from
27 * {@link ConnectorPositions}: <br />
28 *
29 * <pre>
30 * // get the ConnectorPosition instance for the postion after the last
31 * // {@link org.settings4j.connector.SystemPropertyConnector}
32 * ConnectorPositions.afterLast(SystemPropertyConnector.class);
33 * </pre>
34 *
35 * @author brabenetz
36 */
37 public interface ConnectorPosition {
38
39 /**
40 * the position value it the position cannot be determined.
41 */
42 int UNKNOWN_POSITION = -1;
43
44 /**
45 * @param connectors the existing list of connectors.
46 * @return the position where the new Connector should be added.
47 */
48 int getPosition(List<Connector> connectors);
49 }