Mercurial > projects > dwt2

comparison org.eclipse.core.commands/src/org/eclipse/core/commands/operations/OperationHistoryFactory.d @ 12:bc29606a740c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added dwt-addons in original directory structure of eclipse.org
author Frank Benoit <benoit@tionex.de>
date Sat, 14 Mar 2009 18:23:29 +0100
parents
children
comparison
equal deleted inserted replaced
11:43904fec5dca 12:bc29606a740c
1 /*******************************************************************************
2 * Copyright (c) 2005 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module org.eclipse.core.commands.operations.OperationHistoryFactory;
14
15 import org.eclipse.core.commands.operations.IOperationHistory;
16 import org.eclipse.core.commands.operations.DefaultOperationHistory;
17
18 import java.lang.all;
19
20 /**
21 * <p>
22 * This class is used to maintain the instance of the operation history that
23 * should be used by classes that access the undo or redo history and add
24 * undoable operations to the history.
25 *
26 * <p>
27 * It is intended that an application can create an operation history appropriate
28 * for its needs and set it into this class. Otherwise, a default operation history
29 * will be created. The operation history may only be set one time. All classes that
30 * access an operations history use this class to obtain the correct instance.
31 *
32 * @since 3.1
33 */
34 public final class OperationHistoryFactory {
35
36 private static IOperationHistory operationHistory;
37
38 /**
39 * Return the operation history to be used for managing undoable operations.
40 *
41 * @return the operation history to be used for executing, undoing, and
42 * redoing operations.
43 */
44 public static IOperationHistory getOperationHistory() {
45 if (operationHistory is null) {
46 operationHistory = new DefaultOperationHistory();
47 }
48 return operationHistory;
49 }
50
51 /**
52 * Set the operation history to be used for managing undoable operations.
53 * This method may only be called one time, and must be called before any
54 * request to get the history. Attempts to set the operation history will
55 * be ignored after it has been already set, or after a default one has
56 * been created.
57 *
58 * @param history
59 * the operation history to be used for executing, undoing, and
60 * redoing operations.
61 */
62 public static void setOperationHistory(IOperationHistory history) {
63 // If one has already been set or created, ignore this request.
64 if (operationHistory is null) {
65 operationHistory = history;
66 }
67 }
68
69 private this() {
70 // may not be instantiated
71 }
72
73 }