1 package org.springframework.roo.file.undo;
2
3 import java.util.Stack;
4
5 /**
6 * Provides the ability to undo changes to a file system.
7 *
8 * <p>
9 * Note that the complexities of file system I/O are significant and Java does not provide full
10 * access to a file lock API that would simplify coding of implementations. Therefore undoing
11 * changes to the file system is a best-effort basis only, and designs should not rely on
12 * robust, guaranteed, fail-safe undo semantics.
13 *
14 * @author Ben Alex
15 * @since 1.0
16 *
17 */
18 public interface UndoManager {
19
20 /**
21 * Registers an undoable operation in the {@link Stack}.
22 *
23 * @param undoableOperation to register in a {@link Stack} (required)
24 */
25 void add(UndoableOperation undoableOperation);
26
27 /**
28 * Replays the undo {@link Stack}, and guarantees to clear the {@link Stack}.
29 *
30 * <p>
31 * The first operation that returns false to {@link UndoableOperation#undo()} will cause the remainder
32 * of the {@link Stack} to stop undoing.
33 *
34 * <p>
35 * Executing this command guarantees the {@link Stack} will be empty upon return, with every element either
36 * undone or reset.
37 *
38 * @return true if all {@link UndoableOperation}s in the {@link Stack} were successfully undone
39 */
40 boolean undo();
41
42 /**
43 * Resets the undo {@link Stack}, and guarantees to clear the {@link Stack}.
44 *
45 * <p>
46 * Executing this command guarantees the {@link Stack} will be empty upon return, with every element reset.
47 */
48 void reset();
49 }