01: /*BEGIN_COPYRIGHT_BLOCK
02: *
03: * Copyright (c) 2001-2007, JavaPLT group at Rice University (javaplt@rice.edu)
04: * All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions are met:
08: * * Redistributions of source code must retain the above copyright
09: * notice, this list of conditions and the following disclaimer.
10: * * Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * * Neither the names of DrJava, the JavaPLT group, Rice University, nor the
14: * names of its contributors may be used to endorse or promote products
15: * derived from this software without specific prior written permission.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
21: * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
24: * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25: * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26: * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28: *
29: * This software is Open Source Initiative approved Open Source Software.
30: * Open Source Initative Approved is a trademark of the Open Source Initiative.
31: *
32: * This file is part of DrJava. Download the current version of this project
33: * from http://www.drjava.org/ or http://sourceforge.net/projects/drjava/
34: *
35: * END_COPYRIGHT_BLOCK*/
36:
37: package edu.rice.cs.drjava.model;
38:
39: import java.util.List;
40: import java.util.LinkedList;
41:
42: /**
43: * Model class for clipboard history.
44: */
45: public class ClipboardHistoryModel {
46: /** Maximum size of the history. */
47: private int _maxSize;
48:
49: /** The history of strings. The most recent string will be the last. */
50: private LinkedList<String> _history = new LinkedList<String>();
51:
52: /** Singleton instance. */
53: private static ClipboardHistoryModel ONLY = null;
54:
55: /** Singleton accessor. */
56: public static synchronized ClipboardHistoryModel singleton() {
57: if (ONLY == null)
58: ONLY = new ClipboardHistoryModel(10);
59: return ONLY;
60: }
61:
62: /** Create a new clipboard history model.
63: * @param maxSize maximum size of history */
64: private ClipboardHistoryModel(int maxSize) {
65: _maxSize = maxSize;
66: }
67:
68: /** Sets the maximum size. May kick old strings out. */
69: public void resize(int maxSize) {
70: _maxSize = maxSize;
71: while (_history.size() > _maxSize) {
72: _history.removeFirst();
73: }
74: }
75:
76: /** Add a string to the history. If it is already in the history, it will get
77: * moved to the end, making it the most recent string. */
78: public synchronized void put(String s) {
79: _history.remove(s);
80: _history.add(s);
81: while (_history.size() > _maxSize) {
82: _history.removeFirst();
83: }
84: }
85:
86: /** Return a copy of the history of strings. */
87: public synchronized List<String> getStrings() {
88: return new LinkedList<String>(_history);
89: }
90:
91: /** Return the most recent string, or null if nothing is in the history. */
92: public synchronized String getMostRecent() {
93: if (_history.size() == 0) {
94: return null;
95: } else {
96: return _history.getLast();
97: }
98: }
99: }
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