01: /* ====================================================================
02: The Jicarilla Software License
03:
04: Copyright (c) 2003 Leo Simons.
05: All rights reserved.
06:
07: Permission is hereby granted, free of charge, to any person obtaining
08: a copy of this software and associated documentation files (the
09: "Software"), to deal in the Software without restriction, including
10: without limitation the rights to use, copy, modify, merge, publish,
11: distribute, sublicense, and/or sell copies of the Software, and to
12: permit persons to whom the Software is furnished to do so, subject to
13: the following conditions:
14:
15: The above copyright notice and this permission notice shall be
16: included in all copies or substantial portions of the Software.
17:
18: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19: EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20: MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21: IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
22: CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23: TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24: SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25: ==================================================================== */
26: package org.jicarilla.lang;
27:
28: /**
29: * Convenience class for supporting {@link ReadonlyEnabled} semantics. This is
30: * a trivial class that sets a boolean flag to <code>true</code> when
31: * {@link #makeReadOnly()} is called. Subclasses can check for it using the
32: * {@link #isReadOnly()} method. In addition, the {@link #checkReadOnly()}
33: * method is provided which will throw an {@link IllegalStateException} if the
34: * flag is set.
35: *
36: * @author <a href="lsimons at jicarilla dot org">Leo Simons</a>
37: * @version $Id: AbstractReadonlyEnabled.java,v 1.2 2003/10/07 19:17:53 lsimons
38: * Exp $
39: */
40: public abstract class AbstractReadonlyEnabled implements
41: ReadonlyEnabled {
42: /** The readonly flag. */
43: protected boolean m_readOnly = false;
44:
45: /**
46: * Sets the readonly flag to <code>true</code>.
47: */
48: public void makeReadOnly() {
49: m_readOnly = true;
50: }
51:
52: /**
53: * Determine whether makeReadOnly() has been called.
54: *
55: * @return true if it has been called, false otherwise
56: */
57: protected boolean isReadOnly() {
58: return m_readOnly;
59: }
60:
61: /**
62: * Throw an IllegalStateException if makeReadOnly() has been called.
63: */
64: protected void checkReadOnly() {
65: if (m_readOnly) {
66: throw new IllegalStateException(
67: "This object is m_readOnly so you're not allowed to modify its state!");
68: }
69: }
70: }
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