1/*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the  "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 *     http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18/*
19 * $Id: XBoolean.java 469368 2006-10-31 04:41:36Z minchau $
20 */
21package org.apache.xpath.objects;
22
23/**
24 * This class represents an XPath boolean object, and is capable of
25 * converting the boolean to other types, such as a string.
26 * @xsl.usage advanced
27 */
28public class XBoolean extends XObject
29{
30    static final long serialVersionUID = -2964933058866100881L;
31
32  /**
33   * A true boolean object so we don't have to keep creating them.
34   * @xsl.usage internal
35   */
36  public static final XBoolean S_TRUE = new XBooleanStatic(true);
37
38  /**
39   * A true boolean object so we don't have to keep creating them.
40   * @xsl.usage internal
41   */
42  public static final XBoolean S_FALSE = new XBooleanStatic(false);
43
44  /** Value of the object.
45   *  @serial         */
46  private final boolean m_val;
47
48  /**
49   * Construct a XBoolean object.
50   *
51   * @param b Value of the boolean object
52   */
53  public XBoolean(boolean b)
54  {
55
56    super();
57
58    m_val = b;
59  }
60
61  /**
62   * Construct a XBoolean object.
63   *
64   * @param b Value of the boolean object
65   */
66  public XBoolean(Boolean b)
67  {
68
69    super();
70
71    m_val = b.booleanValue();
72    setObject(b);
73  }
74
75
76  /**
77   * Tell that this is a CLASS_BOOLEAN.
78   *
79   * @return type of CLASS_BOOLEAN
80   */
81  public int getType()
82  {
83    return CLASS_BOOLEAN;
84  }
85
86  /**
87   * Given a request type, return the equivalent string.
88   * For diagnostic purposes.
89   *
90   * @return type string "#BOOLEAN"
91   */
92  public String getTypeString()
93  {
94    return "#BOOLEAN";
95  }
96
97  /**
98   * Cast result object to a number.
99   *
100   * @return numeric value of the object value
101   */
102  public double num()
103  {
104    return m_val ? 1.0 : 0.0;
105  }
106
107  /**
108   * Cast result object to a boolean.
109   *
110   * @return The object value as a boolean
111   */
112  public boolean bool()
113  {
114    return m_val;
115  }
116
117  /**
118   * Cast result object to a string.
119   *
120   * @return The object's value as a string
121   */
122  public String str()
123  {
124    return m_val ? "true" : "false";
125  }
126
127  /**
128   * Return a java object that's closest to the representation
129   * that should be handed to an extension.
130   *
131   * @return The object's value as a java object
132   */
133  public Object object()
134  {
135    if(null == m_obj)
136      setObject(new Boolean(m_val));
137    return m_obj;
138  }
139
140  /**
141   * Tell if two objects are functionally equal.
142   *
143   * @param obj2 Object to compare to this
144   *
145   * @return True if the two objects are equal
146   *
147   * @throws javax.xml.transform.TransformerException
148   */
149  public boolean equals(XObject obj2)
150  {
151
152    // In order to handle the 'all' semantics of
153    // nodeset comparisons, we always call the
154    // nodeset function.
155    if (obj2.getType() == XObject.CLASS_NODESET)
156      return obj2.equals(this);
157
158    try
159    {
160      return m_val == obj2.bool();
161    }
162    catch(javax.xml.transform.TransformerException te)
163    {
164      throw new org.apache.xml.utils.WrappedRuntimeException(te);
165    }
166  }
167
168}
169