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1 /*
2  * Copyright 2013, Google Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  *     * Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *     * Redistributions in binary form must reproduce the above
12  * copyright notice, this list of conditions and the following disclaimer
13  * in the documentation and/or other materials provided with the
14  * distribution.
15  *     * Neither the name of Google Inc. nor the names of its
16  * contributors may be used to endorse or promote products derived from
17  * this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 package org.jf.util;
33 
34 import java.io.FilterWriter;
35 import java.io.IOException;
36 import java.io.Writer;
37 
38 /**
39  * Writer that wraps another writer and passes width-limited and
40  * optionally-prefixed output to its subordinate. When lines are
41  * wrapped they are automatically indented based on the start of the
42  * line.
43  */
44 public final class OldWrappedIndentingWriter extends FilterWriter {
45     /** null-ok; optional prefix for every line */
46     private final String prefix;
47 
48     /** > 0; the maximum output width */
49     private final int width;
50 
51     /** > 0; the maximum indent */
52     private final int maxIndent;
53 
54     /** >= 0; current output column (zero-based) */
55     private int column;
56 
57     /** whether indent spaces are currently being collected */
58     private boolean collectingIndent;
59 
60     /** >= 0; current indent amount */
61     private int indent;
62 
63     /**
64      * Constructs an instance.
65      *
66      * @param out non-null; writer to send final output to
67      * @param width >= 0; the maximum output width (not including
68      * <code>prefix</code>), or <code>0</code> for no maximum
69      * @param prefix non-null; the prefix for each line
70      */
OldWrappedIndentingWriter(Writer out, int width, String prefix)71     public OldWrappedIndentingWriter(Writer out, int width, String prefix) {
72         super(out);
73 
74         if (out == null) {
75             throw new NullPointerException("out == null");
76         }
77 
78         if (width < 0) {
79             throw new IllegalArgumentException("width < 0");
80         }
81 
82         if (prefix == null) {
83             throw new NullPointerException("prefix == null");
84         }
85 
86         this.width = (width != 0) ? width : Integer.MAX_VALUE;
87         this.maxIndent = width >> 1;
88         this.prefix = (prefix.length() == 0) ? null : prefix;
89 
90         bol();
91     }
92 
93     /**
94      * Constructs a no-prefix instance.
95      *
96      * @param out non-null; writer to send final output to
97      * @param width &gt;= 0; the maximum output width (not including
98      * <code>prefix</code>), or <code>0</code> for no maximum
99      */
OldWrappedIndentingWriter(Writer out, int width)100     public OldWrappedIndentingWriter(Writer out, int width) {
101         this(out, width, "");
102     }
103 
104     /** {@inheritDoc} */
105     @Override
write(int c)106     public void write(int c) throws IOException {
107         synchronized (lock) {
108             if (collectingIndent) {
109                 if (c == ' ') {
110                     indent++;
111                     if (indent >= maxIndent) {
112                         indent = maxIndent;
113                         collectingIndent = false;
114                     }
115                 } else {
116                     collectingIndent = false;
117                 }
118             }
119 
120             if ((column == width) && (c != '\n')) {
121                 out.write('\n');
122                 column = 0;
123                 /*
124                  * Note: No else, so this should fall through to the next
125                  * if statement.
126                  */
127             }
128 
129             if (column == 0) {
130                 if (prefix != null) {
131                     out.write(prefix);
132                 }
133 
134                 if (!collectingIndent) {
135                     for (int i = 0; i < indent; i++) {
136                         out.write(' ');
137                     }
138                     column = indent;
139                 }
140             }
141 
142             out.write(c);
143 
144             if (c == '\n') {
145                 bol();
146             } else {
147                 column++;
148             }
149         }
150     }
151 
152     /** {@inheritDoc} */
153     @Override
write(char[] cbuf, int off, int len)154     public void write(char[] cbuf, int off, int len) throws IOException {
155         synchronized (lock) {
156             while (len > 0) {
157                 write(cbuf[off]);
158                 off++;
159                 len--;
160             }
161         }
162     }
163 
164     /** {@inheritDoc} */
165     @Override
write(String str, int off, int len)166     public void write(String str, int off, int len) throws IOException {
167         synchronized (lock) {
168             while (len > 0) {
169                 write(str.charAt(off));
170                 off++;
171                 len--;
172             }
173         }
174     }
175 
176     /**
177      * Indicates that output is at the beginning of a line.
178      */
bol()179     private void bol() {
180         column = 0;
181         collectingIndent = (maxIndent != 0);
182         indent = 0;
183     }
184 }
185