1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17
18 package org.apache.logging.log4j.core.pattern;
19
20 /**
21 * Modifies the output of a pattern converter for a specified minimum and maximum width and alignment.
22 */
23 public final class FormattingInfo {
24 /**
25 * Array of spaces.
26 */
27 private static final char[] SPACES = new char[] { ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' };
28
29 /**
30 * Default instance.
31 */
32 private static final FormattingInfo DEFAULT = new FormattingInfo(false, 0, Integer.MAX_VALUE);
33
34 /**
35 * Minimum length.
36 */
37 private final int minLength;
38
39 /**
40 * Maximum length.
41 */
42 private final int maxLength;
43
44 /**
45 * Alignment.
46 */
47 private final boolean leftAlign;
48
49 /**
50 * Creates new instance.
51 *
52 * @param leftAlign
53 * left align if true.
54 * @param minLength
55 * minimum length.
56 * @param maxLength
57 * maximum length.
58 */
59 public FormattingInfo(final boolean leftAlign, final int minLength, final int maxLength) {
60 this.leftAlign = leftAlign;
61 this.minLength = minLength;
62 this.maxLength = maxLength;
63 }
64
65 /**
66 * Gets default instance.
67 *
68 * @return default instance.
69 */
70 public static FormattingInfo getDefault() {
71 return DEFAULT;
72 }
73
74 /**
75 * Determine if left aligned.
76 *
77 * @return true if left aligned.
78 */
79 public boolean isLeftAligned() {
80 return leftAlign;
81 }
82
83 /**
84 * Get minimum length.
85 *
86 * @return minimum length.
87 */
88 public int getMinLength() {
89 return minLength;
90 }
91
92 /**
93 * Get maximum length.
94 *
95 * @return maximum length.
96 */
97 public int getMaxLength() {
98 return maxLength;
99 }
100
101 /**
102 * Adjust the content of the buffer based on the specified lengths and alignment.
103 *
104 * @param fieldStart
105 * start of field in buffer.
106 * @param buffer
107 * buffer to be modified.
108 */
109 public void format(final int fieldStart, final StringBuilder buffer) {
110 final int rawLength = buffer.length() - fieldStart;
111
112 if (rawLength > maxLength) {
113 buffer.delete(fieldStart, buffer.length() - maxLength);
114 } else if (rawLength < minLength) {
115 if (leftAlign) {
116 final int fieldEnd = buffer.length();
117 buffer.setLength(fieldStart + minLength);
118
119 for (int i = fieldEnd; i < buffer.length(); i++) {
120 buffer.setCharAt(i, ' ');
121 }
122 } else {
123 int padLength = minLength - rawLength;
124
125 for (; padLength > SPACES.length; padLength -= SPACES.length) {
126 buffer.insert(fieldStart, SPACES);
127 }
128
129 buffer.insert(fieldStart, SPACES, 0, padLength);
130 }
131 }
132 }
133
134 /**
135 * Returns a String suitable for debugging.
136 *
137 * @return a String suitable for debugging.
138 */
139 @Override
140 public String toString() {
141 StringBuilder sb = new StringBuilder();
142 sb.append(super.toString());
143 sb.append("[leftAlign=");
144 sb.append(leftAlign);
145 sb.append(", maxLength=");
146 sb.append(maxLength);
147 sb.append(", minLength=");
148 sb.append(minLength);
149 sb.append("]");
150 return sb.toString();
151 }
152
153 }