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
7 * "License"); you may not use this file except in compliance
8 * with the License. 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,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.creadur.whisker.out.velocity;
20
21 import java.io.BufferedReader;
22 import java.io.IOException;
23 import java.io.StringReader;
24
25 import org.apache.commons.lang3.StringUtils;
26
27 /**
28 * Manages indentation level.
29 */
30 public class Indentation {
31
32 /**
33 * Creates appropriate indentation, padding with spaces.
34 * @param indentation not null
35 * @param source not null
36 * @return appropriate indentation, not null
37 * @throws IOException when source cannot be read
38 */
39 public final String indent(
40 final int indentation, final Object source) throws IOException {
41 return this.indent(indentation, source, ' ');
42 }
43
44 /**
45 * Creates appropriate indentation.
46 * @param indentation not null
47 * @param source not null
48 * @param pad padding
49 * @return appropriate indentation, not null
50 * @throws IOException when source cannot be read
51 */
52 public final String indent(
53 final int indentation, final Object source, final char pad)
54 throws IOException {
55 final String result;
56 if (source == null) {
57 result = "";
58 } else {
59 result = prefixLine(source, StringUtils.repeat(pad, indentation));
60 }
61 return result;
62 }
63
64 /**
65 * Creates appropriate indentation.
66 * @param source not null
67 * @param prefix not null
68 * @return appropriate indentation, not null
69 * @throws IOException when source cannot be read
70 */
71 private String prefixLine(final Object source, final String prefix)
72 throws IOException {
73 final String result;
74 final StringBuilder builder = new StringBuilder();
75 final BufferedReader lineReader =
76 new BufferedReader(new StringReader(source.toString()));
77 String line = lineReader.readLine();
78 while (line != null) {
79 builder.append('\n').append(prefix).append(line);
80 line = lineReader.readLine();
81 }
82 result = builder.toString();
83 return result;
84 }
85 }