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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  }