1 package org.codehaus.mojo.taglist.tags;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Locale;
23
24 /** The abstract base class for tags.
25 * <p>
26 * This class defines the required functions that each type of
27 * tag must implement. The goal here is to allow different types
28 * of tags to be created by the user, but the call processing
29 * for each tag can be generic.
30 * <p>
31 * For example, a generic tag might search files for an exact string
32 * match of the tag, but a regex tag will use regular expressions in
33 * its searching. Either way, the processing classes call each tag
34 * with the same function and get the same results.
35 *
36 */
37 public abstract class AbsTag {
38 /** The int value for no tag match found.
39 * This value matches what is returned from Java String class
40 * indexOf(..string..) function. */
41 static final int NO_MATCH = -1;
42
43 /**
44 * The tag string for this tag. The string here is generic, and its use is defined by the derived tag objects.
45 */
46 protected String tagString;
47
48 /** Check to see if the string contains this tag.
49 * If there is a match, return the index within the string; otherwise,
50 * return NO_MATCH.
51 *
52 * @param currentLine the string for the current line being scanned.
53 * @param locale the Locale of the currentLine.
54 * @return the index within the string of the matched tag, or TagClass.NO_MATCH
55 * if not match was found.
56 */
57 public abstract int contains(final String currentLine, final Locale locale);
58
59 /** Check to see if the string starts with this tag.
60 * If there is a match, return true.
61 *
62 * @param currentLine the string for the current line being scanned.
63 * @param locale the Locale of the currentLine.
64 * @return true if the string starts with this tag.
65 */
66 public abstract boolean startsWith(final String currentLine, final Locale locale);
67
68 /** Return the length of the last matched tag.
69 * <p>
70 * Normally this is the length of the tag; however, some tags
71 * are dynamic. For example a regular expression tag might be
72 * 10 characters; however, the matched string may only be 5.
73 * <p>
74 * Calling this function allows the tag object to return the
75 * correct length for the last matched tag.
76 *
77 * @return the length of the last matched tag.
78 */
79 public abstract int getLastTagMatchLength();
80
81 /** Constructor.
82 *
83 * @param tag the tag string to be used for this tag.
84 */
85 protected AbsTag(final String tag) {
86 tagString = tag;
87 }
88 }