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 package org.apache.pdfbox.cos;
18
19 import org.apache.pdfbox.exceptions.COSVisitorException;
20
21 /**
22 * An interface for visiting a PDF document at the type (COS) level.
23 *
24 * @author Michael Traut
25 * @version $Revision: 1.6 $
26 */
27 public interface ICOSVisitor
28 {
29 /**
30 * Notification of visit to Array object.
31 *
32 * @param obj The Object that is being visited.
33 * @return any Object depending on the visitor implementation, or null
34 * @throws COSVisitorException If there is an error while visiting this object.
35 */
36 public Object visitFromArray( COSArray obj ) throws COSVisitorException;
37
38 /**
39 * Notification of visit to boolean object.
40 *
41 * @param obj The Object that is being visited.
42 * @return any Object depending on the visitor implementation, or null
43 * @throws COSVisitorException If there is an error while visiting this object.
44 */
45 public Object visitFromBoolean( COSBoolean obj ) throws COSVisitorException;
46
47 /**
48 * Notification of visit to dictionary object.
49 *
50 * @param obj The Object that is being visited.
51 * @return any Object depending on the visitor implementation, or null
52 * @throws COSVisitorException If there is an error while visiting this object.
53 */
54 public Object visitFromDictionary( COSDictionary obj ) throws COSVisitorException;
55
56 /**
57 * Notification of visit to document object.
58 *
59 * @param obj The Object that is being visited.
60 * @return any Object depending on the visitor implementation, or null
61 * @throws COSVisitorException If there is an error while visiting this object.
62 */
63 public Object visitFromDocument( COSDocument obj ) throws COSVisitorException;
64
65 /**
66 * Notification of visit to float object.
67 *
68 * @param obj The Object that is being visited.
69 * @return any Object depending on the visitor implementation, or null
70 * @throws COSVisitorException If there is an error while visiting this object.
71 */
72 public Object visitFromFloat( COSFloat obj ) throws COSVisitorException;
73
74 /**
75 * Notification of visit to integer object.
76 *
77 * @param obj The Object that is being visited.
78 * @return any Object depending on the visitor implementation, or null
79 * @throws COSVisitorException If there is an error while visiting this object.
80 */
81 public Object visitFromInt( COSInteger obj ) throws COSVisitorException;
82
83 /**
84 * Notification of visit to name object.
85 *
86 * @param obj The Object that is being visited.
87 * @return any Object depending on the visitor implementation, or null
88 * @throws COSVisitorException If there is an error while visiting this object.
89 */
90 public Object visitFromName( COSName obj ) throws COSVisitorException;
91
92 /**
93 * Notification of visit to null object.
94 *
95 * @param obj The Object that is being visited.
96 * @return any Object depending on the visitor implementation, or null
97 * @throws COSVisitorException If there is an error while visiting this object.
98 */
99 public Object visitFromNull( COSNull obj ) throws COSVisitorException;
100
101 /**
102 * Notification of visit to stream object.
103 *
104 * @param obj The Object that is being visited.
105 * @return any Object depending on the visitor implementation, or null
106 * @throws COSVisitorException If there is an error while visiting this object.
107 */
108 public Object visitFromStream( COSStream obj ) throws COSVisitorException;
109
110 /**
111 * Notification of visit to string object.
112 *
113 * @param obj The Object that is being visited.
114 * @return any Object depending on the visitor implementation, or null
115 * @throws COSVisitorException If there is an error while visiting this object.
116 */
117 public Object visitFromString( COSString obj ) throws COSVisitorException;
118 }