01: /*
02: * Copyright (c) 2007, intarsys consulting GmbH
03: *
04: * Redistribution and use in source and binary forms, with or without
05: * modification, are permitted provided that the following conditions are met:
06: *
07: * - Redistributions of source code must retain the above copyright notice,
08: * this list of conditions and the following disclaimer.
09: *
10: * - Redistributions in binary form must reproduce the above copyright notice,
11: * this list of conditions and the following disclaimer in the documentation
12: * and/or other materials provided with the distribution.
13: *
14: * - Neither the name of intarsys nor the names of its contributors may be used
15: * to endorse or promote products derived from this software without specific
16: * prior written permission.
17: *
18: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28: * POSSIBILITY OF SUCH DAMAGE.
29: */
30: package de.intarsys.pdf.cos;
31:
32: import java.util.HashSet;
33: import java.util.Set;
34:
35: /**
36: * Adapter implementation for visiting a COS object structure, including
37: * indirect references.
38: * <p>
39: * Every object in the potential cyclic data structure is visited exactly once.
40: *
41: */
42: public class COSObjectWalkerDeep extends COSObjectWalkerShallow {
43: private Set visited;
44:
45: private boolean swap;
46:
47: public COSObjectWalkerDeep() {
48: this (true);
49: }
50:
51: public COSObjectWalkerDeep(boolean swap) {
52: visited = new HashSet();
53: this .swap = swap;
54: }
55:
56: public Set getVisited() {
57: return visited;
58: }
59:
60: public Object visitFromIndirectObject(COSIndirectObject io)
61: throws COSVisitorException {
62: if (getVisited().contains(io)) {
63: return null;
64: }
65: getVisited().add(io);
66: if (swap || !io.isSwapped()) {
67: io.dereference().accept(this);
68: }
69: return null;
70: }
71: }
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