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1
4 package net.sourceforge.pmd.jaxen;
5
6 import net.sourceforge.pmd.ast.Node;
7
8 import java.util.Iterator  ;
9 import java.util.NoSuchElementException ;
10
11
14 public abstract class NodeIterator implements Iterator {
15
16 private Node node;
17
18 public NodeIterator(Node contextNode) {
19 this.node = getFirstNode(contextNode);
20 }
21
22 public boolean hasNext() {
23 return node != null;
24 }
25
26 public Object next() {
27 if (node == null)
28 throw new NoSuchElementException ();
29 Node ret = node;
30 node = getNextNode(node);
31 return ret;
32 }
33
34 public void remove() {
35 throw new UnsupportedOperationException ();
36 }
37
38 protected abstract Node getFirstNode(Node contextNode);
39
40 protected abstract Node getNextNode(Node contextNode);
41
42 protected Node getPreviousSibling(Node contextNode) {
43 Node parentNode = contextNode.jjtGetParent();
44 if (parentNode != null) {
45 int prevPosition = getPositionFromParent(contextNode) - 1;
46 if (prevPosition >= 0) {
47 return parentNode.jjtGetChild(prevPosition);
48 }
49 }
50 return null;
51 }
52
53 private int getPositionFromParent(Node contextNode) {
54 Node parentNode = contextNode.jjtGetParent();
55 for (int i = 0; i < parentNode.jjtGetNumChildren(); i++) {
56 if (parentNode.jjtGetChild(i) == contextNode) {
57 return i;
58 }
59 }
60 throw new RuntimeException ("Node was not a child of it's parent ???");
61 }
62
63 protected Node getNextSibling(Node contextNode) {
64 Node parentNode = contextNode.jjtGetParent();
65 if (parentNode != null) {
66 int nextPosition = getPositionFromParent(contextNode) + 1;
67 if (nextPosition < parentNode.jjtGetNumChildren()) {
68 return parentNode.jjtGetChild(nextPosition);
69 }
70 }
71 return null;
72 }
73
74 protected Node getFirstChild(Node contextNode) {
75 if (contextNode.jjtGetNumChildren() > 0) {
76 return contextNode.jjtGetChild(0);
77 } else {
78 return null;
79 }
80 }
81
82 protected Node getLastChild(Node contextNode) {
83 if (contextNode.jjtGetNumChildren() > 0) {
84 return contextNode.jjtGetChild(contextNode.jjtGetNumChildren() - 1);
85 } else {
86 return null;
87 }
88 }
89 } |
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