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Java > Open Source Codes > org > apache > cayenne > util > HierarchicalTreeVisitor


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19
20 package org.apache.cayenne.util;
21
22 import org.apache.cayenne.project.ProjectPath;
23
24 /**
25  * A hierarchical visitor interface used for tree structures traversal.
26  *
27  * @author Andrus Adamchik
28  */
29 // TODO, andrus, 4/24/2006 - move to Cayenne core in 2.0
30 public interface HierarchicalTreeVisitor {
31
32     /**
33      * Invoked in the beginning of the element subtree traversal. Traversal is done in a
34      * depth-first manner, so returning false from this method would suppress child
35      * elements traversal.
36      */
37     boolean onStartNode(ProjectPath path);
38
39     /**
40      * Invoked at the end of the annotation tree traversal, which is done in a depth-first
41      * manner.
42      */
43     void onFinishNode(ProjectPath path);
44
45     /**
46      * Returns an instance of the child visitor for a given project path and a type of
47      * child. Returning null would result in skipping the particular child type.
48      */
49     HierarchicalTreeVisitor childVisitor(ProjectPath path, Class JavaDoc childType);
50 }
51
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