source: trunk/docx4j/src/main/java/org/docx4j/utils/CompoundTraversalUtilVisitorCallback.java @ 1803

package org.docx4j.utils;

import java.util.HashMap;
import java.util.List;
import java.util.LinkedList;
import java.util.Map;
import java.util.Map.Entry;

/** 
 * Use this if there is more than one object type (eg Tables and Paragraphs)
 * you are interested in doing something with during the traversal.
 * 
 * @author alberto
 */
public class CompoundTraversalUtilVisitorCallback extends
                AbstractTraversalUtilVisitorCallback {

        Map<Class, List<TraversalUtilVisitor>> visitorMap = null;

        public CompoundTraversalUtilVisitorCallback(
                        List<TraversalUtilVisitor> visitorList) {

                visitorMap = setupTraversalVistorMap(visitorList);
        }

        protected Map<Class, List<TraversalUtilVisitor>> setupTraversalVistorMap(
                        List<TraversalUtilVisitor> visitorList) {

                Map<Class, List<TraversalUtilVisitor>> ret = new HashMap<Class, List<TraversalUtilVisitor>>();
                Class visitorClass = null;
                List<TraversalUtilVisitor> classVisitorList = null;
                for (TraversalUtilVisitor visitor : visitorList) {
                        visitorClass = findClassParameter(visitor.getClass());
                        if (visitorClass == null) {
                                throw new IllegalArgumentException(
                                                "Can't identify the parameter class of the visitor "
                                                                + visitor.getClass().getName());
                        }
                        classVisitorList = ret.get(visitorClass);
                        if (classVisitorList == null) {
                                classVisitorList = new LinkedList<TraversalUtilVisitor>();
                                ret.put(visitorClass, classVisitorList);
                        }
                        classVisitorList.add(visitor);
                }
                return ret;
        }

        @Override
        protected List<Object> apply(Object child, Object parent, List siblings) {
                for (final Entry<Class, List<TraversalUtilVisitor>> entrySet : visitorMap.entrySet()) {
                        final Class currentClass = entrySet.getKey();
                        if (currentClass.isAssignableFrom(child.getClass())) {
                                List<TraversalUtilVisitor> classVisitorList = entrySet.getValue();
                                if (null != classVisitorList) {
                                        for (TraversalUtilVisitor visitor : classVisitorList) {
                                                visitor.apply(child, parent, siblings);
                                        }
                                }
                        }
                }
                return null;
        }

}