MutableToManyRelationshipChange.java

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package org.apache.cayenne.lifecycle.changemap;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

import org.apache.cayenne.ObjectId;

/**
 * @since 4.0
 */
public class MutableToManyRelationshipChange implements ToManyRelationshipChange {

	private Collection<ObjectId> added;
	private Collection<ObjectId> removed;

	@Override
	public <T> T accept(PropertyChangeVisitor<T> visitor) {
		return visitor.visitToManyRelationship(this);
	}

	@Override
	public Collection<ObjectId> getAdded() {
		return added == null ? Collections.<ObjectId> emptyList() : added;
	}

	@Override
	public Collection<ObjectId> getRemoved() {
		return removed == null ? Collections.<ObjectId> emptyList() : removed;
	}

	public void connected(ObjectId o) {

		// TODO: cancel previously removed ?
		if (added == null) {
			added = new ArrayList<>();
		}

		added.add(o);
	}

	public void disconnected(ObjectId o) {

		// TODO: cancel previously added ?
		if (removed == null) {
			removed = new ArrayList<>();
		}

		removed.add(o);
	}
}