AbstractContentTraverseProcessor.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.kie.workbench.common.stunner.core.graph.processing.traverse.content;

import javax.inject.Inject;

import org.kie.workbench.common.stunner.core.graph.Edge;
import org.kie.workbench.common.stunner.core.graph.Graph;
import org.kie.workbench.common.stunner.core.graph.Node;
import org.kie.workbench.common.stunner.core.graph.content.view.View;
import org.kie.workbench.common.stunner.core.graph.processing.traverse.tree.TreeTraverseCallback;
import org.kie.workbench.common.stunner.core.graph.processing.traverse.tree.TreeWalkTraverseProcessor;

public abstract class AbstractContentTraverseProcessor<C, N extends Node<View, Edge>, E extends Edge<C, Node>, K extends ContentTraverseCallback<C, N, E>>
        implements ContentTraverseProcessor<C, N, E, K> {

    TreeWalkTraverseProcessor treeWalkTraverseProcessor;

    @Inject
    public AbstractContentTraverseProcessor(final TreeWalkTraverseProcessor treeWalkTraverseProcessor) {
        this.treeWalkTraverseProcessor = treeWalkTraverseProcessor;
    }

    protected abstract TreeWalkTraverseProcessor.EdgeVisitorPolicy getPolicy();

    @SuppressWarnings("unchecked")
    protected boolean doStartEdgeTraversal(final Edge edge,
                                           final K callback) {
        if (accepts(edge)) {
            callback.startEdgeTraversal((E) edge);
            return true;
        }
        return false;
    }

    @SuppressWarnings("unchecked")
    protected boolean doEndEdgeTraversal(final Edge edge,
                                         final K callback) {
        if (accepts(edge)) {
            callback.endEdgeTraversal((E) edge);
            return true;
        }
        return false;
    }

    protected boolean accepts(final Edge edge) {
        return true;
    }

    @SuppressWarnings("unchecked")
    protected void doStartGraphTraversal(final Graph graph,
                                         final K callback) {
        if (graph.getContent() instanceof View) {
            callback.startGraphTraversal(graph);
        }
    }

    @SuppressWarnings("unchecked")
    protected boolean doStartNodeTraversal(final Node node,
                                           final K callback) {
        if (node.getContent() instanceof View) {
            callback.startNodeTraversal((N) node);
            return true;
        }
        return false;
    }

    @SuppressWarnings("unchecked")
    protected void doEndNodeTraversal(final Node node,
                                      final K callback) {
        if (node.getContent() instanceof View) {
            callback.endNodeTraversal((N) node);
        }
    }

    protected void doEndGraphTraversal(final Graph graph,
                                       final K callback) {
        callback.endGraphTraversal();
    }

    @Override
    public void traverse(final Graph<View, N> graph,
                         final K callback) {
        treeWalkTraverseProcessor
                .useEdgeVisitorPolicy(getPolicy())
                .traverse(graph,
                          new TreeTraverseCallback<Graph, Node, Edge>() {

                              @Override
                              public void startGraphTraversal(final Graph graph) {
                                  AbstractContentTraverseProcessor.this.doStartGraphTraversal(graph,
                                                                                              callback);
                              }

                              @Override
                              public boolean startNodeTraversal(final Node node) {
                                  return AbstractContentTraverseProcessor.this.doStartNodeTraversal(node,
                                                                                                    callback);
                              }

                              @Override
                              public boolean startEdgeTraversal(final Edge edge) {
                                  return AbstractContentTraverseProcessor.this.doStartEdgeTraversal(edge,
                                                                                                    callback);
                              }

                              @Override
                              public void endNodeTraversal(final Node node) {
                                  AbstractContentTraverseProcessor.this.doEndNodeTraversal(node,
                                                                                           callback);
                              }

                              @Override
                              public void endEdgeTraversal(final Edge edge) {
                                  AbstractContentTraverseProcessor.this.doEndEdgeTraversal(edge,
                                                                                           callback);
                              }

                              @Override
                              public void endGraphTraversal() {
                                  AbstractContentTraverseProcessor.this.doEndGraphTraversal(graph,
                                                                                            callback);
                              }
                          });
    }
}