NodeInterceptor.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.api.data.tree;

import org.eclipse.che.api.promises.client.Promise;
import org.eclipse.che.ide.api.data.tree.Node;

import java.util.List;

/**
 * Perform children interception to check if current children are available for conversion.
 * This usually useful in case if we want to display instead of file node (*.java) node that
 * represents java class (with inner classes or interfaces) or if file node is under version
 * control system then mark this file with appropriately status in index.
 *
 * @author Vlad Zhukovskiy
 */
public interface NodeInterceptor {

    /**
     * The minimum priority that a interceptor can have.
     */
    int MIN_PRIORITY = 1;

    /**
     * The default priority that is assigned to a interceptor.
     */
    int NORM_PRIORITY = 5;

    /**
     * The maximum priority that a interceptor can have.
     */
    int MAX_PRIORITY = 10;

    /**
     * Intercept nodes and perform operations with them, e.g. settings additional properties,
     * replace ones child with other, etc.
     *
     * @param parent
     *         parent node
     * @param children
     *         children which should be intercepted and transformed if it need
     * @return intercepted and/or transformed children
     */
    Promise<List<Node>> intercept(Node parent, List<Node> children);

    /**
     * Priority of the run.
     *
     * @return priority for the interceptor in which it should be runned
     */
    int getPriority();
}