Application: gvSIG desktop » Library: org.gvsig.tools

package org.gvsig.tools.bookmarksandhistory.impl;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

import org.gvsig.tools.bookmarksandhistory.History;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 *

 * @author jjdelcerro

 * @param <T>

 */

public class BaseHistory<T>

        implements History<T> {

    private static final Logger LOG = LoggerFactory.getLogger(BaseHistory.class);

    protected int maxsize;

    protected List<T> history;

    public BaseHistory(int size) {

        this.maxsize = size;

        this.history = new ArrayList<>();

    }

    /**

     *

     * @param element

     * @return

     */

    @Override

    public boolean add(T element) {

        if (element == null) {

            LOG.warn("Element not been add to history because it's null.");

            return false;

        }

        if (!this.history.isEmpty()) {

            T last = this.history.get(0);

                if (element.equals(last)) {

                    return true;

                }

        }

        this.history.add(0, element);

        if (this.history.size() > this.maxsize) {

            this.history.remove(this.history.size() - 1);

        }

        return true;

    }

    @Override

    public List<T> toList() {

        return Collections.unmodifiableList(this.history);

    }

    @Override

    public void clear() {

        this.history.clear();

    }

    @Override

    public boolean isEmpty() {

        return this.history.isEmpty();

    }

    @Override

    public int size() {

        return this.history.size();

    }

    @Override

    public Iterator<T> iterator() {

        return this.history.iterator();

    }

    @Override

    public T get(int position) {

        return this.history.get(position);

    }

}