Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.Expression;

import org.gvsig.expressionevaluator.History;

/**

 *

 * @author jjdelcerro

 */

public class DefaultHistory 

        implements History

    {

    public int maxsize;

    public List<Expression> history;

    public DefaultHistory(int size) {

        this.maxsize = size;

        this.history = new ArrayList<>();

    }

    @Override

    public boolean add(Expression element) {

        if( element == null || element.isPhraseEmpty() ) {

            return true;

        }

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

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

            String lastPhrase = StringUtils.normalizeSpace(last.getPhrase());

            String curPhrase = StringUtils.normalizeSpace(element.getPhrase());

            if( StringUtils.equals(curPhrase, lastPhrase) ) {

                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<Expression> 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<Expression> iterator() {

        return this.history.iterator();

    }

    @Override

    public Expression get(int position) {

        return this.history.get(position);

    }

}