package cn.myapps.runtime.report.model;
/*
 * JasperReports - Free Java Reporting Library.
 * Copyright (C) 2001 - 2018 TIBCO Software Inc. All rights reserved.
 * http://www.jaspersoft.com
 *
 * Unless you have purchased a commercial license agreement from Jaspersoft,
 * the following license terms apply:
 *
 * This program is part of JasperReports.
 *
 * JasperReports is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JasperReports is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with JasperReports. If not, see <http://www.gnu.org/licenses/>.
 */
import java.util.Collection;
import java.util.Iterator;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRField;
import net.sf.jasperreports.engine.data.JRAbstractBeanDataSource;


/**
 * A data source implementation that wraps a collection of JavaBean objects.
 * <p>
 * It is common to access application data through object persistence layers like EJB,
 * Hibernate, or JDO. Such applications may need to generate reports using data they
 * already have available as arrays or collections of in-memory JavaBean objects.
 * </p><p>
 * This JavaBean-compliant data source can be used when data comes in a
 * <code>java.util.Collection</code> of JavaBean objects.
 *
 * @author Teodor Danciu (teodord@users.sourceforge.net)
 */
public class JRBeanCollectionDataSource extends JRAbstractBeanDataSource
{


    /**
     *
     */
    private Collection<?> data;
    private Iterator<?> iterator;
    private Object currentBean;


    /**
     *
     */
    public JRBeanCollectionDataSource(Collection<?> beanCollection)
    {
        this(beanCollection, true);
    }


    /**
     *
     */
    public JRBeanCollectionDataSource(Collection<?> beanCollection, boolean isUseFieldDescription)
    {
        super(isUseFieldDescription);

        this.data = beanCollection;

        if (this.data != null)
        {
            this.iterator = this.data.iterator();
        }
    }


    @Override
    public boolean next()
    {
        boolean hasNext = false;

        if (this.iterator != null)
        {
            hasNext = this.iterator.hasNext();

            if (hasNext)
            {
                this.currentBean = this.iterator.next();
            }else{
                moveFirst();
            }
        }

        return hasNext;
    }


    @Override
    public Object getFieldValue(JRField field) throws JRException
    {
        return getFieldValue(currentBean, field);
    }


    @Override
    public void moveFirst()
    {
        if (this.data != null)
        {
            this.iterator = this.data.iterator();
        }
    }

    /**
     * Returns the underlying bean collection used by this data source.
     *
     * @return the underlying bean collection
     */
    public Collection<?> getData()
    {
        return data;
    }

    /**
     * Returns the total number of records/beans that this data source
     * contains.
     *
     * @return the total number of records of this data source
     */
    public int getRecordCount()
    {
        return data == null ? 0 : data.size();
    }

    /**
     * Clones this data source by creating a new instance that reuses the same
     * underlying bean collection.
     *
     * @return a clone of this data source
     */
    public JRBeanCollectionDataSource cloneDataSource()
    {
        return new JRBeanCollectionDataSource(data);
    }
}
