abstractcategoryitemlabelgenerator.java

jfreechart安装程序和使用说明

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------------------------------
 * AbstractCategoryItemLabelGenerator.java
 * ---------------------------------------
 * (C) Copyright 2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: AbstractCategoryItemLabelGenerator.java,v 1.1 2004/08/31 14:36:24 mungady Exp $
 *
 * Changes
 * -------
 * 11-May-2004 : Version 1, distilled from StandardCategoryItemLabelGenerator (DG);
 *
 */

package org.jfree.chart.labels;

import java.io.Serializable;
import java.text.DateFormat;
import java.text.MessageFormat;
import java.text.NumberFormat;

import org.jfree.data.category.CategoryDataset;
import org.jfree.util.ObjectUtils;
import org.jfree.util.PublicCloneable;

/**
 * A base class that can be used to create a label or tooltip generator that can be 
 * assigned to a {@link org.jfree.chart.renderer.category.CategoryItemRenderer}.
 */
public abstract class AbstractCategoryItemLabelGenerator implements PublicCloneable,
                                                                    Cloneable, 
                                                                    Serializable {

    /** 
     * The label format string (used by a MessageFormat object to combine the standard
     * items. {0} = series name, {1} = category, {2} = value.
     */
    private String labelFormat;
    
    /** 
     * A number formatter (used to preformat the value before it is passed to the
     * MessageFormat object. 
     */
    private NumberFormat numberFormat;

    /**
     * A date formatter (used to preformat the value before it is passed to the
     * MessageFormat object.
     */ 
    private DateFormat dateFormat;
    
    /**
     * Creates a label generator with the specified number formatter.
     *
     * @param labelFormat  the label format string (<code>null</code> not permitted).
     * @param formatter  the number formatter (<code>null</code> not permitted).
     */
    protected AbstractCategoryItemLabelGenerator(String labelFormat, NumberFormat formatter) {
        if (labelFormat == null) {
            throw new IllegalArgumentException("Null 'labelFormat' argument.");
        }
        if (formatter == null) {
            throw new IllegalArgumentException("Null 'formatter' argument.");
        }
        this.labelFormat = labelFormat;
        this.numberFormat = formatter;
        this.dateFormat = null;
    }

    /**
     * Creates a label generator with the specified date formatter.
     *
     * @param labelFormat  the label format string (<code>null</code> not permitted).
     * @param formatter  the date formatter (<code>null</code> not permitted).
     */
    protected AbstractCategoryItemLabelGenerator(String labelFormat, DateFormat formatter) {
        if (labelFormat == null) {
            throw new IllegalArgumentException("Null 'labelFormat' argument.");
        }
        if (formatter == null) {
            throw new IllegalArgumentException("Null 'formatter' argument.");
        }
        this.labelFormat = labelFormat;
        this.numberFormat = null;
        this.dateFormat = formatter;
    }
    
    /**
     * Returns the label format string.
     * 
     * @return The label format string (never <code>null</code>).
     */
    public String getLabelFormat() {
        return this.labelFormat;   
    }
    
    /**
     * Returns the number formatter.
     *
     * @return The number formatter (possibly <code>null</code>).
     */
    public NumberFormat getNumberFormat() {
        return this.numberFormat;
    }

    /**
     * Returns the date formatter.
     *
     * @return The date formatter (possibly <code>null</code>).
     */
    public DateFormat getDateFormat() {
        return this.dateFormat;
    }

    /**
     * Generates a for the specified item.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     *
     * @return The label (possibly <code>null</code>).
     */
    protected String generateLabelString(CategoryDataset dataset, int row, int column) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        String result = null;   
        Object[] items = createItemArray(dataset, row, column);
        result = MessageFormat.format(this.labelFormat, items);
        return result;

    }

    /**
     * Creates the array of items that can be passed to the {@link MessageFormat} class
     * for creating labels.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     *
     * @return The items (never <code>null</code>).
     */
    protected Object[] createItemArray(CategoryDataset dataset, int row, int column) {
        Object[] result = new Object[3];
        result[0] = dataset.getRowKey(row).toString();
        result[1] = dataset.getColumnKey(column).toString();
        Number value = dataset.getValue(row, column);
        if (this.numberFormat != null) {
            result[2] = this.numberFormat.format(value);  
        }
        else if (this.dateFormat != null) {
            result[2] = this.dateFormat.format(value);
        }
        return result;
    }

    /**
     * Tests this object for equality with an arbitrary object.
     *
     * @param obj  the other object (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (obj instanceof AbstractCategoryItemLabelGenerator) {
            AbstractCategoryItemLabelGenerator g = (AbstractCategoryItemLabelGenerator) obj;
            boolean b0 = this.labelFormat.equals(g.labelFormat);
            boolean b1 = ObjectUtils.equal(this.dateFormat, g.dateFormat);
            boolean b2 = ObjectUtils.equal(this.numberFormat, g.numberFormat);
            return b0 && b1 && b2;
        }
        return false;
    }
    
    /**
     * Returns an independent copy of the generator.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException  should not happen.
     */
    public Object clone() throws CloneNotSupportedException {
        
        AbstractCategoryItemLabelGenerator clone 
            = (AbstractCategoryItemLabelGenerator) super.clone();
        
        if (this.numberFormat != null) {
            clone.numberFormat = (NumberFormat) this.numberFormat.clone();
        } 
        
        if (this.dateFormat != null) {
            clone.dateFormat = (DateFormat) this.dateFormat.clone();
        } 
        
        return clone;
        
    }

}