subcategoryaxis.java

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/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, 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.]
 *
 * --------------------
 * SubCategoryAxis.java
 * --------------------
 * (C) Copyright 2004, 2005, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert;
 * Contributor(s):   -;
 *
 * $Id: SubCategoryAxis.java,v 1.6 2005/05/19 13:58:11 mungady Exp $
 *
 * Changes
 * -------
 * 12-May-2004 : Version 1 (DG);
 * 30-Sep-2004 : Moved drawRotatedString() from RefineryUtilities 
 *               --> TextUtilities (DG);
 * 26-Apr-2005 : Removed logger (DG);
 *
 */

package org.jfree.chart.axis;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;

import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.data.category.CategoryDataset;
import org.jfree.io.SerialUtilities;
import org.jfree.text.TextUtilities;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.TextAnchor;

/**
 * A specialised category axis that can display sub-categories.
 */
public class SubCategoryAxis extends CategoryAxis 
                             implements Cloneable, Serializable {
    
    /** For serialization. */
    private static final long serialVersionUID = -1279463299793228344L;
    
    /** Storage for the sub-categories (these need to be set manually). */
    private List subCategories;
    
    /** The font for the sub-category labels. */
    private Font subLabelFont = new Font("SansSerif", Font.PLAIN, 10);
    
    /** The paint for the sub-category labels. */
    private transient Paint subLabelPaint = Color.black;
    
    /**
     * Creates a new axis.
     * 
     * @param label  the axis label.
     */
    public SubCategoryAxis(String label) {
        super(label);
        this.subCategories = new java.util.ArrayList();
    }

    /**
     * Adds a sub-category to the axis.
     * 
     * @param subCategory  the sub-category.
     */
    public void addSubCategory(Comparable subCategory) {
        this.subCategories.add(subCategory);    
    }
    
    /**
     * Returns the font used to display the sub-category labels.
     * 
     * @return The font (never <code>null</code>).
     */
    public Font getSubLabelFont() {
        return this.subLabelFont;   
    }
    
    /**
     * Sets the font used to display the sub-category labels and sends an 
     * {@link AxisChangeEvent} to all registered listeners.
     * 
     * @param font  the font (<code>null</code> not permitted).
     */
    public void setSubLabelFont(Font font) {
        if (font == null) {
            throw new IllegalArgumentException("Null 'font' argument.");   
        }
        this.subLabelFont = font;
        notifyListeners(new AxisChangeEvent(this));
    }
    
    /**
     * Returns the paint used to display the sub-category labels.
     * 
     * @return The paint (never <code>null</code>).
     */
    public Paint getSubLabelPaint() {
        return this.subLabelPaint;   
    }
    
    /**
     * Sets the paint used to display the sub-category labels and sends an 
     * {@link AxisChangeEvent} to all registered listeners.
     * 
     * @param paint  the paint (<code>null</code> not permitted).
     */
    public void setSubLabelPaint(Paint paint) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");   
        }
        this.subLabelPaint = paint;
        notifyListeners(new AxisChangeEvent(this));
    }
    
    /**
     * Estimates the space required for the axis, given a specific drawing area.
     *
     * @param g2  the graphics device (used to obtain font information).
     * @param plot  the plot that the axis belongs to.
     * @param plotArea  the area within which the axis should be drawn.
     * @param edge  the axis location (top or bottom).
     * @param space  the space already reserved.
     *
     * @return The space required to draw the axis.
     */
    public AxisSpace reserveSpace(Graphics2D g2, Plot plot, 
                                  Rectangle2D plotArea, 
                                  RectangleEdge edge, AxisSpace space) {

        // create a new space object if one wasn't supplied...
        if (space == null) {
            space = new AxisSpace();
        }
        
        // if the axis is not visible, no additional space is required...
        if (!isVisible()) {
            return space;
        }

        space = super.reserveSpace(g2, plot, plotArea, edge, space);
        double maxdim = getMaxDim(g2, edge);
        if (RectangleEdge.isTopOrBottom(edge)) {
            space.add(maxdim, edge);
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            space.add(maxdim, edge);
        }
        return space;
    }
    
    /**
     * Returns the maximum of the relevant dimension (height or width) of the 
     * subcategory labels.
     * 
     * @param g2  the graphics device.
     * @param edge  the edge.
     * 
     * @return The maximum dimension.
     */
    private double getMaxDim(Graphics2D g2, RectangleEdge edge) {
        double result = 0.0;
        g2.setFont(this.subLabelFont);
        FontMetrics fm = g2.getFontMetrics();
        Iterator iterator = this.subCategories.iterator();
        while (iterator.hasNext()) {
            Comparable subcategory = (Comparable) iterator.next();
            String label = subcategory.toString();
            Rectangle2D bounds = TextUtilities.getTextBounds(label, g2, fm);
            double dim = 0.0;
            if (RectangleEdge.isLeftOrRight(edge)) {
                dim = bounds.getWidth();   
            }
            else {  // must be top or bottom
                dim = bounds.getHeight();
            }
            result = Math.max(result, dim);
        }   
        return result;
    }
    
    /**
     * Draws the axis on a Java 2D graphics device (such as the screen or a 
     * printer).