/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2006, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * -----------------
 * AreaRenderer.java
 * -----------------
 * (C) Copyright 2002-2006, by Jon Iles and Contributors.
 *
 * Original Author:  Jon Iles;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *                   Christian W. Zuckschwerdt;
 *
 * $Id: AreaRenderer.java,v 1.6.2.6 2006/12/01 13:57:09 mungady Exp $
 *
 * Changes:
 * --------
 * 21-May-2002 : Version 1, contributed by John Iles (DG);
 * 29-May-2002 : Now extends AbstractCategoryItemRenderer (DG);
 * 11-Jun-2002 : Updated Javadoc comments (DG);
 * 25-Jun-2002 : Removed unnecessary imports (DG);
 * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 10-Oct-2002 : Added constructors and basic entity support (DG);
 * 24-Oct-2002 : Amendments for changes in CategoryDataset interface and 
 *               CategoryToolTipGenerator interface (DG);
 * 05-Nov-2002 : Replaced references to CategoryDataset with TableDataset (DG);
 * 06-Nov-2002 : Renamed drawCategoryItem() --> drawItem() and now using axis 
 *               for category spacing.  Renamed AreaCategoryItemRenderer 
 *               --> AreaRenderer (DG);
 * 17-Jan-2003 : Moved plot classes into a separate package (DG);
 * 25-Mar-2003 : Implemented Serializable (DG);
 * 10-Apr-2003 : Changed CategoryDataset to KeyedValues2DDataset in 
 *               drawItem() method (DG);
 * 12-May-2003 : Modified to take into account the plot orientation (DG);
 * 30-Jul-2003 : Modified entity constructor (CZ);
 * 13-Aug-2003 : Implemented Cloneable (DG);
 * 07-Oct-2003 : Added renderer state (DG);
 * 05-Nov-2004 : Modified drawItem() signature (DG);
 * 20-Apr-2005 : Apply tooltips and URLs to legend items (DG);
 * 09-Jun-2005 : Use addItemEntity() method from superclass (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 11-Oct-2006 : Fixed bug in equals() method (DG);
 * 30-Nov-2006 : Added checks for series visibility (DG);
 * 
 */

package org.jfree.chart.renderer.category;

import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.chart.LegendItem;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.AreaRendererEndType;
import org.jfree.data.category.CategoryDataset;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.PublicCloneable;

/**
 * A category item renderer that draws area charts.  You can use this renderer 
 * with the {@link org.jfree.chart.plot.CategoryPlot} class.
 */
public class AreaRenderer extends AbstractCategoryItemRenderer 
                          implements Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -4231878281385812757L;
    
    /** A flag that controls how the ends of the areas are drawn. */
    private AreaRendererEndType endType;
    
    /**
     * Creates a new renderer.
     */
    public AreaRenderer() {
        super();
        this.endType = AreaRendererEndType.TAPER;
    }

    /**
     * Returns a token that controls how the renderer draws the end points.
     * The default value is {@link AreaRendererEndType#TAPER}.
     * 
     * @return The end type (never <code>null</code>).
     *
     * @see #setEndType
     */
    public AreaRendererEndType getEndType() {
        return this.endType;   
    }
    
    /**
     * Sets a token that controls how the renderer draws the end points, and 
     * sends a {@link RendererChangeEvent} to all registered listeners.
     * 
     * @param type  the end type (<code>null</code> not permitted).
     *
     * @see #getEndType()
     */
    public void setEndType(AreaRendererEndType type) {
        if (type == null) {
            throw new IllegalArgumentException("Null 'type' argument.");   
        }
        this.endType = type;
        notifyListeners(new RendererChangeEvent(this));
    }
    
    /**
     * Returns a legend item for a series.
     *
     * @param datasetIndex  the dataset index (zero-based).
     * @param series  the series index (zero-based).
     *
     * @return The legend item.
     */
    public LegendItem getLegendItem(int datasetIndex, int series) {

        // if there is no plot, there is no dataset to access...
        CategoryPlot cp = getPlot();
        if (cp == null) {
            return null;
        }
        
        // check that a legend item needs to be displayed...
        if (!isSeriesVisible(series) || !isSeriesVisibleInLegend(series)) {
            return null;
        }

        CategoryDataset dataset;
        dataset = cp.getDataset(datasetIndex);
        String label = getLegendItemLabelGenerator().generateLabel(dataset, 
                series);
        String description = label;
        String toolTipText = null; 
        if (getLegendItemToolTipGenerator() != null) {
            toolTipText = getLegendItemToolTipGenerator().generateLabel(
                    dataset, series);   
        }
        String urlText = null;
        if (getLegendItemURLGenerator() != null) {
            urlText = getLegendItemURLGenerator().generateLabel(dataset, 
                    series);   
        }
        Shape shape = new Rectangle2D.Double(-4.0, -4.0, 8.0, 8.0);
        Paint paint = getSeriesPaint(series);
        Paint outlinePaint = getSeriesOutlinePaint(series);
        Stroke outlineStroke = getSeriesOutlineStroke(series);

        return new LegendItem(label, description, toolTipText, urlText, 
                shape, paint, outlineStroke, outlinePaint);

    }

    /**
     * Draw a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the data plot area.
     * @param plot  the plot.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the dataset.
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     * @param pass  the pass index.
     */
    public void drawItem(Graphics2D g2,
                         CategoryItemRendererState state,
                         Rectangle2D dataArea,
                         CategoryPlot plot,
                         CategoryAxis domainAxis,
                         ValueAxis rangeAxis,
                         CategoryDataset dataset,
                         int row,
                         int column,
                         int pass) {

        // do nothing if item is not visible
        if (!getItemVisible(row, column)) {
            return;   
        }

        // plot non-null values only...
        Number value = dataset.getValue(row, column);
        if (value != null) {
            PlotOrientation orientation = plot.getOrientation();
            RectangleEdge axisEdge = plot.getDomainAxisEdge();
            int count = dataset.getColumnCount();
            float x0 = (float) domainAxis.getCategoryStart(column, count, 
                    dataArea, axisEdge);
            float x1 = (float) domainAxis.getCategoryMiddle(column, count, 
                    dataArea, axisEdge);
            float x2 = (float) domainAxis.getCategoryEnd(column, count, 
                    dataArea, axisEdge);

            x0 = Math.round(x0);
            x1 = Math.round(x1);
            x2 = Math.round(x2);

            if (this.endType == AreaRendererEndType.TRUNCATE) {
                if (column == 0) {
                    x0 = x1;   
                }
                else if (column == getColumnCount() - 1) {
                    x2 = x1;   
                }
            }
            
            double yy1 = value.doubleValue();

            double yy0 = 0.0;
            if (column > 0) {
                Number n0 = dataset.getValue(row, column - 1);
                if (n0 != null) {
                    yy0 = (n0.doubleValue() + yy1) / 2.0;
                }
            }

            double yy2 = 0.0;
            if (column < dataset.getColumnCount() - 1) {
                Number n2 = dataset.getValue(row, column + 1);
                if (n2 != null) {
                    yy2 = (n2.doubleValue() + yy1) / 2.0;
                }
            }

            RectangleEdge edge = plot.getRangeAxisEdge();
            float y0 = (float) rangeAxis.valueToJava2D(yy0, dataArea, edge);
            float y1 = (float) rangeAxis.valueToJava2D(yy1, dataArea, edge);
            float y2 = (float) rangeAxis.valueToJava2D(yy2, dataArea, edge);
            float yz = (float) rangeAxis.valueToJava2D(0.0, dataArea, edge);

            g2.setPaint(getItemPaint(row, column));
            g2.setStroke(getItemStroke(row, column));

            GeneralPath area = new GeneralPath();

            if (orientation == PlotOrientation.VERTICAL) {
                area.moveTo(x0, yz);
                area.lineTo(x0, y0);
                area.lineTo(x1, y1);
                area.lineTo(x2, y2);
                area.lineTo(x2, yz);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                area.moveTo(yz, x0);
                area.lineTo(y0, x0);
                area.lineTo(y1, x1);
                area.lineTo(y2, x2);
                area.lineTo(yz, x2);
            }
            area.closePath();

            g2.setPaint(getItemPaint(row, column));
            g2.fill(area);

            // draw the item labels if there are any...
            if (isItemLabelVisible(row, column)) {
                drawItemLabel(g2, orientation, dataset, row, column, x1, y1, 
                        (value.doubleValue() < 0.0));
            }

            // add an item entity, if this information is being collected
            EntityCollection entities = state.getEntityCollection();
            if (entities != null) {
                addItemEntity(entities, dataset, row, column, area);
            }
        }

    }
    
    /**
     * Tests this instance for equality with an arbitrary object.
     *
     * @param obj  the object to test (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {    
            return true;
        }
        if (!(obj instanceof AreaRenderer)) {
            return false;
        }
        AreaRenderer that = (AreaRenderer) obj;
        if (!this.endType.equals(that.endType)) {
            return false;
        }
        return super.equals(obj);
    }
    
    /**
     * Returns an independent copy of the renderer.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException  should not happen.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}
