/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-present, by David Gilbert 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.
 *
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 *
 * --------------------
 * XYAreaRenderer2.java
 * --------------------
 * (C) Copyright 2004-present, by Hari and Contributors.
 *
 * Original Author:  Hari (ourhari@hotmail.com);
 * Contributor(s):   David Gilbert;
 *                   Richard Atkinson;
 *                   Christian W. Zuckschwerdt;
 *                   Martin Krauskopf;
 *                   Ulrich Voigt (patch #312);
 */

package org.jfree.chart.renderer.xy;

import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Area;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.jfree.chart.LegendItem;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.entity.XYItemEntity;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.labels.XYSeriesLabelGenerator;
import org.jfree.chart.labels.XYToolTipGenerator;
import org.jfree.chart.plot.CrosshairState;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.urls.XYURLGenerator;
import org.jfree.chart.util.Args;
import org.jfree.chart.util.PublicCloneable;
import org.jfree.chart.util.SerialUtils;
import org.jfree.chart.util.ShapeUtils;
import org.jfree.data.xy.XYDataset;

/**
 * Area item renderer for an {@link XYPlot}. The example shown here is
 * generated by the {@code XYAreaRenderer2Demo1.java} program included in
 * the JFreeChart demo collection:
 * <br><br>
 * <img src="doc-files/XYAreaRenderer2Sample.png"
 * alt="XYAreaRenderer2Sample.png">
 */
public class XYAreaRenderer2 extends AbstractXYItemRenderer
        implements XYItemRenderer, PublicCloneable {

    /** For serialization. */
    private static final long serialVersionUID = -7378069681579984133L;

    /** A flag that controls whether or not the outline is shown. */
    private boolean showOutline;

    /**
     * The shape used to represent an area in each legend item (this should
     * never be {@code null}).
     */
    private transient Shape legendArea;

    /**
     * Constructs a new renderer.
     */
    public XYAreaRenderer2() {
        this(null, null);
    }

    /**
     * Constructs a new renderer.
     *
     * @param labelGenerator  the tool tip generator to use ({@code null} 
     *     permitted).
     * @param urlGenerator  the URL generator ({@code null} permitted).
     */
    public XYAreaRenderer2(XYToolTipGenerator labelGenerator,
                           XYURLGenerator urlGenerator) {
        super();
        this.showOutline = false;
        setDefaultToolTipGenerator(labelGenerator);
        setURLGenerator(urlGenerator);
        GeneralPath area = new GeneralPath();
        area.moveTo(0.0f, -4.0f);
        area.lineTo(3.0f, -2.0f);
        area.lineTo(4.0f, 4.0f);
        area.lineTo(-4.0f, 4.0f);
        area.lineTo(-3.0f, -2.0f);
        area.closePath();
        this.legendArea = area;
    }

    /**
     * Returns a flag that controls whether or not outlines of the areas are
     * drawn.
     *
     * @return The flag.
     *
     * @see #setOutline(boolean)
     */
    public boolean isOutline() {
        return this.showOutline;
    }

    /**
     * Sets a flag that controls whether or not outlines of the areas are
     * drawn, and sends a {@link RendererChangeEvent} to all registered
     * listeners.
     *
     * @param show  the flag.
     *
     * @see #isOutline()
     */
    public void setOutline(boolean show) {
        this.showOutline = show;
        fireChangeEvent();
    }

    /**
     * Returns the shape used to represent an area in the legend.
     *
     * @return The legend area (never {@code null}).
     *
     * @see #setLegendArea(Shape)
     */
    public Shape getLegendArea() {
        return this.legendArea;
    }

    /**
     * Sets the shape used as an area in each legend item and sends a
     * {@link RendererChangeEvent} to all registered listeners.
     *
     * @param area  the area ({@code null} not permitted).
     *
     * @see #getLegendArea()
     */
    public void setLegendArea(Shape area) {
        Args.nullNotPermitted(area, "area");
        this.legendArea = area;
        fireChangeEvent();
    }

    /**
     * Returns a default legend item for the specified series.  Subclasses
     * should override this method to generate customised items.
     *
     * @param datasetIndex  the dataset index (zero-based).
     * @param series  the series index (zero-based).
     *
     * @return A legend item for the series.
     */
    @Override
    public LegendItem getLegendItem(int datasetIndex, int series) {
        LegendItem result = null;
        XYPlot xyplot = getPlot();
        if (xyplot != null) {
            XYDataset dataset = xyplot.getDataset(datasetIndex);
            if (dataset != null) {
                XYSeriesLabelGenerator lg = getLegendItemLabelGenerator();
                String label = lg.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);
                }
                Paint paint = lookupSeriesPaint(series);
                result = new LegendItem(label, description, toolTipText,
                        urlText, this.legendArea, paint);
                result.setLabelFont(lookupLegendTextFont(series));
                Paint labelPaint = lookupLegendTextPaint(series);
                if (labelPaint != null) {
                    result.setLabelPaint(labelPaint);
                }
                result.setDataset(dataset);
                result.setDatasetIndex(datasetIndex);
                result.setSeriesKey(dataset.getSeriesKey(series));
                result.setSeriesIndex(series);
            }
        }
        return result;
    }

    /**
     * Draws the visual representation of a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the area within which the data is being drawn.
     * @param info  collects information about the drawing.
     * @param plot  the plot (can be used to obtain standard color
     *              information etc).
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the dataset.
     * @param series  the series index (zero-based).
     * @param item  the item index (zero-based).
     * @param crosshairState  crosshair information for the plot
     *                        ({@code null} permitted).
     * @param pass  the pass index.
     */
    @Override
    public void drawItem(Graphics2D g2, XYItemRendererState state,
         Rectangle2D dataArea, PlotRenderingInfo info, XYPlot plot,
         ValueAxis domainAxis, ValueAxis rangeAxis, XYDataset dataset,
         int series, int item, CrosshairState crosshairState, int pass) {

        if (!getItemVisible(series, item)) {
            return;
        }
        // get the data point...
        double x1 = dataset.getXValue(series, item);
        double y1 = dataset.getYValue(series, item);
        if (Double.isNaN(y1)) {
            y1 = 0.0;
        }

        double transX1 = domainAxis.valueToJava2D(x1, dataArea,
                plot.getDomainAxisEdge());
        double transY1 = rangeAxis.valueToJava2D(y1, dataArea,
                plot.getRangeAxisEdge());

        // get the previous point and the next point so we can calculate a
        // "hot spot" for the area (used by the chart entity)...
        double x0 = dataset.getXValue(series, Math.max(item - 1, 0));
        double y0 = dataset.getYValue(series, Math.max(item - 1, 0));
        if (Double.isNaN(y0)) {
            y0 = 0.0;
        }
        double transX0 = domainAxis.valueToJava2D(x0, dataArea,
                plot.getDomainAxisEdge());
        double transY0 = rangeAxis.valueToJava2D(y0, dataArea,
                plot.getRangeAxisEdge());

        int itemCount = dataset.getItemCount(series);
        double x2 = dataset.getXValue(series, Math.min(item + 1,
                itemCount - 1));
        double y2 = dataset.getYValue(series, Math.min(item + 1,
                itemCount - 1));
        if (Double.isNaN(y2)) {
            y2 = 0.0;
        }
        double transX2 = domainAxis.valueToJava2D(x2, dataArea,
                plot.getDomainAxisEdge());
        double transY2 = rangeAxis.valueToJava2D(y2, dataArea,
                plot.getRangeAxisEdge());

        double transZero = rangeAxis.valueToJava2D(0.0, dataArea,
                plot.getRangeAxisEdge());
        GeneralPath hotspot = new GeneralPath();
        if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
            moveTo(hotspot, transZero, ((transX0 + transX1) / 2.0));
            lineTo(hotspot, ((transY0 + transY1) / 2.0),
                            ((transX0 + transX1) / 2.0));
            lineTo(hotspot, transY1, transX1);
            lineTo(hotspot, ((transY1 + transY2) / 2.0),
                            ((transX1 + transX2) / 2.0));
            lineTo(hotspot, transZero, ((transX1 + transX2) / 2.0));
        }
        else {  // vertical orientation
            moveTo(hotspot, ((transX0 + transX1) / 2.0), transZero);
            lineTo(hotspot, ((transX0 + transX1) / 2.0),
                            ((transY0 + transY1) / 2.0));
            lineTo(hotspot, transX1, transY1);
            lineTo(hotspot, ((transX1 + transX2) / 2.0),
                            ((transY1 + transY2) / 2.0));
            lineTo(hotspot, ((transX1 + transX2) / 2.0), transZero);
        }
        hotspot.closePath();

        PlotOrientation orientation = plot.getOrientation();
        Paint paint = getItemPaint(series, item);
        Stroke stroke = getItemStroke(series, item);
        g2.setPaint(paint);
        g2.setStroke(stroke);

        // Check if the item is the last item for the series.
        // and number of items > 0.  We can't draw an area for a single point.
        g2.fill(hotspot);

        // draw an outline around the Area.
        if (isOutline()) {
            g2.setStroke(lookupSeriesOutlineStroke(series));
            g2.setPaint(lookupSeriesOutlinePaint(series));
            g2.draw(hotspot);
        }
        int datasetIndex = plot.indexOf(dataset);
        updateCrosshairValues(crosshairState, x1, y1, datasetIndex,
                transX1, transY1, orientation);

        // collect entity and tool tip information...
        if (state.getInfo() != null) {
            EntityCollection entities = state.getEntityCollection();
            if (entities != null) {
                // limit the entity hotspot area to the data area
                Area dataAreaHotspot = new Area(hotspot);
                dataAreaHotspot.intersect(new Area(dataArea));
                if (!dataAreaHotspot.isEmpty()) {
                    String tip = null;
                    XYToolTipGenerator generator = getToolTipGenerator(series,
                         item);
                    if (generator != null) {
                        tip = generator.generateToolTip(dataset, series, item);
                    }
                    String url = null;
                    if (getURLGenerator() != null) {
                        url = getURLGenerator().generateURL(dataset, series, 
                                item);
                    }
                    XYItemEntity entity = new XYItemEntity(dataAreaHotspot, 
                            dataset, series, item, tip, url);
                    entities.add(entity);
                }
            }
        }

    }

    /**
     * Tests this renderer for equality with an arbitrary object.
     *
     * @param obj  the object ({@code null} not permitted).
     *
     * @return A boolean.
     */
    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof XYAreaRenderer2)) {
            return false;
        }
        XYAreaRenderer2 that = (XYAreaRenderer2) obj;
        if (this.showOutline != that.showOutline) {
            return false;
        }
        if (!ShapeUtils.equal(this.legendArea, that.legendArea)) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Returns a clone of the renderer.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException  if the renderer cannot be cloned.
     */
    @Override
    public Object clone() throws CloneNotSupportedException {
        XYAreaRenderer2 clone = (XYAreaRenderer2) super.clone();
        clone.legendArea = ShapeUtils.clone(this.legendArea);
        return clone;
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream)
            throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.legendArea = SerialUtils.readShape(stream);
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtils.writeShape(this.legendArea, stream);
    }

}