/* ===========================================================
 * 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.]
 *
 * -----------------
 * AreaRenderer.java
 * -----------------
 * (C) Copyright 2002-present, by Jon Iles and Contributors.
 *
 * Original Author:  Jon Iles;
 * Contributor(s):   David Gilbert;
 *                   Christian W. Zuckschwerdt;
 *
 */

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.chart.ui.RectangleEdge;
import org.jfree.chart.util.Args;
import org.jfree.chart.util.PublicCloneable;
import org.jfree.data.category.CategoryDataset;

/**
 * A category item renderer that draws area charts.  You can use this renderer
 * with the {@link CategoryPlot} class.  The example shown here is generated
 * by the {@code AreaChartDemo1.java} program included in the JFreeChart
 * Demo Collection:
 * <br><br>
 * <img src="doc-files/AreaRendererSample.png" alt="AreaRendererSample.png">
 */
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;
        setDefaultLegendShape(new Rectangle2D.Double(-4.0, -4.0, 8.0, 8.0));
    }

    /**
     * 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}).
     *
     * @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} not permitted).
     *
     * @see #getEndType()
     */
    public void setEndType(AreaRendererEndType type) {
        Args.nullNotPermitted(type, "type");
        this.endType = type;
        fireChangeEvent();
    }

    /**
     * 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.
     */
    @Override
    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 = 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 = lookupLegendShape(series);
        Paint paint = lookupSeriesPaint(series);
        Paint outlinePaint = lookupSeriesOutlinePaint(series);
        Stroke outlineStroke = lookupSeriesOutlineStroke(series);

        LegendItem result = new LegendItem(label, description, toolTipText,
                urlText, shape, paint, outlineStroke, outlinePaint);
        result.setLabelFont(lookupLegendTextFont(series));
        Paint labelPaint = lookupLegendTextPaint(series);
        if (labelPaint != null) {
            result.setLabelPaint(labelPaint);
        }
        result.setDataset(dataset);
        result.setDatasetIndex(datasetIndex);
        result.setSeriesKey(dataset.getRowKey(series));
        result.setSeriesIndex(series);
        return result;

    }

    /**
     * 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.
     */
    @Override
    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 or null
        if (!getItemVisible(row, column)) {
            return;
        }
        Number value = dataset.getValue(row, column);
        if (value == null) {
            return;
        }
        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 (this.endType == AreaRendererEndType.LEVEL) {
            yy0 = yy1;
        }
        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;
            }
        }
        else if (this.endType == AreaRendererEndType.LEVEL) {
            yy2 = yy1;
        }

        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);
        double labelXX = x1;
        double labelYY = y1;
        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);
            double temp = labelXX;
            labelXX = labelYY;
            labelYY = temp;
        }
        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, labelXX,
                    labelYY, (value.doubleValue() < 0.0));
        }

        // submit the current data point as a crosshair candidate
        int datasetIndex = plot.indexOf(dataset);
        updateCrosshairValues(state.getCrosshairState(), 
                dataset.getRowKey(row), dataset.getColumnKey(column), yy1,
                datasetIndex, x1, y1, orientation);

        // 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} permitted).
     *
     * @return A boolean.
     */
    @Override
    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.
     */
    @Override
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}
