/* ===========================================================
 * 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.]
 *
 * -----------------------
 * XYStepAreaRenderer.java
 * -----------------------
 * (C) Copyright 2003, 2004, by Matthias Rose and Contributors.
 *
 * Original Author:  Matthias Rose (based on XYAreaRenderer.java);
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: XYStepAreaRenderer.java,v 1.3 2004/11/12 09:31:44 mungady Exp $
 *
 * Changes:
 * --------
 * 07-Oct-2003 : Version 1, contributed by Matthias Rose (DG);
 * 10-Feb-2004 : Added some getter and setter methods (DG);
 * 25-Feb-2004 : Replaced CrosshairInfo with CrosshairState.  Renamed 
 *               XYToolTipGenerator --> XYItemLabelGenerator (DG);
 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with getYValue() (DG);
 * 11-Nov-2004 : Now uses ShapeUtilities to translate shapes (DG);
 * 
 */

package org.jfree.chart.renderer.xy;

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

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.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.data.xy.XYDataset;
import org.jfree.util.PublicCloneable;
import org.jfree.util.ShapeUtilities;

/**
 * A step chart renderer that fills the area between the step and the x-axis.
 */
public class XYStepAreaRenderer extends AbstractXYItemRenderer 
                                implements XYItemRenderer, 
                                           Cloneable,
                                           PublicCloneable,
                                           Serializable {

    /** Useful constant for specifying the type of rendering (shapes only). */
    public static final int SHAPES = 1;

    /** Useful constant for specifying the type of rendering (area only). */
    public static final int AREA = 2;

    /** Useful constant for specifying the type of rendering (area and shapes). */
    public static final int AREA_AND_SHAPES = 3;

    /** A flag indicating whether or not shapes are drawn at each XY point. */
    private boolean plotShapes;

    /** A flag that controls whether or not shapes are filled for ALL series. */
    private boolean shapesFilled;

    /** A flag indicating whether or not Area are drawn at each XY point. */
    private boolean plotArea;

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

    /** Area of the complete series */
    protected transient Polygon pArea = null;

    /** The value on the range axis which defines the 'lower' border of the area. */
    private double rangeBase;

    /**
     * Constructs a new renderer.
     */
    public XYStepAreaRenderer() {
        this(AREA);
    }

    /**
     * Constructs a new renderer.
     *
     * @param type  the type of the renderer.
     */
    public XYStepAreaRenderer(int type) {
        this(type, null, null);
    }

    /**
     * Constructs a new renderer.
     * <p>
     * To specify the type of renderer, use one of the constants:
     * AREA, SHAPES or AREA_AND_SHAPES.
     *
     * @param type  the type of renderer.
     * @param toolTipGenerator  the tool tip generator to use (<code>null</code> permitted).
     * @param urlGenerator  the URL generator (<code>null</code> permitted).
     */
    public XYStepAreaRenderer(int type,
                              XYToolTipGenerator toolTipGenerator, XYURLGenerator urlGenerator) {

        super();
        setToolTipGenerator(toolTipGenerator);
        setURLGenerator(urlGenerator);

        if (type == AREA) {
            this.plotArea = true;
        }
        else if (type == SHAPES) {
            this.plotShapes = true;
        }
        else if (type == AREA_AND_SHAPES) {
            this.plotArea = true;
            this.plotShapes = true;
        }
        this.showOutline = false;
    }

    /**
     * Returns a flag that controls whether or not outlines of the areas are drawn.
     *
     * @return the flag.
     */
    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.
     */
    public void setOutline(boolean show) {
        this.showOutline = show;
        notifyListeners(new RendererChangeEvent(this));
    }

    /**
     * Returns true if shapes are being plotted by the renderer.
     *
     * @return  <code>true</code> if shapes are being plotted by the renderer.
     */
    public boolean getPlotShapes() {
        return this.plotShapes;
    }
    
    /**
     * Sets the flag that controls whether or not shapes are displayed for each data item.
     * 
     * @param flag  the flag.
     */
    public void setPlotShapes(boolean flag) {
        this.plotShapes = flag;
        notifyListeners(new RendererChangeEvent(this));
    }

    /**
     * Returns the flag that controls whether or not the shapes are filled.
     * 
     * @return a boolean.
     */
    public boolean isShapesFilled() {
        return this.shapesFilled;
    }
    
    /**
     * Sets the 'shapes filled' for ALL series.
     *
     * @param filled  the flag.
     */
    public void setShapesFilled(boolean filled) {
        this.shapesFilled = filled;
        notifyListeners(new RendererChangeEvent(this));
    }

    /**
     * Returns true if Area is being plotted by the renderer.
     *
     * @return  <code>true</code> if Area is being plotted by the renderer.
     */
    public boolean getPlotArea() {
        return this.plotArea;
    }

    /**
     * Sets a flag that controls whether or not areas are drawn for each data item.
     * 
     * @param flag  the flag.
     */
    public void setPlotArea(boolean flag) {
        this.plotArea = flag;
        notifyListeners(new RendererChangeEvent(this));
    }
    
    /**
     * Returns the value on the range axis which defines the 'lower' border of the area.
     *
     * @return <code>double</code> the value on the range axis which defines the 'lower' border of
     *         the area.
     */
    public double getRangeBase() {
        return this.rangeBase;
    }

    /**
     * Sets the value on the range axis which defines the default border of the area.
     * E.g. setRangeBase(Double.NEGATIVE_INFINITY) lets areas always reach the lower border of the
     * plotArea. 
     * 
     * @param val  the value on the range axis which defines the default border of the area.
     */
    public void setRangeBase(double val) {
        this.rangeBase = val;
        notifyListeners(new RendererChangeEvent(this));
    }

    /**
     * Initialises the renderer.  Here we calculate the Java2D y-coordinate for
     * zero, since all the bars have their bases fixed at zero.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area inside the axes.
     * @param plot  the plot.
     * @param data  the data.
     * @param info  an optional info collection object to return data back to the caller.
     *
     * @return The number of passes required by the renderer.
     */
    public XYItemRendererState initialise(Graphics2D g2,
                                          Rectangle2D dataArea,
                                          XYPlot plot,
                                          XYDataset data,
                                          PlotRenderingInfo info) {

        return super.initialise(g2, dataArea, plot, data, info);

    }


    /**
     * 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</code> permitted).
     * @param pass  the pass index.
     */
    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) {
                             
        PlotOrientation orientation = plot.getOrientation();
        
        // Get the item count for the series, so that we can know which is the end of the series.
        int itemCount = dataset.getItemCount(series);

        Paint paint = getItemPaint(series, item);
        Stroke seriesStroke = getItemStroke(series, item);
        g2.setPaint(paint);
        g2.setStroke(seriesStroke);

        // get the data point...
        Number x1 = dataset.getX(series, item);
        Number y1 = dataset.getY(series, item);
        double x = x1.doubleValue();
        double y = y1 == null ? getRangeBase() : y1.doubleValue();
        double transX1 = domainAxis.valueToJava2D(x, dataArea, plot.getDomainAxisEdge());
        double transY1 = rangeAxis.valueToJava2D(y, dataArea, plot.getRangeAxisEdge());
                                                          
        // avoid possible sun.dc.pr.PRException: endPath: bad path
        transY1 = restrictValueToDataArea(transY1, plot, dataArea);         

        if (this.pArea == null && y1 != null) {

            // Create a new Area for the series
            this.pArea = new Polygon();
        
            // start from Y = rangeBase
            double transY2 = rangeAxis.valueToJava2D(
                getRangeBase(), dataArea, plot.getRangeAxisEdge()
            );
        
            // avoid possible sun.dc.pr.PRException: endPath: bad path
            transY2 = restrictValueToDataArea(transY2, plot, dataArea);         
        
            // The first point is (x, this.baseYValue)
            if (orientation == PlotOrientation.VERTICAL) {
                this.pArea.addPoint((int) transX1, (int) transY2);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                this.pArea.addPoint((int) transY2, (int) transX1);
            }
        }

        double transX0 = 0;
        double transY0 = restrictValueToDataArea(getRangeBase(), plot, dataArea);           
        
        Number x0 = null;
        Number y0 = null;
        if (item > 0) {
            // get the previous data point...
            x0 = dataset.getX(series, item - 1);
            y0 = y1 == null ? null : dataset.getY(series, item - 1);

            x = x0.doubleValue();
            y = y0 == null ? getRangeBase() : y0.doubleValue();
            transX0 = domainAxis.valueToJava2D(x, dataArea, plot.getDomainAxisEdge());
            transY0 = rangeAxis.valueToJava2D(y, dataArea, plot.getRangeAxisEdge());

            // avoid possible sun.dc.pr.PRException: endPath: bad path
            transY0 = restrictValueToDataArea(transY0, plot, dataArea);
                        
            if (y1 == null) {
                // NULL value -> insert point on base line
                // instead of 'step point'
                transX1 = transX0;
                transY0 = transY1;          
            }
            if (transY0 != transY1) {
                // not just a horizontal bar but need to perform a 'step'.
                if (orientation == PlotOrientation.VERTICAL) {
                    this.pArea.addPoint((int) transX1, (int) transY0);                       
                }
                else if (orientation == PlotOrientation.HORIZONTAL) {
                    this.pArea.addPoint((int) transY0, (int) transX1);
                }
            }
        }           

        Shape shape = null;
        if (y1 != null) {
            // Add each point to Area (x, y)
            if (orientation == PlotOrientation.VERTICAL) {
                this.pArea.addPoint((int) transX1, (int) transY1);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                this.pArea.addPoint((int) transY1, (int) transX1);
            }

            if (getPlotShapes()) {
                shape = getItemShape(series, item);
                if (orientation == PlotOrientation.VERTICAL) {
                    shape = ShapeUtilities.createTranslatedShape(shape, transX1, transY1);
                }
                else if (orientation == PlotOrientation.HORIZONTAL) {
                    shape = ShapeUtilities.createTranslatedShape(shape, transY1, transX1);
                }
                if (isShapesFilled()) {
                    g2.fill(shape);
                }   
                else {
                    g2.draw(shape);
                }   
            }
            else {
                if (orientation == PlotOrientation.VERTICAL) {
                    shape = new Rectangle2D.Double(transX1 - 2, transY1 - 2, 4.0, 4.0);
                }
                else if (orientation == PlotOrientation.HORIZONTAL) {
                    shape = new Rectangle2D.Double(transY1 - 2, transX1 - 2, 4.0, 4.0);
                }
            }
        }

        // Check if the item is the last item for the series or if it
        // is a NULL value and number of items > 0.  We can't draw an area for a single point.
        if (getPlotArea() && item > 0 && this.pArea != null 
                          && (item == (itemCount - 1) || y1 == null)) {

            double transY2 = rangeAxis.valueToJava2D(
                getRangeBase(), dataArea, plot.getRangeAxisEdge()
            );

            // avoid possible sun.dc.pr.PRException: endPath: bad path
            transY2 = restrictValueToDataArea(transY2, plot, dataArea);         

            if (orientation == PlotOrientation.VERTICAL) {
                // Add the last point (x,0)
                this.pArea.addPoint((int) transX1, (int) transY2);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                // Add the last point (x,0)
                this.pArea.addPoint((int) transY2, (int) transX1);
            }

            // fill the polygon
            g2.fill(this.pArea);

            // draw an outline around the Area.
            if (isOutline()) {
                g2.setStroke(plot.getOutlineStroke());
                g2.setPaint(plot.getOutlinePaint());
                g2.draw(this.pArea);
            }

            // start new area when needed (see above)
            this.pArea = null;
        }

        // do we need to update the crosshair values?
        if (y1 != null) {
            updateCrosshairValues(
                crosshairState, x1.doubleValue(), y1.doubleValue(), transX1, transY1, orientation
            );
        }

        // collect entity and tool tip information...
        if (state.getInfo() != null) {
            EntityCollection entities = state.getInfo().getOwner().getEntityCollection();
            if (entities != null && shape != null) {
                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(shape, dataset, series, item, tip, url);
                entities.add(entity);
            }
        }
    }

    /**
     * Returns a clone of the renderer.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException  if the renderer cannot be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
    
    /**
     * Helper method which returns a value if it lies
     * inside the visible dataArea and otherwise the corresponding
     * coordinate on the border of the dataArea. The PlotOrientation
     * is taken into account. 
     * Useful to avoid possible sun.dc.pr.PRException: endPath: bad path
     * which occurs when trying to draw lines/shapes which in large part
     * lie outside of the visible dataArea.
     * 
     * @param value the value which shall be 
     * @param dataArea  the area within which the data is being drawn.
     * @param plot  the plot (can be used to obtain standard color information etc).
     * @return <code>double</code> value inside the data area.
     */
    protected static double restrictValueToDataArea(double value, 
                                                    XYPlot plot, 
                                                    Rectangle2D dataArea) {
        double min = 0;
        double max = 0;
        if (plot.getOrientation() == PlotOrientation.VERTICAL) {
            min = dataArea.getMinY();
            max = dataArea.getMaxY();
        } 
        else if (plot.getOrientation() ==  PlotOrientation.HORIZONTAL) {
            min = dataArea.getMinX();
            max = dataArea.getMaxX();
        }       
        if (value < min) {
            value = min;
        }
        else if (value > max) {
            value = max;
        }
        return value;
    }

}