StandardXYItemRenderer.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, 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.]
*
* ---------------------------
* StandardXYItemRenderer.java
* ---------------------------
* (C) Copyright 2001-2022, by David Gilbert and Contributors.
*
* Original Author: David Gilbert;
* Contributor(s): Mark Watson (www.markwatson.com);
* Jonathan Nash;
* Andreas Schneider;
* Norbert Kiesel (for TBD Networks);
* Christian W. Zuckschwerdt;
* Bill Kelemen;
* Nicolas Brodu (for Astrium and EADS Corporate Research
* Center);
*
*/
package org.jfree.chart.renderer.xy;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Paint;
import java.awt.Point;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.jfree.chart.legend.LegendItem;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.labels.XYToolTipGenerator;
import org.jfree.chart.plot.CrosshairState;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.api.RectangleEdge;
import org.jfree.chart.urls.XYURLGenerator;
import org.jfree.chart.internal.Args;
import org.jfree.chart.api.PublicCloneable;
import org.jfree.chart.internal.SerialUtils;
import org.jfree.chart.internal.ShapeUtils;
import org.jfree.chart.api.UnitType;
import org.jfree.chart.internal.CloneUtils;
import org.jfree.data.xy.XYDataset;
/**
* Standard item renderer for an {@link XYPlot}. This class can draw (a)
* shapes at each point, or (b) lines between points, or (c) both shapes and
* lines.
* <P>
* This renderer has been retained for historical reasons and, in general, you
* should use the {@link XYLineAndShapeRenderer} class instead.
*/
public class StandardXYItemRenderer extends AbstractXYItemRenderer
implements XYItemRenderer, Cloneable, PublicCloneable, Serializable {
/** For serialization. */
private static final long serialVersionUID = -3271351259436865995L;
/** Constant for the type of rendering (shapes only). */
public static final int SHAPES = 1;
/** Constant for the type of rendering (lines only). */
public static final int LINES = 2;
/** Constant for the type of rendering (shapes and lines). */
public static final int SHAPES_AND_LINES = SHAPES | LINES;
/** Constant for the type of rendering (images only). */
public static final int IMAGES = 4;
/** Constant for the type of rendering (discontinuous lines). */
public static final int DISCONTINUOUS = 8;
/** Constant for the type of rendering (discontinuous lines). */
public static final int DISCONTINUOUS_LINES = LINES | DISCONTINUOUS;
/** A flag indicating whether or not shapes are drawn at each XY point. */
private boolean baseShapesVisible;
/** A flag indicating whether or not lines are drawn between XY points. */
private boolean plotLines;
/** A flag indicating whether or not images are drawn between XY points. */
private boolean plotImages;
/** A flag controlling whether or not discontinuous lines are used. */
private boolean plotDiscontinuous;
/** Specifies how the gap threshold value is interpreted. */
private UnitType gapThresholdType = UnitType.RELATIVE;
/** Threshold for deciding when to discontinue a line. */
private double gapThreshold = 1.0;
/**
* A table of flags that control (per series) whether or not shapes are
* filled.
*/
private Map<Integer, Boolean> seriesShapesFilledMap;
/** The default value returned by the getShapeFilled() method. */
private boolean baseShapesFilled;
/**
* A flag that controls whether or not each series is drawn as a single
* path.
*/
private boolean drawSeriesLineAsPath;
/**
* The shape that is used to represent a line in the legend.
* This should never be set to {@code null}.
*/
private transient Shape legendLine;
/**
* Constructs a new renderer.
*/
public StandardXYItemRenderer() {
this(LINES, null);
}
/**
* Constructs a new renderer. To specify the type of renderer, use one of
* the constants: {@link #SHAPES}, {@link #LINES} or
* {@link #SHAPES_AND_LINES}.
*
* @param type the type.
*/
public StandardXYItemRenderer(int type) {
this(type, null);
}
/**
* Constructs a new renderer. To specify the type of renderer, use one of
* the constants: {@link #SHAPES}, {@link #LINES} or
* {@link #SHAPES_AND_LINES}.
*
* @param type the type of renderer.
* @param toolTipGenerator the item label generator ({@code null}
* permitted).
*/
public StandardXYItemRenderer(int type,
XYToolTipGenerator toolTipGenerator) {
this(type, toolTipGenerator, null);
}
/**
* Constructs a new renderer. To specify the type of renderer, use one of
* the constants: {@link #SHAPES}, {@link #LINES} or
* {@link #SHAPES_AND_LINES}.
*
* @param type the type of renderer.
* @param toolTipGenerator the item label generator ({@code null}
* permitted).
* @param urlGenerator the URL generator.
*/
public StandardXYItemRenderer(int type, XYToolTipGenerator toolTipGenerator,
XYURLGenerator urlGenerator) {
super();
setDefaultToolTipGenerator(toolTipGenerator);
setURLGenerator(urlGenerator);
if ((type & SHAPES) != 0) {
this.baseShapesVisible = true;
}
if ((type & LINES) != 0) {
this.plotLines = true;
}
if ((type & IMAGES) != 0) {
this.plotImages = true;
}
if ((type & DISCONTINUOUS) != 0) {
this.plotDiscontinuous = true;
}
this.seriesShapesFilledMap = new HashMap<>();
this.baseShapesFilled = true;
this.legendLine = new Line2D.Double(-7.0, 0.0, 7.0, 0.0);
this.drawSeriesLineAsPath = false;
}
/**
* Returns true if shapes are being plotted by the renderer.
*
* @return {@code true} if shapes are being plotted by the renderer.
*
* @see #setBaseShapesVisible
*/
public boolean getBaseShapesVisible() {
return this.baseShapesVisible;
}
/**
* Sets the flag that controls whether or not a shape is plotted at each
* data point.
*
* @param flag the flag.
*
* @see #getBaseShapesVisible
*/
public void setBaseShapesVisible(boolean flag) {
if (this.baseShapesVisible != flag) {
this.baseShapesVisible = flag;
fireChangeEvent();
}
}
// SHAPES FILLED
/**
* Returns the flag used to control whether or not the shape for an item is
* filled.
* <p>
* The default implementation passes control to the
* {@code getSeriesShapesFilled()} method. You can override this method
* if you require different behaviour.
*
* @param series the series index (zero-based).
* @param item the item index (zero-based).
*
* @return A boolean.
*
* @see #getSeriesShapesFilled(int)
*/
public boolean getItemShapeFilled(int series, int item) {
// otherwise look up the paint table
Boolean flag = this.seriesShapesFilledMap.get(series);
if (flag != null) {
return flag;
} else {
return this.baseShapesFilled;
}
}
/**
* Returns the flag used to control whether or not the shapes for a series
* are filled.
*
* @param series the series index (zero-based).
*
* @return A boolean.
*/
public Boolean getSeriesShapesFilled(int series) {
return this.seriesShapesFilledMap.get(series);
}
/**
* Sets the 'shapes filled' flag for a series and sends a
* {@link RendererChangeEvent} to all registered listeners.
*
* @param series the series index (zero-based).
* @param flag the flag.
*
* @see #getSeriesShapesFilled(int)
*/
public void setSeriesShapesFilled(int series, Boolean flag) {
this.seriesShapesFilledMap.put(series, flag);
fireChangeEvent();
}
/**
* Returns the base 'shape filled' attribute.
*
* @return The base flag.
*
* @see #setBaseShapesFilled(boolean)
*/
public boolean getBaseShapesFilled() {
return this.baseShapesFilled;
}
/**
* Sets the base 'shapes filled' flag and sends a
* {@link RendererChangeEvent} to all registered listeners.
*
* @param flag the flag.
*
* @see #getBaseShapesFilled()
*/
public void setBaseShapesFilled(boolean flag) {
this.baseShapesFilled = flag;
}
/**
* Returns true if lines are being plotted by the renderer.
*
* @return {@code true} if lines are being plotted by the renderer.
*
* @see #setPlotLines(boolean)
*/
public boolean getPlotLines() {
return this.plotLines;
}
/**
* Sets the flag that controls whether or not a line is plotted between
* each data point and sends a {@link RendererChangeEvent} to all
* registered listeners.
*
* @param flag the flag.
*
* @see #getPlotLines()
*/
public void setPlotLines(boolean flag) {
if (this.plotLines != flag) {
this.plotLines = flag;
fireChangeEvent();
}
}
/**
* Returns the gap threshold type (relative or absolute).
*
* @return The type.
*
* @see #setGapThresholdType(UnitType)
*/
public UnitType getGapThresholdType() {
return this.gapThresholdType;
}
/**
* Sets the gap threshold type and sends a {@link RendererChangeEvent} to
* all registered listeners.
*
* @param thresholdType the type ({@code null} not permitted).
*
* @see #getGapThresholdType()
*/
public void setGapThresholdType(UnitType thresholdType) {
Args.nullNotPermitted(thresholdType, "thresholdType");
this.gapThresholdType = thresholdType;
fireChangeEvent();
}
/**
* Returns the gap threshold for discontinuous lines.
*
* @return The gap threshold.
*
* @see #setGapThreshold(double)
*/
public double getGapThreshold() {
return this.gapThreshold;
}
/**
* Sets the gap threshold for discontinuous lines and sends a
* {@link RendererChangeEvent} to all registered listeners.
*
* @param t the threshold.
*
* @see #getGapThreshold()
*/
public void setGapThreshold(double t) {
this.gapThreshold = t;
fireChangeEvent();
}
/**
* Returns true if images are being plotted by the renderer.
*
* @return {@code true} if images are being plotted by the renderer.
*
* @see #setPlotImages(boolean)
*/
public boolean getPlotImages() {
return this.plotImages;
}
/**
* Sets the flag that controls whether or not an image is drawn at each
* data point and sends a {@link RendererChangeEvent} to all registered
* listeners.
*
* @param flag the flag.
*
* @see #getPlotImages()
*/
public void setPlotImages(boolean flag) {
if (this.plotImages != flag) {
this.plotImages = flag;
fireChangeEvent();
}
}
/**
* Returns a flag that controls whether or not the renderer shows
* discontinuous lines.
*
* @return {@code true} if lines should be discontinuous.
*/
public boolean getPlotDiscontinuous() {
return this.plotDiscontinuous;
}
/**
* Sets the flag that controls whether or not the renderer shows
* discontinuous lines, and sends a {@link RendererChangeEvent} to all
* registered listeners.
*
* @param flag the new flag value.
*/
public void setPlotDiscontinuous(boolean flag) {
if (this.plotDiscontinuous != flag) {
this.plotDiscontinuous = flag;
fireChangeEvent();
}
}
/**
* Returns a flag that controls whether or not each series is drawn as a
* single path.
*
* @return A boolean.
*
* @see #setDrawSeriesLineAsPath(boolean)
*/
public boolean getDrawSeriesLineAsPath() {
return this.drawSeriesLineAsPath;
}
/**
* Sets the flag that controls whether or not each series is drawn as a
* single path.
*
* @param flag the flag.
*
* @see #getDrawSeriesLineAsPath()
*/
public void setDrawSeriesLineAsPath(boolean flag) {
this.drawSeriesLineAsPath = flag;
}
/**
* Returns the shape used to represent a line in the legend.
*
* @return The legend line (never {@code null}).
*
* @see #setLegendLine(Shape)
*/
public Shape getLegendLine() {
return this.legendLine;
}
/**
* Sets the shape used as a line in each legend item and sends a
* {@link RendererChangeEvent} to all registered listeners.
*
* @param line the line ({@code null} not permitted).
*
* @see #getLegendLine()
*/
public void setLegendLine(Shape line) {
Args.nullNotPermitted(line, "line");
this.legendLine = line;
fireChangeEvent();
}
/**
* Returns a legend item for a series.
*
* @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) {
XYPlot plot = getPlot();
if (plot == null) {
return null;
}
LegendItem result = null;
XYDataset dataset = plot.getDataset(datasetIndex);
if (dataset != null) {
if (getItemVisible(series, 0)) {
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);
boolean shapeFilled = getItemShapeFilled(series, 0);
Paint paint = lookupSeriesPaint(series);
Paint linePaint = paint;
Stroke lineStroke = lookupSeriesStroke(series);
result = new LegendItem(label, description, toolTipText,
urlText, this.baseShapesVisible, shape, shapeFilled,
paint, !shapeFilled, paint, lineStroke,
this.plotLines, this.legendLine, lineStroke, linePaint);
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;
}
/**
* Records the state for the renderer. This is used to preserve state
* information between calls to the drawItem() method for a single chart
* drawing.
*/
public static class State extends XYItemRendererState {
/** The path for the current series. */
public GeneralPath seriesPath;
/** The series index. */
private int seriesIndex;
/**
* A flag that indicates if the last (x, y) point was 'good'
* (non-null).
*/
private boolean lastPointGood;
/**
* Creates a new state instance.
*
* @param info the plot rendering info.
*/
public State(PlotRenderingInfo info) {
super(info);
}
/**
* Returns a flag that indicates if the last point drawn (in the
* current series) was 'good' (non-null).
*
* @return A boolean.
*/
public boolean isLastPointGood() {
return this.lastPointGood;
}
/**
* Sets a flag that indicates if the last point drawn (in the current
* series) was 'good' (non-null).
*
* @param good the flag.
*/
public void setLastPointGood(boolean good) {
this.lastPointGood = good;
}
/**
* Returns the series index for the current path.
*
* @return The series index for the current path.
*/
public int getSeriesIndex() {
return this.seriesIndex;
}
/**
* Sets the series index for the current path.
*
* @param index the index.
*/
public void setSeriesIndex(int index) {
this.seriesIndex = index;
}
}
/**
* Initialises the renderer.
* <P>
* This method will be called before the first item is rendered, giving the
* renderer an opportunity to initialise any state information it wants to
* maintain. The renderer can do nothing if it chooses.
*
* @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 renderer state.
*/
@Override
public XYItemRendererState initialise(Graphics2D g2, Rectangle2D dataArea,
XYPlot plot, XYDataset data, PlotRenderingInfo info) {
State state = new State(info);
state.seriesPath = new GeneralPath();
state.seriesIndex = -1;
return state;
}
/**
* 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) {
boolean itemVisible = getItemVisible(series, item);
// setup for collecting optional entity info...
Shape entityArea = null;
EntityCollection entities = null;
if (info != null) {
entities = info.getOwner().getEntityCollection();
}
PlotOrientation orientation = plot.getOrientation();
Paint paint = getItemPaint(series, item);
Stroke seriesStroke = getItemStroke(series, item);
g2.setPaint(paint);
g2.setStroke(seriesStroke);
// get the data point...
double x1 = dataset.getXValue(series, item);
double y1 = dataset.getYValue(series, item);
if (Double.isNaN(x1) || Double.isNaN(y1)) {
itemVisible = false;
}
RectangleEdge xAxisLocation = plot.getDomainAxisEdge();
RectangleEdge yAxisLocation = plot.getRangeAxisEdge();
double transX1 = domainAxis.valueToJava2D(x1, dataArea, xAxisLocation);
double transY1 = rangeAxis.valueToJava2D(y1, dataArea, yAxisLocation);
if (getPlotLines()) {
if (this.drawSeriesLineAsPath) {
State s = (State) state;
if (s.getSeriesIndex() != series) {
// we are starting a new series path
s.seriesPath.reset();
s.lastPointGood = false;
s.setSeriesIndex(series);
}
// update path to reflect latest point
if (itemVisible && !Double.isNaN(transX1)
&& !Double.isNaN(transY1)) {
float x = (float) transX1;
float y = (float) transY1;
if (orientation == PlotOrientation.HORIZONTAL) {
x = (float) transY1;
y = (float) transX1;
}
if (s.isLastPointGood()) {
// TODO: check threshold
s.seriesPath.lineTo(x, y);
}
else {
s.seriesPath.moveTo(x, y);
}
s.setLastPointGood(true);
}
else {
s.setLastPointGood(false);
}
if (item == dataset.getItemCount(series) - 1) {
if (s.seriesIndex == series) {
// draw path
g2.setStroke(lookupSeriesStroke(series));
g2.setPaint(lookupSeriesPaint(series));
g2.draw(s.seriesPath);
}
}
}
else if (item != 0 && itemVisible) {
// get the previous data point...
double x0 = dataset.getXValue(series, item - 1);
double y0 = dataset.getYValue(series, item - 1);
if (!Double.isNaN(x0) && !Double.isNaN(y0)) {
boolean drawLine = true;
if (getPlotDiscontinuous()) {
// only draw a line if the gap between the current and
// previous data point is within the threshold
int numX = dataset.getItemCount(series);
double minX = dataset.getXValue(series, 0);
double maxX = dataset.getXValue(series, numX - 1);
if (this.gapThresholdType == UnitType.ABSOLUTE) {
drawLine = Math.abs(x1 - x0) <= this.gapThreshold;
}
else {
drawLine = Math.abs(x1 - x0) <= ((maxX - minX)
/ numX * getGapThreshold());
}
}
if (drawLine) {
double transX0 = domainAxis.valueToJava2D(x0, dataArea,
xAxisLocation);
double transY0 = rangeAxis.valueToJava2D(y0, dataArea,
yAxisLocation);
// only draw if we have good values
if (Double.isNaN(transX0) || Double.isNaN(transY0)
|| Double.isNaN(transX1) || Double.isNaN(transY1)) {
return;
}
if (orientation == PlotOrientation.HORIZONTAL) {
state.workingLine.setLine(transY0, transX0,
transY1, transX1);
}
else if (orientation == PlotOrientation.VERTICAL) {
state.workingLine.setLine(transX0, transY0,
transX1, transY1);
}
if (state.workingLine.intersects(dataArea)) {
g2.draw(state.workingLine);
}
}
}
}
}
// we needed to get this far even for invisible items, to ensure that
// seriesPath updates happened, but now there is nothing more we need
// to do for non-visible items...
if (!itemVisible) {
return;
}
if (getBaseShapesVisible()) {
Shape shape = getItemShape(series, item);
if (orientation == PlotOrientation.HORIZONTAL) {
shape = ShapeUtils.createTranslatedShape(shape, transY1,
transX1);
}
else if (orientation == PlotOrientation.VERTICAL) {
shape = ShapeUtils.createTranslatedShape(shape, transX1,
transY1);
}
if (shape.intersects(dataArea)) {
if (getItemShapeFilled(series, item)) {
g2.fill(shape);
}
else {
g2.draw(shape);
}
}
entityArea = shape;
}
if (getPlotImages()) {
Image image = getImage(plot, series, item, transX1, transY1);
if (image != null) {
Point hotspot = getImageHotspot(plot, series, item, transX1,
transY1, image);
g2.drawImage(image, (int) (transX1 - hotspot.getX()),
(int) (transY1 - hotspot.getY()), null);
entityArea = new Rectangle2D.Double(transX1 - hotspot.getX(),
transY1 - hotspot.getY(), image.getWidth(null),
image.getHeight(null));
}
}
double xx = transX1;
double yy = transY1;
if (orientation == PlotOrientation.HORIZONTAL) {
xx = transY1;
yy = transX1;
}
// draw the item label if there is one...
if (isItemLabelVisible(series, item)) {
drawItemLabel(g2, orientation, dataset, series, item, xx, yy,
(y1 < 0.0));
}
int datasetIndex = plot.indexOf(dataset);
updateCrosshairValues(crosshairState, x1, y1, datasetIndex,
transX1, transY1, orientation);
// add an entity for the item...
if (entities != null && ShapeUtils.isPointInRect(dataArea, xx, yy)) {
addEntity(entities, entityArea, dataset, series, item, xx, yy);
}
}
/**
* Tests this renderer for equality with another object.
*
* @param obj the object ({@code null} permitted).
*
* @return A boolean.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof StandardXYItemRenderer)) {
return false;
}
StandardXYItemRenderer that = (StandardXYItemRenderer) obj;
if (this.baseShapesVisible != that.baseShapesVisible) {
return false;
}
if (this.plotLines != that.plotLines) {
return false;
}
if (this.plotImages != that.plotImages) {
return false;
}
if (this.plotDiscontinuous != that.plotDiscontinuous) {
return false;
}
if (this.gapThresholdType != that.gapThresholdType) {
return false;
}
if (this.gapThreshold != that.gapThreshold) {
return false;
}
if (!this.seriesShapesFilledMap.equals(that.seriesShapesFilledMap)) {
return false;
}
if (this.baseShapesFilled != that.baseShapesFilled) {
return false;
}
if (this.drawSeriesLineAsPath != that.drawSeriesLineAsPath) {
return false;
}
if (!ShapeUtils.equal(this.legendLine, that.legendLine)) {
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 {
StandardXYItemRenderer clone = (StandardXYItemRenderer) super.clone();
clone.seriesShapesFilledMap = new HashMap<>(this.seriesShapesFilledMap);
clone.legendLine = CloneUtils.clone(this.legendLine);
return clone;
}
////////////////////////////////////////////////////////////////////////////
// PROTECTED METHODS
// These provide the opportunity to subclass the standard renderer and
// create custom effects.
////////////////////////////////////////////////////////////////////////////
/**
* Returns the image used to draw a single data item.
*
* @param plot the plot (can be used to obtain standard color information
* etc).
* @param series the series index.
* @param item the item index.
* @param x the x value of the item.
* @param y the y value of the item.
*
* @return The image.
*
* @see #getPlotImages()
*/
protected Image getImage(Plot plot, int series, int item,
double x, double y) {
// this method must be overridden if you want to display images
return null;
}
/**
* Returns the hotspot of the image used to draw a single data item.
* The hotspot is the point relative to the top left of the image
* that should indicate the data item. The default is the center of the
* image.
*
* @param plot the plot (can be used to obtain standard color information
* etc).
* @param image the image (can be used to get size information about the
* image)
* @param series the series index
* @param item the item index
* @param x the x value of the item
* @param y the y value of the item
*
* @return The hotspot used to draw the data item.
*/
protected Point getImageHotspot(Plot plot, int series, int item,
double x, double y, Image image) {
int height = image.getHeight(null);
int width = image.getWidth(null);
return new Point(width / 2, height / 2);
}
/**
* 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.legendLine = 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.legendLine, stream);
}
}