org.jfree.chart

Class JFreeChart

public class JFreeChart extends Object implements Drawable, TitleChangeListener, PlotChangeListener, Serializable, Cloneable

A chart class implemented using the Java 2D APIs. The current version supports bar charts, line charts, pie charts and xy plots (including time series data).

JFreeChart coordinates several objects to achieve its aim of being able to draw a chart on a Java 2D graphics device: a list of Title objects (which often includes the chart's legend), a Plot and a Dataset (the plot in turn manages a domain axis and a range axis).

You should use a ChartPanel to display a chart in a GUI.

The ChartFactory class contains static methods for creating 'ready-made' charts.

See Also: ChartPanel ChartFactory Title Plot

Field Summary
static ImageDEFAULT_BACKGROUND_IMAGE
The default background image.
static intDEFAULT_BACKGROUND_IMAGE_ALIGNMENT
The default background image alignment.
static floatDEFAULT_BACKGROUND_IMAGE_ALPHA
The default background image alpha.
static PaintDEFAULT_BACKGROUND_PAINT
The default background color.
static FontDEFAULT_TITLE_FONT
The default font for titles.
static ProjectInfoINFO
Information about the project.
Constructor Summary
JFreeChart(Plot plot)
Creates a new chart based on the supplied plot.
JFreeChart(String title, Plot plot)
Creates a new chart with the given title and plot.
JFreeChart(String title, Font titleFont, Plot plot, boolean createLegend)
Creates a new chart with the given title and plot.
Method Summary
voidaddChangeListener(ChartChangeListener listener)
Registers an object for notification of changes to the chart.
voidaddLegend(LegendTitle legend)
Adds a legend to the plot and sends a ChartChangeEvent to all registered listeners.
voidaddProgressListener(ChartProgressListener listener)
Registers an object for notification of progress events relating to the chart.
voidaddSubtitle(Title subtitle)
Adds a chart subtitle, and notifies registered listeners that the chart has been modified.
voidaddSubtitle(int index, Title subtitle)
Adds a subtitle at a particular position in the subtitle list, and sends a ChartChangeEvent to all registered listeners.
voidclearSubtitles()
Clears all subtitles from the chart and sends a ChartChangeEvent to all registered listeners.
Objectclone()
Clones the object, and takes care of listeners.
BufferedImagecreateBufferedImage(int width, int height)
Creates and returns a buffered image into which the chart has been drawn.
BufferedImagecreateBufferedImage(int width, int height, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.
BufferedImagecreateBufferedImage(int width, int height, int imageType, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.
BufferedImagecreateBufferedImage(int imageWidth, int imageHeight, double drawWidth, double drawHeight, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.
voiddraw(Graphics2D g2, Rectangle2D area)
Draws the chart on a Java 2D graphics device (such as the screen or a printer).
voiddraw(Graphics2D g2, Rectangle2D area, ChartRenderingInfo info)
Draws the chart on a Java 2D graphics device (such as the screen or a printer).
voiddraw(Graphics2D g2, Rectangle2D chartArea, Point2D anchor, ChartRenderingInfo info)
Draws the chart on a Java 2D graphics device (such as the screen or a printer).
protected EntityCollectiondrawTitle(Title t, Graphics2D g2, Rectangle2D area, boolean entities)
Draws a title.
booleanequals(Object obj)
Tests this chart for equality with another object.
voidfireChartChanged()
Sends a default ChartChangeEvent to all registered listeners.
booleangetAntiAlias()
Returns a flag that indicates whether or not anti-aliasing is used when the chart is drawn.
ImagegetBackgroundImage()
Returns the background image for the chart, or null if there is no image.
intgetBackgroundImageAlignment()
Returns the background image alignment.
floatgetBackgroundImageAlpha()
Returns the alpha-transparency for the chart's background image.
PaintgetBackgroundPaint()
Returns the paint used for the chart background.
PaintgetBorderPaint()
Returns the paint used to draw the chart border (if visible).
StrokegetBorderStroke()
Returns the stroke used to draw the chart border (if visible).
CategoryPlotgetCategoryPlot()
Returns the plot cast as a CategoryPlot.
LegendTitlegetLegend()
Returns the legend for the chart, if there is one.
LegendTitlegetLegend(int index)
Returns the nth legend for a chart, or null.
RectangleInsetsgetPadding()
Returns the padding between the chart border and the chart drawing area.
PlotgetPlot()
Returns the plot for the chart.
RenderingHintsgetRenderingHints()
Returns the collection of rendering hints for the chart.
TitlegetSubtitle(int index)
Returns a chart subtitle.
intgetSubtitleCount()
Returns the number of titles for the chart.
ListgetSubtitles()
Returns the list of subtitles for the chart.
ObjectgetTextAntiAlias()
Returns the current value stored in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING.
TextTitlegetTitle()
Returns the main chart title.
XYPlotgetXYPlot()
Returns the plot cast as an XYPlot.
voidhandleClick(int x, int y, ChartRenderingInfo info)
Handles a 'click' on the chart.
booleanisBorderVisible()
Returns a flag that controls whether or not a border is drawn around the outside of the chart.
booleanisNotify()
Returns a flag that controls whether or not change events are sent to registered listeners.
static voidmain(String[] args)
Prints information about JFreeChart to standard output.
protected voidnotifyListeners(ChartChangeEvent event)
Sends a ChartChangeEvent to all registered listeners.
protected voidnotifyListeners(ChartProgressEvent event)
Sends a ChartProgressEvent to all registered listeners.
voidplotChanged(PlotChangeEvent event)
Receives notification that the plot has changed, and passes this on to registered listeners.
voidremoveChangeListener(ChartChangeListener listener)
Deregisters an object for notification of changes to the chart.
voidremoveLegend()
Removes the first legend in the chart and sends a ChartChangeEvent to all registered listeners.
voidremoveProgressListener(ChartProgressListener listener)
Deregisters an object for notification of changes to the chart.
voidremoveSubtitle(Title title)
Removes the specified subtitle and sends a ChartChangeEvent to all registered listeners.
voidsetAntiAlias(boolean flag)
Sets a flag that indicates whether or not anti-aliasing is used when the chart is drawn.
voidsetBackgroundImage(Image image)
Sets the background image for the chart and sends a ChartChangeEvent to all registered listeners.
voidsetBackgroundImageAlignment(int alignment)
Sets the background alignment.
voidsetBackgroundImageAlpha(float alpha)
Sets the alpha-transparency for the chart's background image.
voidsetBackgroundPaint(Paint paint)
Sets the paint used to fill the chart background and sends a ChartChangeEvent to all registered listeners.
voidsetBorderPaint(Paint paint)
Sets the paint used to draw the chart border (if visible).
voidsetBorderStroke(Stroke stroke)
Sets the stroke used to draw the chart border (if visible).
voidsetBorderVisible(boolean visible)
Sets a flag that controls whether or not a border is drawn around the outside of the chart.
voidsetNotify(boolean notify)
Sets a flag that controls whether or not listeners receive ChartChangeEvent notifications.
voidsetPadding(RectangleInsets padding)
Sets the padding between the chart border and the chart drawing area, and sends a ChartChangeEvent to all registered listeners.
voidsetRenderingHints(RenderingHints renderingHints)
Sets the rendering hints for the chart.
voidsetSubtitles(List subtitles)
Sets the title list for the chart (completely replaces any existing titles) and sends a ChartChangeEvent to all registered listeners.
voidsetTextAntiAlias(boolean flag)
Sets the value in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING to either RenderingHints#VALUE_TEXT_ANTIALIAS_ON or RenderingHints#VALUE_TEXT_ANTIALIAS_OFF, then sends a ChartChangeEvent to all registered listeners.
voidsetTextAntiAlias(Object val)
Sets the value in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING and sends a ChartChangeEvent to all registered listeners.
voidsetTitle(TextTitle title)
Sets the main title for the chart and sends a ChartChangeEvent to all registered listeners.
voidsetTitle(String text)
Sets the chart title and sends a ChartChangeEvent to all registered listeners.
voidtitleChanged(TitleChangeEvent event)
Receives notification that a chart title has changed, and passes this on to registered listeners.

Field Detail

DEFAULT_BACKGROUND_IMAGE

public static final Image DEFAULT_BACKGROUND_IMAGE
The default background image.

DEFAULT_BACKGROUND_IMAGE_ALIGNMENT

public static final int DEFAULT_BACKGROUND_IMAGE_ALIGNMENT
The default background image alignment.

DEFAULT_BACKGROUND_IMAGE_ALPHA

public static final float DEFAULT_BACKGROUND_IMAGE_ALPHA
The default background image alpha.

DEFAULT_BACKGROUND_PAINT

public static final Paint DEFAULT_BACKGROUND_PAINT
The default background color.

DEFAULT_TITLE_FONT

public static final Font DEFAULT_TITLE_FONT
The default font for titles.

INFO

public static final ProjectInfo INFO
Information about the project.

Constructor Detail

JFreeChart

public JFreeChart(Plot plot)
Creates a new chart based on the supplied plot. The chart will have a legend added automatically, but no title (although you can easily add one later).

Note that the ChartFactory class contains a range of static methods that will return ready-made charts, and often this is a more convenient way to create charts than using this constructor.

Parameters: plot the plot (null not permitted).

JFreeChart

public JFreeChart(String title, Plot plot)
Creates a new chart with the given title and plot. A default font (DEFAULT_TITLE_FONT) is used for the title, and the chart will have a legend added automatically.

Note that the ChartFactory class contains a range of static methods that will return ready-made charts, and often this is a more convenient way to create charts than using this constructor.

Parameters: title the chart title (null permitted). plot the plot (null not permitted).

JFreeChart

public JFreeChart(String title, Font titleFont, Plot plot, boolean createLegend)
Creates a new chart with the given title and plot. The createLegend argument specifies whether or not a legend should be added to the chart.

Note that the ChartFactory class contains a range of static methods that will return ready-made charts, and often this is a more convenient way to create charts than using this constructor.

Parameters: title the chart title (null permitted). titleFont the font for displaying the chart title (null permitted). plot controller of the visual representation of the data (null not permitted). createLegend a flag indicating whether or not a legend should be created for the chart.

Method Detail

addChangeListener

public void addChangeListener(ChartChangeListener listener)
Registers an object for notification of changes to the chart.

Parameters: listener the listener (null not permitted).

See Also: removeChangeListener

addLegend

public void addLegend(LegendTitle legend)
Adds a legend to the plot and sends a ChartChangeEvent to all registered listeners.

Parameters: legend the legend (null not permitted).

See Also: removeLegend

addProgressListener

public void addProgressListener(ChartProgressListener listener)
Registers an object for notification of progress events relating to the chart.

Parameters: listener the object being registered.

See Also: removeProgressListener

addSubtitle

public void addSubtitle(Title subtitle)
Adds a chart subtitle, and notifies registered listeners that the chart has been modified.

Parameters: subtitle the subtitle (null not permitted).

See Also: JFreeChart

addSubtitle

public void addSubtitle(int index, Title subtitle)
Adds a subtitle at a particular position in the subtitle list, and sends a ChartChangeEvent to all registered listeners.

Parameters: index the index (in the range 0 to getSubtitleCount). subtitle the subtitle to add (null not permitted).

Since: 1.0.6

clearSubtitles

public void clearSubtitles()
Clears all subtitles from the chart and sends a ChartChangeEvent to all registered listeners.

See Also: addSubtitle

clone

public Object clone()
Clones the object, and takes care of listeners. Note: caller shall register its own listeners on cloned graph.

Returns: A clone.

Throws: CloneNotSupportedException if the chart is not cloneable.

createBufferedImage

public BufferedImage createBufferedImage(int width, int height)
Creates and returns a buffered image into which the chart has been drawn.

Parameters: width the width. height the height.

Returns: A buffered image.

createBufferedImage

public BufferedImage createBufferedImage(int width, int height, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.

Parameters: width the width. height the height. info carries back chart state information (null permitted).

Returns: A buffered image.

createBufferedImage

public BufferedImage createBufferedImage(int width, int height, int imageType, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.

Parameters: width the width. height the height. imageType the image type. info carries back chart state information (null permitted).

Returns: A buffered image.

createBufferedImage

public BufferedImage createBufferedImage(int imageWidth, int imageHeight, double drawWidth, double drawHeight, ChartRenderingInfo info)
Creates and returns a buffered image into which the chart has been drawn.

Parameters: imageWidth the image width. imageHeight the image height. drawWidth the width for drawing the chart (will be scaled to fit image). drawHeight the height for drawing the chart (will be scaled to fit image). info optional object for collection chart dimension and entity information.

Returns: A buffered image.

draw

public void draw(Graphics2D g2, Rectangle2D area)
Draws the chart on a Java 2D graphics device (such as the screen or a printer).

This method is the focus of the entire JFreeChart library.

Parameters: g2 the graphics device. area the area within which the chart should be drawn.

draw

public void draw(Graphics2D g2, Rectangle2D area, ChartRenderingInfo info)
Draws the chart on a Java 2D graphics device (such as the screen or a printer). This method is the focus of the entire JFreeChart library.

Parameters: g2 the graphics device. area the area within which the chart should be drawn. info records info about the drawing (null means collect no info).

draw

public void draw(Graphics2D g2, Rectangle2D chartArea, Point2D anchor, ChartRenderingInfo info)
Draws the chart on a Java 2D graphics device (such as the screen or a printer).

This method is the focus of the entire JFreeChart library.

Parameters: g2 the graphics device. chartArea the area within which the chart should be drawn. anchor the anchor point (in Java2D space) for the chart (null permitted). info records info about the drawing (null means collect no info).

drawTitle

protected EntityCollection drawTitle(Title t, Graphics2D g2, Rectangle2D area, boolean entities)
Draws a title. The title should be drawn at the top, bottom, left or right of the specified area, and the area should be updated to reflect the amount of space used by the title.

Parameters: t the title (null not permitted). g2 the graphics device (null not permitted). area the chart area, excluding any existing titles (null not permitted). entities a flag that controls whether or not an entity collection is returned for the title.

Returns: An entity collection for the title (possibly null).

equals

public boolean equals(Object obj)
Tests this chart for equality with another object.

Parameters: obj the object (null permitted).

Returns: A boolean.

fireChartChanged

public void fireChartChanged()
Sends a default ChartChangeEvent to all registered listeners.

This method is for convenience only.

getAntiAlias

public boolean getAntiAlias()
Returns a flag that indicates whether or not anti-aliasing is used when the chart is drawn.

Returns: The flag.

See Also: JFreeChart

getBackgroundImage

public Image getBackgroundImage()
Returns the background image for the chart, or null if there is no image.

Returns: The image (possibly null).

See Also: setBackgroundImage

getBackgroundImageAlignment

public int getBackgroundImageAlignment()
Returns the background image alignment. Alignment constants are defined in the org.jfree.ui.Align class in the JCommon class library.

Returns: The alignment.

See Also: JFreeChart

getBackgroundImageAlpha

public float getBackgroundImageAlpha()
Returns the alpha-transparency for the chart's background image.

Returns: The alpha-transparency.

See Also: JFreeChart

getBackgroundPaint

public Paint getBackgroundPaint()
Returns the paint used for the chart background.

Returns: The paint (possibly null).

See Also: setBackgroundPaint

getBorderPaint

public Paint getBorderPaint()
Returns the paint used to draw the chart border (if visible).

Returns: The border paint.

See Also: setBorderPaint

getBorderStroke

public Stroke getBorderStroke()
Returns the stroke used to draw the chart border (if visible).

Returns: The border stroke.

See Also: setBorderStroke

getCategoryPlot

public CategoryPlot getCategoryPlot()
Returns the plot cast as a CategoryPlot.

NOTE: if the plot is not an instance of CategoryPlot, then a ClassCastException is thrown.

Returns: The plot.

See Also: getPlot

getLegend

public LegendTitle getLegend()
Returns the legend for the chart, if there is one. Note that a chart can have more than one legend - this method returns the first.

Returns: The legend (possibly null).

See Also: JFreeChart

getLegend

public LegendTitle getLegend(int index)
Returns the nth legend for a chart, or null.

Parameters: index the legend index (zero-based).

Returns: The legend (possibly null).

See Also: addLegend

getPadding

public RectangleInsets getPadding()
Returns the padding between the chart border and the chart drawing area.

Returns: The padding (never null).

See Also: setPadding

getPlot

public Plot getPlot()
Returns the plot for the chart. The plot is a class responsible for coordinating the visual representation of the data, including the axes (if any).

Returns: The plot.

getRenderingHints

public RenderingHints getRenderingHints()
Returns the collection of rendering hints for the chart.

Returns: The rendering hints for the chart (never null).

See Also: setRenderingHints

getSubtitle

public Title getSubtitle(int index)
Returns a chart subtitle.

Parameters: index the index of the chart subtitle (zero based).

Returns: A chart subtitle.

See Also: addSubtitle

getSubtitleCount

public int getSubtitleCount()
Returns the number of titles for the chart.

Returns: The number of titles for the chart.

See Also: getSubtitles

getSubtitles

public List getSubtitles()
Returns the list of subtitles for the chart.

Returns: The subtitle list (possibly empty, but never null).

See Also: setSubtitles

getTextAntiAlias

public Object getTextAntiAlias()
Returns the current value stored in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING.

Returns: The hint value (possibly null).

Since: 1.0.5

See Also: setTextAntiAlias

getTitle

public TextTitle getTitle()
Returns the main chart title. Very often a chart will have just one title, so we make this case simple by providing accessor methods for the main title. However, multiple titles are supported - see the addSubtitle method.

Returns: The chart title (possibly null).

See Also: setTitle

getXYPlot

public XYPlot getXYPlot()
Returns the plot cast as an XYPlot.

NOTE: if the plot is not an instance of XYPlot, then a ClassCastException is thrown.

Returns: The plot.

See Also: getPlot

handleClick

public void handleClick(int x, int y, ChartRenderingInfo info)
Handles a 'click' on the chart. JFreeChart is not a UI component, so some other object (for example, ChartPanel) needs to capture the click event and pass it onto the JFreeChart object. If you are not using JFreeChart in a client application, then this method is not required.

Parameters: x x-coordinate of the click (in Java2D space). y y-coordinate of the click (in Java2D space). info contains chart dimension and entity information (null not permitted).

isBorderVisible

public boolean isBorderVisible()
Returns a flag that controls whether or not a border is drawn around the outside of the chart.

Returns: A boolean.

See Also: JFreeChart

isNotify

public boolean isNotify()
Returns a flag that controls whether or not change events are sent to registered listeners.

Returns: A boolean.

See Also: JFreeChart

main

public static void main(String[] args)
Prints information about JFreeChart to standard output.

Parameters: args no arguments are honored.

notifyListeners

protected void notifyListeners(ChartChangeEvent event)
Sends a ChartChangeEvent to all registered listeners.

Parameters: event information about the event that triggered the notification.

notifyListeners

protected void notifyListeners(ChartProgressEvent event)
Sends a ChartProgressEvent to all registered listeners.

Parameters: event information about the event that triggered the notification.

plotChanged

public void plotChanged(PlotChangeEvent event)
Receives notification that the plot has changed, and passes this on to registered listeners.

Parameters: event information about the plot change.

removeChangeListener

public void removeChangeListener(ChartChangeListener listener)
Deregisters an object for notification of changes to the chart.

Parameters: listener the listener (null not permitted)

See Also: addChangeListener

removeLegend

public void removeLegend()
Removes the first legend in the chart and sends a ChartChangeEvent to all registered listeners.

See Also: getLegend

removeProgressListener

public void removeProgressListener(ChartProgressListener listener)
Deregisters an object for notification of changes to the chart.

Parameters: listener the object being deregistered.

See Also: addProgressListener

removeSubtitle

public void removeSubtitle(Title title)
Removes the specified subtitle and sends a ChartChangeEvent to all registered listeners.

Parameters: title the title.

See Also: addSubtitle

setAntiAlias

public void setAntiAlias(boolean flag)
Sets a flag that indicates whether or not anti-aliasing is used when the chart is drawn.

Anti-aliasing usually improves the appearance of charts, but is slower.

Parameters: flag the new value of the flag.

See Also: getAntiAlias

setBackgroundImage

public void setBackgroundImage(Image image)
Sets the background image for the chart and sends a ChartChangeEvent to all registered listeners.

Parameters: image the image (null permitted).

See Also: getBackgroundImage

setBackgroundImageAlignment

public void setBackgroundImageAlignment(int alignment)
Sets the background alignment. Alignment options are defined by the org.jfree.ui.Align class.

Parameters: alignment the alignment.

See Also: getBackgroundImageAlignment

setBackgroundImageAlpha

public void setBackgroundImageAlpha(float alpha)
Sets the alpha-transparency for the chart's background image. Registered listeners are notified that the chart has been changed.

Parameters: alpha the alpha value.

See Also: getBackgroundImageAlpha

setBackgroundPaint

public void setBackgroundPaint(Paint paint)
Sets the paint used to fill the chart background and sends a ChartChangeEvent to all registered listeners.

Parameters: paint the paint (null permitted).

See Also: getBackgroundPaint

setBorderPaint

public void setBorderPaint(Paint paint)
Sets the paint used to draw the chart border (if visible).

Parameters: paint the paint.

See Also: getBorderPaint

setBorderStroke

public void setBorderStroke(Stroke stroke)
Sets the stroke used to draw the chart border (if visible).

Parameters: stroke the stroke.

See Also: getBorderStroke

setBorderVisible

public void setBorderVisible(boolean visible)
Sets a flag that controls whether or not a border is drawn around the outside of the chart.

Parameters: visible the flag.

See Also: isBorderVisible

setNotify

public void setNotify(boolean notify)
Sets a flag that controls whether or not listeners receive ChartChangeEvent notifications.

Parameters: notify a boolean.

See Also: isNotify

setPadding

public void setPadding(RectangleInsets padding)
Sets the padding between the chart border and the chart drawing area, and sends a ChartChangeEvent to all registered listeners.

Parameters: padding the padding (null not permitted).

See Also: getPadding

setRenderingHints

public void setRenderingHints(RenderingHints renderingHints)
Sets the rendering hints for the chart. These will be added (using the Graphics2D.addRenderingHints() method) near the start of the JFreeChart.draw() method.

Parameters: renderingHints the rendering hints (null not permitted).

See Also: getRenderingHints

setSubtitles

public void setSubtitles(List subtitles)
Sets the title list for the chart (completely replaces any existing titles) and sends a ChartChangeEvent to all registered listeners.

Parameters: subtitles the new list of subtitles (null not permitted).

See Also: getSubtitles

setTextAntiAlias

public void setTextAntiAlias(boolean flag)
Sets the value in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING to either RenderingHints#VALUE_TEXT_ANTIALIAS_ON or RenderingHints#VALUE_TEXT_ANTIALIAS_OFF, then sends a ChartChangeEvent to all registered listeners.

Parameters: flag the new value of the flag.

Since: 1.0.5

See Also: getTextAntiAlias setTextAntiAlias

setTextAntiAlias

public void setTextAntiAlias(Object val)
Sets the value in the rendering hints table for RenderingHints#KEY_TEXT_ANTIALIASING and sends a ChartChangeEvent to all registered listeners.

Parameters: val the new value (null permitted).

Since: 1.0.5

See Also: getTextAntiAlias JFreeChart

setTitle

public void setTitle(TextTitle title)
Sets the main title for the chart and sends a ChartChangeEvent to all registered listeners. If you do not want a title for the chart, set it to null. If you want more than one title on a chart, use the addSubtitle method.

Parameters: title the title (null permitted).

See Also: getTitle

setTitle

public void setTitle(String text)
Sets the chart title and sends a ChartChangeEvent to all registered listeners. This is a convenience method that ends up calling the setTitle method. If there is an existing title, its text is updated, otherwise a new title using the default font is added to the chart. If text is null the chart title is set to null.

Parameters: text the title text (null permitted).

See Also: getTitle

titleChanged

public void titleChanged(TitleChangeEvent event)
Receives notification that a chart title has changed, and passes this on to registered listeners.

Parameters: event information about the chart title change.

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