jfreechart-builder

A builder pattern module for working with the jfreechart library.

It's a companion to ChartFactory.java for using a declarative approach to creating complex charts with fewer lines of code.

Features

• XY time series charts using CombinedDomainXYPlot for data alignment on sub-plots.
• Stockmarket OHLC candlestick and volume bar charts.
• A time gap removal solution (see JfreeChart Issue #197).
• A combined axis sub-plot crosshair synchronization solution.
• Easy time axis tick format control including a minimalist date format solution.
• Easy markers and annotations (arrows, boxes, images, lines, polygons, text, titles).
• Easy color, line style, and gridline control.
• A Demo app for testing and prototyping.

Note: all charts use a CombinedDomainXYPlot even if there's one plot in order to ease the maintenance of this framework.

In the future, more facilities may be added to leverage more of what jfreechart provides.

Samples

A simple annotated plot

ChartBuilder.get()
  .title("Simple Time Series With Annotations")
  .timeData(timeArray)
  .xyPlot(XYTimeSeriesPlotBuilder.get()
    .series(XYTimeSeriesBuilder.get().name("Amplitude").data(array1).color(Color.BLUE).style(SOLID_LINE))
    .annotation(XYArrowBuilder.get().x(arrowX).y(arrowY).angle(180.0).color(Color.RED).text(arrowTxt))
    .annotation(XYArrowBuilder.get().x(arrowX).y(arrowY).angle(0.0).color(Color.RED))
    .annotation(XYTextBuilder.get().x(arrowX).y(arrowY).color(DARK_GREEN)
        .text("This value!").textPaddingLeft(5).textAlign(TextAnchor.BASELINE_LEFT).angle(90.0)))
  .build();

Multiple series plots

ChartBuilder.get()

  .title("Multi Plot Minute Time Series")
  .timeData(timeArray)

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Values")
    .backgroundColor(Color.DARK_GRAY).axisColor(Color.RED).axisFontColor(Color.BLUE)
    .series(XYTimeSeriesBuilder.get().data(array1).color(Color.YELLOW).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().data(array2).color(Color.RED).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().data(array3).color(Color.GREEN).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().data(array4).color(Color.MAGENTA).style(SOLID_LINE)))

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Amplitudes").noGridLines()
    .series(XYTimeSeriesBuilder.get().data(array2).color(Color.BLACK).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().data(array3).color(Color.LIGHT_GRAY).style(SOLID_LINE)))

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Series 1")
    .backgroundColor(DARK_GREEN).axisColor(Color.RED).axisFontColor(Color.BLUE)
    .series(XYTimeSeriesBuilder.get().data(array1).color(Color.GREEN).style(SOLID_LINE)))

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Series 2")
    .backgroundColor(DARK_RED).axisColor(Color.RED).axisFontColor(Color.BLUE)
    .series(XYTimeSeriesBuilder.get().data(array2).color(Color.RED).style(SOLID_LINE)))

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Series 3")
    .backgroundColor(DARK_BLUE).axisColor(Color.RED).axisFontColor(Color.BLUE)
    .series(XYTimeSeriesBuilder.get().data(array3).color(Color.CYAN).style(SOLID_LINE)))

  .build();

Stock market plots

ChartBuilder.get()

  .title("Stock Chart Time Series With Weekend Gaps, Lines, and Annotations")
  .timeData(timeArray)

  .xyPlot(OhlcPlotBuilder.get().yAxisName("Price").plotWeight(3)
    .series(OhlcSeriesBuilder.get().ohlcv(dohlcv).upColor(Color.WHITE).downColor(Color.RED))
    .series(XYTimeSeriesBuilder.get().name("MA(20)").data(sma20).color(Color.MAGENTA).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().name("MA(50)").data(sma50).color(Color.BLUE).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().name("MA(200)").data(sma200).color(Color.RED).style(SOLID_LINE))
    .annotation(XYArrowBuilder.get().x(stockEventDate).y(stockEventPrice).angle(270.0).color(DARK_GREEN)
      .textAlign(TextAnchor.BOTTOM_CENTER).text(String.format("%.2f", stockEventPrice)))
    .marker(MarkerBuilder.get().horizontal().at(resistanceLevel).color(Color.LIGHT_GRAY).style(SOLID_LINE)))

  .xyPlot(VolumeXYPlotBuilder.get().yAxisName("Volume").yTickFormat(volNumFormat)
    .series(VolumeXYTimeSeriesBuilder.get().ohlcv(dohlcv).upColor(Color.DARK_GRAY).downColor(Color.RED))
    .series(XYTimeSeriesBuilder.get().name("MA(90)").data(volSma90).color(Color.BLUE).style(SOLID_LINE))
    .annotation(XYArrowBuilder.get().x(stockEventDate).y(stockEventVolume).angle(270.0).color(DARK_GREEN)
      .textAlign(TextAnchor.BOTTOM_CENTER).text(String.format("%.0f", stockEventVolume)))
    .marker(MarkerBuilder.get().horizontal().at(volumeLine).color(DARK_GREEN).style(SOLID_LINE)))

  .xyPlot(XYTimeSeriesPlotBuilder.get().yAxisName("Stoch").yAxisRange(0.0, 100.0).yAxisTickSize(50.0)
    .series(XYTimeSeriesBuilder.get().name("K(" + K + ")").data(stoch.getPctK()).color(Color.RED).style(SOLID_LINE))
    .series(XYTimeSeriesBuilder.get().name("D(" + D + ")").data(stoch.getPctD()).color(Color.BLUE).style(SOLID_LINE))
    .marker(MarkerBuilder.get().horizontal().at(80.0).color(Color.BLACK).style(SOLID_LINE))
    .marker(MarkerBuilder.get().horizontal().at(50.0).color(Color.BLUE).style(SOLID_LINE))
    .marker(MarkerBuilder.get().horizontal().at(20.0).color(Color.BLACK).style(SOLID_LINE)))

  .build();

Time Gap Removal

Implements a solution for removing visible time gaps where no data exists (like on weekends). Accomplishes this with a family of adapter classes mapping NumberAxis values as indices in time value arrays.

Configured using showTimeGaps(boolean):

ChartBuilder.get()

  .title("Stock Chart Time Series No Gaps for Weekends")
  .showTimeGaps(false)

  ...

Note: the x-axis month label in the gapless time chart currently doesn't always correspond to the first day (or trading day) of the month.

Sub-plot Crosshair Synchronization

ChartCombinedAxisClickDispatcher was created to dispatch JfreeChart ChartMouseEvents to combined axis sub-plots. This leverages JFreeChart's built-in updating of crosshairs and emulates the perpendicular ChartPanel trace lines like a snapshot of them. The demo app has example code but essentially you add a chart mouse listener to the panel:

ChartPanel panel = new ChartPanel();

...

ChartMouseListener clickDispatcher = new ChartCombinedAxisClickDispatcher(panel);

panel.addChartMouseListener(clickDispatcher);

Now a click on any combined axis sub-plot will make all sub-plots get a handleClick() call.

To remove this, pass the same listener object to the remove method:

panel.removeChartMouseListener(clickDispatcher);

ChartCombinedAxisClickDispatcher is extendable for other customizations.

Time Axis Tick Label Formats

You can supply DateFormat instances to render time axis tick labels by calling dateFormat(DateFormat format). You can even implement your own sub-class.

You can also set the vertical label flag to draw them vertically.

ChartBuilder.get()

  .dateFormat( /* supply your DateFormat instance here */ )

  .verticalTickLabels(true)

  ...

Convenience Minimal Tick Format

An optional MinimalDateFormat class is implemented to format dates with month letter(s) on first instance of a new month then only month days until a new month is reached.

Demo App

See the demo-app solution for an interactive demo. Used for development and testing.

To launch it see Testing section further down.

Incorporating into your project

The module is not published to Maven Central so you must build the solution locally and install it in local Maven repositories.

Prerequisites

• JDK 8 or greater [1] [2] installed.
• Apache Maven installed.
• Internet connection for Maven dependency downloads or you add those to your local Maven repo yourself.

Installing source code

git clone <this repo's URL>

Versioning

The major and minor numbers are the same as the jfreechart major and minor to denote compatibility.

The incremental ("patch") number is the monolithic version number of jfreechart-builder.

Branching model

The latest and greatest but unreleased contributions are on the develop branch. These commits give you a preview of what's to come.

Each time develop is merged into main, a version tag is added onto that merge commit.

Each commit to main represents the next released version.

Folder Structure

framework/ contains the builder library code and produces the consumable jfreechart-builder JAR file.

demo-app/ contains the demo app code and produces the launchable jfreechart-builder-demo JAR file.

Build and install the jars into your local Maven repo

Set the desired branch

cd path/to/cloned/repo

git checkout <desired branch or tag>

Build and install everything:

mvn install

Or build and install modules independently:

cd framework
mvn install

cd ../demo-app
mvn install

Note: to build the jars without installing use mvn package instead of mvn install . They'll be in the framework/target/ and demo-app/target/ folders.

Add the jfreechart-builder JAR to a client project

Add this dependency to your project's .pom file:

<dependency>
  <groupId>com.jfcbuilder</groupId>
  <artifactId>jfreechart-builder</artifactId>
  <version>1.5.8</version>
<dependency>

Testing

Run the demo-app from your IDE or launch it from the command line:

java -jar jfreechart-builder-demo.jar

Test Coverage Warning

Testing of jfreechart-builder is limited to manually running the jfreechart-builder-demo application locally on Windows or Linux. It's rarely (if ever) run on both operating systems for the same code changes being merged. As of this writing the author(s)/maintainer(s) have not tested it on MacOS.

There is a reliance on the cross-platform natured promise of Java.

There are currently no runnable or automated unit tests, integration tests, regression tests, and the like.

Testing is done by visual inspection of the jfreechart-builder-demo app user interface.

You should thoroughly test the use of jfreechart-builder in your project and environment to satisfy yourself it does what you need and expect.

If you feel a capability is missing or there's a bug feel free to create an issue or start a discussion thread. Contributions are also welcome (see Contributing below)!

Javadoc

The latest release Javadoc is hosted here.

Generating Javadoc locally

mvn javadoc:javadoc -Dsource=8

Use a browser to open framework/target/site/apidocs/index.html

Alternatively, run the generation script by specifying what version tag to associate with the Javadoc:

./scripts/generate-javadoc.sh v1.5.8

That output will be in target/site/apidocs/javadoc

Thread-safety and garbage collection

No thread-safety measures are deliberately taken. If you require thread-safety then provide deep copies of objects, don't share builders, don't share charts, or you could add synchronization to your business logic.

Generally, primitive data arrays are copied into jfreechart objects. jfreechart-builder will maintain references to other objects passed-in like strings, colors, and drawing strokes. When the builders and charts they produce go out of scope, the objects you provided (and other objects that may be referencing them) should be garbage collected as applicable.

License

jfreechart-builder is not affiliated with the jfreechart project but for compatibility it and the jfreechart-builder-demo app are provided under the terms of the same LGPL 2.1 license.

You should be aware of the contents of the jfreechart-builder JAR file built from this project.

It should contain the compiled .class files only of jfreechart-builder and should not incorporate any from jfreechart, however you must verify its contents to know what the build tools are actually producing.

If you need clarification on the LGPL vs. Java, please see the FSF's tech note about it.

Contributing

Contributions are welcome and will be accepted as the maintainers' time permits.

• Please use indentations of two spaces (no tabs)
• Wrap lines at a width of 100 characters.
• Write good Javadoc at least for interfaces, class descriptions, and public methods.