How to use JFreeChart with SWT (includes sample code)

[Robert Gash]

I have seen a number of posts asking how to use JFreeChart within SWT applications. Most solutions appear to rely on converting AWT Image's into SWT Image's. That process works fine, but seems overly tiedious.

Newer SWT implementations are beginning to provide very rough wrappers around a java.awt.Panel that allow older AWT/Swing components to be reused inside of SWT applications. Currently only Win32 platforms are supported, although I imagine that other ports aren't far off.

Here's a quick and dirty example of how to use JFreeChart "natively" (without converting Images, etc.) inside of your Win32 SWT application. This has been tested on the Eclipse 3.0M1 SWT drop (build 3007). This WILL NOT work with older 2.x SWT drops.

0) Take a look at

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org.eclipse.swt.internal.SWT_AWT

, all of the functionality to create a Panel backed by our Composite resides here in the

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new_Panel

method.

1) Create a simple SWT Composite that will contain your AWT/Swing components (in this case a ChartPanel). Align the Composite using your usual SWT layout managers.

2) Create a JFreeChart based on your data using the usual ChartFactory methods.

3) Create a new java.awt.Panel that is backed by your SWT Composite. Optionally you may wish to set the background color to that of the composite and add a layout manager if you want to have several JFreeChart's in the same Composite, or you want the chart to resize itself based on the size of the SWT Composite.

4) Create ChartPanel's and add them to your java.awt.Panel that you obtained from SWT_AWT in step 3.

5) Sit back and enjoy!

Sounds easy, doesn't it? Here's the code (tested using SWT 3.0M1, JFreeChart 0.9.8, JCommon 0.8.3, J2SDK 1.4.2 on Win32 [Win2k]).

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/// STEP 1 ////////////////////////////////////////////////
// create a composite suitable for displaying all of our chart data
Composite chartComposite = new Composite(/* options */);
chartComposite.setLayoutData(/* set the layout options */);

/// STEP 2 ////////////////////////////////////////////////
// create the dataset for the pie chart of the distribution
DefaultPieDataset pieData = new DefaultPieDataset();
/* populate the pieData here */

JFreeChart chart = ChartFactory.createPie3DChart(/* some options */);
// OPTIONAL: tinkering with plot options here

/// STEP 3 ////////////////////////////////////////////////
// Grab the background color from the SWT Composite
// so our AWT panel "matches" the SWT Composite
Color backgroundColor = chartComposite.getBackground();

// create the panel
Panel chartPanel = SWT_AWT.new_Panel(chartComposite);

// set the panel's background (defaults to pure white)
chartPanel.setBackground(new java.awt.Color(backgroundColor.getRed(),
                                                    backgroundColor.getGreen(),
                                                    backgroundColor.getBlue()));
// set the AWT layout manager
chartPanel.setLayout(/* some AWT/Swing layout manager like BoxLayout */);

/// STEP 4 ////////////////////////////////////////////////       
ChartPanel jfreeChartPanel = new ChartPanel(chart);
chartPanel.add(jfreeChartPanel);


-Robert Gash, Software Developer, Enkia Corporation
gashalot <at> enkia.com

[david.gilbert]

Hi Robert,

Thanks for your post. I get the occasional question about using JFreeChart in SWT (I've never tried SWT myself) so this is useful...

[Murali]

I have attempted the above method in linux under Eclipse 2.1.1. Got the chart, everything working!

[Shilpa]

Hi Thanx its v good..

[Jon]

When I upgraded to ver 3 of eclipse to try and get JFreeChart to work inside swt it no longer recognised

Panel chartPanel = SWT_AWT.new_Panel(chartComposite);

From random reading on web i found:

Panel org.eclipse.swt.internal.awt.win32.SWT_AWT.new_Panel(Composite)

The new_Panel method has one parameter, an SWT Composite object, and
it returns an AWT Panel object. The awt Panel is contained within the
swt Composite, and is constructed using a WEmbeddedFrame from Sun's
internal package sun.awt.windows. Sun has changed this internal code
in jdk 1.4, and so this undocumented Eclipse mechanism does not work
with that version.

Any on e have any suggestions on how I can get graphs to display inside my SWT application?

Cheers

Jon

[Robert Gash]

swt Composite, and is constructed using a WEmbeddedFrame from Sun's
internal package sun.awt.windows. Sun has changed this internal code
in jdk 1.4, and so this undocumented Eclipse mechanism does not work
with that version.

Any on e have any suggestions on how I can get graphs to display inside my SWT application?

Jon,

I actually just tested a new demo using SWT 3.0M8, J2SDK 1.4.2_03, and JFreeChart 0.9.17 on my Windows XP system (SP1). I was able to use JFreeChart without any problems.

The sample code can be found at http://www.gashalot.com/software/JFreeChartSWTDemo.java.

Let me know if you have any questions.

-R

[Chengdong]

Hi, there:

I tried the suggestions here and found it was okay for just showing a chart in SWT application by using SWT_AWT. However there are still some potential problems exist:

SWT and AWT has diffent UI loop, they can not iteroperate seamlessly which is also discouraged by Eclipse developers.

For example, can somebody show me how to solve this problem:
==========================================
Show the pie-chart first, then click pie-chart, this will show a new bar-chart beside the pie-chart; click the bar-chart, then only show the piechart.

I tried to make this run by dynimically disposing the SWT_AWT widget, it gave me some error from SWT AWT interoperation sometime and did not work.

I think only pure SWT implementation of JFreeChart can solve this problem.

Can anybody give me some suggestion?

You can answer me by email: cli4@uky.edu

Thanks in advance.

-Chengdong

[ftam_ftp]

I've tried the solution above, and after working out that I should be using SWT_AWT.new_Frame(), I get an IllegalArgumentException. I've tried passing both the Composite, and the Shell as an argument, but it makes no difference. I also tried the JFreeChartSWTDemo with the same results. I'm running Eclipse 2.1.2 Build 200311030802, and using the SWT drop 3.0RC1 build 3054. Any ideas?

Thanks

[Geoffrey Peart]

swt Composite, and is constructed using a WEmbeddedFrame from Sun's
internal package sun.awt.windows. Sun has changed this internal code
in jdk 1.4, and so this undocumented Eclipse mechanism does not work
with that version.

Any on e have any suggestions on how I can get graphs to display inside my SWT application?

Jon,

I actually just tested a new demo using SWT 3.0M8, J2SDK 1.4.2_03, and JFreeChart 0.9.17 on my Windows XP system (SP1). I was able to use JFreeChart without any problems.

The sample code can be found at http://www.gashalot.com/software/JFreeChartSWTDemo.java.

Let me know if you have any questions.

-R

Robert, I attempted to run the code at that link, I am running
eclipse 3.0.0 GA with J2SDK 1.4.2_03, and I have tried jFreeChart 0.9.17 and the recent .21 releases. I enccounter two issues. the first is this:

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java.lang.NoClassDefFoundError: org/jfree/util/PublicCloneable
   at java.lang.ClassLoader.defineClass0(Native Method)
   at java.lang.ClassLoader.defineClass(Unknown Source)
   at java.security.SecureClassLoader.defineClass(Unknown Source)
   at java.net.URLClassLoader.defineClass(Unknown Source)
   at java.net.URLClassLoader.access$100(Unknown Source)
   at java.net.URLClassLoader$1.run(Unknown Source)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.net.URLClassLoader.findClass(Unknown Source)
   at java.lang.ClassLoader.loadClass(Unknown Source)
   at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
   at java.lang.ClassLoader.loadClass(Unknown Source)
   at java.lang.ClassLoader.loadClassInternal(Unknown Source)
   at com.gashalot.sample.JFreeChartSWTDemo.main(JFreeChartSWTDemo.java:45)
Exception in thread "main"

That is occuring on this line :

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JFreeChart chart = ChartFactory.createPieChart3D("Sample Chart", pieData, true, true, false);

If I comment that, and the ones depend on it, I end up with:

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java.lang.IllegalArgumentException: Argument not valid
   at org.eclipse.swt.SWT.error(SWT.java:2677)
   at org.eclipse.swt.SWT.error(SWT.java:2616)
   at org.eclipse.swt.SWT.error(SWT.java:2587)
   at org.eclipse.swt.awt.SWT_AWT.new_Frame(SWT_AWT.java:118)
   at com.gashalot.sample.JFreeChartSWTDemo.main(JFreeChartSWTDemo.java:48)
Exception in thread "main"

on line

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Frame chartFrame = SWT_AWT.new_Frame(shell);

Is there anything I am missing here?

If you check this, I could use your help, or anyones.

Thanks in advance.

[Geoffrey Peart]

Okay first error because I am a fool I didn't include the jcommon.jar in my class path. The second one, well here is the javadoc for SWT_AWT class

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Creates a new java.awt.Frame. This frame is the root for the AWT components that will be embedded within the composite. In order for the embedding to succeed, the composite must have been created with the SWT.EMBEDDED style.

so I changed the new shell(display) to this

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Shell shell = new Shell(display,SWT.EMBEDDED);

worked like a charm, not sure if that is a new release of SWT going on there or what, but it works so I'm happy. Thanks Robert for the good sample.

g

[Tim99]

Unfortunately I can't use this method on Mac OS X because of this bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=67384

Mixing up AWT and SWT with Eclipse (Mac OS X) doesn't seem to work.

Any suggestions?

[Giuseppe]

Hi
I'm an italian designer and I don't speak english very well, sorry.
I have seen your message but I'm not able to put into practice your solution because eclipse tell me that the method SWT_AWT.new_Composite not exists. How can I do?

Thanks in advance,
Giuseppe

[pixeldude]

1. you have to create a display and a shell

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Display display = new Display();
Shell shell = new Shell(display);

2. Create an SWT composite with the style SWT.EMBEDDED

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Composite chartComposite = new Composite(shell, SWT.EMBEDDED);

3. Create an AWT Frame using SWT_AWT

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Frame chartFrame = SWT_AWT.new_Frame(chartComposite);

4. Go on with JFreeChart

This worked for me with SWT 3.0

[Guest]

Unfortunately I can't use this method on Mac OS X because of this bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=67384

Mixing up AWT and SWT with Eclipse (Mac OS X) doesn't seem to work.

Any suggestions?

I had the same problem with Linux, too. But there is a way. You can save the image in a local buffer using AWT and load it from that buffer using SWT afterwards.

This is a little bit ugly, but it works...

Here is my code:

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  public static Image createChartImage(Control parent, JFreeChart chart,
    int width, int height)
  {
    // Color adjustment
    Color swtBackground = parent.getBackground();
    java.awt.Color awtBackground = new java.awt.Color(swtBackground.getRed(),
                                                      swtBackground.getGreen(),
                                                      swtBackground.getBlue());
    chart.setBackgroundPaint(awtBackground);
   
    try {
      // Write the image to a buffer in memory using AWT
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      ChartUtilities.writeChartAsPNG(out, chart, width, height);
      out.close();
     
      // Load the image from the same buffer using SWT
      ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
      Image swtImage = new Image(display, in);
      in.close();
     
      return swtImage;
    }
    catch (Exception exc) {
      exc.printStackTrace();
      return null;
    }
  }

[Til]

I'm the "Guest" who wrote the last post...

I just found a faster way without the indirection over creating PNG data.

Here is the code:

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  public static Image createChartImage(Control parent, JFreeChart chart,
    int width, int height)
  {
    // Color adjustment
    Color swtBackground = parent.getBackground();
    java.awt.Color awtBackground = new java.awt.Color(swtBackground.getRed(),
                                                      swtBackground.getGreen(),
                                                      swtBackground.getBlue());
    chart.setBackgroundPaint(awtBackground);

    // Draw the chart in an AWT buffered image
    BufferedImage bufferedImage
      = chart.createBufferedImage(width, height, null);

    // Get the data buffer of the image
    DataBuffer buffer = bufferedImage.getRaster().getDataBuffer();
    DataBufferInt intBuffer = (DataBufferInt) buffer;
   
    // Copy the data from the AWT buffer to a SWT buffer
    PaletteData paletteData = new PaletteData(0x00FF0000, 0x0000FF00, 0x000000FF);
    ImageData imageData = new ImageData(width, height, 32, paletteData);
    for (int bank = 0; bank < intBuffer.getNumBanks(); bank++) {
      int[] bankData = intBuffer.getData(bank);
      imageData.setPixels(0, bank, bankData.length, bankData, 0);     
    }
   
    // Create an SWT image
    return new Image(parent.getDisplay(), imageData);
}