Editing a Component using JTable

[knrajwan@ncsu.edu]

Hi,

My name is Kailash. I am currently enrolled for CSC 517 class at North Carolina State University. Myself and my team partner are working on JFreeChart and trying to implement below requirement in JFreeChart:

"Write an editing component that uses a JTable to display the values in a PieDataset and allows those values to be edited (added, deleted or modified).
• For a more challenging project, do the same for a CategoryDataset or an XYDataset."

Could you please provide more details in order for us to figure out what files we have to modify and it would be nice if the requirement is explained with an example?

We tried to execute PieChartDemo1.Java file and when we right click on the demo image and view Properties -> other, we see
Series Paint: No editor implemented (with Edit button disabled)
Series Stroke: No editor implemented (with Edit button disabled)
Series Outline Paint: No editor implemented (with Edit button disabled)
Series Outline Stroke: No editor implemented (with Edit button disabled)

Are we supposed to implement the above missing features? Or

Do we have to introduce a new button on any chart (say Edit), clicking on Edit would populate the dataset in JTable.

[david.gilbert]

Hi Kailash,

The task isn't to integrate this directly into JFreeChart, just to provide a self-contained component that will allow you to pass in any PieDataset---the component will then display the data in a JTable---and allow full editing (modification of keys and values, addition and deletion of key, value pairs) with some validation to prevent duplicate keys and negative values. Ideally, this component should provide some notification mechanism so that a listener can be registered to get notified when the dataset has been modified. And you probably want to provide an option to cancel the editing and restore the original dataset, but that's up to you.

To demonstrate that your component works, you should create a simple Swing application that displays a dataset in a table (using your component) plus a chart somewhere else in the UI, and have the chart automatically updating when you edit the table.

[vindsr2211]

I am also working on the same project.
I have this issues currently.

The approach I decided was :
1. Accept column names and then make the table editable.
2. Convert the DefaultTableModel to DefaultPieDataset.
3. Draw the piechart for the pie dataset hence obtained.

Is this approach right?

I am able to do the first step.
I am not able to convert the DefaultTableModel to DefaultPieDataset.
I am able to draw the PieChart for some defaultly given PieDataset.

So, what is the method to convert the DefaultTableModel to DefaultPieDataset?

[vindsr2211]

I am giving the default data for the DefaultPieDataset as follows:

Code: Select all

        final DefaultPieDataset result = new DefaultPieDataset();
        result.setValue("ABC", new Double(12.3));
        result.setValue("DEF", new Double(4.5));

Using the above e.g., I am trying to convert the TableModel to PieDataset as follows:

Code: Select all

result.setValue((String)tabModel.getValueAt(i,0),Double.parseDouble((String)tabModel.getValueAt(i,1)));

Is this the right way?
But the above line of code works for 2 columns only.
How to work for multiple columns??

[MitchBuell]

What you described is one way, and would be how I would first try it. Basically, you're creating a user interface to edit a PieDataset. A table would be a natural choice, with some logic to populate the table and save the table values back to the dataset.

[vindsr2211]

private PieDataset createSampleDataset() {

final DefaultPieDataset result = new DefaultPieDataset();
for(int i=0;i<numrows;i++)
{
System.out.println("\n val 1 in Row: "+i+"="+tabModel.getValueAt(i,0));
System.out.println("\n val 2 in Row: "+i+"="+tabModel.getValueAt(i,1));

result.setValue((String)tabModel.getValueAt(i,0),(Double)tabModel.getValueAt(i,1));

}

return result;
}

Considering only 2 columns, how do i pass values in the result.setValue function?
Is that way right?
When I do this there is no Piedataset being created!.

Can you find the flaw in this code?

[MitchBuell]

I don't see what's wrong with that code. Do you have an Exception or stack trace?

[vindsr2211]

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Double
at Java4.createSampleDataset(Java4.java:84)
at Java4.drawChart(Java4.java:231)
at Java4.actionPerformed(Java4.java:165)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6263)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6028)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4630)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2475)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[vindsr2211]

private PieDataset createSampleDataset() {

final DefaultPieDataset result = new DefaultPieDataset();
for(int i=0;i<numrows;i++)
{
System.out.println("\n val 1 in Row: "+i+"="+tabModel.getValueAt(i,0));
System.out.println("\n val 2 in Row: "+i+"="+tabModel.getValueAt(i,1));

try{
result.setValue((String)tabModel.getValueAt(i,0),(Double)tabModel.getValueAt(i,1));}
catch(Exception e)
{
System.out.println("\n Creation of sample dataset.. exception "+e);
}

}

return result;

}

for this piece of code.. I caught an exception..

Creation of sample dataset.. exception java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Double

[vindsr2211]

result.setValue((String)tabModel.getValueAt(i,0),(String)tabModel.getValueAt(i,1));}

If I give the result.setValue thing as such, I am not able to compile the program.

The following error is shown:
Java4.java:85: cannot find symbol
symbol : method setValue(java.lang.String,java.lang.String)
location: class org.jfree.data.general.DefaultPieDataset
result.setValue((String)tabModel.getValueAt(i,0),(String)tabModel.getValueAt(i,1));}
^

[MitchBuell]

The exception is "java.lang.String cannot be cast to java.lang.Double" and the only place that I can see where you are trying to cast a String to a Double is "(Double)tabModel.getValueAt(i,1)". You need to look at exactly what tabModel.getValueAt(i,1) is returning. According to the Exception, getValueAt is returning a String. To convert a String to a Double, you need to do Double.valueOf(tabModel.getValueAt(i,1))

The setValue method takes a String and a Number, not a String and a String. You want: result.setValue((String)tabModel.getValueAt(i,0),Double.valueOf(tabModel.getValueAt(i,1)));

[vindsr2211]

Code: Select all

				result.setValue((String)tabModel.getValueAt(i,0),Double.ValueOf(tabModel.getValueAt(i,1))); 

I did this.

But still Ive been getting the following error:

Code: Select all

Java4.java:86: cannot find symbol
symbol  : method ValueOf(java.lang.Object)
location: class java.lang.Double
                        result.setValue((String)tabModel.getValueAt(i,0),Double.ValueOf(tabModel.getValueAt(i,1)));
                                                                               ^

[MitchBuell]

You have Double.ValueOf, but the method is Double.valueOf. You have the V in valueOf capitalized.

[vindsr2211]

Inspite of the editing also, the error remains at the same place.
Java4.java:86: cannot find symbol
symbol : method valueOf(java.lang.Object)
location: class java.lang.Double
result.setValue((String)tabModel.getValueAt(i,0),Double.valueOf(tabModel.getValueAt(i,1)));
^

[skunk]

Try

Code: Select all

Double.valueOf((String)tabModel.getValueAt(i,1))