my notebook

I had my first encounter with JFreeChart and I was impressed. It was simple, productive.

The process to design and create a chart is a 3-step process:

1. create a dataset
2. populate a dataset
3. create a chart
4. draw the chart to some target output

We needed to provide an ability to drill down within charts, say it’s a daily chart and we you click on a specific hour, we expect a 5 minute chart for that hour and so on.

This was acheived by adding a listener chartMouseClicked and parsing the ChartMouseEvent Object with getEntity().getToolTipText(). Once data was acquired, by using substring, the new graph would be drawn.

The graphs could also retrieve its data from a database. A major plus for the JFreeChart.

This should serve as a short example for using JFreeChart:

import org.jfree.data.general.DefaultPieDataset;
import org.jfree.chart.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class MyFirstChart implements ChartMouseListener {
	JFrame chartFrame = new JFrame();
	JPanel chartPanel;
	JPanel firstPanel;
	boolean firstTime = true;

	public void chart(String type1, String type2, String type3, double val1,
			double val2, double val3) {
		// create a dataset
		// note: there are different Dataset values
		// such as:
		// DefaultPieDataset: Pie charts
		// DefaultCategoryDataset: for line charts
		// XYSeriesCollection: also for line charts
		// :it holds mutiple XYSeries (mutiple lines)
		// :it is casted to XYDataSet
		// TimeSeriesCollection: for dates and numbers (X: date, Y: a number)
		// : will contain one or more TimeSeries

		DefaultPieDataset dataset = new DefaultPieDataset();

		// note: the below numbers are fraction of a chart whose area if equal
		// to the sum of all so the first would be: 10.2 out of (10.2 + 27.9 +
		// 19.5)

		dataset.setValue(type1, val1);
		dataset.setValue(type2, val2);
		dataset.setValue(type3, val3);

		// create a chart
		JFreeChart chart = ChartFactory.createPieChart("Select One!", // title
				dataset, // pass the dataset
				true, // legend?
				true, // tooltips?
				false // URLs?
				);

		// we will use ChartPanel to display the chart
		// ChartPanel extends JPanel
		// get the panel
		ChartPanel chartPanel = new ChartPanel(chart);

		// add a mouse listener to the panel (only can be added to the panel)
		chartPanel.addChartMouseListener(this);

		JFrame chartFrame = new JFrame();
		chartFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		chartFrame.getContentPane().add(chartPanel, BorderLayout.CENTER);
		chartFrame.pack();
		chartFrame.setVisible(true);
	}

	public static void main(String[] args) {
		try {
			// Set cross-platform Java L&F (also called "Metal")
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (Exception e) {
			// handle exception
			e.printStackTrace();
		}
		MyFirstChart myChart = new MyFirstChart();
		myChart.chart("Apples", "Oranges", "Donuts", 10, 18, 10);
	}

	public void chartMouseClicked(ChartMouseEvent chartMouseEvent) {
		String type = chartMouseEvent.getEntity().getToolTipText().substring(0,
				chartMouseEvent.getEntity().getToolTipText().indexOf(":"))
				.trim();

		if (type.compareTo("Apples") == 0) {
			chart("Red Apples", "Green Apples", "Yellow Apples", 12.2, 13.6,
					44.5);
		} else if (type.compareTo("Oranges") == 0) {
			chart("Florida Oranges", "California Oranges", "Local Oranges",
					22.2, 23.6, 24.5);
		} else if (type.compareTo("Donuts") == 0) {
			chart("Chocolate Frosted", "Apple Donuts", "Boston Creme", 22.2,
					33, 14.5);
		}
	}

	public void chartMouseMoved(ChartMouseEvent chartMouseEvent) {
	}
}