JFreechart light chart - weird drag and drop behavior

Question

This is the next question from this question .

The following happens:

When I start the chart, and I drag the chart around, something strange happens: after a certain period of time every 7 periods, the candlesticks become smaller and smaller, until they are just a strip. Then, as I stretch further, they become thicker again until they become normal. It seems to happen every 7 periods.

An example of this phenomenon is displayed in the following 3 pictures:

The following code will show exactly what I mean. Just compile and run it. Then press and hold CTRL and click and hold on the chart. Now try dragging the chart to the right or left. After some “drag and drop” you will notice an error.

My question is: how to prevent / trick this?

the code:

  import org.jfree.chart.*; import org.jfree.chart.axis.*; import org.jfree.chart.plot.XYPlot; import org.jfree.chart.renderer.xy.CandlestickRenderer; import org.jfree.data.xy.*; import javax.swing.*; import java.awt.*; import java.io.*; import java.net.URL; import java.text.*; import java.util.*; import java.util.List; public class CandlestickDemo2 extends JFrame { public CandlestickDemo2(String stockSymbol) { super("CandlestickDemo"); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); DateAxis domainAxis = new DateAxis("Date"); NumberAxis rangeAxis = new NumberAxis("Price"); CandlestickRenderer renderer = new CandlestickRenderer(); XYDataset dataset = getDataSet(stockSymbol); XYPlot mainPlot = new XYPlot(dataset, domainAxis, rangeAxis, renderer); //Do some setting up, see the API Doc renderer.setSeriesPaint(0, Color.BLACK); renderer.setDrawVolume(false); rangeAxis.setAutoRangeIncludesZero(false); domainAxis.setTimeline( SegmentedTimeline.newMondayThroughFridayTimeline() ); //Now create the chart and chart panel JFreeChart chart = new JFreeChart(stockSymbol, null, mainPlot, false); ChartPanel chartPanel = new ChartPanel(chart, false); chartPanel.setPreferredSize(new Dimension(600, 300)); mainPlot.setDomainPannable(true); mainPlot.setRangePannable(true); this.add(chartPanel); this.pack(); } protected AbstractXYDataset getDataSet(String stockSymbol) { //This is the dataset we are going to create DefaultOHLCDataset result = null; //This is the data needed for the dataset OHLCDataItem[] data; //This is where we go get the data, replace with your own data source data = getData(stockSymbol); //Create a dataset, an Open, High, Low, Close dataset result = new DefaultOHLCDataset(stockSymbol, data); return result; } //This method uses yahoo finance to get the OHLC data protected OHLCDataItem[] getData(String stockSymbol) { List<OHLCDataItem> dataItems = new ArrayList<OHLCDataItem>(); try { String strUrl= "http://ichart.yahoo.com/table.csv?s=GOOG&a=2&b=1&c=2013&d=4&e=24&f=2013&g=d&ignore=.csv"; URL url = new URL(strUrl); BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream())); DateFormat df = new SimpleDateFormat("yMd"); String inputLine; in.readLine(); while ((inputLine = in.readLine()) != null) { StringTokenizer st = new StringTokenizer(inputLine, ","); Date date = df.parse( st.nextToken() ); double open = Double.parseDouble( st.nextToken() ); double high = Double.parseDouble( st.nextToken() ); double low = Double.parseDouble( st.nextToken() ); double close = Double.parseDouble( st.nextToken() ); double volume = Double.parseDouble( st.nextToken() ); double adjClose = Double.parseDouble( st.nextToken() ); OHLCDataItem item = new OHLCDataItem(date, open, high, low, close, volume); dataItems.add(item); } in.close(); } catch (Exception e) { e.printStackTrace(); } //Data from Yahoo is from newest to oldest. Reverse so it is oldest to newest Collections.reverse(dataItems); //Convert the list into an array OHLCDataItem[] data = dataItems.toArray(new OHLCDataItem[dataItems.size()]); return data; } public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { new CandlestickDemo2("GOOG").setVisible(true); } }); } } 

Update

This error is now a registered error on the sourceforge JFreeChart page.

This error can be tracked here .

Answer 1

I can reproduce the described effect. As before, the effect appears only with SegmentedTimeline ; this is not obvious with DefaultTimeline . It seems that it accompanies the drag and drop of the "hidden" days off from Monday to Friday, but I do not see an obvious error.

One way to solve the problem may be to select a TimeLine user using an adjacent control, as suggested in this. Since DefaultTimeline is private , you must save the result from getTimeline() to calling setTimeline() in the control's handler.

Appendix: Here is a variation of the program that uses the JCheckBox to switch TimeLine . Check the box to enable SegmentedTimeline ; pan horizontally to see the effect (right-click on Windows, right-click on Mac).

 import org.jfree.chart.*; import org.jfree.chart.axis.*; import org.jfree.chart.plot.XYPlot; import org.jfree.chart.renderer.xy.CandlestickRenderer; import org.jfree.data.xy.*; import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.io.*; import java.net.URL; import java.text.*; import java.util.*; import java.util.List; /** * @see https://stackoverflow.com/a/18421887/230513 * @see http://www.jfree.org/forum/viewtopic.php?f=10&t=24521 */ public class CandlestickDemo2 extends JFrame { public CandlestickDemo2(String stockSymbol) { super("CandlestickDemo2"); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); final DateAxis domainAxis = new DateAxis("Date"); NumberAxis rangeAxis = new NumberAxis("Price"); CandlestickRenderer renderer = new CandlestickRenderer(); XYDataset dataset = getDataSet(stockSymbol); XYPlot mainPlot = new XYPlot(dataset, domainAxis, rangeAxis, renderer); //Do some setting up, see the API Doc renderer.setSeriesPaint(0, Color.BLACK); renderer.setDrawVolume(false); rangeAxis.setAutoRangeIncludesZero(false); //Now create the chart and chart panel JFreeChart chart = new JFreeChart(stockSymbol, null, mainPlot, false); ChartPanel chartPanel = new ChartPanel(chart, false); chartPanel.setPreferredSize(new Dimension(600, 300)); mainPlot.setDomainPannable(true); mainPlot.setRangePannable(true); this.add(chartPanel); // Add tiemline toggle final Timeline oldTimeline = domainAxis.getTimeline(); final Timeline newTimeline = SegmentedTimeline.newMondayThroughFridayTimeline(); this.add(new JCheckBox(new AbstractAction("Segmented Timeline") { @Override public void actionPerformed(ActionEvent e) { JCheckBox jcb = (JCheckBox) e.getSource(); if (jcb.isSelected()) { domainAxis.setTimeline(newTimeline); } else { domainAxis.setTimeline(oldTimeline); } } }), BorderLayout.SOUTH); this.pack(); this.setLocationRelativeTo(null); } private AbstractXYDataset getDataSet(String stockSymbol) { //This is the dataset we are going to create DefaultOHLCDataset result; //This is the data needed for the dataset OHLCDataItem[] data; //This is where we go get the data, replace with your own data source data = getData(stockSymbol); //Create a dataset, an Open, High, Low, Close dataset result = new DefaultOHLCDataset(stockSymbol, data); return result; } //This method uses yahoo finance to get the OHLC data protected OHLCDataItem[] getData(String stockSymbol) { List<OHLCDataItem> dataItems = new ArrayList<OHLCDataItem>(); try { String strUrl = "http://ichart.yahoo.com/table.csv?s=" + stockSymbol + "&a=4&b=1&c=2013&d=6&e=1&f=2013&g=d&ignore=.csv"; URL url = new URL(strUrl); BufferedReader in = new BufferedReader( new InputStreamReader(url.openStream())); DateFormat df = new SimpleDateFormat("yMd"); String inputLine; in.readLine(); while ((inputLine = in.readLine()) != null) { StringTokenizer st = new StringTokenizer(inputLine, ","); Date date = df.parse(st.nextToken()); double open = Double.parseDouble(st.nextToken()); double high = Double.parseDouble(st.nextToken()); double low = Double.parseDouble(st.nextToken()); double close = Double.parseDouble(st.nextToken()); double volume = Double.parseDouble(st.nextToken()); double adjClose = Double.parseDouble(st.nextToken()); OHLCDataItem item = new OHLCDataItem(date, open, high, low, close, volume); dataItems.add(item); } in.close(); } catch (Exception e) { e.printStackTrace(System.err); } //Data from Yahoo is from newest to oldest. Reverse so it is oldest to newest Collections.reverse(dataItems); //Convert the list into an array OHLCDataItem[] data = dataItems.toArray(new OHLCDataItem[dataItems.size()]); return data; } public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { new CandlestickDemo2("AAPL").setVisible(true); } }); } }