Series: Provide Data

• Aug 27, 2019
• 4 minutes to read

Series use Data interfaces to interact with their data sources. This allows you to provide data point parameters from your data sets.

Note that different series types use different data interfaces. A Pie series uses the PieSeriesData interface and a Cartesian series uses interfaces that extend the XYSeriesData interface. Besides, different Cartesian series should use different base interface descendants, because series visualize different value numbers. Additionally, a Cartesian series should use a data interface compatible with an X-axis type; otherwise the chart does not plot the series.

Below is a table of interfaces’ use cases.

Data Interface	Compatible X-Axis	Used in Series	Argument/Label Type	Values
PieSeriesData	None	Pie series	java.lang.String	Value
QualitativeSeriesData	QualitativeAxisX	Common Cartesian series	java.lang.String	Value
WeightedQualitativeSeriesData	QualitativeAxisX	The Bubble series	java.lang.String	Value, Weight
NumericSeriesData	NumericAxisX	Common Cartesian series	double	Value
WeightedNumericSeriesData	NumericAxisX	The Bubble series	double	Value, Weight
DateTimeSeriesData	DateTimeAxisX	Common Cartesian series	java.util.Date	Value
WeightedDateTimeSeriesData	DateTimeAxisX	The Bubble series	java.util.Date	Value, Weight
FinancialSeriesData	DateTimeAxisX	Financial series	java.util.Date	Open, High, Low, Close

The following sections explain how to perform typical data providing scenarios.

How to: Provide series data

The following code snippet demonstrates how to implement a NumericSeriesData interface:

Java

class GdpData implements NumericSeriesData {
    private List<Gdp> gdps = new ArrayList<>();

    public  GdpData(Gdp... points) { for (Gdp point : points) gdps.add(point); }

    @Override
    public int getDataCount() { return gdps.size(); }

    @Override
    public double getArgument(int i) { return gdps.get(i).getYear(); }

    @Override
    public double getValue(int i) { return gdps.get(i).getProduct(); }
}
class Gdp {
      int mYear;
      double mProduct;
      public Gdp(int year, double product) { mYear = year; mProduct = product; }
      public int getYear() { return mYear; }
      public double getProduct() { return mProduct; }
}
// ...
Series line = new LineSeries();
line.setData(new GdpData(gdps));
mChart.addSeries(line);
// ...

C#

public class GdpData : Java.Lang.Object, INumericSeriesData {
    List<Gdp> gdps;
    public int DataCount { get { return gdps.Count; } }
    public SimpleDateTimeDataAdapter(List<Gdp> gdps) {
        this.gdps = gdps;
    }
    public double GetArgument(int i) {
        return gdps[i].Year;
    } 
    public double GetValue(int i) {
        return gdps[i].Product;
    }
}
public class Gdp {
      public int Year { get; set; }
      public double Product { get; set; }
      public Gdp(int year, double product) { this.Year = year; this.Product = product; }
}
//...
Series lineSeries = new LineSeries();
lineSeries.Data = new GdpData(gdps);
chart.AddSeries(lineSeries);
//...

Symbols required to specify data.

Symbol	Description
PieSeries.getData()	Returns the Pie series‘s data.
PieSeries.setData(PieSeriesData)	Specifies the Pie series‘s data.
Series.getData()	Returns the Cartesian series‘s data.
Series.setData(XYSeriesData)	Specifies the Cartesian series‘s data.

How to: Update series data on a data source change

Your data class should implement the optional ChangeableSeriesData interface that allows you to send redraw requests to a chart when data changes:

Java

class GdpData implements NumericSeriesData, ChangeableSeriesData {
    private List<Gdp> mGdps = new ArrayList<>();
    private List<SeriesDataChangedListener> mListeners = new ArrayList<>();

    public  GdpData(Gdp... points) {
        for (Gdp point : points) mGdps.add(point);
    }

    public void addGdp(Gdp point) {
        mGdps.add(point);
        // Notify all listeners about data changes.
        for (SeriesDataChangedListener listener : mListeners) {
            listener.onItemAdded();
        }
    }

    @Override
    public int getDataCount() { return mGdps.size(); }

    @Override
    public double getArgument(int i) { return mGdps.get(i).getYear(); }

    @Override
    public double getValue(int i) { return mGdps.get(i).getProduct(); }

 // The add and remove methods below allow to configure the notification listener set. 
    @Override
    public void addChangedListener(SeriesDataChangedListener dataChangedListener) {
        mListeners.add(dataChangedListener);
    }

    @Override
    public void removeChangedListener(SeriesDataChangedListener dataChangedListener) {
        mListeners.remove(dataChangedListener);
    }
}

// ...
// The chart starts to listen to notifications automatically.
Series line = new LineSeries();
line.setData(new GdpData(gdps));
mChart.addSeries(line);
// ...

C#

public class GdpData : Java.Lang.Object, INumericSeriesData, IChangeableSeriesData {
    List<Gdp> gdps;
    ISeriesDataChangedListener listener;

    public GdpData(List<Gdp> gdps) {
        this.gdps = gdps;
    }
    public void Add(Gdp point) {
        gdps.Add(point);
        // Notify the listener about data changes.
        if (listener != null) {
            listener.OnItemAdded();
        }
    }      
    public int DataCount {
        get {
            return gdps.Count;
        }
    }
    public double GetArgument(int p0) {
        return gdps[p0].Year;
    }   
    public double GetValue(int p0) {
        return gdps[p0].Product;
    }        
    // The add and remove methods below allow to configure the notification listener set. 
    public void AddChangedListener(ISeriesDataChangedListener p0) {
        listener = p0;
    }       
    public void RemoveChangedListener(ISeriesDataChangedListener p0) {
        if (listener == p0) {
            listener = null;
        }
    }
}
//...
// The chart starts to listen to notifications automatically.
Series line = new LineSeries();
line.Data = new GdpData(gdps);
chart.AddSeries(line);
//...

The code above uses the following symbols:

Symbol	Description
ChangeableSeriesData	The interface that should be implemented by the data adapter notifying a chart about data changes.