Pie Charts

Description

Pie charts are often used to display percentage data.

Types

• Pie Chart
• Doughnut Chart
• Multilevel Pie Chart
• Multilevel Doughnut Chart

Example

	public Chart createChart(Composite parent) {

		double[] values = {337309, 131646, 128948, 100123, 81708, 70478, 58226, 47806, 4067, 265783};
		String[] labels = {"USA", "Spain", "Italy", "Germany", "China", "France", "Iran", "UK", "India", "Other"};

		Chart chart = new Chart(parent, SWT.NONE);
		chart.getTitle().setText("Doughnut Chart");
		ICircularSeries<?> circularSeries = (ICircularSeries<?>)chart.getSeriesSet().createSeries(SeriesType.DOUGHNUT, "pie series");
		circularSeries.setSeries(labels, values);
		Color color = Display.getDefault().getSystemColor(SWT.COLOR_DARK_RED);
		circularSeries.setColor("India", color);
		//
		return chart;
	}

ReadyMade APIs

• SWTChart Basic
• SWTChart Extensions
• SWTChart Parallel Pie Charts

Basic

org.eclipse.swtchart

Pie Charts and Doughnut Charts in the SWTChart bundle support building single level and MultiLevel Charts.

Initializing

    Chart chart = new Chart(parent, SWT.NONE);
	chart.getTitle().setText("Title");

The only point where the APIs for Pie Chart and Doughnut Chart differ is this.

Pie Charts

	ICircularSeries<?> circularSeries = (ICircularSeries<?>)chart.getSeriesSet().createSeries(SeriesType.PIE, "series title here");

Doughnut Charts

	ICircularSeries<?> circularSeries = (ICircularSeries<?>)chart.getSeriesSet().createSeries(SeriesType.DOUGHNUT, "series title here");

Setting Data

Set the base series

    circularSeries.setSeries(String[] labels, double[] values);

Error is thrown if labels.length != values.length

Set the children of any element.

    circularSeries.getNodeById("Element Label").addChildren(String[] childrenLabels, double  childrenValues);

Set settings

Change color of a node

    circularSeries.setColor("Label of Node", Color color);

Highlight a node

    multiLevelPie.setHighlightedNode(multiLevelPie.getNodeById("Label"));

Set the highlight settings

    circularSeries.setHighlightLineWidth(int width);
    circularSeries.setHighlightColor(Color color);

Border settings

    circularSeries.setBorderStyle(int borderStyle);
    circularSeries.setBorderWidth(int borderWidth);
    circularSeries.setBorderColor(Color color);

Use the same data for different circular chart

    circularSeries.setDataModel(IdNodeDataModel data);
    circularSeries.getModel();

Get the node from the position

    circularSeries.getPieSliceFromPosition(int x, int y);

Extensions

org.eclipse.swtchart.extensions

Initialize

For both Pie Chart and Doughnut Chart,

    PieChart circularChart = new PieChart(Composite parent, int style);

Set Data

    ICircularSeriesData circularSeriesData = new CircularSeriesData();
    circularSeriesData.setSeries(String[] labels, double[] values);
    circularSeriesData.getNodeById("Element Label").addChildren(String[] childrenLabels, double  childrenValues);

Set the settings, before applying the data to the chart

    circularChart.addSeriesData(circularSeriesData);

Set Series Settings

    ICircularSettings circularSettings = circularSeriesData.getSettings();

Set SeriesType

    circularSettings.setSeriesType(SeriesType type);

setting to render chart dynamically

    circularSettings.setRedrawOnClick(boolean setRedrawOnClick);
    // set true to render chart dynamically. If false, will highlight the node on click.

when false

on clicking on Asia

when true

on clicking Asia

setting to maximise the space utilised by the charts

    circularSettings.setFillEntireSpace(boolean fillEntireSpace);
    //set true to enable

Set Chart Settings

	IChartSettings chartSettings = getChartSettings();

Set tooltip

Displays data of the node on hover.

    chartSettings.setShowLegendMarker(boolean showLegendMarker);

Parallel Pie Charts

Initialization

    ParallelPieCharts(Composite parent, SeriesType type, boolean redraw);

• SeriesType is SeriesType.PIE for Pie Charts, SeriesType.Doughnut for Doughnut Charts
• The third Parameter is true if dynamically the charts need to be redrawn, else they will be highlighted in sync.

Data Series

Each chart is drawn separately, but are in sync with each other. The APIs cover all the functionalities that individual Pie Charts can offer.

Single Level parallel Pies

    addPieChartSeries(String labels[], double val[][]);

• The first argument denotes the label of each pie slice of a chart.
• The size of the second argument is same as that of the first, and each of the element is the list of values the label string in the corresponding first argument will take in the charts. (Same as in Linux Pie Chart Tools)

Multi-level parallel pies

    addChild(String parentId, String childId, double[] vals);

• The first argument is the label of the Pie Slice to which we are adding the Child
• The second argument is the label of the node we wish to introduce into the charts
• The third argument is the list of values that the node takes in all the charts.

Setting Chart Titles

    setChartTitles(String[] titles);

• Sets the titles of the charts