Feature data point labels in line plot

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/AbstractExtendedChart.java

@@ -10,6 +10,7 @@
  * Contributors:
  * Philip Wenig - initial API and implementation
  * Frank Buloup - Internationalization
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
@@ -394,6 +395,7 @@ public ISeries<?> createSeries(ISeriesData seriesData, ISeriesSettings seriesSet
 				 */
 				double[] xSeries = seriesData.getXSeries();
 				double[] ySeries = seriesData.getYSeries();
+				String[] labels = seriesData.getLabels();
 
 				if(xSeries.length == ySeries.length) {
 					/*
@@ -405,6 +407,9 @@ public ISeries<?> createSeries(ISeriesData seriesData, ISeriesSettings seriesSet
 					ISeries<?> series = seriesSet.createSeries(seriesType, id);
 					series.setXSeries(xSeries);
 					series.setYSeries(ySeries);
+					if(labels != null) {
+						series.setLabels(labels);
+					}
 					calculateCoordinates(series);
 					return series;
 				} else {

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/ChartSettings.java

@@ -10,6 +10,7 @@
  * Contributors:
  * Philip Wenig - initial API and implementation
  * Frank Buloup - Internationalization
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
@@ -105,6 +106,7 @@ public class ChartSettings implements IChartSettings {
 	private boolean showAxisZeroMarker = false;
 	private Color colorAxisZeroMarker;
 	private boolean showSeriesLabelMarker = false;
+	private boolean showSeriesDataPointLabelMarker = false;
 	private Color colorSeriesLabelMarker;
 
 	private boolean createMenu = true;
@@ -609,6 +611,18 @@ public void setShowSeriesLabelMarker(boolean showSeriesLabelMarker) {
 		this.showSeriesLabelMarker = showSeriesLabelMarker;
 	}
 
+	@Override
+	public boolean isShowSeriesDataPointLabelMarker() {
+
+		return showSeriesDataPointLabelMarker;
+	}
+
+	@Override
+	public void setShowSeriesDataPointLabelMarker(boolean showSeriesDataPointLabelMarker) {
+
+		this.showSeriesDataPointLabelMarker = showSeriesDataPointLabelMarker;
+	}
+
 	@Override
 	public Color getColorSeriesLabelMarker() {
 

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/IChartSettings.java

@@ -8,7 +8,8 @@
  * SPDX-License-Identifier: EPL-2.0
  * 
  * Contributors:
- * Dr. Philip Wenig - initial API and implementation
+ * Philip Wenig - initial API and implementation
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
@@ -179,6 +180,10 @@ public interface IChartSettings {
 
 	void setShowSeriesLabelMarker(boolean showSeriesLabelMarker);
 
+	boolean isShowSeriesDataPointLabelMarker();
+
+	void setShowSeriesDataPointLabelMarker(boolean showSeriesDataPointLabelMarker);
+
 	boolean isUseSeriesLabelDescription();
 
 	void setUseSeriesLabelDescription(boolean useSeriesLabelDescription);

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/ISeriesData.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2017, 2019 Lablicate GmbH.
+ * Copyright (c) 2017, 2025 Lablicate GmbH.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -8,7 +8,8 @@
  * SPDX-License-Identifier: EPL-2.0
  * 
  * Contributors:
- * Dr. Philip Wenig - initial API and implementation
+ * Philip Wenig - initial API and implementation
+ * Lorenz Gerber - add DataPoint labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
@@ -18,5 +19,7 @@ public interface ISeriesData {
 
 	double[] getYSeries();
 
+	String[] getLabels();
+
 	String getId();
 }

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/ScrollableChart.java

@@ -12,6 +12,7 @@
  * Christoph Läubrich - rework redraw of the plot area, enhance menu item handling
  * Frank Buloup - Internationalization
  * Himanshu Balasamanta - Circular charts
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
@@ -78,6 +79,7 @@
 import org.eclipse.swtchart.extensions.internal.marker.LegendMarker;
 import org.eclipse.swtchart.extensions.internal.marker.PlotCenterMarker;
 import org.eclipse.swtchart.extensions.internal.marker.PositionMarker;
+import org.eclipse.swtchart.extensions.internal.marker.SeriesDataPointLabelMarker;
 import org.eclipse.swtchart.extensions.internal.marker.SeriesLabelMarker;
 import org.eclipse.swtchart.extensions.internal.marker.UserRestrictionMarker;
 import org.eclipse.swtchart.extensions.linecharts.LineChart;
@@ -124,6 +126,7 @@ public class ScrollableChart extends Composite implements IScrollableChart, IEve
 	private LegendMarker legendMarker;
 	private AxisZeroMarker axisZeroMarker;
 	private SeriesLabelMarker seriesLabelMarker;
+	private SeriesDataPointLabelMarker seriesDataPointLabelMarker;
 	private UserRestrictionMarker userRestrictionMarker;
 	/*
 	 * Integer.MAX_VALUE doesn't work under Windows.
@@ -814,6 +817,7 @@ private void setCustomPaintListener() {
 		setLegendMarker();
 		setAxisZeroMarker();
 		setSeriesLabelMarker();
+		setSeriesDataPointLabelMarker();
 		setUserRestrictionMarker();
 	}
 
@@ -918,6 +922,26 @@ private void setSeriesLabelMarker() {
 		}
 	}
 
+	private void setSeriesDataPointLabelMarker() {
+
+		IPlotArea plotArea = baseChart.getPlotArea();
+		IChartSettings chartSettings = baseChart.getChartSettings();
+
+		if(seriesDataPointLabelMarker != null) {
+			plotArea.removeCustomPaintListener(seriesDataPointLabelMarker);
+		}
+
+		seriesDataPointLabelMarker = new SeriesDataPointLabelMarker(baseChart);
+		seriesDataPointLabelMarker.setForegroundColor(chartSettings.getColorSeriesLabelMarker());
+		plotArea.addCustomPaintListener(seriesDataPointLabelMarker);
+
+		if(chartSettings.isShowSeriesDataPointLabelMarker()) {
+			seriesDataPointLabelMarker.setDraw(true);
+		} else {
+			seriesDataPointLabelMarker.setDraw(false);
+		}
+	}
+
 	private void setUserRestrictionMarker() {
 
 		IPlotArea plotArea = baseChart.getPlotArea();

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/core/SeriesData.java

@@ -8,14 +8,16 @@
  * SPDX-License-Identifier: EPL-2.0
  * 
  * Contributors:
- * Dr. Philip Wenig - initial API and implementation
+ * Philip Wenig - initial API and implementation
+ * Lorenz Gerber - add datapoint labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.core;
 
 public class SeriesData implements ISeriesData {
 
 	private double[] xSeries;
 	private double[] ySeries;
+	private String[] labels;
 	private String id;
 
 	/**
@@ -51,6 +53,10 @@ public SeriesData(double[] ySeries, int xStart, String id) {
 		for(int i = 0; i < ySeries.length; i++) {
 			xSeries[i] = xStart++;
 		}
+
+		for(int i = 0; i < ySeries.length; i++) {
+			labels[i] = Integer.toString(xStart++);
+		}
 	}
 
 	/**
@@ -71,6 +77,28 @@ public SeriesData(double[] xSeries, double[] ySeries, String id) {
 		this.id = id;
 	}
 
+	/**
+	 * sets the series
+	 * 
+	 * @param xSeries
+	 * @param ySeries
+	 * @param labels
+	 * @param id
+	 */
+	public SeriesData(double[] xSeries, double[] ySeries, String[] labels, String id) {
+
+		assert (xSeries != null);
+		assert (ySeries != null);
+		assert (labels != null);
+		assert (id != null);
+
+		this.xSeries = xSeries;
+		this.ySeries = ySeries;
+		this.labels = labels;
+		this.id = id;
+
+	}
+
 	@Override
 	public double[] getXSeries() {
 
@@ -83,6 +111,12 @@ public double[] getYSeries() {
 		return ySeries;
 	}
 
+	@Override
+	public String[] getLabels() {
+
+		return labels;
+	}
+
 	@Override
 	public String getId() {
 

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/internal/marker/SeriesDataPointLabelMarker.java

@@ -0,0 +1,71 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Lablicate GmbH.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ * 
+ * Contributors:
+ * Lorenz Gerber - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swtchart.extensions.internal.marker;
+
+import org.eclipse.swt.events.PaintEvent;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swtchart.ISeries;
+import org.eclipse.swtchart.ISeriesSet;
+import org.eclipse.swtchart.extensions.core.BaseChart;
+import org.eclipse.swtchart.extensions.core.IPointSeriesSettings;
+import org.eclipse.swtchart.extensions.core.ISeriesSettings;
+import org.eclipse.swtchart.extensions.marker.AbstractBaseChartPaintListener;
+import org.eclipse.swtchart.extensions.marker.IBaseChartPaintListener;
+
+public class SeriesDataPointLabelMarker extends AbstractBaseChartPaintListener implements IBaseChartPaintListener {
+
+	public SeriesDataPointLabelMarker(BaseChart baseChart) {
+
+		super(baseChart);
+	}
+
+	@Override
+	public void paintControl(PaintEvent e) {
+
+		if(isDraw()) {
+			if(isDraw()) {
+				BaseChart baseChart = getBaseChart();
+				ISeriesSet seriesSet = baseChart.getSeriesSet();
+				ISeries<?>[] series = seriesSet.getSeries();
+				for(ISeries<?> serie : series) {
+					String id = serie.getId();
+					/*
+					 * get label series here
+					 */
+					String[] labels = serie.getLabels();
+					ISeriesSettings seriesSettings = baseChart.getSeriesSettings(id);
+					if(seriesSettings.isVisible()) {
+						/*
+						 * Only draw is series is visible.
+						 */
+						int symbolSize = 1;
+						if(seriesSettings instanceof IPointSeriesSettings) {
+							symbolSize = ((IPointSeriesSettings)seriesSettings).getSymbolSize();
+						}
+						/*
+						 * Draw the label
+						 */
+						e.gc.setForeground(getForegroundColor());
+						for(int i = 0; i < serie.getXSeries().length; i++) {
+							Point point = serie.getPixelCoordinates(i);
+							if(labels != null && labels.length != 0) {
+								Point labelSize = e.gc.textExtent(labels[i]);
+								e.gc.drawText(labels[i], (int)(point.x - labelSize.x / 2.0d), (int)(point.y - labelSize.y - symbolSize / 2.0d), true);
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}

org.eclipse.swtchart.extensions/src/org/eclipse/swtchart/extensions/piecharts/CircularSeriesLegend.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2023 Lablicate GmbH.
+ * Copyright (c) 2023, 2025 Lablicate GmbH.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -9,6 +9,7 @@
  * 
  * Contributors:
  * Philip Wenig - initial API and implementation
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart.extensions.piecharts;
 
@@ -85,4 +86,10 @@ public void setNodeDataModel(NodeDataModel nodeDataModel) {
 
 		this.nodeDataModel = nodeDataModel;
 	}
+
+	@Override
+	public void setLabels(String[] labels) {
+		// Not implemented yet
+
+	}
 }

org.eclipse.swtchart/src/org/eclipse/swtchart/ISeries.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2023 SWTChart project.
+ * Copyright (c) 2008, 2025 SWTChart project.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -12,6 +12,7 @@
  * Christoph Läubrich - add support for datamodel
  * Frank Buloup - Internationalization
  * Philip Wenig - refactoring type model
+ * Lorenz Gerber - DataPoint Labels
  *******************************************************************************/
 package org.eclipse.swtchart;
 
@@ -136,6 +137,16 @@ public String label() {
 	 */
 	void setYSeries(double[] series);
 
+	/**
+	 * This is a legacy/convenient method to create series.
+	 * Sets the Data Point Label series.
+	 * A DoubleArraySeriesModel will be created.
+	 * 
+	 * @param labels
+	 *            the Data Point series
+	 */
+	void setLabels(String[] labels);
+
 	@Deprecated
 	void setXDateSeries(Date[] series);
 
@@ -165,6 +176,16 @@ public String label() {
 	 */
 	double[] getYSeries();
 
+	/**
+	 * This is a legacy/convenient method.
+	 * Gets the Data Point Label series. If the Data Point Label series haven't been set yet, empty array will be
+	 * returned.
+	 * Better use getDataModel() to retrieve the data point labels array.
+	 * 
+	 * @return the data point label series
+	 */
+	String[] getLabels();
+
 	/**
 	 * Set the model for this series
 	 *