JavaFX 2.x : How to highlight plotted data on a chart?

Question

I would like to export (.txt or .cvs) data plotted on a graph by left mouse click, highlight it then right mouse click opens a pop-up then a file chooser dialog to save data

Here is a picture example

and here is a sample code

public class BaseXYChart extends Application {

@Override
public void start(Stage stage) {
   stage.setTitle("Linear plot");

   final CategoryAxis xAxis = new CategoryAxis();
   final NumberAxis yAxis = new NumberAxis(0, 22, 0.5);

   yAxis.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis){
        @Override
    public String toString(Number object){
        return String.format("%7.2f", object);
    }
});
final LineChart<String, Number>lineChart = new LineChart<String, Number>(xAxis, yAxis);

   lineChart.setCreateSymbols(false);
   lineChart.setAlternativeRowFillVisible(false);
   lineChart.setLegendVisible(false);

   XYChart.Series series1 = new XYChart.Series();

    series1.getData().add(new XYChart.Data("Jan", 1));
    series1.getData().add(new XYChart.Data("Feb", 1.5));
    series1.getData().add(new XYChart.Data("Mar", 2));
    series1.getData().add(new XYChart.Data("Apr", 2.5));
    series1.getData().add(new XYChart.Data("May", 3));
    series1.getData().add(new XYChart.Data("Jun", 4));
    series1.getData().add(new XYChart.Data("Jul", 6));
    series1.getData().add(new XYChart.Data("Aug", 9));
    series1.getData().add(new XYChart.Data("Sep", 12));
    series1.getData().add(new XYChart.Data("Oct", 15));
    series1.getData().add(new XYChart.Data("Nov", 20));
    series1.getData().add(new XYChart.Data("Dec", 22));

    BorderPane pane = new BorderPane();
    pane.setCenter(lineChart);          
    Scene scene = new Scene(pane, 800, 600);
    lineChart.getData().addAll(series1);

    stage.setScene(scene);
    stage.show();
}

public static void main(String[] args) {
    launch(args);
}   

}

My question is then how to do to select the line data plotted in order to then open a pop-up.

Thanks

Answer 1

Check the modified code of yours below out.

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Cursor;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.effect.DropShadow;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class BaseXYChart extends Application {

    private DropShadow ds = new DropShadow();

    private ContextMenu contextMenu;

    private XYChart.Series selectedSeries;

    @Override
    public void start(Stage stage) {
        stage.setTitle("Linear plot");

        final CategoryAxis xAxis = new CategoryAxis();
        final NumberAxis yAxis = new NumberAxis(0, 22, 0.5);

        yAxis.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis) {

            @Override
            public String toString(Number object) {
                return String.format("%7.2f", object);
            }
        });
        final LineChart<String, Number> lineChart = new LineChart<String, Number>(xAxis, yAxis);

        lineChart.setCreateSymbols(false);
        lineChart.setAlternativeRowFillVisible(false);
        lineChart.setLegendVisible(false);

        final XYChart.Series series1 = new XYChart.Series();

        series1.getData().add(new XYChart.Data("Jan", 1));
        series1.getData().add(new XYChart.Data("Feb", 1.5));
        series1.getData().add(new XYChart.Data("Mar", 2));
        series1.getData().add(new XYChart.Data("Apr", 2.5));
        series1.getData().add(new XYChart.Data("May", 3));
        series1.getData().add(new XYChart.Data("Jun", 4));
        series1.getData().add(new XYChart.Data("Jul", 6));
        series1.getData().add(new XYChart.Data("Aug", 9));
        series1.getData().add(new XYChart.Data("Sep", 12));
        series1.getData().add(new XYChart.Data("Oct", 15));
        series1.getData().add(new XYChart.Data("Nov", 20));
        series1.getData().add(new XYChart.Data("Dec", 22));

        BorderPane pane = new BorderPane();
        pane.setCenter(lineChart);
        Scene scene = new Scene(pane, 800, 600);
        lineChart.getData().addAll(series1);

        contextMenu = new ContextMenu();
        MenuItem menuItem = new MenuItem("Save data");
        contextMenu.getItems().add(menuItem);
        menuItem.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent arg0) {
                if (selectedSeries != null) {
                    System.out.println("Save data of " + selectedSeries.getData());
                    // Saving logic here
                }
            }
        });

        // for every series in linechart
        applyMouseEvents(series1);

        stage.setScene(scene);
        stage.show();
    }

    private void applyMouseEvents(final XYChart.Series series) {

        final Node node = series.getNode();

        node.setOnMouseEntered(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent arg0) {
                node.setEffect(ds);
                node.setCursor(Cursor.HAND);
            }
        });

        node.setOnMouseExited(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent arg0) {
                node.setEffect(null);
                node.setCursor(Cursor.DEFAULT);
            }
        });

        node.setOnMouseReleased(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent mouseEvent) {
                if (mouseEvent.getButton().equals(MouseButton.SECONDARY)) {
                    contextMenu.show(node, mouseEvent.getScreenX() + 1, mouseEvent.getScreenY() + 1);
                    // Set as selected
                    selectedSeries = series;
                    System.out.println("Selected Series data " + selectedSeries.getData());
                }
            }
        });
    }

    public static void main(String[] args) {
        launch(args);
    }
}