import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

import java.util.Random;

public class Main extends Application {

    @Override
    public void start(final Stage primaryStage) throws Exception{

        final LineChart lineChart = new LineChart(new NumberAxis(), new NumberAxis());
        final XYChart.Series<Integer, Integer> series = new XYChart.Series<Integer, Integer>();
        ObservableList<XYChart.Series<Integer, Integer>> seriesDataSet = FXCollections.observableArrayList();

        lineChart.setAnimated(false);
        lineChart.setPrefWidth(800);
        lineChart.setPrefHeight(600);
        seriesDataSet.add(series);
        lineChart.setData(seriesDataSet);

        for (int n = 0; n < 50; ++n) {
            series.getData().add(new XYChart.Data<Integer, Integer>(n, new Random().nextInt(20)));
        }

        Pane pane = new Pane();
        pane.getChildren().add(lineChart);

        primaryStage.setScene(new Scene(pane, 800, 600));
        primaryStage.show();

        // Get a display
        System.out.println(lineChart.getXAxis().getDisplayPosition(2));
        // The value is now correct and different from the previous one
        System.out.println(lineChart.getXAxis().getDisplayPosition(2));

        // Add data to the chart
        for (int n = 51; n < 80; ++n) {
            series.getData().add(new XYChart.Data<Integer, Integer>(n, new Random().nextInt(20)));
        }

        // Get a display
        System.out.println(lineChart.getXAxis().getDisplayPosition(2));
        // The value is now correct and different from the previous one
        System.out.println(lineChart.getXAxis().getDisplayPosition(2));

        pane.setOnMouseClicked(new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent mouseEvent) {
                System.out.println(lineChart.getXAxis().getDisplayPosition(2));
            }
        });
    }


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