This code plots a LineChart upper pane and a bar Chart in lower pane.
There is also a vertical line plotted left/right X move with pointer.
I would like to extend this vertical line also to the lower subpane, such as the attached picture

How to accomplish this?
Thanks.
Here is the code
import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.geometry.Orientation;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.chart.*;
import javafx.scene.control.SplitPane;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.scene.shape.LineBuilder;
import javafx.stage.Stage;
public class XyChartInSplitOnlyCursor extends Application {
SplitPane splitPane1 = null;
BorderPane pane1;
BorderPane pane2;
Line LV;
XYChart.Series series1 = new XYChart.Series();
XYChart.Series series2 = new XYChart.Series();
@Override
public void start(Stage stage) {
stage.setTitle("Lines plot");
final NumberAxis xAxis = new NumberAxis(1, 12, 1);
final NumberAxis yAxis = new NumberAxis(0.53000, 0.53910, 0.0005);
xAxis.setAnimated(false);
xAxis.setScaleX(0);
yAxis.setAnimated(false);
yAxis.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis) {
@Override
public String toString(Number object) {
return String.format("%7.5f", object);
}
});
final LineChart<Number, Number> lineChart1 = new LineChart<Number, Number>(xAxis, yAxis);
lineChart1.setCreateSymbols(false);
lineChart1.setAlternativeRowFillVisible(false);
lineChart1.setAnimated(false);
lineChart1.setLegendVisible(false);
series1.getData().add(new XYChart.Data(1, 0.53185));
series1.getData().add(new XYChart.Data(2, 0.532235));
series1.getData().add(new XYChart.Data(3, 0.53234));
series1.getData().add(new XYChart.Data(4, 0.538765));
series1.getData().add(new XYChart.Data(5, 0.53442));
series1.getData().add(new XYChart.Data(6, 0.534658));
series1.getData().add(new XYChart.Data(7, 0.53023));
series1.getData().add(new XYChart.Data(8, 0.53001));
series1.getData().add(new XYChart.Data(9, 0.53589));
series1.getData().add(new XYChart.Data(10, 0.53476));
series1.getData().add(new XYChart.Data(11, 0.530123));
series1.getData().add(new XYChart.Data(12, 0.531035));
lineChart1.getData().addAll(series1);
pane1 = new BorderPane();
pane1.setCenter(lineChart1);
splitPane1 = new SplitPane();
splitPane1.setOrientation(Orientation.VERTICAL);
splitPane1.getItems().addAll(pane1);
splitPane1.setDividerPosition(0, 1);
final CategoryAxis xAxis2 = new CategoryAxis();
final NumberAxis yAxis2 = new NumberAxis();
yAxis2.setTickUnit(1);
yAxis2.setPrefWidth(35);
yAxis2.setMinorTickCount(10);
yAxis2.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis2){
@Override
public String toString(Number object){
String label;
label = String.format("%7.2f", object.floatValue());
return label;
}
});
final BarChart<String, Number>BarChart = new BarChart<String, Number>(xAxis2, yAxis2);
BarChart.setAlternativeRowFillVisible(false);
BarChart.setLegendVisible(false);
BarChart.setAnimated(false);
XYChart.Series series2 = new XYChart.Series();
series2.getData().add(new XYChart.Data("Jan", 1));
series2.getData().add(new XYChart.Data("Feb", 3));
series2.getData().add(new XYChart.Data("Mar", 1.5));
series2.getData().add(new XYChart.Data("Apr", 3));
series2.getData().add(new XYChart.Data("May", 4.5));
series2.getData().add(new XYChart.Data("Jun", 5));
series2.getData().add(new XYChart.Data("Jul", 4));
series2.getData().add(new XYChart.Data("Aug", 8));
series2.getData().add(new XYChart.Data("Sep", 16.5));
series2.getData().add(new XYChart.Data("Oct", 13.9));
series2.getData().add(new XYChart.Data("Nov", 17));
series2.getData().add(new XYChart.Data("Dec", 20));
BarChart.getData().addAll(series2);
pane2 = new BorderPane();
pane2.setCenter(BarChart);
Platform.runLater(new Runnable() {
@Override
public void run() {
double percSplit;
splitPane1.getItems().addAll(pane2);
ObservableList<SplitPane.Divider> splitDiv = splitPane1.getDividers();
percSplit = 1/(double)(splitDiv.size()+1);
for (int i = 0; i< splitDiv.size(); i++) {
splitPane1.setDividerPosition(i, percSplit);
percSplit += 1/(double)(splitDiv.size()+1);
}
}
});
Scene scene = new Scene(splitPane1, 800, 600);
stage.setScene(scene);
pane1.setOnMouseMoved(mouseHandler);
LV=LineBuilder.create()
.startX(0)
.startY(0)
.endX(10)
.endY(.535)
.strokeWidth(1)
.stroke(Color.BLACK)
.build();
pane1.getChildren().add(LV);
stage.show();
}
EventHandler<MouseEvent> mouseHandler = new EventHandler<MouseEvent>() {
@Override
public void handle(MouseEvent mouseEvent) {
if (mouseEvent.getEventType() == MouseEvent.MOUSE_MOVED) {
LineChart<Number, Number> lineChart = (LineChart<Number, Number>) pane1.getCenter();
NumberAxis yAxis = (NumberAxis) lineChart.getYAxis();
NumberAxis xAxis = (NumberAxis) lineChart.getXAxis();
double newXlower=xAxis.getLowerBound(), newXupper=xAxis.getUpperBound();
double xAxisShift = getSceneShift(xAxis);
double yAxisShift = getSceneShift(yAxis);
if(mouseEvent.getX()>xAxisShift && mouseEvent.getX()<xAxisShift+xAxis.getWidth()){
LV.setStartX(mouseEvent.getX());
LV.setStartY(yAxisShift);
LV.setEndX(mouseEvent.getX());
LV.setEndY(yAxisShift+yAxis.getHeight());
}
}
}
};
private static double getSceneShift(Node node) {
double shift = 0;
do {
shift += node.getLayoutX();
node = node.getParent();
} while (node != null);
return shift;
}
public static void main(String[] args) {
launch(args);
}
}
Edit: added picture after jewelsea modify

Don’t add the line to the pane in the SplitPane, instead create a Group which layers the line over the SplitPane.
If you want the Scene resizable, you can use a StackPane instead of a Group and bind the lines length to the scene height to get it to fill the Scene.
Here is a sample of applying using a StackPane and binding to extend the line in a resizable scene. Note, similarly to the originally posted code, the code is explicitly coded to only move the line when the mouse is inside the plot area of the top chart.