Center bars in a bar chart - javafx

Question

I modified the bar chart example of the Oracle website and reduced the bars to 1 per series. Unfortunately the bars aren't centered above the tick marks.
Does anyone know how to get the bars centered horizontally above the tick marks?
Here's the code:
public class BarChartDemo extends Application {
final static String austria = "Austria";
final static String brazil = "Brazil";
final static String france = "France";
#Override
public void start(Stage stage) {
stage.setTitle("Bar Chart Sample");
final CategoryAxis xAxis = new CategoryAxis();
final NumberAxis yAxis = new NumberAxis();
final BarChart<String, Number> bc = new BarChart<String, Number>(xAxis, yAxis);
bc.setTitle("Country Summary");
xAxis.setLabel("Country");
yAxis.setLabel("Value");
XYChart.Series series1 = new XYChart.Series();
series1.setName("2003");
series1.getData().add(new XYChart.Data(austria, 25601.34));
XYChart.Series series2 = new XYChart.Series();
series2.setName("2004");
series2.getData().add(new XYChart.Data(brazil, 41941.19));
XYChart.Series series3 = new XYChart.Series();
series3.setName("2005");
series3.getData().add(new XYChart.Data(france, 18722.18));
Scene scene = new Scene(bc, 800, 600);
bc.getData().addAll(series1, series2, series3);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
And this is how it looks like:
Thank you very much!

Answer 1

Problem
The problem with your BarChart is that you are adding 3 Series, but just one unique country in each of the series. The BarChart inherently leaves space for 2 other series.
Solution
The correct way of achieving this is using one XYChart.Series and later, add colors to each of the bars. Here is a sample application, which does the same.
public class BarChartDemo extends Application {
final static String austria = "Austria";
final static String brazil = "Brazil";
final static String france = "France";
#Override
public void start(Stage stage) {
stage.setTitle("Bar Chart Sample");
final CategoryAxis xAxis = new CategoryAxis();
final NumberAxis yAxis = new NumberAxis();
final BarChart<String, Number> bc = new BarChart<String, Number>(xAxis, yAxis);
bc.setTitle("Country Summary");
xAxis.setLabel("Country");
yAxis.setLabel("Value");
XYChart.Series series1 = new XYChart.Series();
series1.setName("2003");
final XYChart.Data<String, Number> dataAustria = new XYChart.Data(austria, 25601.34);
final XYChart.Data<String, Number> dataBrazil = new XYChart.Data(brazil, 41941.19);
final XYChart.Data<String, Number> dataFrance = new XYChart.Data(france, 35000.19);
series1.getData().add(dataAustria);
series1.getData().add(dataBrazil);
series1.getData().add(dataFrance);
Scene scene = new Scene(bc, 800, 600);
bc.getData().addAll(series1);
stage.setScene(scene);
stage.show();
dataAustria.getNode().setStyle("-fx-bar-fill: CHART_COLOR_1;");
dataBrazil.getNode().setStyle("-fx-bar-fill: CHART_COLOR_2;");
dataFrance.getNode().setStyle("-fx-bar-fill: CHART_COLOR_3;");
}
public static void main(String[] args) {
launch(args);
}
}
The output looks something that you are looking for:
Note : You need to apply style to the nodes after they have been displayed on the Stage. Alternatively, you can use xyChartData.nodeProperty().addListener() and apply style into it.
dataAustria.nodeProperty().addListener((ov, oldNode, newNode) -> {
if(null != newNode) {
newNode.setStyle("-fx-bar-fill: red;");
}
});