JavaFX XYChart's weird behaviour on replacing all series - javafx

Question

once again, I scratch my head while working with JavaFX-Charts... :-(
I have a usecase for which I need to replace all series in the chart, I create everything from scratch. When adding after clearing the previous data, the chart assigns the wrong style-classes for default-color to some of the added series...
More precisely, the assigned class-numbers get shifted... why on earth did they implement that with modulo, which by default limits to only 8 (!) different color-symbol-combinations...?!
The first 8 (hint: mod 8...) default-colors are correct:
default-color0
...
default-color7
and for the first run, it continues, also correct, again with 0:
default-color0
...
default-color6 (for 15 series in my example)
for the second run, I get:
default-color0
...
default-color7
default-color7 <-- shift from here
default-color0
...
default-color5
as you can see, the it is shifted, having two times 7 and then only running until 5.
For another run, the shift continues:
default-color0
...
default-color7
default-color6 <-- shift from here
default-color7
default-color0
...
default-color4
the amount of shifting is dependent on the number of series - for 16, everything is fine, for 14, it shifts 2 each time and so on.
In the chart this is nicely visible if you watch the legend changing...
I tried different methods of replacing the data, but none of them was successful, see comments in the code below.
An actual solution, but in my eyes not a very pretty one, is to manually overwrite the style-class, which isn't that easy as well, because of the aggressive habits of the task-class... wtf?!
whatever - if anyone has any helpful idea on that? maybe I'm missing something?
Note: To see the weired results, remove the lines marked as DIRTY-WORKAROUND-SOLUTION. Otherwise it would work... ;-)
Bonus-Question: maybe I'm silly, working with that JavaFX-Charts... some things are cool, but often times, I have a weired feeling about it... are there better alternatives you would recommend me to checo out?
Thanks!
import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.ScatterChart;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import java.util.ArrayList;
import java.util.List;
public class ChartSeriesReplacing extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
VBox root = new VBox();
ScatterChart<Number, Number> chart = new ScatterChart<>(new NumberAxis(), new NumberAxis());
Button refresh = new Button("Refresh");
refresh.setOnAction(clicked -> {
List<XYChart.Series<Number, Number>> seriesList = new ArrayList<>();
for (int i = 0; i < 15; i++) {
XYChart.Series<Number, Number> series = new XYChart.Series<>();
series.setName(i + "");
XYChart.Data<Number, Number> data = new XYChart.Data<>(Math.random(), Math.random());
int finalI = i;
data.nodeProperty().addListener(__ -> {
if (data.getNode() != null) {
data.getNode().getStyleClass().addListener((InvalidationListener) ___ -> {
System.out.println("[pre] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());
// DIRTY-WORKAROUND-SOLUTION:
// (has to live in listener, otherwise the chart erases any custom styling on adding... :-/ )
String colorString = "default-color" + finalI % 8;
data.getNode().getStyleClass().removeIf(s -> s.startsWith("default-color") && !s.equals(colorString));
if (!data.getNode().getStyleClass().contains(colorString)) {
data.getNode().getStyleClass().add(colorString);
}
// --------------------------
System.out.println("[post] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());
});
}
});
series.getData().add(data);
seriesList.add(series);
}
System.out.println("-----------------");
// What I tried:
// 1)
chart.getData().setAll(seriesList);
// 2)
// chart.dataProperty().setValue(FXCollections.observableArrayList(seriesList));
// 3)
// chart.getData().clear();
// 3a)
// chart.getData().addAll(seriesList);
// 3b)
// seriesList.forEach(series->chart.getData().add(series));
});
root.getChildren().add(chart);
root.getChildren().add(refresh);
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
}
Java-Version jdk1.8.0_171 (x64)