How to get rid of extra-space (padding) between piechart and its border in JavaFX / TornadoFX?

Question

I have a simple piechart without name, labels, legend. I need only a circle itself. But I can't get rid of that padding between borders and content. I've tried these all and received no result (TornadoFX CSS):

diagram {
  padding = box(0.px)
  labelPadding = box(0.px)

  borderImageInsets += box(0.px)
  borderInsets += box(0.px)
  backgroundInsets += box(0.px)

  maxWidth = 25.px
  maxHeight = 25.px
  labelLineLength = 0.px
  borderColor += box(Color.GREEN)
}

I want to get rid of this extra-space between a circle and green borders. Does anybody know any Java / CSS / TornadoFX solutions/options here ?

Answer 1

You can use a negative value for e. g. padding. Please have a look at this small example (JavaFX):

package sample;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.chart.PieChart;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage stage) {

        VBox vBox = new VBox();
        ObservableList<PieChart.Data> pieChartData =
                FXCollections.observableArrayList(
                        new PieChart.Data("", 75),
                        new PieChart.Data("", 25));
        final PieChart chart = new PieChart(pieChartData);
        chart.setLegendVisible(false);

        // Negative value for padding:
        chart.setStyle("-fx-padding: -35; -fx-border-color: green; -fx-border-width: 3;");

        vBox.getChildren().addAll(chart);
        stage.setScene(new Scene(vBox));
        stage.show();

        //chart.setMaxWidth(400d); // careful
    }


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

You can also quickly set a maximum width for the chart to make the green box a square but be careful please, it could mess with the overall layout: