如何在JavaFX中更改TreeItem的下划线颜色？

Question

I have a JavaFX TreeView which has TreeItems with two basic colors , red and white . When they are selected they both have -fx-underline:true but i have a problem with the line being Red or White i want the underline to be always white , is that possible with css in JavaFX ?

I have tried the below but it doesn't work .

.tree-cell-white:selected {
    -fx-font-weight: bold ;
    -fx-text-fill:white; 
    -fx-underline: true;
    -fx-underline-fill: orange;
    -fx-underline-color: blue;
}

.tree-cell-red:selected {
 -fx-font-weight: bold ;
 -fx-text-fill:firebrick; 
 -fx-underline: true;
}

Answer 1

Unfortunately I could not find how to do it by JavaFX CSS, but I found another solution. That is I created MyTrack class that derives from HBox and added an ImageView as an music/mp3 icon and Label with text. Here is a little trick I underlined label by setting its bottom border color and set MyTrack as a graphic for TreeItem .

package underlined.treeview;

import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.stage.Stage;

import java.util.Arrays;
import java.util.List;

public class TreeViewApp extends Application {

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

    private Parent createContent() {
        TreeItem<String> treeRoot = new TreeItem<>("Root node");
        List<TreeItem<String>> tracks = Arrays.asList(
                new TreeItem<>(""),
                new TreeItem<>(""),
                new TreeItem<>(""));

        for (TreeItem<String> track : tracks)
            track.setGraphic(new MyTrack("Track"));

        treeRoot.getChildren().addAll(tracks);

        TreeView treeView = new TreeView();
        treeView.setShowRoot(true);
        treeView.setRoot(treeRoot);
        treeRoot.setExpanded(true);
        return treeView;
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        Scene scene = new Scene(createContent());
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

and MyTrack class:

package underlined.treeview;

import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.HBox;

public class MyTrack extends HBox {

    public MyTrack(String text) {

        Label label = new Label(text);
        label.setStyle("-fx-border-color: aqua;" +
                "-fx-border-width: 0 0 1 0;");

        Image image = new Image(getClass().getResource("/img/icon/mp3.png")
                .toExternalForm());
        ImageView imageView = new ImageView(image);
        imageView.setFitWidth(16);
        imageView.setFitHeight(16);

        getChildren().addAll(imageView, label);
    }
}

And Voila!!!

In my example bottom border color is aqua here. Note that TreeItem should be instantiated with empty String . It was just an example you need to optimize it yourself.