import com.sun.javafx.scene.control.skin.TreeCellSkin;
import javafx.application.Application;
import javafx.css.CssMetaData;
import javafx.css.Styleable;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeView;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderWidths;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.List;

public class StylesTest2 extends Application{


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

    @Override
    public void start(Stage stage) throws Exception {
        TreeView view = new TreeView();
        TreeCell cell = new TreeCell();
        cell.updateTreeView(view);
        cell.setSkin(new TreeCellSkin(cell));
        getListWithSubProperty(cell.getCssMetaData())
                .stream().filter((e) -> "-fx-cell-size".equals(e.getProperty()))
        .forEach((e) -> {
            CssMetaData<TreeCell, Double> cssMetaData = (CssMetaData<TreeCell, Double>) e;
            System.out.println(cssMetaData.getInitialValue(cell));
        });
    }


    private List<CssMetaData<? extends Styleable, ?>> getListWithSubProperty(List<CssMetaData<? extends Styleable, ?>> list) {
        ArrayList<CssMetaData<? extends Styleable, ?>> newList = new ArrayList<>(list);
        for (CssMetaData data : list) {
            List<CssMetaData<? extends Styleable, ?>> sub = data.getSubProperties();
            if (sub != null && sub.size() > 0) {
                newList.addAll(getListWithSubProperty(sub));
            }
        }
        return newList;
    }
}