Swing 中的 JavaFX 集成

Question

我是 JavaFX 的新手，在弄清楚如何在我的 swing 应用程序中集成 fxml 文件时遇到了一些问题。 在线阅读我找到了一种加载 fxml 文件的方法，并按照本指南将其显示在屏幕上: Integrating JavaFX into Swing Applications

我的代码应该做的是加载我开始使用 JavaFX Scene Builder 设计的 fxml 文件，将 JFXPanel 添加到 JPanel，并通过方法调用返回它。然后将其添加到主应用程序中的 tabbedPanel(因此可能同时打开多个不同的 JFXPanel)。

我已经解决了一些问题，但我不确定如何继续。我能够运行一个面板，但正如我发布的教程中一样，使用了静态方法，因此我无法拥有多个不同的面板。我做了一些改变，但现在我完全陷入困境。

这是我当前的 FXML:

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.SplitPane?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.Pane?>

<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="1000.0" xmlns="http://javafx.com/javafx/8.0.121" xmlns:fx="http://javafx.com/fxml/1" fx:controller="GUI.fcmModeler.fcmPanel">
   <children>
      <AnchorPane prefHeight="25.0" prefWidth="1000.0">
         <children>
            <Button fx:id="addComponent" layoutX="161.0" mnemonicParsing="false" onMouseClicked="#addComponent" prefHeight="25.0" prefWidth="600.0" text="+ Add Component" textAlignment="CENTER" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
         </children>
      </AnchorPane>
      <SplitPane dividerPositions="0.1713426853707415" layoutY="25.0" prefHeight="577.0" prefWidth="1000.0">
        <items>
          <AnchorPane fx:id="leftPane" maxWidth="160.0" minHeight="0.0" minWidth="160.0" prefHeight="575.0" prefWidth="160.0" />
          <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="546.0" prefWidth="683.0" />
        </items>
      </SplitPane>
   </children>
</Pane>

这是我的 Controller 类:

package GUI.fcmModeler;

import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.fxml.FXMLLoader;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;

import javax.swing.*;
import java.io.IOException;
import java.util.Random;

public class fcmPanel extends JPanel {

    private JPanel frame;
    private static Group root=new Group();
    private boolean firstRun=true;
    Scene scene=null;

    private void initAndShowGUI() {
        // This method is invoked on the EDT thread
        final JFXPanel fxPanel = new JFXPanel();
        frame.add(fxPanel);
        frame.setSize(1200, 1200);
        frame.setVisible(true);

        Platform.runLater(new Runnable() {
            @Override
            public void run() {
                initFX(fxPanel);
            }
        });

        frame.add(fxPanel);
        frame.setVisible(true);
    }

    private void initFX(JFXPanel fxPanel) {
        // This method is invoked on the JavaFX thread
        Scene scene = createScene();
        fxPanel.setScene(scene);
    }

    private Scene createScene() {
        //if(firstRun){
            //root = new Group();
            if(scene==null) {
                scene = new Scene(root, Color.ALICEBLUE);
            }
            try {
                Node newLoadedPane = FXMLLoader.load(fcmPanel.class.getResource("/fxml/fcmPanel.fxml"));
                root.getChildren().add(newLoadedPane);
            } catch (IOException e) {
                System.out.print("the file doesn'e exist.\n");
                e.printStackTrace();
            }
        //}

        return (scene);
    }

    public JPanel returnPanel() {
        System.out.println("returnpanel");
//        if(frame==null){
//            frame = new JPanel();
//        }
        //initFcmPanel();
        return frame;
    }

    public fcmPanel(){
        frame = new JPanel();
        //root=g;
        initFcmPanel();
    }


    public void initFcmPanel() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                initAndShowGUI();
            }
        });
    }

    public void addComponent(){
        Platform.runLater(new Runnable() {
            @Override
            public void run() {
                System.out.println("added component2");
                Circle circle = new Circle(new Random().nextInt(50),Color.BLUE);
                root.getChildren().add(circle);
                circle.relocate(new Random().nextInt(600),new Random().nextInt(600));
            }
        });

    }

}

JFXPanel 通过此调用添加到选项卡式面板:

tabbedPanel.addTab(newTabName , null,new fcmPanel().returnPanel(), filePath  );

目前，我面临以下问题

Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: Group@3e0f3500[styleClass=root]is already set as root of another scene

我理解错误消息，但不知道如何解决。

提前谢谢您。

Answer 1

我不确定您想要实现什么目标。发布的代码无法按发布的方式运行，因此我创建了一个快速而肮脏的mcve您的代码运行没有错误的版本，希望它能帮助您了解问题所在或阐明您的需求:

import java.awt.Dimension;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.fxml.FXMLLoader;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.paint.Color;

public class FcmPanel {

    private static Group root=new Group();
    Scene scene=null;

    private void initAndShowGUI() {

        // This method is invoked on the EDT thread
        final JFXPanel fxPanel = new JFXPanel();
        fxPanel.setPreferredSize(new Dimension(600, 400));
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Platform.runLater(()-> initFX(fxPanel));

        JTabbedPane tabbedPanel = new JTabbedPane();
        tabbedPanel.addTab("Just an emty tab", new JPanel() );
        tabbedPanel.addTab("FcmPanel", fxPanel );
        frame.add(tabbedPanel);
        frame.pack();
        frame.setVisible(true);
    }

    private void initFX(JFXPanel fxPanel) {
        Scene scene = createScene();
        fxPanel.setScene(scene);
    }

    private Scene createScene() {

        if(scene==null) {
            scene = new Scene(root, Color.ALICEBLUE);
        }
        try {
            Node newLoadedPane = FXMLLoader.load(getClass().
                    getResource("FcmPanel.fxml"));
            root.getChildren().add(newLoadedPane);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return (scene);
    }

    public static void main(String[] args) {
        FcmPanel p = new FcmPanel();
        p.initAndShowGUI();
    }
} 

fxml 本质上是相同的。只需将 Button 更改为不需要 Controller 的 Label :

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Label?>
<?import javafx.scene.control.SplitPane?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.Pane?>

<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="1000.0" xmlns="http://javafx.com/javafx/8.0.121" xmlns:fx="http://javafx.com/fxml/1" >
   <children>
      <AnchorPane prefHeight="25.0" prefWidth="1000.0">
         <children>
            <Label fx:id="addComponent" layoutX="161.0" mnemonicParsing="false"  prefHeight="25.0" prefWidth="600.0" text="+ Add Component" textAlignment="CENTER" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
         </children>
      </AnchorPane>
      <SplitPane dividerPositions="0.1713426853707415" layoutY="25.0" prefHeight="577.0" prefWidth="1000.0">
        <items>
          <AnchorPane fx:id="leftPane" maxWidth="160.0" minHeight="0.0" minWidth="160.0" prefHeight="575.0" prefWidth="160.0" />
          <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="546.0" prefWidth="683.0" />
        </items>
      </SplitPane>
   </children>
</Pane>