I need a JPanel to be displayed when I click on a JToggleButton

问题

I have a JFrame divided in two on one side I have a JPanel that has some JToggleButtons on it. in the other side I need to show the right JPanel when one of the JToggleButtons is clicked. Right now am using only one thread to do this.

here is the JFrame

public class AppFrame extends JFrame{
    private JPanel content ;
    private JPanel menu;

    public AppFrame() {
        super("Title");
        setLayout(BorderLayout());
        //content is gonna hold JPanel1 or JPanel2
        content = new JPanel();
        menu = new menu();
        this.add(menu, BorderLayout.WEST);
        this.add(content , BorderLayout.CENTER);
    }

    public void setContet(JPanel activePanel){
        content = activePanel;
        this.add(content , BorderLayout.CENTER);
    }
}

here is the JPanel holding the JToggleButtons (MenuJPanel)

public class MenuJPanel extends JPanel{
private final LayoutManager innerLayout = new GridLayout(3,1,1,1);
private final JToggleButton button1;
private final JToggleButton button1;

public MenuPanel() {
    super();
    SwitchHandler sHandler = new SwitchHandler();
    this.setLayout(innerLayout);
    this.add(button1);
    this.add(button2);
    button1.addActionListener(sHandler);
    button2.addActionListener(sHandler);
}

class SwitchHandler implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == button1){
            button2.setSelected(false);
            //at this point I want the frame to display JPanel1
            //I tried this
            AppFrame frame = (AppFrame)getTopLevelAncestor();
            frame.setContet(new JPanel1());
        } else {
            button1.setSelected(false);
            //at this point I want the frame to display JPanel2                
            //I tried this
            AppFrame frame = (AppFrame)getTopLevelAncestor();
            frame.setContet(new JPanel2());
        }
    }
}

Can someone tell me how can I open these panels in the frame when the event is triggered. thanks

回答1:

The basic answer is to use a CardLayout, see How to Use CardLayout for more details.

There's so many ways you might be able to do this, but I prefer to use some kind of "navigation controller" which is responsible for actually taking care of the dirty details of making it work, this means if you decide to change the way you switch views, the reset of your code doesn't care, for example...

import java.awt.CardLayout;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JToggleButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public enum Page {
        MENU("menu"),
        HERE("here"),
        THERE("there");

        private String pageName;

        private Page(String name) {
            pageName = name;
        }

        public String getPageName() {
            return pageName;
        }

    }

    public interface Navigator {
        public void showPage(Page page);
    }

    public class TestPane extends JPanel implements Navigator {

        private CardLayout cardLayout;

        public TestPane() {
            cardLayout = new CardLayout();
            setLayout(cardLayout);
            add(new MenuPanel(this), Page.MENU.getPageName());
            add(new StuffOverHere(), Page.HERE.getPageName());
            add(new StuffOverThere(), Page.THERE.getPageName());
            showPage(Page.MENU);
        }

        @Override
        public void showPage(Page page) {
            cardLayout.show(this, page.getPageName());
        }

    }

    public class StuffOverHere extends JPanel {

        public StuffOverHere() {
            setLayout(new GridBagLayout());
            JLabel label = new JLabel("Over here");
            add(label);
        }

    }
    public class StuffOverThere extends JPanel {

        public StuffOverThere() {
            setLayout(new GridBagLayout());
            JLabel label = new JLabel("Over there");
            add(label);
        }

    }

    public class MenuPanel extends JPanel {

        private final LayoutManager innerLayout = new GridLayout(3, 1, 1, 1);
        private final JToggleButton button1 = new JToggleButton("Stuff over here");
        private final JToggleButton button2 = new JToggleButton("Stuff over there");

        private Navigator navigator;

        public MenuPanel(Navigator navigator) {
            super();
            SwitchHandler sHandler = new SwitchHandler();
            this.setLayout(innerLayout);
            this.add(button1);
            this.add(button2);
            button1.addActionListener(sHandler);
            button2.addActionListener(sHandler);
            this.navigator = navigator;
        }

        class SwitchHandler implements ActionListener {

            @Override
            public void actionPerformed(ActionEvent e) {
                if (e.getSource() == button1) {
                    navigator.showPage(Page.HERE);
                } else {
                    navigator.showPage(Page.THERE);
                }
            }
        }
    }
}

来源：https://stackoverflow.com/questions/36637989/i-need-a-jpanel-to-be-displayed-when-i-click-on-a-jtogglebutton