移动JButton

Question

What would be the best way for me to move the buttons so they are under each other instead of beside each other (see image below)?

The code for this class is as follows. The Main method is in a different class.

package guiplay;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;



public class MainGUI extends JFrame {

  private JButton openReportSelection = new JButton("Open Report Viewer");
  private JButton closeButton = new JButton("Close Program");



    private JButton getCloseButton(){
        return closeButton;
    }   
    private JButton getOpenReportSelection(){
        return openReportSelection;
}

    public MainGUI(){
        mainInterface(); 
    }

    private void mainInterface(){          
        setTitle("Program Information Application");   
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel centerPanel = new JPanel(new FlowLayout());        
        centerPanel.add(openReportSelection);
        openReportSelection.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent e){
                JFrame reports = new JFrame();
                new ReportGUI();
            }
        });  
        centerPanel.add(closeButton);       
        getCloseButton().addActionListener(new Listener());
        add(centerPanel, BorderLayout.CENTER);
        setSize(700,200);
        setVisible(true);            
    }




}

Answer 1

Don't put the JButtons in a container that uses FlowLayout but rather one that uses another layout that allows stacking of components. A GridLayout comes to mind if the buttons are to be the same size, or if they need to be different sizes, a BoxLayout.

Check out the Layout Manager Tutorial .

Answer 2

You can use a BoxLayout as it aligns all elements either horizontally or vertically. Simply set BoxLayout 's axis to BoxLayout.Y_AXIS .

Example:

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.BoxLayout;
import javax.swing.JButton;

public class BoxLayoutExample extends JFrame {
    private static final long serialVersionUID = 1L;
    private JPanel contentPane;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    BoxLayoutExample frame = new BoxLayoutExample();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public BoxLayoutExample() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 180, 150);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));

        JButton btnOpenReportViewer = new JButton("Open Report Viewer");
        contentPane.add(btnOpenReportViewer);

        JButton btnCloseProgram = new JButton("Close Program");
        contentPane.add(btnCloseProgram);
    }

}

If you want to control the size so that they are similar to each other, you can use a grid layout by setting the JFrame 's content pane to a GridLayout :

contentPane.setLayout(new GridLayout(0, 1, 0, 0)); // the value of 1 here means 1 column

Answer 3

You could try using a BoxLayout instead of a FlowLayout. In that case, you could have:

JPanel centerPanel = new JPanel(new BoxLayout());  
centerPanel.setLayout(new BoxLayout(centerPanel, BoxLayout.Y_AXIS)); // Y_AXIS will cause the components to be added vertically
centerPanel.add(openReportSelection);
centerPanel.add(closeButton);
centerPanel.setMaximumSize(new Dimension(100, 60)); // Set the maximum horizontal and vertical distances used, as BoxLayouts expand to fill the provided area

Or as Hovercraft said, you could use a GridLayout, in which case you would specify it as follows:

JPanel centerPanel = new JPanel(new GridLayout(1,0); // The "0" parameter specifies as many rows as needed, but only one column
centerPanel.add(openReportSelection);
centerPanel.add(closeButton);
centerPanel.setMaximumSize(new Dimension(100, 60)); // GridLayouts will also expand to fill the entire area, so you'll probably want some size parameters.

You could also see this link for more on BoxLayouts, or this link for more on GridLayouts.