Swing GridBagLayout组件调整大小

Question

I am working on a project and my goal is to make the components resize according to the size of the window. I am using GridBagLayout for this, however I am experiencing some problems when making the components resize when the window resizes. When I give my components weighty value, everything is fine, the components resize Vertically. http://imageshack.us/a/img211/9682/d8au.png But when I assign the weightx value, everything is being messed up. The buttons change in size, some gaps appear between Labels. http://imageshack.us/a/img12/6946/ij4.png

I don't assign the weightx and weighty values to all of the components, only the ones I need. I do not code the GUI, I just drag&drop the components, so there is no code. I just need some advice on how to fix this, so that the components are resizing correctly. I suppose, this is because of the weightx , but I don't have an idea on how to make everything work fine.

Answer 1

First of all, don't use null layout as one has suggested on this site. Use of null layouts is often a solution suggested by Swing newbies because on the surface and initially, it is easier to use, but then later you discover all the problems with it, including ugly or non-functioning GUI's when trying to run the application on different platforms, and the extreme difficulty involved if wanting to modify anything in the GUI as this requires hand-modification of all other components that are right or below the modified component. The beauty of use of layout managers is it allows them to do the hard work for you, making maintenance and upgrades a breeze.

I suggesting nesting JPanels with nested layouts. The Calculator buttons for example are behaving as a fixed grid, so use a GridLayout for them with JLabel placeholders where there are no buttons at the bottom.

The outer GUI JPanel can be GridBagLayout if desired, or you could easily mix in other easier layouts.

Answer 2

As I suggested in my comment, and which has already being suggested by Hovercraft, I'd recommend breaking you UI down into sections, focusing on the layout requirements of each section separately, otherwise you will find decisions you make for one component will have adverse effects on others.

I'd also recommend avoiding GUI designers until you have a reasonable understanding of what the layouts are actually doing and code the layouts by hand. Don't get me wrong, I use Netbeans form designer all the time, but I also tweak many of my UIs by hand, especially when you need to produce dynamic and changing UIs

The following demonstrates what I'm talking about. I've highlighted each section of the UI with the use a LineBorder to make it stand it.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class BadLayout25 {

    public static void main(String[] args) {
        new BadLayout25();
    }

    public BadLayout25() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new BasePane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }

        });
    }

    public class BasePane extends JPanel {

        public BasePane() {
            setLayout(new GridBagLayout());

            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.gridwidth = 2;
            gbc.fill = java.awt.GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1.0;
            add(getTopPane(), gbc);

            gbc = new java.awt.GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 1;
            gbc.fill = java.awt.GridBagConstraints.HORIZONTAL;
            gbc.weightx = 0.5;
            add(getOptionsPane(), gbc);

            gbc = new java.awt.GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 2;
            gbc.fill = java.awt.GridBagConstraints.BOTH;
            gbc.weightx = 0.5;
            gbc.weighty = 1.0;
            add(getButtonPane(), gbc);

            JTextArea textArea = new JTextArea(5, 20);

            gbc = new java.awt.GridBagConstraints();
            gbc.gridx = 1;
            gbc.gridy = 1;
            gbc.gridheight = 2;
            gbc.fill = java.awt.GridBagConstraints.BOTH;
            gbc.weightx = 0.5;
            gbc.weighty = 1.0;
            add(new JScrollPane(textArea), gbc);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(800, 400);
        }

        protected JPanel getTopPane() {
            JPanel topPane = new JPanel(new GridBagLayout());
            topPane.setBorder(BorderFactory.createLineBorder(java.awt.Color.RED));
            topPane.add(new JLabel("Lotereya:"));
            topPane.add(new JLabel("Yuklenilir"));
            return topPane;
        }

        protected JPanel getOptionsPane() {
            JPanel optionsPane = new JPanel(new GridBagLayout());
            optionsPane.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 255, 0)));
            GridBagConstraints gbc = new GridBagConstraints();

            gbc = new GridBagConstraints();
            gbc.anchor = java.awt.GridBagConstraints.LINE_START;
            optionsPane.add(new JLabel("Tiraj nomre:"), gbc);

            gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 1;
            gbc.gridwidth = 2;
            gbc.anchor = java.awt.GridBagConstraints.LINE_START;
            optionsPane.add(new JLabel("Sablon nomresi:"), gbc);

            JTextField field = new JTextField(10);
            gbc = new GridBagConstraints();
            gbc.gridx = 2;
            gbc.gridy = 1;
            gbc.anchor = java.awt.GridBagConstraints.LINE_START;
            gbc.weightx = 1.0;
            optionsPane.add(field, gbc);

            JComboBox comboBox = new JComboBox();
            gbc = new GridBagConstraints();
            gbc.gridx = 1;
            gbc.gridy = 0;
            gbc.gridwidth = 2;
            gbc.anchor = java.awt.GridBagConstraints.LINE_START;
            gbc.weightx = 1.0;
            optionsPane.add(comboBox, gbc);

            return optionsPane;
        }

        protected JPanel getButtonPane() {
            JPanel buttonsPane = new JPanel(new GridBagLayout());
            buttonsPane.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 0, 255)));

            GridBagConstraints gbc = new GridBagConstraints();
            gbc = new java.awt.GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = -1;
            gbc.fill = java.awt.GridBagConstraints.BOTH;
            gbc.weightx = 0.25;
            gbc.weighty = 0.25;
            for (int index = 0; index < 9; index++) {
                if (index % 3 == 0) {
                    gbc.gridy++;
                    gbc.gridx = 0;
                } else {
                    gbc.gridx++;
                }
                buttonsPane.add(new JButton(String.valueOf(index + 1)), gbc);
            }
            gbc = new GridBagConstraints();
            gbc.gridx = 1;
            gbc.gridy = 3;
            gbc.fill = java.awt.GridBagConstraints.BOTH;
            gbc.weightx = 0.25;
            gbc.weighty = 0.25;
            buttonsPane.add(new JButton("0"), gbc);

            gbc = new GridBagConstraints();
            gbc.gridx = 3;
            gbc.gridy = 0;
            gbc.fill = java.awt.GridBagConstraints.BOTH;
            gbc.weightx = 0.25;
            gbc.weighty = 0.25;
            buttonsPane.add(new JButton("Tesdiq"), gbc);
            gbc.gridy++;
            buttonsPane.add(new JButton("<ticket.apply>"), gbc);
            gbc.gridy++;
            buttonsPane.add(new JButton("<ticket.cancel>"), gbc);
            gbc.gridy++;
            buttonsPane.add(new JButton("<main menu>"), gbc);

            return buttonsPane;
        }
    }
}