Java：JTextField（仍）根据最小化调整大小（新信息）

Question

I originally posted a question here

I've discovered that the JTextField only resizes if the JScrollPane exists. In other words, I can minimize and maximize it all I want until the scrollbar appears (because there is too much text to fit into the window). After that if I minimize the window, the JTextField triples in vertical size. Hopefully this new information will spark a possible solution. Please post if you have any ideas, thank you.

Answer 1

I am not much of a guy who will use GridBagLayout, seems like the whole issue is with your Layout settings in that.

Seems like you missed to read the GridBagLayout Tutorials , it clearly states that " it is possible to reuse the same GridBagConstraints instance for multiple components, even if the components have different constraints. However, it is recommended that you do not reuse GridBagConstraints, as this can very easily lead to you introducing subtle bugs if you forget to reset the fields for each new instance."

So after reading that I made a small improvement in your code of my own, hope you wont mind that :-)

What i did, is that, I made two different objects of GridBagConstraints, one each of your scrollpane and textfield, so that they can have different values. Since you were using the same object for both the components ie

c.weightx = 1.0;
c.weighty = 1.0;

Now till scroll bar doesn't appears all goes well, but once it does and you minimize the window, and then restores the window, then while repainting the window on the screen, since the values for weights is the same for both the components, hence they try to occupy equal area of the window in terms of Y-axis.

So in order to avoid that, I made two objects with different values for weights along Y-Axis , where JTextArea being mighty has been provided with the higher value ie weighty = 0.8 and JTextField being not so mighty in terms of its use in the present scenario, hence it's been given a weight of weighty = 0.2 .

I had rebuild the code again for your extra understanding. Using different GridBagConstraint objects for different components is the way out of the mess.

Do have a look at the code now :

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class Console extends JPanel implements ActionListener
{
    boolean ready = false;
    protected JTextField textField;
    protected JTextArea textArea;
    private final static String newline = "\n";
    //Game m_game;
    Thread t;

    public Console(/*Game game*/) 
    {
        super(new GridBagLayout());

        //m_game = game;
        textField = new JTextField(20);
        textField.setPreferredSize(null);
        textField.addActionListener(this);

        textArea = new JTextArea(20, 60);
        textArea.setEditable(true);
        textArea.setWrapStyleWord(true);
        textArea.setLineWrap(true);
        Font comic = new Font("Serif", Font.PLAIN, 14);
        textArea.setFont(comic);
        JScrollPane scrollPane = new JScrollPane(textArea);

        //Add Components to this panel.
            // This first object serves as providing values to the TEXTAREA.
        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = GridBagConstraints.REMAINDER;

        c.fill = GridBagConstraints.HORIZONTAL;
        c.fill = GridBagConstraints.BOTH;
        c.weightx = 1.0; 
        c.weighty = 0.8;// This being mighty has been given weight as 0.8, the highest.

        // This second object serves as providing values to the TEXTFIELD.
        GridBagConstraints c1 = new GridBagConstraints();
        c1.gridwidth = GridBagConstraints.REMAINDER;

        c1.fill = GridBagConstraints.HORIZONTAL;
        c1.fill = GridBagConstraints.BOTH;
        c1.weightx = 1.0;
        c1.weighty = 0.2;  // Since this has to occupy less space, hence weight is less also.
        add(scrollPane, c);
        add(textField, c1);
    }

    public void actionPerformed(ActionEvent evt) 
    {
        String text = textField.getText();
        //m_game.input = text;
        textField.selectAll();
        textArea.setCaretPosition(textArea.getDocument().getLength());
        //m_game.wait = false;
        /*synchronized (m_game)
        {
            ready = true;
            m_game.notifyAll();
        }*/
    }

    public static void createAndShowGUI() 
    {
        //Create and set up the window.
        JFrame frame = new JFrame("Game");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Add contents to the window.
        frame.setContentPane(new Console());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
            {
                public void run()
                {
                    createAndShowGUI();
                }
            });
    }
}