Java GUI-JTextArea扩展但不收缩

Question

MAIN PROBLEM: In a JScrollPane with JPanel which contains a JTextArea, text wraps up if GUI is expanded but text does not wrap back when GUI is contracted. See example below

Okay I am building the GUI for an app I am currently working on and I am having a bit of a problem.

The explanation: My GUI is structured as illustrated below:

And this is what it looks like.

Upon expansion the the JTextArea inside the panelWithText expands and resizes the text as such:

But the problem is what happens when you make the GUI smaller. The "problem" is that I want the text to warp back as it was before. I did a little experimenting by implementing a ComponentListener to both the JScrollPane and the panelWithText and found out that componentResized is being called for panelWithText upon expansion but not for contraction. Is there any way to implement the behavior of the text warping back in the panelWithText Component?


PS: Apparently if I switch the JScrollPane with a regular JPanel it works. But I can't do that! I have a LOT of panelWithText to show to the user.

PS PS: Sorry here is the code I am using.
JFrameExt.java

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JScrollPane;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.awt.FlowLayout;
import java.awt.Window.Type;
import javax.swing.ScrollPaneConstants;
import java.awt.CardLayout;
import com.jgoodies.forms.layout.FormLayout;
import com.jgoodies.forms.layout.ColumnSpec;
import com.jgoodies.forms.layout.RowSpec;
import com.jgoodies.forms.factories.FormFactory;


public class JFrameExt extends JFrame {

    private JPanel contentPane;

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

    /**
     * Create the frame.
     */
    public JFrameExt() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 246, 164);
        contentPane = new JPanel();
        contentPane.setBorder(null);
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);

        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportBorder(null);
        scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        contentPane.add(scrollPane, BorderLayout.CENTER);

        JPanel panel = new JPanel();
        scrollPane.setViewportView(panel);
        GridBagLayout gbl_panel = new GridBagLayout();
        gbl_panel.columnWidths = new int[]{0, 0};
        gbl_panel.rowHeights = new int[]{0, 0, 0, 0, 0, 0, 0, 0};
        gbl_panel.columnWeights = new double[]{1.0, Double.MIN_VALUE};
        gbl_panel.rowWeights = new double[]{0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, Double.MIN_VALUE};
        panel.setLayout(gbl_panel);

        panelWithText panelWithText_ = new panelWithText();
        GridBagConstraints gbc_panelWithText_ = new GridBagConstraints();
        gbc_panelWithText_.anchor = GridBagConstraints.NORTH;
        gbc_panelWithText_.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText_.fill = GridBagConstraints.HORIZONTAL;
        gbc_panelWithText_.gridx = 0;
        gbc_panelWithText_.gridy = 0;
        panel.add(panelWithText_, gbc_panelWithText_);

        panelWithText panelWithText__1 = new panelWithText();
        GridBagConstraints gbc_panelWithText__1 = new GridBagConstraints();
        gbc_panelWithText__1.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText__1.anchor = GridBagConstraints.NORTH;
        gbc_panelWithText__1.fill = GridBagConstraints.HORIZONTAL;
        gbc_panelWithText__1.gridx = 0;
        gbc_panelWithText__1.gridy = 1;
        panel.add(panelWithText__1, gbc_panelWithText__1);

        panelWithText panelWithText__2 = new panelWithText();
        GridBagConstraints gbc_panelWithText__2 = new GridBagConstraints();
        gbc_panelWithText__2.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText__2.fill = GridBagConstraints.BOTH;
        gbc_panelWithText__2.gridx = 0;
        gbc_panelWithText__2.gridy = 2;
        panel.add(panelWithText__2, gbc_panelWithText__2);

        panelWithText panelWithText__3 = new panelWithText();
        GridBagConstraints gbc_panelWithText__3 = new GridBagConstraints();
        gbc_panelWithText__3.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText__3.fill = GridBagConstraints.BOTH;
        gbc_panelWithText__3.gridx = 0;
        gbc_panelWithText__3.gridy = 3;
        panel.add(panelWithText__3, gbc_panelWithText__3);

        panelWithText panelWithText__4 = new panelWithText();
        GridBagConstraints gbc_panelWithText__4 = new GridBagConstraints();
        gbc_panelWithText__4.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText__4.fill = GridBagConstraints.BOTH;
        gbc_panelWithText__4.gridx = 0;
        gbc_panelWithText__4.gridy = 4;
        panel.add(panelWithText__4, gbc_panelWithText__4);

        panelWithText panelWithText__5 = new panelWithText();
        GridBagConstraints gbc_panelWithText__5 = new GridBagConstraints();
        gbc_panelWithText__5.insets = new Insets(0, 0, 5, 0);
        gbc_panelWithText__5.fill = GridBagConstraints.BOTH;
        gbc_panelWithText__5.gridx = 0;
        gbc_panelWithText__5.gridy = 5;
        panel.add(panelWithText__5, gbc_panelWithText__5);

        panelWithText panelWithText__6 = new panelWithText();
        GridBagConstraints gbc_panelWithText__6 = new GridBagConstraints();
        gbc_panelWithText__6.fill = GridBagConstraints.BOTH;
        gbc_panelWithText__6.gridx = 0;
        gbc_panelWithText__6.gridy = 6;
        panel.add(panelWithText__6, gbc_panelWithText__6);
        setSize(300,100);
    }

}

panelWithText.java

import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Color;
import javax.swing.JTextArea;
import javax.swing.ImageIcon;
import java.awt.BorderLayout;


public class panelWithText extends JPanel {

    /**
     * Create the panel.
     */
    public void me_resized(Dimension d){
        System.out.println("CALLED..");
        super.setPreferredSize(d);
    }
    public panelWithText() {
        setBackground(Color.DARK_GRAY);
        setForeground(Color.WHITE);
        setLayout(new BorderLayout(0, 0));

        JTextArea txtrIveBeenReading = new JTextArea();
        txtrIveBeenReading.setEditable(false);
        txtrIveBeenReading.setColumns(28);
        txtrIveBeenReading.setFont(new Font("Tahoma", Font.PLAIN, 10));
        txtrIveBeenReading.setLineWrap(true);
        txtrIveBeenReading.setWrapStyleWord(true);
        txtrIveBeenReading.setText("\n A bunch of really important text here... A bunch of really important text here... A bunch of really important text here... A bunch of really important text here...\n");
        txtrIveBeenReading.setForeground(Color.WHITE);
        txtrIveBeenReading.setBackground(Color.DARK_GRAY);
        add(txtrIveBeenReading, BorderLayout.CENTER);

    }

}

Answer 1

After a little playing around, I came up with this...

public class Test {

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

    public static class ScrollablePane extends JPanel implements Scrollable {

        @Override
        public Dimension getPreferredScrollableViewportSize() {
            return new Dimension(100, 100);
        }

        @Override
        public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
            return 64;
        }

        @Override
        public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
            return 128;
        }

        @Override
        public boolean getScrollableTracksViewportWidth() {
            return true;
        }

        @Override
        public boolean getScrollableTracksViewportHeight() {
            return false;
        }

    }

    public static class JFrameExt extends JFrame {

        private JPanel contentPane;

        /**
         * Create the frame.
         */
        public JFrameExt() {
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setBounds(100, 100, 246, 164);
            contentPane = new JPanel();
            contentPane.setBorder(null);
            contentPane.setLayout(new BorderLayout(0, 0));
            setContentPane(contentPane);

            JScrollPane scrollPane = new JScrollPane();
            scrollPane.setViewportBorder(null);
            scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
            contentPane.add(scrollPane, BorderLayout.CENTER);

            JPanel panel = new ScrollablePane();
            scrollPane.setViewportView(panel);
            GridBagLayout gbl_panel = new GridBagLayout();
//            gbl_panel.columnWidths = new int[]{0, 0};
//            gbl_panel.rowHeights = new int[]{0, 0, 0, 0, 0, 0, 0, 0};
//            gbl_panel.columnWeights = new double[]{1.0, Double.MIN_VALUE};
//            gbl_panel.rowWeights = new double[]{0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, Double.MIN_VALUE};
            panel.setLayout(gbl_panel);

            panelWithText panelWithText_ = new panelWithText();
            GridBagConstraints gbc_panelWithText_ = new GridBagConstraints();
            gbc_panelWithText_.anchor = GridBagConstraints.NORTH;
            gbc_panelWithText_.insets = new Insets(0, 0, 5, 0);
            gbc_panelWithText_.fill = GridBagConstraints.HORIZONTAL;
            gbc_panelWithText_.gridx = 0;
            gbc_panelWithText_.gridy = 0;
            gbc_panelWithText_.weightx = 1;
            panel.add(panelWithText_, gbc_panelWithText_);

//            panelWithText panelWithText__1 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__1 = new GridBagConstraints();
//            gbc_panelWithText__1.insets = new Insets(0, 0, 5, 0);
//            gbc_panelWithText__1.anchor = GridBagConstraints.NORTH;
////            gbc_panelWithText__1.fill = GridBagConstraints.HORIZONTAL;
//            gbc_panelWithText__1.gridx = 0;
//            gbc_panelWithText__1.gridy = 1;
//            panel.add(panelWithText__1, gbc_panelWithText__1);
//
//            panelWithText panelWithText__2 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__2 = new GridBagConstraints();
//            gbc_panelWithText__2.insets = new Insets(0, 0, 5, 0);
////            gbc_panelWithText__2.fill = GridBagConstraints.BOTH;
//            gbc_panelWithText__2.gridx = 0;
//            gbc_panelWithText__2.gridy = 2;
//            panel.add(panelWithText__2, gbc_panelWithText__2);
//
//            panelWithText panelWithText__3 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__3 = new GridBagConstraints();
//            gbc_panelWithText__3.insets = new Insets(0, 0, 5, 0);
////            gbc_panelWithText__3.fill = GridBagConstraints.BOTH;
//            gbc_panelWithText__3.gridx = 0;
//            gbc_panelWithText__3.gridy = 3;
//            panel.add(panelWithText__3, gbc_panelWithText__3);
//
//            panelWithText panelWithText__4 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__4 = new GridBagConstraints();
//            gbc_panelWithText__4.insets = new Insets(0, 0, 5, 0);
////            gbc_panelWithText__4.fill = GridBagConstraints.BOTH;
//            gbc_panelWithText__4.gridx = 0;
//            gbc_panelWithText__4.gridy = 4;
//            panel.add(panelWithText__4, gbc_panelWithText__4);
//
//            panelWithText panelWithText__5 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__5 = new GridBagConstraints();
//            gbc_panelWithText__5.insets = new Insets(0, 0, 5, 0);
////            gbc_panelWithText__5.fill = GridBagConstraints.BOTH;
//            gbc_panelWithText__5.gridx = 0;
//            gbc_panelWithText__5.gridy = 5;
//            panel.add(panelWithText__5, gbc_panelWithText__5);
//
//            panelWithText panelWithText__6 = new panelWithText();
//            GridBagConstraints gbc_panelWithText__6 = new GridBagConstraints();
////            gbc_panelWithText__6.fill = GridBagConstraints.BOTH;
//            gbc_panelWithText__6.gridx = 0;
//            gbc_panelWithText__6.gridy = 6;
//            panel.add(panelWithText__6, gbc_panelWithText__6);
            setSize(300, 100);
        }
    }

    public static class panelWithText extends JPanel {

        /**
         * Create the panel.
         */
        public void me_resized(Dimension d) {
            System.out.println("CALLED..");
            super.setPreferredSize(d);
        }

        public panelWithText() {
            setBackground(Color.DARK_GRAY);
            setForeground(Color.WHITE);
            setLayout(new BorderLayout(0, 0));

            JTextArea txtrIveBeenReading = new JTextArea();
            txtrIveBeenReading.setEditable(false);
            txtrIveBeenReading.setColumns(28);
            txtrIveBeenReading.setFont(new Font("Tahoma", Font.PLAIN, 10));
            txtrIveBeenReading.setLineWrap(true);
            txtrIveBeenReading.setWrapStyleWord(true);
            txtrIveBeenReading.setText("\n A bunch of really important text here... A bunch of really important text here... A bunch of really important text here... A bunch of really important text here...\n");
            txtrIveBeenReading.setForeground(Color.WHITE);
            txtrIveBeenReading.setBackground(Color.DARK_GRAY);
            add(txtrIveBeenReading, BorderLayout.CENTER);

        }
    }
}

Basically, you need a container that implements the Scrollable interface. This will allow you to specify that the container should track/match the view ports width. This will cause the container to be laid out when ever the view port changes size...

As a side note, you can use a single copy of the GridBagConstraints , when you add each new component to the container, the GridBagLayout will generate a copy of it's own. This is very powerful when you want to share properties of the GridBagConstraints between components ;)