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JScrollPane words wrap

由 本秂侑毒 提交于 2019-12-05 14:23:33 

import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;

public class Test extends JFrame {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Test frame = new Test();

                    JTextArea message = new JTextArea("Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
                        ,6,40);
                    // make it look & act like a label
                    message.setWrapStyleWord(true);
                    message.setLineWrap(true);
                    message.setEditable(false);
                    message.setFocusable(false);
                    message.setOpaque(false);

                    JScrollPane scrollPane =  new JScrollPane(message,
                        ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
                        ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER
                        );
                    frame.add(scrollPane);
                    frame.pack();
                    frame.setVisible(true);
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public Test() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationByPlatform(true);
    }
}

I think you need to implement the interface Scrollable. Actually JTextArea also implements Scrollable.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Rectangle;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ScrollPaneConstants;
import javax.swing.Scrollable;
import javax.swing.border.EmptyBorder;

public class TestScrollLabel extends JFrame
{

private JPanel contentPane;

/**
 * Launch the application.
 */
public static void main(String[] args)
{
    EventQueue.invokeLater(new Runnable()
    {
        public void run()
        {
            try
            {
                TestScrollLabel frame = new TestScrollLabel();
                JScrollPane scrollPane =  new JScrollPane();
                scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
                JPanel panel = new MyPanel();
                //BorderLayout is a good choice here
                panel.setLayout(new BorderLayout());
                panel.add(new JLabel("<html>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</html>"));
                scrollPane.setViewportView(panel);
                frame.add(scrollPane);
                frame.setVisible(true);
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }
    });
}

static class MyPanel extends JPanel implements Scrollable{

    @Override
    public Dimension getPreferredScrollableViewportSize() {

        return this.getPreferredSize();
    }

    @Override
    public int getScrollableUnitIncrement(Rectangle visibleRect,
            int orientation, int direction) {
        return 50;
    }

    @Override
    public int getScrollableBlockIncrement(Rectangle visibleRect,
            int orientation, int direction) {
        return 80;
    }

    /*
     * (non-Javadoc)
     * @see javax.swing.Scrollable#getScrollableTracksViewportWidth()
     */
    @Override
    public boolean getScrollableTracksViewportWidth() {
        return true;
    }

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

}

/**
 * Create the frame.
 */
public TestScrollLabel()
{
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 300);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    contentPane.setLayout(new BorderLayout(0, 0));
    setContentPane(contentPane);
}

}

JLabel has no word wrap functionality. You can simulate this effect by creating a JTextArea, making it read-only using setEditable(false) and then calling setWrapStyleWord(true) to enable word-wrapping.

I think you can also play around with setBorder() to make it look flatter and more like a plain label, but this may give different effects on different platforms depending on look and feel.

标签
java
swing
jscrollpane
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