Get height of multi line text with fixed width to

2020-06-13 06:26发布

站内问答 / Java
1937 3 4

I want to create a dialog that contains some kind of text element (JLabel/JTextArea etc) that is multi lined and wrap the words. I want the dialog to be of a fixed width but adapt the height depending on how big the text is. I have this code:

import static javax.swing.GroupLayout.DEFAULT_SIZE;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class TextSizeProblem extends JFrame {
  public TextSizeProblem() {

    String dummyString = "";
    for (int i = 0; i < 100; i++) {
      dummyString += " word" + i;  //Create a long text
    }
    JLabel text = new JLabel();
    text.setText("<html>" + dummyString + "</html>");

    JButton packMeButton = new JButton("pack");
    packMeButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        pack();
      }
    });

    GroupLayout layout = new GroupLayout(this.getContentPane());
    getContentPane().setLayout(layout);
    layout.setVerticalGroup(layout.createParallelGroup()
        .addComponent(packMeButton)
        .addComponent(text)
    );
    layout.setHorizontalGroup(layout.createSequentialGroup()
        .addComponent(packMeButton)
        .addComponent(text, DEFAULT_SIZE, 400, 400) //Lock the width to 400
    );

    pack();
  }

  public static void main(String args[]) {
    SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        JFrame frame = new TextSizeProblem();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
      }
    });
  }
}

When running the program it looks like this: alt text
(source: lesc.se)

But I would like the dialog to look like this (as when you press the pack-button): alt text
(source: lesc.se)

I'm guessing that the problem is that the layout manager had not been able to determine the proper height of the text before displaying it to the screen. I have tried various validate(), invalidate(), validateTree() etc but have not succeed.

3条回答
趁早两清
2楼-- · 2020-06-13 06:30

I think this is what you want:

JLabel label = new JLabel("<html><div style=\"width:200px;\">Lots of text here...</div></html>");
// add the label to some Container.

This will restrict the JLabel to being 200 pixels wide and automatically adjust the height to fit the text.

查看更多
0人赞 添加讨论(0) 举报
啃猪蹄的小仙女
3楼-- · 2020-06-13 06:47

Here is an adaptation of your code, doing what you want. But it needs a little trick to calculate the size of the label and set its preferred Size.

I found the solution here

import static javax.swing.GroupLayout.DEFAULT_SIZE;

import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import javax.swing.text.View;

public class TextSizeProblem extends JFrame {
    public TextSizeProblem() {

        String dummyString = "";
        for (int i = 0; i < 100; i++) {
            dummyString += " word" + i; // Create a long text
        }
        JLabel text = new JLabel();
        text.setText("<html>" + dummyString + "</html>");

        Dimension prefSize = getPreferredSize(text.getText(), true, 400);

        JButton packMeButton = new JButton("pack");
        packMeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                pack();
            }
        });



        GroupLayout layout = new GroupLayout(this.getContentPane());
        getContentPane().setLayout(layout);
        layout.setVerticalGroup(layout.createParallelGroup().addComponent(packMeButton)
                .addComponent(text,DEFAULT_SIZE, prefSize.height, prefSize.height));
        layout.setHorizontalGroup(layout.createSequentialGroup().addComponent(packMeButton)
                .addComponent(text, DEFAULT_SIZE, prefSize.width, prefSize.width) // Lock the width to 400
                );

        pack();
    }

    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new TextSizeProblem();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }

    private static final JLabel resizer = new JLabel();

    /**
     * Returns the preferred size to set a component at in order to render an html string. You can
     * specify the size of one dimension.
     */
    public static java.awt.Dimension getPreferredSize(String html, boolean width, int prefSize) {

        resizer.setText(html);

        View view = (View) resizer.getClientProperty(javax.swing.plaf.basic.BasicHTML.propertyKey);

        view.setSize(width ? prefSize : 0, width ? 0 : prefSize);

        float w = view.getPreferredSpan(View.X_AXIS);
        float h = view.getPreferredSpan(View.Y_AXIS);

        return new java.awt.Dimension((int) Math.ceil(w), (int) Math.ceil(h));
    }
}
查看更多
0人赞 添加讨论(0) 举报
家丑人穷心不美
4楼-- · 2020-06-13 06:49

I found a solution to my problem. By replacing the JLabel with a JTextArea:

JTextArea text = new JTextArea();
text.setText(dummyString);
text.setLineWrap(true);
text.setWrapStyleWord(true);

And calling pack() followed by an invocation to the layout manager to layout the components again followed by another pack:

pack();
layout.invalidateLayout(this.getContentPane());
pack();

This will cause the layout manager to adapt to the width.

The complete code:

import static javax.swing.GroupLayout.DEFAULT_SIZE;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class TextSizeProblem3 extends JFrame {
  public TextSizeProblem3() {

    String dummyString = "";
    for (int i = 0; i < 100; i++) {
      dummyString += " word" + i;  //Create a long text
    }
    JTextArea text = new JTextArea();
    text.setText(dummyString);
    text.setLineWrap(true);
    text.setWrapStyleWord(true);

    JButton packMeButton = new JButton("pack");
    packMeButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        pack();
      }
    });

    GroupLayout layout = new GroupLayout(this.getContentPane());
    getContentPane().setLayout(layout);
    layout.setVerticalGroup(layout.createParallelGroup()
        .addComponent(packMeButton)
        .addComponent(text)
    );
    layout.setHorizontalGroup(layout.createSequentialGroup()
        .addComponent(packMeButton)
        .addComponent(text, DEFAULT_SIZE, 400, 400) //Lock the width to 400
    );

    pack();
    layout.invalidateLayout(this.getContentPane());
    pack();
  }

  public static void main(String args[]) {
    SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        JFrame frame = new TextSizeProblem3();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
      }
    });
  }
}

(you can add some customization (border, color etc) so it looks just like the JLabel but I have omitted that)

查看更多
0人赞 添加讨论(0) 举报
登录 后发表回答
相关问题
查看全部
相关文章
查看全部
收藏的人(4)