Get height of multi line text with fixed width to make dialog resize properly
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:
(source: lesc.se)
But I would like the dialog to look like this (as when you press the pack-button):
(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.
Answer
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.
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));
}
}