JFrame extended Example
It can sometimes be convenient to extend the class JFrame in the way shown. Class Guht is a JFrame subclass. Notice how the first line of the constructor calls super(). This allows the program to pass a title for the frame to JFrame's constructor.
The program uses a JTextPane and SimpleAttributeSet to present some text to the user.
// JFrame extended example
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;
class JFrameExtendedExample extends JFrame {
private JTextPane jtp;
public JFrameExtendedExample() {
super("JFrame extended");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jtp = new JTextPane();
jtp.setFont(new Font("SansSerif", Font.PLAIN, 18));
SimpleAttributeSet as0 = new SimpleAttributeSet();
StyleConstants.setForeground(as0, Color.blue);
StyleConstants.setItalic(as0, true);
SimpleAttributeSet as1 = new SimpleAttributeSet();
StyleConstants.setForeground(as1, Color.orange);
StyleConstants.setBold(as1, true);
appendText("It was a bright ", null);
appendText("cold", as0);
appendText(" day in ", null);
appendText("April", as1);
getContentPane().add(new JScrollPane(jtp));
setSize(180,150);
setVisible(true);
}
private void appendText(String s, AttributeSet attributes) {
Document d = jtp.getDocument();
try {
d.insertString(d.getLength(), s, attributes);
}
catch (BadLocationException e) {}
}
public static void main(String[] args) {
new JFrameExtendedExample();
}
}