test.java

《Java2图形设计卷II：Swing》配套光盘源码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import java.io.FileReader;

public class Test extends JApplet {
	private JTextArea textArea = new JTextArea();
	private Container contentPane = getContentPane();

	public void init() {
		readFile(textArea, "text");
		contentPane.add(new ControlPanel(), BorderLayout.NORTH);
		contentPane.add(new JScrollPane(textArea), 
						BorderLayout.CENTER);
	}
	private void readFile(JTextComponent textComponent,String s) {
		try { (new DefaultEditorKit()).read(
			   new FileReader(s), textComponent.getDocument(), 0);
		} catch(Exception ex) { ex.printStackTrace(); }
	}
	class ControlPanel extends JPanel { 
		JRadioButton radioButtons[] = new JRadioButton[] {
			new JRadioButton("wrap off"),
			new JRadioButton("wrap characters"),
			new JRadioButton("wrap words"),
		};

		public ControlPanel() {
			ButtonGroup group = new ButtonGroup();
			Listener listener = new Listener();

			for(int i=0; i < radioButtons.length; ++i) {
				JRadioButton b = radioButtons[i];

				b.addActionListener(listener);
				group.add(b);
				add(b);

				if(i == 0) 
					b.setSelected(true); // "wrap off"
			}
		}
		class Listener implements ActionListener {
			public void actionPerformed(ActionEvent e) {
				String action = e.getActionCommand();

				textArea.setLineWrap(!action.equals("wrap off"));
				textArea.setWrapStyleWord(
									action.equals("wrap words"));
				//textArea.repaint();

				showStatus("rows: " + textArea.getRows() +
					", columns: " + textArea.getColumns() +
					", lines: " + textArea.getLineCount());

			}
		};
	}
}