java 事件回滚 java滚动条事件

import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class Main {
String TEXT = "This \r\n" + " Is\r\n" + " A\r\n" + " Testing\r\n"
+ " To\r\n" + " Test\r\n" + " ScrollPane.";
JTextArea jTextArea_content;
JScrollPane jScrollPane_descContent;
private void initUI() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getJTextArea_content().setText(TEXT);
frame.add(getJScrollPane_descContent());
frame.pack();
frame.setVisible(true);
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
getJTextArea_content().scrollRectToVisible(new Rectangle());
}
});
}
private JTextArea getJTextArea_content() {
if (jTextArea_content == null) {
jTextArea_content = new JTextArea(3, 30);
jTextArea_content.setBounds(new Rectangle(75, 224, 678, 47));
}
return jTextArea_content;
}
private JScrollPane getJScrollPane_descContent() {
if (jScrollPane_descContent == null) {
jScrollPane_descContent = new JScrollPane(getJTextArea_content());
jScrollPane_descContent.setBounds(new Rectangle(75, 224, 660, 47));
}
return jScrollPane_descContent;
}
public static void main(String[] args) {
new Main().initUI();
}
}