I'm having some problem finding a way to add a scrollbar in a JFrame
. I found a method to redirect System.{in,out,err}
to a JTextArea
but I was not successful in adding a scrollbar. I hope this question is not redundant.
public class console extends JTextArea {
public static JTextArea console(final InputStream out, final PrintWriter in) {
final JTextArea area = new JTextArea();
new SwingWorker<Void, String>() {
@Override protected Void doInBackground() throws Exception {
Scanner s = new Scanner(out);
while (s.hasNextLine()) publish(s.nextLine() + "\n");
return null;
}
@Override protected void process(List<String> chunks) {
for (String line : chunks) area.append(line);
}
}.execute();
area.addKeyListener(new KeyAdapter() {
private StringBuffer line = new StringBuffer();
public void keyTyped(KeyEvent e) {
char c = e.getKeyChar();
if (c == KeyEvent.VK_ENTER) {
in.println(line);
line.setLength(0);
} else if (c == KeyEvent.VK_BACK_SPACE) {
line.setLength(line.length() - 1);
} else if (!Character.isISOControl(c)) {
line.append(e.getKeyChar());
}
}
});
return area;
}
public static void main(String[] args) throws IOException {
PipedInputStream inPipe = new PipedInputStream();
PipedInputStream outPipe = new PipedInputStream();
System.setIn(inPipe);
System.setOut(new PrintStream(new PipedOutputStream(outPipe), true));
PrintWriter inWriter = new PrintWriter(new PipedOutputStream(inPipe), true);
JFrame frame = new JFrame("\"Console\"");
frame.getContentPane().add(console(outPipe, inWriter));
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
// my code
}
Create a new JScrollPane
object and set the ScrollBarPolicies
.
If you do not want to the scollbars to appear always, just delete the policies.
EDIT
Also, don't use KeyListener on text components, use a combination of DocumentListener
and key bindings instead. (Thanks to @MadProgrammer)
JScrollPane jsp = new JScrollPane(console(outPipe, inWriter));
jsp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
jsp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
frame.getContentPane().add(jsp);