Updating JTextArea from Observer
Hello everyone,
I was trying to update my UI by using an observer which notifies me whenever something changes.
The problem I have is that my UI always freezes until my function is done running and then parses all the info the observer passed to the TextArea instead of parsing it whenever I do the notify. Though if I write the info the oberserver passes to the console window it works properly. Now I read it has something to do with multithreading. The UI is locked because my functions is running and thus can't update.
But I have no clue how to solve it. Can someone give me a hint on how to make it work?
Below you can find a simple example.
Thanks in advance for any help.
My Main Class (The observer)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Observable;
import java.util.Observer;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
publicclass Mainextends JFrameimplements ActionListener,Observer{
private JTextArea txtTest;
private JPanel pnlTest;
private JButton btnTest;
public Main(){
pnlTest =new JPanel(null);
txtTest =new JTextArea();
txtTest.setBounds(250, 325, 550, 150);
txtTest.setEditable(false);
btnTest =new JButton("Test");
btnTest.setBounds(400, 500, 150, 25);
btnTest.addActionListener(this);
pnlTest.add(txtTest);
pnlTest.add(btnTest);
this.getContentPane().add(pnlTest);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Test");
this.setSize(1024,784);
this.show();
}
publicstaticvoid main(String[] args){
Main m =new Main();
}
publicsynchronizedvoid update(Observable o,final Object arg){
txtTest.append(arg.toString());
System.out.println(arg);
}
publicvoid actionPerformed(ActionEvent arg0){
Object obj = arg0.getSource();
if(obj == btnTest){
testRun tr =new testRun();
tr.addObserver(this);
tr.run();
}
}
}
My Class containing the function (Observable)
import java.util.Observable;
publicclass testRunextends Observable{
public testRun(){
}
publicvoid run(){
for(int i=0; i <= 1000; i++){
setChanged();
notifyObservers("a");
}
}
}
Observer interface
import java.util.Observable;
publicinterface Observer{
publicvoid upate(Observable o,Object arg);
}
Message was edited by:
lemr
Message was edited by:
lemr
