Thread: GUI button not linking back to code

Hello, I have started coding recently and been working on a simple java timer. My problem is that the button does not show any response even though an action has been done via actionlistener.
Example: When I press the "Start Timing" button, it should start timing and output the counter to Static Timer but instead of doing that, it does nothing.

The important bits are under Timer code and Button Start Timing
Is their something that I'm missing?

//--- All imports have been handled --- 
public class GUI {
	double counter = 1;
	double inputA = 1;
	int delay = 1000;
	Timer timer = new Timer(delay, null);
 
//--- Timer Code ---	
 
	public void timer(){
	    timer = new Timer(delay, new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	            if (counter <= inputA) {
	            	txtEnterHowLong.setEditable(true);
	                timer.stop();
	            } else {
	            	inputA = Double.parseDouble(txtEnterHowLong.getText());
	            	txtEnterHowLong.setEditable(false);
	            	System.out.println(counter);
	            	counter++;
	            	txtCounter.setText(counter + ""); 
	            }
	        }
	    });
	}
 
//-------------------
 
	private JFrame frmTimer;
	private JTextField txtEnterHowLong;
 
//Launch the Application
 
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					GUI window = new GUI();
					window.frmTimer.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
 
//--- Create the Application ---
 
	private JTextField txtCounter;
	private JPanel panel;
	private JTextField txtCurrentTimer;
	public GUI() {
		initialize();
	}
 
//--- Initialize contents of frame ---
 
	private void initialize() {
		frmTimer = new JFrame();
		frmTimer.setTitle("Timer");
		frmTimer.setBounds(100, 100, 350, 200);
		frmTimer.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frmTimer.getContentPane().setLayout(null);
 
//--- Button "Start Timing" created ---
 
		JButton btnStartTiming = new JButton("Start Timing");
	    btnStartTiming.addActionListener(new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	        inputA = Double.parseDouble(txtEnterHowLong.getText());
	        timer.start();
	        }
	    });
		btnStartTiming.setRequestFocusEnabled(false);
 
		panel = new JPanel();
		panel.setBounds(10, 11, 200, 22);
		frmTimer.getContentPane().add(panel);
		panel.setLayout(null);
 
//--- Input field created ---
 
		txtEnterHowLong = new JTextField();
		txtEnterHowLong.setEditable(true);
		txtEnterHowLong.setBounds(0, 0, 200, 22);
		panel.add(txtEnterHowLong);
		txtEnterHowLong.setToolTipText("Time in Seconds");
		btnStartTiming.setBounds(220, 10, 110, 23);
		frmTimer.getContentPane().add(btnStartTiming);
 
//--- Button "Stop Timing" created ---
 
		JButton btnStopTiming = new JButton("Stop Timing");
		btnStopTiming.setBounds(220, 40, 110, 23);
		frmTimer.getContentPane().add(btnStopTiming);
 
//--- Radio button "Play sound" created ---
 
		JRadioButton rdbtnPlaySoundWhen = new JRadioButton("Play sound when time is up?");
		rdbtnPlaySoundWhen.setBounds(10, 40, 188, 22);
		frmTimer.getContentPane().add(rdbtnPlaySoundWhen);
 
//--- Static counter created ---
 
		txtCounter = new JTextField();
		txtCounter.setText("Static Timer");
		txtCounter.setToolTipText("Shows total time that has passed.");
		txtCounter.setBounds(110, 69, 100, 20);
		frmTimer.getContentPane().add(txtCounter);
		txtCounter.setColumns(10);
 
//--- Current timer created ---
 
		txtCurrentTimer = new JTextField();
		txtCurrentTimer.setToolTipText("Shows current time that has passed.");
		txtCurrentTimer.setText("Current Timer");
		txtCurrentTimer.setBounds(10, 69, 86, 20);
		frmTimer.getContentPane().add(txtCurrentTimer);
		txtCurrentTimer.setColumns(10);
 
//------------------------------
 
		JMenuBar menuBar = new JMenuBar();
		frmTimer.setJMenuBar(menuBar);
 
		JMenu mnView = new JMenu("View");
		menuBar.add(mnView);
 
		JMenu mnAbout = new JMenu("About");
		menuBar.add(mnAbout);
	}
}

Originally Posted by andbin

I have not analyzed all the code (there can be other bad things) but one thing is clear: your timer() method is never invoked. So remains the new Timer(delay, null) object that does nothing.

As soon as I think I've fixed it, the whole code dies on me. It requests me to put in some } at the end to fix syntax errors and all of the code basically becomes corrupt and dependent on other things (not imports).

Updated broken code:

public class GUI {
	double counter = 1;
	double inputA = 5;
	int delay = 1000;
 
//--- Timer Code ---	
 
	public void timer(){
		Timer timer = new Timer(delay, null);
	}
		 ActionListener counting = new ActionListener() {
		      public void actionPerformed(ActionEvent evt) {
		            if (counter <= inputA) {
		                timer.stop();
		            } else {
		            	System.out.println(counter);
		            	counter++;
		            	txtCounter.setText(counter + ""); 
		            }
	}
 
//-------------------
 
	private JFrame frmTimer;
	private JTextField txtEnterHowLong;
 
//Launch the Application
 
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					GUI window = new GUI();
					window.frmTimer.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
 
//--- Create the Application ---
 
	private JTextField txtCounter;
	private JPanel panel;
	private JTextField txtCurrentTimer;
	private final Checkbox checkbox = new Checkbox("Play sound when time is up?");
	public GUI() {
		initialize();
	}
 
//--- Initialize contents of frame ---
 
	public void initialize() {
		frmTimer = new JFrame();
		frmTimer.setTitle("Timer");
		frmTimer.setBounds(100, 100, 350, 160);
		frmTimer.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frmTimer.getContentPane().setLayout(null);
 
//--- Button "Start Timing" created ---
 
		JButton btnStartTiming = new JButton("Start Timing");
	    btnStartTiming.addActionListener(new ActionListener(){
	        public void actionPerformed(ActionEvent counting) {
	        	new Timer(delay, counting).start();
 
	        }
	    });
		btnStartTiming.setRequestFocusEnabled(false);
 
		panel = new JPanel();
		panel.setBounds(10, 11, 200, 22);
		frmTimer.getContentPane().add(panel);
		panel.setLayout(null);
 
//--- Input field created ---
 
		txtEnterHowLong = new JTextField();
		txtEnterHowLong.setEditable(true);
		txtEnterHowLong.setBounds(0, 0, 200, 22);
		panel.add(txtEnterHowLong);
		txtEnterHowLong.setToolTipText("Time in Seconds");
		btnStartTiming.setBounds(220, 10, 110, 23);
		frmTimer.getContentPane().add(btnStartTiming);
 
//--- Button "Stop Timing" created ---
 
		JButton btnStopTiming = new JButton("Stop Timing");
		btnStopTiming.setBounds(220, 40, 110, 23);
		frmTimer.getContentPane().add(btnStopTiming);
 
//--- Static counter created ---
 
		txtCounter = new JTextField();
		txtCounter.setText("Static Timer");
		txtCounter.setToolTipText("Shows total time that has passed.");
		txtCounter.setBounds(108, 67, 100, 20);
		frmTimer.getContentPane().add(txtCounter);
		txtCounter.setColumns(10);
 
//--- Current timer created ---
 
		txtCurrentTimer = new JTextField();
		txtCurrentTimer.setToolTipText("Shows current time that has passed.");
		txtCurrentTimer.setText("Current Timer");
		txtCurrentTimer.setBounds(10, 67, 86, 20);
		frmTimer.getContentPane().add(txtCurrentTimer);
		txtCurrentTimer.setColumns(10);
 
 
//--- Checkbox ---		
 
		checkbox.setFont(new Font("Dialog", Font.BOLD, 12));
		checkbox.setBounds(10, 32, 200, 31);
		frmTimer.getContentPane().add(checkbox);
				checkbox.addItemListener(new ItemListener() {
			public void itemStateChanged(ItemEvent arg0) {
				 if (counter == inputA) {
					 sound.play("test.wav");
		            } else {
                     //Do nothing
		            }
			}
		});
 
//------------------------------
 
		JMenuBar menuBar = new JMenuBar();
		frmTimer.setJMenuBar(menuBar);
 
		JMenu mnView = new JMenu("View");
		menuBar.add(mnView);
 
		JMenu mnAbout = new JMenu("About");
		menuBar.add(mnAbout);
	}
		 };
}

The code just goes AWOL after this point. No automatic eclipse fixes will help me fix the errors that keep popping up consistently.
If I try to run the code with errors it gives me: Error: Main method not found in class GUI, please define the main method as:
public static void main(String[] args)

Originally Posted by andbin

Just after the timer() method there is ActionListener counting = .... that the compiler interprets as an instance variable. But this declaration doesn't close correctly. And I suppose it's not what you wanted.

I see also a:
new Timer(delay, counting).start();

where counting is the ActionEvent, which is wrong.

I think i have figured out the problem,

//--- Button "Start Timing" created ---
 
		JButton btnStartTiming = new JButton("Start Timing");
	    btnStartTiming.addActionListener(new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	        inputA = Double.parseDouble(txtEnterHowLong.getText());
	        timer.start();
	        }
	    });
		btnStartTiming.setRequestFocusEnabled(false);
 
		panel = new JPanel();
		panel.setBounds(10, 11, 200, 22);
		frmTimer.getContentPane().add(panel);
		panel.setLayout(null);

the timer.start does not reach my code that the timer should fulfill and instead runs this code

Timer timer = new Timer(delay, ActionEvent);

when it should run this:

        public void timer(ActionListener ActionEvent){	
		timer = new Timer(delay, new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	            if (counter <= inputA) {
 
	            } else {
	            	System.out.println(counter);
	            	counter++;
	            	txtCounter.setText(counter + ""); 
	            }
	        }
	    });
	}

Is their a way to organize the code so that the code above will be available to the whole program instead of just that part?

--- Update ---

I think I have slimmed down the code just to this part now:

//--- Timer Code ---	
	Timer timer = new Timer(delay, ActionEvent);
 
	public void timer(){	
		timer = new Timer(delay, new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	        	inputA = Double.parseDouble(txtEnterHowLong.getText());
	            if (counter >= inputA) {
 
	            } else {
	            	System.out.println(counter);
	            	counter++;
	            	txtCounter.setText(counter + ""); 
	            }
	        }
	    });
	    btnStartTiming.addActionListener(new ActionListener(){
	        public void actionPerformed(ActionEvent e) {
	            timer.start();
	        }
	    });}

but it still will not link to the button when I click on it.

This is the code that creates the JButton and adds an action listener to it:

JButton btnStartTiming = new JButton("Start Timing");
 
btnStartTiming.addActionListener(new ActionListener()
{
    public void actionPerformed(ActionEvent e)
    {
        inputA = Double.parseDouble(txtEnterHowLong.getText());
        timer.start();
    }
} );

If you want the button presses to do something else or to execute the other code you've posted, then put that code into the actionPerformed() method above or call that code as a method from the actionPerformed() method.

Originally Posted by GregBrannon

This is the code that creates the JButton and adds an action listener to it:

JButton btnStartTiming = new JButton("Start Timing");
 
btnStartTiming.addActionListener(new ActionListener()
{
    public void actionPerformed(ActionEvent e)
    {
        inputA = Double.parseDouble(txtEnterHowLong.getText());
        timer.start();
    }
} );

If you want the button presses to do something else or to execute the other code you've posted, then put that code into the actionPerformed() method above or call that code as a method from the actionPerformed() method.

This is the code that I came up with,

		JButton btnStartTiming = new JButton("Start Timing");
		btnStartTiming.addActionListener(new ActionListener(){
			Timer timer = new Timer(delay, ActionEvent);
		    public void actionPerformed(ActionEvent e)
		    {
                try{
                    inputA = Double.parseDouble(txtEnterHowLong.getText());
                   }catch(NumberFormatException ex){
                   }
		        while (counter <= inputA) {
		        	timer.start();		        	
		        	System.out.println(counter);
		        	txtCounter.setText(counter + ""); 
		        	counter++;
 
		        }
		    }
		} );

It still doesn't have a delay though. Delay is set to 1000.

Creating a new Timer each time the button is clicked is probably unnecessary, but I have no idea what this code is supposed to do. Have you described that anywhere? It seems that you're not only coding without knowing what to code - that's okay and why you've come here - but without knowing what the code is supposed to do. Those two put together usually result in a mess, and at that I think you've been highly successful.

To help get you back on track, please describe what the finished product is supposed to do. What is happening before the button is pressed, and what effect is produced by pressing the button? What is supposed to be delayed? What happens after the delay is over?

Originally Posted by GregBrannon

Creating a new Timer each time the button is clicked is probably unnecessary, but I have no idea what this code is supposed to do. Have you described that anywhere? It seems that you're not only coding without knowing what to code - that's okay and why you've come here - but without knowing what the code is supposed to do. Those two put together usually result in a mess, and at that I think you've been highly successful.

To help get you back on track, please describe what the finished product is supposed to do. What is happening before the button is pressed, and what effect is produced by pressing the button? What is supposed to be delayed? What happens after the delay is over?

Basically, when the button is pressed, it should delay these commands for one second

		        	System.out.println(counter);
		        	txtCounter.setText(counter + ""); 
		        	counter++;

then repeat the commands until the counter reaches the users input without freezing the GUI.

If an action is already occurring at 1-second intervals, what will be the apparent effect of pausing that action for 1 second? Hint: None. Please, describe it again after thinking it through. Another possibility is that you've already accomplished what you've described and just didn't realize it.

Originally Posted by GregBrannon

If an action is already occurring at 1-second intervals, what will be the apparent effect of pausing that action for 1 second? Hint: None. Please, describe it again after thinking it through. Another possibility is that you've already accomplished what you've described and just didn't realize it.

The problem is that the delay doesn't actually occur.

This should work but it does not delay -.-

		JButton btnStartTiming = new JButton("Start Timing");
		btnStartTiming.addActionListener(new ActionListener(){
		    public void actionPerformed(ActionEvent e){		        	
		    	Timer displayTimer = new Timer(delay, null);
                try{
                    inputA = Double.parseDouble(txtEnterHowLong.getText());
                   }catch(NumberFormatException ex){
                   }
		        while (counter <= inputA) {      	
		        	displayTimer.restart();
		        	System.out.println(counter);
		        	txtCounter.setText(counter + ""); 
		        	counter++;
 
		        }
		    }
		} );

Originally Posted by andbin

The following can serve you as a good "lesson":

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class CounterTimer {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new CounterTimerFrame().setVisible(true);
            }
        });
    }
}
 
class CounterTimerFrame extends JFrame {
    private int counter;
    private JButton startButton;
    private JLabel counterLabel;
    private Timer timer;
 
    public CounterTimerFrame() {
        super("Counter Timer");
 
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(250, 200);
 
        startButton = new JButton("Start");
        counterLabel = new JLabel("Counter: ");
 
        startButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                startEvent();
            }
        });
 
        timer = new Timer(500, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                timerEvent();
            }
        });
 
        getContentPane().add(startButton, BorderLayout.NORTH);
        getContentPane().add(counterLabel, BorderLayout.SOUTH);
    }
 
    private void startEvent() {
        counter = 1;
        timer.start();
        startButton.setEnabled(false);
    }
 
    private void timerEvent() {
        counterLabel.setText("Counter: " + counter);
 
        if (counter < 10) {    // 10 is fixed here but could be a variable
            counter++;
        } else {
            timer.stop();
            startButton.setEnabled(true);
        }
    }
}

Thankyou so much dude. It took me a while to figure that out.