loop in a JFrame

[james kinyua]

is it possible to implement for loop in JFrame

[Stephan van Hulst]

You can not implement a for loop. 'for' is a keyword.

You need to be more specific what you want to achieve.

[Campbell Ritchie]

You can write a for statement almost anywhere. But writing it in a display class looks like possibly poor design to me.

[james kinyua]

i want to convert this loop into a jframe and am not sure how to go about it

  public void run()
    {
        int x = runs;
        double Tfw = 0,tbags=0;

        for(x=1; x<=runs; x++){
            
            System.out.println("Enter time out in run " +x);
              t1=input.next();
            System.out.println("Enter time in for run " +x);
              t2=input.next();
              
		try {
			Date d1 = format.parse(t1);
			Date d2= format.parse(t2);
 
			//in milliseconds
			long diff = d2.getTime() - d1.getTime();
 
			//long diffSeconds = diff / 1000 % 60;
                       long diffHours = diff / (60 * 60 * 1000) % 24;
                       long diffMinutes = diff / (60 * 1000) % 60;
 
		System.out.println("FIELD TIME FOR RUN" +" "+x +" "+ "is");
		System.out.println(diffHours + " hours, ");
		System.out.println(diffMinutes + " minutes, ");
                     } catch (Exception e) {
                }

[Campbell Ritchie]

You can in theory run such code anywhere. But why? A frame is intended for displaying things, not for running loops. If you simply run that loop, you will be asking for information much faster than you can write in the fields.
What you might do is add listeners to text fields, or to buttons. I think you can add action listeners which are fired when you push the enter key on a text component. You can have a label where you set the text something like

Enter In Time No 123

adjacent to a text field where you can enter the time. You can use the enter key on the text fields or a button to fire an action.

Have you got the logic for that loop working correctly? Why have you got an empty catch statement? That is dangerous because Exceptions can occur and you would never know. Don't even think about a GUI until you have that loop working correctly.

[james kinyua]

Thanks, i had the idea but i never thought it would be possible in a button.
i have another problem when i try to add a button in the GroupLayout.

package vt;
import javax.swing.*;

public class Vt extends JPanel {

    final JLabel label1 = new JLabel("Enter Vehicle Registration:");
    final JTextField field1 = new JTextField(10);
    final JLabel label2 = new JLabel("Enter Number Of Runs:");
    final JTextField field2 = new JTextField(10);


    final JButton bt = new JButton("Submit");
    public Vt() {
        GroupLayout layout = new GroupLayout(this);          
        this.setLayout(layout);
        layout.setAutoCreateGaps(true);
        layout.setAutoCreateContainerGaps(true);
        layout.setHorizontalGroup(layout.createSequentialGroup()
            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.TRAILING)
                .addComponent(label1)
                .addComponent(label2)
                .addComponent(bt)
)
            .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                .addComponent(field1)
                .addComponent(field2)
                )

        );
        
    }

    private static void display() {
        JFrame f = new JFrame("Vehicle Turnabout");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setLayout(new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
        f.add(new Vt());
        f.add(Box.createVerticalGlue());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
       display();
       
    
    }
}

Also how do i center the button?

[Campbell Ritchie]

Don't know. Surely the GUI Builder in NetBeans will do any centring for you?