/*
   DaGui1.java
   CIS 160
   2014-10-23
   David Klick

   Very basic GUI demonstration with listener for button.
*/

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

public class DaGui1 extends JFrame implements ActionListener {
    // Declare a global label so two different methods can access it.
    private JLabel label = null;
    
    // Create global counter to make state persistent.
    private int counter = 0;
    
    // Create a new object of ourself when program starts.
    public static void main(String[] args) {
        new DaGui1();
    }
    
    // Default constructor
    public DaGui1() {
        // Create a thread to set up the GUI when the EDT
        // (Event Dispatch Thread) gets time.
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
    
    // This method sets up and displays the GUI.
    public void createAndShowGUI() {
        // Get a container for the GUI components.
        Container c = getContentPane();
        
        // Set the layout manager for the container.
        c.setLayout(new BorderLayout());
        
        // Create the widgets.
        label = new JLabel("Hi");
        JButton btn = new JButton("Klick me");
        
        // Add this object as the event listener for the button.
        btn.addActionListener(this);
        
        // Add widgets to container.
        c.add(btn, BorderLayout.CENTER);
        c.add(label, BorderLayout.NORTH);
        
        // Set close operation and display GUI.
        setSize(500, 400);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    // This method handles button clicks.
    public void actionPerformed(ActionEvent e) {
        // If number of clicks on the button is less than
        // 5, then display "Go away!", else end the program.
        counter++;
        if (counter < 5) {
            label.setText("Go away!");
        } else {
            System.exit(0);
        }
    }
}