package examples;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
 * CS401 Example 33d
 * 
 * <p>
 * Compare to ex33b and ex33c. Now we have added a JTextField to the JFrame,
 * which allows us to change the label on the JButton. However, since we need to
 * access both the JButton and the JTextField from the same ActionListener, the
 * program is now written in a fundamentally different way:
 * </p>
 * <ul>
 * <li>Note that the component references are now instance variables, not
 * method variables.</li>
 * <li>Now the "setup" of the JFrame is done in the constructor, not in the
 * main program. The main program simply creates an ex33d object and the rest is
 * handled within the constructor.</li>
 * <li>The MyListener class is now an INNER CLASS. this means that it is
 * declared WITHIN another class. This allows MyListener to access the instance
 * variables of the ex33d class, so it can access the JButton and JTextField
 * references directly.</li>
 * </ul>
 * <p>
 * If you compare the general structure of this program with the previous three,
 * you will see that this is in fact more "object-oriented" in its design. Note
 * how simple the main() method is. Most of the work is done through objects in
 * the program interacting with each other.
 * </p>
 * 
 * @author Dr. Ramirez, PJ Dillon
 */
public class ex33d
{
	private JFrame theWindow;
	private JButton theButton;
	private JTextField theText;
	private MyListener theListener;

	public ex33d()
	{
		theWindow = new JFrame("Example 33d");
		theWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		theButton = new JButton("Change Color");
		theButton.setFont(new Font("Serif", Font.ITALIC + Font.BOLD, 28));
		
		theListener = new MyListener();
		theButton.addActionListener(theListener);

		theText = new JTextField();
		theText.setFont(new Font("Serif", Font.BOLD, 28));
		theText.addActionListener(theListener);

		Container thePane = theWindow.getContentPane();
		thePane.setLayout(new GridLayout(2,1));
		thePane.add(theButton);
		thePane.add(theText);

		theWindow.setSize(400, 200);
		theWindow.setVisible(true);
	}

	/**
	 * Note that BOTH the JButton and the JTextField are using the same
	 * ActionListener, as defined below. This is not required, but it is
	 * convenient in this case. Because different events could trigger this
	 * listener, the actionPerformed method must test to see which reference
	 * actually generated the ActionEvent.
	 */
	private class MyListener implements ActionListener
	{
		/*
		 * Inner classes cannot have static instance members(variables or methods)
		 * unless the inner class, itself, is declared to be static, in which case
		 * it is then not allowed to access the instance members of its outer class,
		 * such as theButton.
		 */
		final Color [] theColors = {Color.RED, Color.BLUE, Color.CYAN,
									 Color.ORANGE, Color.MAGENTA};
		int index = 0;

		public void actionPerformed(ActionEvent e)
		{
			Component theEventer = (Component) e.getSource();
			
			/*
			 * If event was generated by the JButton, do as we did in ex14b -- change
			 * the color
			 */
			if (theEventer == theButton)
			{
				theEventer.setForeground(theColors[index]);
				index = (index + 1) % theColors.length;
			}
			
			/*
			 * If event was generated by the JTextField, take the text from the
			 * JTextField and use it to set the text of the JButton. Then blank out
			 * the JTextField.
			 */
			else if (theEventer == theText)
			{
				theButton.setText(theText.getText());
				theText.setText("");
			}
		}
	}

	/*
	 * Note how simple the main is here -- just one line. Creating the object
	 * causes the constructor to be called, which sets up the JFrame. Even though
	 * it looks like the program should then end, when graphical components are
	 * used, the program will not terminate unless done so explicitly (through
	 * closing the window in this case).
	 */
	public static void main(String [] args)
	{
		new ex33d();
	}
}