/**
 * WhileLoopEx
 *
 * This program demonstrates while loops structures.
 *
 * @author Brad Rippe
 */

 import javax.swing.*;
 import java.awt.*;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
 import java.awt.event.ActionListener;
 import java.awt.event.ActionEvent;
 import java.awt.Container;
 import javax.swing.UIManager;

 public class WhileLoopEx {

 	public static void main(String[] args) {

		/** DON'T BE CONCERNED WITH THIS SECTION **/
		JFrame frame = new JFrame( "While Loop Demo" );

		try {
	        UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
    	} catch (Exception e) { }


    	frame.addWindowListener(new WindowAdapter() {
        	public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
	    });

		final JTextArea textArea = new JTextArea( 35, 35 );

		JScrollPane scrollPane = new JScrollPane( textArea );
		scrollPane.setPreferredSize( new Dimension( 600, 300 ) );
		frame.getContentPane().add( scrollPane, BorderLayout.CENTER );

		JButton codeButton = new JButton( "Show Code" );
		codeButton.addActionListener( new ActionListener() {
			public void actionPerformed( ActionEvent e ) {
				textArea.setFont( new Font("Courier", Font.BOLD, 16 ) );
				textArea.setText( "While Loop\n\n" +
								  "String message = \"\";\n\n" +
								  "int i = 0;\n\n" +
								  "// Counter-Control\n\n" +
								  "while( i <= 25 ) {\n\n" +
								  "  message += \"Just a simple loop on iteration \" + i + \"\\n\";\n\n" +
								  "  i++;\n\n" +
								  "}\n\n" +
								  "// Sentinal Control\n\n" +
								  "final int SENTINAL = -1;\n\n" +
								  "String ageString = \"\";\n\n" +
								  "int age = 0;\n\n" +
								  "while( SENTINAL != age ) {\n\n" +
								  "  ageString = JOptionPane.showInputDialog( frame, \"How old are you?\" );\n\n" +
								  "  age = Integer.parseInt( ageString );\n\n" +
								  "  JOptionPane.showMessageDialog( frame, \"I will ask you this until you type -1!\" );\n\n" +
								  "}\n\n" +
								  "tA.setText( message );" );
			}
		});

        frame.getContentPane().add( codeButton, BorderLayout.SOUTH );
	    frame.pack();
      	frame.setVisible(true);

		testLoop( frame, textArea );
	}

	public static void testLoop(JFrame frame, JTextArea tA) {

		/***** THIS IS THE SECTION OF INTEREST *****/
		String message = "";
		int i = 0;

		// Counter-Control
		while( i <= 25 ) {
			message += "Just a simple loop on iteration " + i + "\n";
			i++;
		}

		// Sentinal Control
		final int SENTINAL = -1;
		String ageString = "";
		int age = 0;

		while( SENTINAL != age ) {
			ageString = JOptionPane.showInputDialog( frame, "How old are you?" );
			age = Integer.parseInt( ageString );
			JOptionPane.showMessageDialog( frame, "I will ask you this until you type -1!" );
		}
		tA.setText( message );
	}

}