/**
 * IfStatementEx
 *
 * This program demonstrates loop statements - "The Fibonacci Series.
 * The Fibonacci series is a sequence of numbers in which each successive number is the sum of the two preceding numbers.
 * The sequence begins 1, 1, 2, 3, 5, 8, 13, 21, etc.
 *
 * @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 FiboEx {
 
 	public static void main(String[] args) {
	
		/** DON'T BE CONCERNED WITH THIS SECTION **/		
		JFrame frame = new JFrame( "Fibonacci Series 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( "Fibonacci Series\n\n" +
								  "int currentNum, prevNum = 1, prevprevNum = 0;	// Initialize all variables\n\n" +
								  "for(int i = 0; i <= 50; i++) {\n\n" +
								  "  currentNum = prevNum +  prevprevNum;	// sum of the two preceding numbers\n\n" +
								  "  if( currentNum >= 50 )	// if currentNum >= 50 exit\n" +
								  "	   break;\n\n" + 
								  "  message += currentNum + \"\\n\";" +
								  "     				// Reset variables\n\n" +
								  "  prevpreNum = prevNum;	// previous number is now the previous to the previous\n\n" +
								  "  prevNum = currentNum;	// current number is now the previous\n\n" +
								  "}\n\n" +
								  "tA.setText( message );	// Output series" );
			}
		});
		
        frame.getContentPane().add( codeButton, BorderLayout.SOUTH );					
	    frame.pack();
      	frame.setVisible(true);
		
		testFibo( frame, textArea );
	}
	
	public static void testFibo(JFrame frame, JTextArea tA) {
		
		JOptionPane.showMessageDialog( frame, "Are you ready for the Fibonacci Series from 1 to 50" );
		
		String message = "";							//initialize a message variable
		/***** THIS IS THE SECTION OF INTEREST *****/
		
		int currentNum, prevNum = 1, prevprevNum = 0;	// Initialize all variables
		
		for(int i = 0; i <= 50; ) {
						
			currentNum = prevNum +  prevprevNum;		// sum of the two preceding numbers
			
			if( currentNum >= 50 )						// if currentNum >= 50 exit
				break;
				
			message += currentNum + "\n";
														// Reset variables
			prevprevNum = prevNum;						// previous number is now the previous to the previous 
			prevNum = currentNum;						// current number is now the previous
			i = currentNum;								// set iterator to current number			
		}
		
		tA.setText( message );							// Output series
	}
	
}