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

/**
 * A GUI application including JTextFields for numeric
 * input and output; lets user enter 2 numbers for multiplying
 * 
 * @author Sharon Tuttle
 * @version 2015-09-23
 */

public class Mult2
{
    /**
     * creates a Mult2Frame
     * 
     * @param args not used here
     */
    
    public static void main(String args[])
    { 
        EventQueue.invokeLater(
            new Runnable()
            {
                public void run()
                {
                    Mult2Frame mainFrame = new Mult2Frame();
                    mainFrame.setDefaultCloseOperation( 
                        JFrame.EXIT_ON_CLOSE );    
                    mainFrame.setVisible(true); 
                }
            });
    }
}

/** 
 * A frame with a panel containing several elements to allow a user
 * to find the product of two values
 */

class Mult2Frame extends JFrame
{
    // data fields
    
    private final static int DEFAULT_WIDTH = 325;
    private final static int DEFAULT_HEIGHT = 250;
    
    /**
     * constructs a Mult2Frame instance
     */
    
    public Mult2Frame()
    {    
        this.setTitle("Mult2");
        this.setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        // add Mult2 panel to frame
        
        Mult2Panel panel = new Mult2Panel();
        this.add(panel);
    }
}

/**
 * A panel containing elements to determine the product
 *    for two values
 */

class Mult2Panel extends JPanel
{
    // data fields for Mult2Panel
    
    private JTextField val1Field, val2Field;
    private JTextField resultField;
    
    /**
     * constructs a Mult2 panel instance
     */
    
    public Mult2Panel()
    {        
        // set up a welcome label for the panel
        
        JLabel welcome =  new JLabel("Mult2");
        welcome.setForeground(Color.BLUE);
        this.add(welcome);
        
        // set up user instructions
        
        JLabel instructions = new JLabel("Enter values to be multiplied, then click multiply");
        this.add(instructions);
               
        // set up places to enter the desired values
        
        val1Field = new JTextField(5);
        val1Field.setText("0");
        this.add(val1Field);
        
        val2Field = new JTextField(5);
        val2Field.setText("0");
        this.add(val2Field);

        // set up button user uses to ask for multiplication to be done
        
        JButton multButton = new JButton("Multiply Values");
        this.add(multButton);
        multButton.addActionListener(new MultAction());        

        // set up the result label and textfield
        
        JLabel resultLabel = new JLabel("   And the product is:   ");
        this.add(resultLabel);
        
        resultField = new JTextField("0", 8);
        resultField.setForeground(Color.blue);
        this.add(resultField);

    } // end Mult2Panel constructor  
    
    /**
     * An action listener that tries to multiply the values in
     * val1Field and val2Field and show the result in resultField
     */
    
    private class MultAction implements ActionListener
    {   
        // default constructor will suffice, in this case
        
        /**
         * tries to multiply the values in val1Field and val2Field
         * and display the result in resultField
         * 
         * @param event the mult button push
         */
        
        public void actionPerformed(ActionEvent event)
        {            
            double currVal1 = Double.parseDouble(val1Field.getText());
            double currVal2 = Double.parseDouble(val2Field.getText());
          
            // set product computed appropriately
            
            double currProduct = currVal1 * currVal2;            
            resultField.setText("" + currProduct);
        }
    }
}