package example6_2;

import javax.swing.JOptionPane;
import java.util.Scanner;

/**
 * This example illustrates how to reduce JOptionPane pain.
 */
public class JOptionPain {
    public static void main(String[] args) {
        // The old way:
        String input = null;
        double consumedKg = -1;
        String message = "Please enter the amount you ate at Christmas, in kg: ";
        while(input == null || consumedKg < 0) {
            input = JOptionPane.showInputDialog(message);
            if(input != null) {
                // REPLACE THIS PART WITH Double.parseDouble()
                // and try/catch
                // No need to loop.
                // You can just catch "Exception"
                Scanner line = new Scanner(input); // Yes, this works!
                if(line.hasNextDouble()) {
                    consumedKg = line.nextDouble();
                } else {
                    message = "Please enter the amount you ate at Christmas, in kg.  Needs to be a double.";
                }

                if(consumedKg < 0) {
                    message = "Please enter the amount you ate at Christmas, in kg.  Needs to be positive.";
                }
            } else {
                message = "Please enter the amount you ate at Christmas, in kg.  Escape not optional.";
            }
        }
        JOptionPane.showMessageDialog(null,"You ate "+consumedKg+" kg of food!?!??!");
    }
}