/** Pizza GUI based on book pp. 498-501.  Practice making radio buttons,
*   check boxes, text fields, etc.
*/
import java.text.*;         // NumberFormat
import java.awt.*;          // GridLayout, etc.
import java.awt.event.*;    // ActionListener, etc.
import javax.swing.*;       // JFrame, JRadioButton, etc.
import javax.swing.border.*;

public class PizzaFrame extends JFrame
{
  private JRadioButton smallButton;
  private JRadioButton mediumButton;
  private JRadioButton largeButton;
  private JCheckBox pepperoniBox;
  private JCheckBox anchoviesBox;
  private ActionListener listener;  // needs to update price
  private JLabel priceArea;         // doesn't need to be (big) text area

  /** We want our frame to consist of 3 basic parts:
   *  A set of radio buttons for size of pizza
   *  a couple check boxes to choose toppings (pepperoni and/or anchovies)
   *  a section where the price of the pizza is to be shown.
   *  So that this method doesn't get too long, these 3 parts will be
   *  created in other methods.
   */
  public PizzaFrame()
  {
    class DetectInput implements ActionListener
    {
      public void actionPerformed(ActionEvent e)
      {
        updatePrice();
      }
    }
    listener = new DetectInput();

    JPanel sizePanel = createButtons();
    JPanel toppingPanel = createBoxes();

    // put first 2 panels into another panel to group them
    JPanel centerPanel = new JPanel();
    centerPanel.add(sizePanel);
    centerPanel.add(toppingPanel);

    JPanel pricePanel = createOutput();

    getContentPane().add(centerPanel, BorderLayout.CENTER);
    getContentPane().add(pricePanel, BorderLayout.SOUTH);
    pack();
  }

  public JPanel createButtons()
  {
    // make 3 buttons, and attach the listener to them; make medium default
    smallButton = new JRadioButton("Small");
    mediumButton = new JRadioButton("Medium");
    largeButton = new JRadioButton("Large");
    smallButton.addActionListener(listener);
    mediumButton.addActionListener(listener);
    largeButton.addActionListener(listener);
    mediumButton.setSelected(true);

    // We need a button group because we want only 1 button to appear chosen
    // at a time.
    ButtonGroup group = new ButtonGroup();
    group.add(smallButton);
    group.add(mediumButton);
    group.add(largeButton);

    // make a panel for the radio buttons
    JPanel radioButtonPanel = new JPanel();
    radioButtonPanel.setLayout(new GridLayout(3,1));
    // do we need a border?
    radioButtonPanel.add(smallButton);
    radioButtonPanel.add(mediumButton);
    radioButtonPanel.add(largeButton);

    return radioButtonPanel;
  }

  public JPanel createBoxes()
  {
    // make 2 buttons for the toppings boxes
    pepperoniBox = new JCheckBox("Pepperoni");
    anchoviesBox = new JCheckBox("Anchovies");
    pepperoniBox.addActionListener(listener);
    anchoviesBox.addActionListener(listener);

    JPanel boxPanel = new JPanel();
    boxPanel.setLayout(new GridLayout(2,1));
    boxPanel.add(pepperoniBox);
    boxPanel.add(anchoviesBox);

    // do we want border around panel?
    return boxPanel;
  }

  public JPanel createOutput()
  {
    JPanel pricePanel = new JPanel();
    pricePanel.add(new JLabel("Your Price:  "));

    // initialize price and put it in panel too
    priceArea = new JLabel();
    updatePrice();                      // find price of default pizza
    pricePanel.add(priceArea);

    return pricePanel;
  }

  public void updatePrice()
  {
    double price;

    if (smallButton.isSelected())
      price = 5.25;
    else if (mediumButton.isSelected())
      price = 6.50;
    else        // then it must be large
      price = 7.75;

    if (pepperoniBox.isSelected())
    {
      price += 0.60;
    }
    if (anchoviesBox.isSelected())
    {
      price += 0.30;
    }

    // format the price and put it in the priceArea label
    NumberFormat money = NumberFormat.getCurrencyInstance();
    String output = money.format(price);
    priceArea.setText("" + output);
    repaint();
  }
}