// structure/presentation-model/CalcViewController.java
// Fred Swartz - December 2004.

// GUI Organization - GUI independent of model.
//
//     GUI subclasses JFrame and builds it in the constructor.
//
//     The GUI creates a calculator model object, but knows nothing
//     about the internal implementation of the calculator.

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

public class CalcViewController extends JFrame {
    //============================================================= Constants
    private static final String INITIAL_VALUE = "1";

    //========================================================= instance vars
    //... The Model.
    private CalcModel  m_logic;

    //... Components
    private JTextField m_userInputTf = new JTextField(5);
    private JTextField m_totalTf     = new JTextField(20);
    private JButton    m_multiplyBtn = new JButton("Multiply");
    private JButton    m_clearBtn    = new JButton("Clear");

    //=========================================================== constructor
    /** Constructor */
    CalcViewController() {
        //... Set up the logic
        m_logic = new CalcModel();
        m_logic.setValue(INITIAL_VALUE);

        //... Initialize components
        m_totalTf.setText(m_logic.getValue());
        m_totalTf.setEditable(false);

        //... Layout the components.
        JPanel content = new JPanel();
        content.setLayout(new FlowLayout());
        content.add(new JLabel("Input"));
        content.add(m_userInputTf);
        content.add(m_multiplyBtn);
        content.add(new JLabel("Total"));
        content.add(m_totalTf);
        content.add(m_clearBtn);

        //... Add button listeners.
        m_multiplyBtn.addActionListener(new MultiplyListener());
        m_clearBtn.addActionListener(new ClearListener());

        //... finalize layout and set window parameters.
        this.setContentPane(content);
        this.pack();
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("Simple Calc - Presentation-Model");
    }//end constructor


    ////////////////////////////////////////// inner class MultiplyListener
    /** When a multiplication is requested.
     *  1. Get the user input number.
     *  2. Call the model to mulitply by this number.
     *  3. Get the result from the Model.
     *  4. Set the Total textfield to this result.
     * If there was an error, display it in a JOptionPane.
     */
    class MultiplyListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            String userInput = "";
            try {
                userInput = m_userInputTf.getText();
                m_logic.multiplyBy(userInput);
                m_totalTf.setText(m_logic.getValue());
            } catch (NumberFormatException nfex) {
                JOptionPane.showMessageDialog(CalcViewController.this,
                                      "Bad input: '" + userInput + "'");
            }
        }
    }//end inner class MultiplyListener


    //////////////////////////////////////////// inner class ClearListener
    /**  1. Reset model.
     *   2. Put model's value into Total textfield.
     */
    class ClearListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            m_logic.reset();
            m_totalTf.setText(m_logic.getValue());
        }
    }
}