/*
 * This class represents what we want to put on a Window.
 * For now we are just indicating that the class MouseHandler
 * will take care of Mouse events.
 */
import java.awt.event.*;
import java.awt.*;
import java.awt.event.ActionEvent;

import javax.swing.*;

public class MyPanel extends JPanel implements ActionListener {
    private final static int NUMBER_OF_BUTTONS = 3;
    private JButton[] buttons;
    private JTextArea textArea;
    private RequestProcessor processor;
    private int textAreaHeight;
    private int textAreaWidth;
    
    public MyPanel(RequestProcessor processor,
            	   int frameWidth, 
            	   int frameHeight) {
        
        textAreaWidth  = frameWidth / 12;
        textAreaHeight = frameHeight /32;
       
        drawGUI();
        addThisClassAsListener();
        
        /* Setting a reference to the object that will actually */
        /* process the requests generated by the selection of   */
        /* a buttonn */
        
        this.processor = processor;
    }
    
    /* Allow us to write to the text area (display) */
    private void writeToDisplay(String text) {
        textArea.setText(text);
    }
    
    /* This method defines the current object as the one that */
    /* will take care of handling the processing associated   */
    /* with selecting a button                                */
    private void addThisClassAsListener() {
        for (int i=0; i<buttons.length; i++) {
            buttons[i].addActionListener(this);
        }
    }
    
    private void drawGUI() {       
        /* The main Panel has two subpanels: an upper panel and a lower lower            */
        /* The upper one has a couple of buttons and the lower one a text (display) area */
        
        /* Upper Panel: Collection of buttons */
        JPanel upperPanel = new JPanel();
        int rows = 0, columns = 3, verticalGap = 10, horizontalGap = 10;
        upperPanel.setLayout(new GridLayout(rows, columns, verticalGap, horizontalGap));
        // Adding some widgets to upper panel
        buttons = new JButton[NUMBER_OF_BUTTONS];
        for (int i=0; i<NUMBER_OF_BUTTONS; i++)
            upperPanel.add(buttons[i] = new JButton("Choice" + i));
        
        /* Lower Panel: A display area with scroll bars*/
        JPanel lowerPanel = new JPanel();
        textArea = new JTextArea(textAreaHeight,textAreaWidth);
        JScrollPane scrollDisplay = new JScrollPane(textArea);
        lowerPanel.add(scrollDisplay);   
        
        /* Creating a header */
        Font headerFont = new Font("SansSerif", Font.BOLD + Font.ITALIC, 24);
        JLabel headerLabel = new JLabel("Welcome", JLabel.CENTER);
        headerLabel.setFont(headerFont);
        
        /* Adding header and subpanels to main panel */
        setLayout(new BorderLayout());  // Allow us to place header and subpanels on top of each other
        add(headerLabel, BorderLayout.NORTH);
        add(upperPanel, BorderLayout.CENTER);
        add(lowerPanel, BorderLayout.SOUTH);
    }
    
    /* This method gets called when a button is selected */
    public void actionPerformed(ActionEvent event) {
        String results ="";
        
        /* Identifying the selected button */
        if (event.getActionCommand().equals("Choice0")) {
            /* Calling the method in charge of the actual processing */
            results = processor.evenNumbers();
        } else if (event.getActionCommand().equals("Choice1")) {
            results = processor.oddNumbers();
        } else if (event.getActionCommand().equals("Choice2")) {
            results = "NOT IMPLEMENTED YET";
        }
        writeToDisplay(results);
    }
}