FlightSearchApplet.java

/*
<APPLET CODE="FlightSearchApplet.class" WIDTH=400 HEIGHT=200></APPLET>
 */

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

/**
 * A Java applet that has an interface that could be used for a flight search.
 * This is the same as the earlier applet with the addition of two
 * buttons for clear and swap.
 *
 * @author Jim Glenn
 * @version 0.3 10/5/2005
 */

public class FlightSearchApplet extends JApplet
{
    // these are declared as fields instead of local to the constructor
    // so they can be used outside the constructor

    private JTextField fromInput, toInput, resultOutput;

    /**
     * Creates the interface for this applet.
     */

    public void init()
    {
	// use a border layout for the applet

	getContentPane().setLayout(new BorderLayout());
	
	// create the panel for the From and To inputs

	JPanel routePanel = new JPanel();
	routePanel.setLayout(new GridLayout(2, 2));

	// create the label next to the "to" input area
	
	JLabel fromLabel = new JLabel("From:");
	routePanel.add(fromLabel);
	
	// create the "to" input area

	fromInput = new JTextField(10);
	routePanel.add(fromInput);
	
	// create the label and the input area for "from"

	JLabel toLabel = new JLabel("To:");
	routePanel.add(toLabel);
	
	toInput = new JTextField(10);
	routePanel.add(toInput);
	
	// create the panel for the class dropdown and the non-stop checkbox

	JPanel optionPanel = new JPanel(new GridLayout(2, 1));

	// create the panel for the class drop-down

	JPanel classPanel = new JPanel();
	
	classPanel.add(new JLabel("Class:"));
	
	// create an empty dropdown for class and put the 3 options in

	JComboBox classBox = new JComboBox();
	classBox.addItem("1st Class");
	classBox.addItem("Business");
	classBox.addItem("Coach");
	classPanel.add(classBox);
	
	optionPanel.add(classPanel);
	
	// create the checkbox and add to panel

	JCheckBox nonstop = new JCheckBox("Non-stop only");
	optionPanel.add(nonstop);
	
	// create a panel that holds everything but the search button and
	// search results and put the panels in it

	JPanel topPanel = new JPanel(new BorderLayout());
	topPanel.add(routePanel, BorderLayout.CENTER);
	topPanel.add(optionPanel, BorderLayout.EAST);
	
	// add the top panel to the top of the applet

	getContentPane().add(topPanel, BorderLayout.NORTH);
		
	// create a panel for the buttons (to protect them from stretching)

	JPanel buttonPanel = new JPanel(new FlowLayout());
	
	// create and add the buttons

	JButton searchButton = new JButton("Search");
	buttonPanel.add(searchButton);

	JButton clearButton = new JButton("Clear");
	buttonPanel.add(clearButton);

	JButton swapButton = new JButton("Swap");
	buttonPanel.add(swapButton);
	
	getContentPane().add(buttonPanel, BorderLayout.SOUTH);
	
	// create a text field to show results in and add it to the
	// middle of the applet (but this is pretty ugly)

	resultOutput = new JTextField();
	resultOutput.setEditable(false);
	getContentPane().add(resultOutput, BorderLayout.CENTER);
	
	// create the listeners and connect them to the buttons

	searchButton.addActionListener(new SearchListener());

	ButtonListener l = new ButtonListener();
	swapButton.addActionListener(l);
	clearButton.addActionListener(l);
    }

    /**
     * An inner class for the search button's listener.
     */

    private class SearchListener implements ActionListener
    {
	public void actionPerformed(ActionEvent e)
	{
		String from = fromInput.getText();
		String to = toInput.getText();
		
		resultOutput.setText("Searching for flights from " + from + " to " + to + "...failed to connect to database");
	}
    }

    /**
     * An inner class for the other buttons' listeners.  This could be done
     * with two separate classes, but is done with one here to illustrate
     * how actionPerformed can determine which button sent the event.
     */

    private class ButtonListener implements ActionListener
    {
	public void actionPerformed(ActionEvent e)
	{
	    // determine which button sent the event --
	    // the action command is the text on the button by default

	    if (e.getActionCommand().equals("Clear"))
		{
		    fromInput.setText("");
		    toInput.setText("");
		    resultOutput.setText("");
		}
	    else
		{
		    String temp = fromInput.getText();
		    fromInput.setText(toInput.getText());
		    toInput.setText(temp);
		    resultOutput.setText("");
		}
	}
    }
}