import java.awt.*;
import java.awt.event.*;
import FieldModifier;
import StringModifier;
import MakeUpperCase;

/**
 * A simple GUI application that permits the user to enter a string and
 * modify the string in simple ways.
 *
 * @author Samuel A. Rebelsky
 * @version 1.0 of March 1999
 */
public class StringFun
  extends WindowAdapter
  implements ActionListener
{
  // +-----------------------------------------------------------
  // | Fields |
  // +--------+
  
  /** The frame that provides the central action of the program. */
  protected Frame gui;
  /** The text field into which the user enters information. */
  protected TextField info;
  /** The ``convert to uppercase'' button. */
  protected Button upperCase;
  /** The quit button. */
  protected Button quit;
  /** Some instructions. */
  protected Label instructions;
   
  // +--------------+---------------------------------------------
  // | Constructors |
  // +--------------+
  
  /**
   * Build the graphical user interface and go!
   */
  public StringFun() {
    // Create the frame that serves as the base of this application.
    gui = new Frame("Fun with strings");
    gui.setLayout(new FlowLayout());
    gui.addWindowListener(this);
    // Create the various components.
    instructions = new Label("Type in the field, and then click a modifier");
    info = new TextField("            ");
    upperCase = new Button("Convert to UPPERCASE");
    quit = new Button("Quit");
    // Set up the listeners for the various components.
    upperCase.addActionListener(
      new FieldModifier(info,
                        new MakeUpperCase()));
    quit.addActionListener(this);
    // Add the components to the frame.
    gui.add(instructions);
    gui.add(info);
    gui.add(upperCase);
    gui.add(quit);
    // Put the frame together.
    gui.pack();
    // Clear the field.
    info.setText("");
    // And go!
    gui.show();
  } // StringFun()  
  
  // +---------+-------------------------------------------------
  // | Methods |
  // +---------+
  
  /** Quit the program. */
  public void quit() {
    gui.dispose();
    System.exit(0);
  } // quit()
   
  // +----------------+------------------------------------------
  // | Event Handlers |
  // +----------------+
  
  /**
   * When the user clicks the quit button (the only button that
   * this object listens for), quit the program.
   */
  public void actionPerformed(ActionEvent evt) {
    String command = evt.getActionCommand();
    if (command.equals("Quit")) quit();
    else if (command.equals(""));
    else {
      // It's an error, but we do nothing.
    }
  } // actionPerformed(ActionEvent)
  
  /**
   * When the window closes, exit the program.
   */
  public void windowClosing(WindowEvent evt) {
    quit();
  } // windowClosing(WindowEvent)
  
  
  // +------+----------------------------------------------------
  // | Main |
  // +------+
  
  /** Build the GUI and go. */
  public static void main(String[] args) {
    new StringFun();
  } // main(String[])
  
} // class StringFun