import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class Seleccionables extends Applet {
  private boolean isStandalone = false;
  Choice choice1 = new Choice();
  Button button1 = new Button();
  Choice choice2 = new Choice();
  TextField tfResult = new TextField();
  //Obtener el valor de un parámetro
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  //Construir el applet
  public Seleccionables() {
  }
  //Inicializar el applet
  public void init() {
    choice1.addItem("SELECCIONA");
    choice1.addItem("Masa");
    choice1.addItem("Volumen");
    choice1.addItem("Temperatura");
    choice1.addItem("Tiempo");


    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Inicialización de componentes
  private void jbInit() throws Exception {
    this.setLayout(null);
    choice1.setFont(new java.awt.Font("Dialog", 0, 16));
    choice1.setBounds(new Rectangle(26, 17, 159, 25));
    choice1.addItemListener(new Seleccionables_choice1_itemAdapter(this));
    button1.setBackground(Color.red);
    button1.setFont(new java.awt.Font("Dialog", 1, 16));
    button1.setLabel("Seleccionar");
    button1.setBounds(new Rectangle(126, 143, 131, 28));
    button1.addActionListener(new Seleccionables_button1_actionAdapter(this));
    this.setBackground(Color.black);
    choice2.setFont(new java.awt.Font("Dialog", 0, 16));
    choice2.setBounds(new Rectangle(211, 18, 157, 25));
    tfResult.setFont(new java.awt.Font("Dialog", 0, 16));
    tfResult.setText("");
    tfResult.setBounds(new Rectangle(51, 218, 306, 25));
    this.add(choice1, null);
    this.add(choice2, null);
    this.add(button1, null);
    this.add(tfResult, null);
  }
  //Iniciar el applet
  public void start() {
  }
  //Detener el applet
  public void stop() {
  }
  //Destruir el applet
  public void destroy() {
  }
  //Obtener información del applet
  public String getAppletInfo() {
    return "Información del applet";
  }
  //Obtener información del parámetro
  public String[][] getParameterInfo() {
    return null;
  }

  void choice1_itemStateChanged(ItemEvent e) {
    if ("Masa".equals(choice1.getSelectedItem())) {
     choice2.removeAll();
     choice2.addItem("kilogramos (kg)");
     choice2.addItem("gramos (g)");
     choice2.addItem("miligramos (mg)");
    }
    else if ("Volumen".equals(choice1.getSelectedItem())) {
      choice2.removeAll();
      choice2.addItem("Litros (L)");
      choice2.addItem("cm cúbicos cm3");
      choice2.addItem("mm cúbicos (mm3)");
     }
    else if ("Temperatura".equals(choice1.getSelectedItem())) {
      choice2.removeAll();
      choice2.addItem("grado Celsius (ºC)");
      choice2.addItem("kelvin (K)");
      
     }
    else if ("Tiempo".equals(choice1.getSelectedItem()))  {
      choice2.removeAll();
      choice2.addItem("horas (h)");
      choice2.addItem("minutos (min)");
      choice2.addItem("segundos (s)");
      }
    else if ("SELECCIONA".equals(choice1.getSelectedItem()))  {
      choice2.removeAll();
    }
  }

  void button1_actionPerformed(ActionEvent e) {
    String txt = choice2.getSelectedItem();
    tfResult.setText("Has seleccionado:  " + txt);

  }
}

class Seleccionables_choice1_itemAdapter implements java.awt.event.ItemListener {
  Seleccionables adaptee;

  Seleccionables_choice1_itemAdapter(Seleccionables adaptee) {
    this.adaptee = adaptee;
  }
  public void itemStateChanged(ItemEvent e) {
    adaptee.choice1_itemStateChanged(e);
  }
}

class Seleccionables_button1_actionAdapter implements java.awt.event.ActionListener {
  Seleccionables adaptee;

  Seleccionables_button1_actionAdapter(Seleccionables adaptee) {
    this.adaptee = adaptee;
  }
  public void actionPerformed(ActionEvent e) {
    adaptee.button1_actionPerformed(e);
  }
}