sábado, 21 de mayo de 2011

Ejemplo java: VENTANA ActionListener actionPerformed(ActionEvent event)

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
public class ventana 
{
    public static void main(String [] args)
    {
       AppFrame f = new AppFrame();
       f.setSize(200, 200);
       f.addWindowListener(new WindowAdapter() { public void
           windowClosing(WindowEvent e) {System.exit(0);}});
       f.show();
    }
}
class AppFrame extends Frame implements ActionListener
{
    Button b1, b2;
    labelWindow window;
    AppFrame()
    {
        setLayout(new FlowLayout());
        b1 = new Button("Visualizar la ventana");
        add(b1);
        b1.addActionListener(this);
        b2 = new Button("Ocultar la ventana");
        add(b2);
        b2.addActionListener(this);
        window = new labelWindow(this);
        window.setSize(300, 200);
        window.setLocation(300, 200);
    }
    public void actionPerformed(ActionEvent event)
    {
        if(event.getSource() == b1){
            window.setVisible(true);
        }
        if(event.getSource() == b2){
            window.setVisible(false);
        }
    }
}
class labelWindow extends Window {
    Label label;
    labelWindow(AppFrame af){
        super(af);
        setLayout(new FlowLayout());
        label = new Label("¡Hola desde Java!");
        add(label);
    }
    public void paint (Graphics g)
    {
        int width = getSize().width;
        int height = getSize().height;
        g.drawRect(0, 0, --width, --height);
    }
}
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Ejemplo java : FRAME ActionListener MouseListener Applet

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
/*
<APPLET
    CODE=frame.class
    WIDTH=300
    HEIGHT=200 >
</APPLET>
*/
public class frame extends Applet implements ActionListener {
    Button b1, b2;
    labelFrame window;
    public void init()
    {
        b1 = new Button("Visualizar la ventana");
        add(b1);
        b1.addActionListener(this);
        b2 = new Button("Ocultar la ventana");
        add(b2);
        b2.addActionListener(this);
        window = new labelFrame("Ventana Java");
        window.setSize(350, 250);
    }
    public void actionPerformed(ActionEvent event)
    {
        if(event.getSource() == b1){
            window.setVisible(true);
        }
        if(event.getSource() == b2){
            window.setVisible(false);
        }
    }
}
class labelFrame extends Frame implements MouseListener {
    Label label;
    labelFrame(String title){
        super(title);
        setLayout(new FlowLayout());
        label = new Label("¡Hola desde Java! Esta es una ventana frame.");
        add(label);
        addMouseListener(this);
         addWindowListener(new WindowAdapter() {public void
             windowClosing(WindowEvent e) {setVisible(false);}});
    }
    public void mousePressed(MouseEvent e)
    {
        if((e.getModifiers() & InputEvent.BUTTON1_MASK) ==
            InputEvent.BUTTON1_MASK){
            label.setText("Botón izquierdo del ratón pulsado en " + e.getX() + "," + e.getY());
        }
        else{
            label.setText("Botón derecho del ratón pulsado en " + e.getX() + "," + e.getY());
        }
    }
    public void mouseClicked(MouseEvent e)
    {
        label.setText("Pulsó el ratón en " + e.getX() + "," + e.getY());
    }
    public void mouseReleased(MouseEvent e)
    {
        label.setText("Se soltó el botón del ratón.");
    }
    public void mouseEntered(MouseEvent e)
    {
        label.setText("Ratón para introducir.");
    }
    public void mouseExited(MouseEvent e)
    {
        label.setText("Ratón para salir.");
    }
}
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Ejemplo Java MENU ActionListener Frame addWindowListener actionPerformed

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
/*
<APPLET
    CODE=menu.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class menu extends Applet implements ActionListener
{
    Button b1;
    frame menuWindow;
    public void init()
    {
        b1 = new Button("Visualizar el menú de la ventana");
        add(b1);
        b1.addActionListener(this);
        menuWindow = new frame("Menús");
        menuWindow.setSize(200, 200);
    }
    public void actionPerformed(ActionEvent event)
    {
        if(event.getSource() == b1){
            menuWindow.setVisible(true);
        }
    }
}
class frame extends Frame implements ActionListener
{
    Menu menu;
    MenuBar menubar;
    MenuItem menuitem1, menuitem2, menuitem3;
    Label label;
    frame(String title)
    {
        super(title);
        label = new Label("¡Hola desde Java!");
        setLayout(new GridLayout(1, 1));
        add(label);
        menubar = new MenuBar();
        menu = new Menu("Archivo");
        menuitem1 = new MenuItem("Elemento 1");
        menu.add(menuitem1);
        menuitem1.addActionListener(this);
        menuitem2 = new MenuItem("Elemento 2");
        menu.add(menuitem2);
        menuitem2.addActionListener(this);
        menuitem3 = new MenuItem("Elemento 3");
        menu.add(menuitem3);
        menuitem3.addActionListener(this);
        menubar.add(menu);
        setMenuBar(menubar);
         addWindowListener(new WindowAdapter() {public void
              windowClosing(WindowEvent e) {setVisible(false);}});
    }
    public void actionPerformed(ActionEvent event)
    {
        if(event.getSource() == menuitem1){
            label.setText("Eligió el elemento 1");
        } else if(event.getSource() == menuitem2){
            label.setText("Eligió el elemento 2");
        } else if(event.getSource() == menuitem3){
            label.setText("Eligió el elemento 3");
        }
    }
}
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Ejemplo java Menu Emergente - PopupMenu, MouseListener mousePressed

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
/*
<APPLET
    CODE=menuemergente.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class menuemergente extends Applet implements ActionListener, MouseListener {
        Label label;
        PopupMenu popup;
        MenuItem menuitem1, menuitem2, menuitem3, menuitem4;
       
        public void init()
        {
            popup = new PopupMenu("Menu");
            menuitem1 = new MenuItem("Elemento 1");
            menuitem1.addActionListener(this);
            menuitem2 = new MenuItem("Elemento 2");
            menuitem2.addActionListener(this);
            menuitem3 = new MenuItem("Elemento 3");
            menuitem3.addActionListener(this);
            menuitem4 = new MenuItem("Elemento 4");
            menuitem4.addActionListener(this);
            popup.add(menuitem1);
            popup.addSeparator();
            popup.add(menuitem2);
            popup.addSeparator();
            popup.add(menuitem3);
            popup.addSeparator();
            popup.add(menuitem4);
            add(popup);
            label = new Label("¡Hola desde Java!");
            add(label);
            addMouseListener(this);
        }
        public void mousePressed(MouseEvent e)
        {
            if(e.getModifiers() != 0){
                popup.show(this, e.getX(), e.getY());
            }
        }
        public void mouseClicked(MouseEvent e){}
        public void mouseReleased(MouseEvent e){}
        public void mouseEntered(MouseEvent e){}
        public void mouseExited(MouseEvent e){}
        public void actionPerformed(ActionEvent event)
        {
            if(event.getSource() == menuitem1)
                label.setText("Eligió el elemento 1");
            else if(event.getSource() == menuitem2)
                label.setText("Eligió el elemento 2");
            else if(event.getSource() == menuitem3)
                label.setText("Eligió el elemento 3");
            else if(event.getSource() == menuitem4)
                label.setText("Eligió el elemento 4");
        }
    }
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viernes, 20 de mayo de 2011

Ejemplo Java MediaTracker tracker.addImage

import java.awt.*;
import java.applet.*;
/*
  <APPLET
      CODE=mediatracker.class
      WIDTH=600
      HEIGHT=150 >
  </APPLET>
*/
public class mediatracker extends Applet
{
    Image image;
    public void init()
    {
        MediaTracker tracker = new MediaTracker(this);
        image = getImage(getDocumentBase(), "image.jpg");
        tracker.addImage(image, 0);
        try {
            tracker.waitForAll();
        }
        catch (InterruptedException ex) { }
  }
    public void paint(Graphics g)
    {
        g.drawImage(image, 10, 10, this);
    }
}
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Ejemplo JAVA Raton - MouseListener, MouseMotionListener

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=raton.class
    WIDTH=300
    HEIGHT=200 >
</APPLET>
*/
public class raton extends Applet implements MouseListener, MouseMotionListener
{
    TextField text1;
    public void init(){
        text1 = new TextField(35);
        add(text1);
        addMouseListener(this);
        addMouseMotionListener(this);
    }
    public void mousePressed(MouseEvent e)
    {
        if((e.getModifiers() & InputEvent.BUTTON1_MASK) == InputEvent.BUTTON1_MASK){
            text1.setText("Botón izquierdo del ratón apretado en " + e.getX() + "," + e.getY());
        }
        else{
            text1.setText("Botón derecho del ratón apretado en " + e.getX() + "," + e.getY());
        }
    }
    public void mouseClicked(MouseEvent e)
    {
        text1.setText("Hizo clic sobre el ratón en " + e.getX() + "," + e.getY());
    }
    public void mouseReleased(MouseEvent e)
    {
        text1.setText("Se soltó el botón del ratón.");
    }

    public void mouseEntered(MouseEvent e)
    {
        text1.setText("Ratón para introducir.");
    }
    public void mouseExited(MouseEvent e)
    {
        text1.setText("Ratón para salir.");
    }
    public void mouseDragged(MouseEvent e)
    {
        text1.setText("Se arrastó el ratón.");
    }
    public void mouseMoved(MouseEvent e)
    {
        text1.setText("Se movió el ratón.");
    }
}
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Ejemplo JAVA Realzar - createImage(new MemoryImageSource(248, 248, pixels, 0 , 248));

import java.awt.*;
import java.awt.image.*;
import java.applet.*;
/*
  <APPLET
      CODE=realzar.class
      WIDTH=300
      HEIGHT=300 >
  </APPLET>
*/
public class realzar extends Applet
{
    Image image, image2;
    public void init()
    {
        image = getImage(getDocumentBase(), "whirl1.gif");
        int pixels[] = new int[248 * 248];
        PixelGrabber pg = new PixelGrabber(image, 0, 0, 248, 248, pixels, 0, 248);
        try {
            pg.grabPixels();
        }
        catch (InterruptedException e) {}
        for (int x = 2; x < 247; x++){
            for (int y = 2; y < 247; y++){
                int red = ((pixels[(x + 1) * 248 + y + 1] & 0xFF) -
                    (pixels[x * 248 + y] & 0xFF)) + 128;
                int green = (((pixels[(x + 1) * 248 + y + 1] & 0xFF00) / 0x100) %
                    0x100 - ((pixels[x * 248 + y] & 0xFF00) / 0x100) % 0x100) + 128;
                int blue = (((pixels[(x + 1) * 248 + y + 1] &
                    0xFF0000) / 0x10000) % 0x100 - ((pixels[x * 248 + y] &
                    0xFF0000) / 0x10000) % 0x100) + 128;
           
                int avg = (red + green + blue) / 3;
                pixels[x * 248 + y] = (0xff000000 | avg << 16 | avg << 8 | avg);
            }
        }
        image2 = createImage(new MemoryImageSource(248, 248, pixels, 0 , 248));
    }
    public void paint(Graphics g)
    {
        g.drawImage(image2, 0, 0, this);
    }
}
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Ejemplo Java : TECLA : KeyListener keyTyped

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
/*
  <APPLET
      CODE=tecla.class
      WIDTH=300
      HEIGHT=200 >
  </APPLET>
*/
public class tecla extends Applet implements KeyListener {
    String text = "";
    public void init()
    {
        addKeyListener(this);
        requestFocus();
    }
    public void paint(Graphics g)
    {
        g.drawString(text, 0, 100);
    }
    public void keyTyped(KeyEvent e)
    {
        text = text + e.getKeyChar();
        repaint();
    }
    public void keyPressed(KeyEvent e) {}
    public void keyReleased(KeyEvent e) {}
}
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Ejemplo Java CANVAS MouseListener mouseClicked drawOval drawLine

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
  <APPLET
      CODE=canvas.class
      WIDTH=400
      HEIGHT=200 >
  </APPLET>
*/
public class canvas extends java.applet.Applet implements MouseListener {
    graphicsCanvas gc;
    Button button1;
    public void init()
    {
        gc = new graphicsCanvas();
        gc.setSize(100, 100);
        add(gc);
        addMouseListener(this);
    }
   
    public void mousePressed(MouseEvent e){}
    public void mouseClicked(MouseEvent e)
    {
       for(int loop_index = 0; loop_index < 150; loop_index++){
           gc.setLocation(loop_index, 0);
       }
    }
    public void mouseReleased(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
}

class graphicsCanvas extends java.awt.Canvas
{
    public void paint (Graphics g)
    {
        g.drawOval(10, 50, 40, 40);
        g.drawLine(10, 50, 50, 90);
        g.drawLine(50, 50, 10, 90);
    }
}
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Ejemplo Java : Copiar Image createImage MemoryImageSource

import java.awt.*;
import java.applet.*;
import java.awt.image.*;
/*
  <APPLET
      CODE=copiar.class
      WIDTH=600
      HEIGHT=150 >
  </APPLET>
*/
public class copiar extends Applet {
    Image image, image2;
    public void init()
    {
        image = getImage(getDocumentBase(), "image.jpg");
        int pixels[] = new int[485 * 88];
        PixelGrabber pg = new PixelGrabber(image, 0, 0, 485, 88, pixels, 0, 485);
        try {
            pg.grabPixels();
        }
        catch (InterruptedException e) {}
        for (int loop_index = 0; loop_index < 485 * 88; loop_index++){
            int p = pixels[loop_index];
            int red = 0xff & (p >> 16);
            int green = 0xff & (p >> 8);
            int blue = 0xff & p;
            pixels[loop_index] = (0xff000000 | red << 16 | green << 8 | blue);
        }
        image2 = createImage(new MemoryImageSource(485, 88, pixels, 0 , 485));
    }
    public void paint(Graphics g)
    {
        g.drawImage(image2, 10, 10, this);
    }
}
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Ejemplo Java : DIBUJAR rectas óvalos rectángulos redondeados Dibujo libre

import java.awt.*;
import java.lang.Math;
import java.awt.event.*;
import java.awt.Graphics;
import java.applet.Applet;
/*
  <APPLET
      CODE=dibujar.class
      WIDTH=600
      HEIGHT=200 >
  </APPLET>
*/
public class dibujar extends Applet implements ActionListener, MouseListener, MouseMotionListener {
    Button bDraw, bLine, bOval, bRect, bRounded;
    Point dot[] = new Point[1000];
    Point start, end;
    int dots = 0;
    boolean mouseUp = false;
    boolean draw = false;
    boolean line = false;
    boolean oval = false;
    boolean rectangle = false;
    boolean rounded = false;
    public void init()
    {
        bLine = new Button("Dibujar rectas");
        bOval = new Button("Dibujar óvalos");
        bRect = new Button("Dibujar rectángulos");
        bRounded = new Button("Dibujar rectángulos redondeados");
        bDraw = new Button("Dibujo libre");
        add(bLine);
        add(bOval);
        add(bRect);
        add(bRounded);
        add(bDraw);
        bLine.addActionListener(this);
        bOval.addActionListener(this);
        bRect.addActionListener(this);
        bRounded.addActionListener(this);
        bDraw.addActionListener(this);
        addMouseListener(this);
        addMouseMotionListener(this);
    }
   
    public void mousePressed(MouseEvent e)
    {
        mouseUp = false;
        start = new Point(e.getX(), e.getY());
    }
    public void mouseReleased(MouseEvent e)
    {
        if(line){
            end = new Point(e.getX(), e.getY());
        } else {
            end = new Point(Math.max(e.getX(), start.x),
                Math.max(e.getY(), start.y));
            start = new Point(Math.min(e.getX(), start.x),
                Math.min(e.getY(), start.y));
        }
        mouseUp = true;
        repaint();
    }
    public void mouseDragged(MouseEvent e)
    {
        if(draw){
            dot[dots] = new Point(e.getX(), e.getY());
            dots++;
            repaint();
        }
    }
    public void mouseClicked(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
    public void paint (Graphics g)
    {
        if (mouseUp) {
            int width = end.x - start.x;
            int height = end.y - start.y;
            if(line){
                g.drawLine(start.x, start.y, end.x, end.y);
            }
            else if(oval){
                g.drawOval(start.x, start.y, width, height);
            }
            else if(rectangle){
                g.drawRect(start.x, start.y, width, height);
            }
            else if(rounded){
                g.drawRoundRect(start.x, start.y, width, height, 10, 10);
            }
            else if(draw){
                for(int loop_index = 0; loop_index < dots - 1; loop_index++){
                    g.drawLine(dot[loop_index].x, dot[loop_index].y,
                        dot[loop_index + 1].x, dot[loop_index + 1].y);
                }
            }
        }
    }
    public void actionPerformed(ActionEvent e)
    {
        setFlagsFalse();
        if(e.getSource() == bDraw)draw = true;
        if(e.getSource() == bLine)line = true;
        if(e.getSource() == bOval)oval = true;
        if(e.getSource() == bRect)rectangle = true;
        if(e.getSource() == bRounded)rounded = true;
    }
    void setFlagsFalse()
    {
        rounded = false;
        line = false;
        oval = false;
        rectangle = false;
        draw = false;
    }
}
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Ejemplo Java Escala de Grises- createImage MemoryImageSource getImage

import java.awt.*;
import java.applet.*;
import java.awt.image.*;
/*
  <APPLET
      CODE=escaladegrises.class
      WIDTH=300
      HEIGHT=300 >
  </APPLET>
*/
public class escaladegrises extends Applet {
    Image image, image2;
    public void init()
    {
        image = getImage(getDocumentBase(), "whirl1.gif");
        int pixels[] = new int[248 * 248];
        PixelGrabber pg = new PixelGrabber(image, 0, 0, 248, 248, pixels, 0, 248);
        try {
            pg.grabPixels();
        }
        catch (InterruptedException e) {}
      for (int loop_index = 0; loop_index < 248 * 248; loop_index++){
          int p = pixels[loop_index];
          int red = (0xff & (p >> 16));
          int green = (0xff & (p >> 8));
          int blue = (0xff & p);
          int avg = (int) ((red + green + blue) / 3);
          pixels[loop_index] = (0xff000000 | avg << 16 | avg << 8 | avg);
      }
        image2 = createImage(new MemoryImageSource(248, 248, pixels, 0 , 248));
    }
    public void paint(Graphics g)
    {
        g.drawImage(image2, 10, 10, this);
    }
}
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Ejemplo Java : Image getImage paint(Graphics g)

import java.awt.*;
import java.applet.*;
/*
  <APPLET
      CODE=imagen.class
      WIDTH=500
      HEIGHT=150 >
  </APPLET>
*/
public class imagen extends Applet
{
    Image image;
    public void init()
    {
        image = getImage(getDocumentBase(), "image.jpg");
    }
    public void paint(Graphics g)
    {
        g.drawImage(image, 10, 10, this);
    }
}
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Ejemplo Java Image observer getImage

import java.awt.*;
import java.applet.*;
/*
  <APPLET
      CODE=iobserver.class
      WIDTH=600
      HEIGHT=150 >
  </APPLET>
*/
public class iobserver extends Applet
{
    Image image;
    public void init()
    {
        image = getImage(getDocumentBase(), "image.jpg");
    }
    public void paint(Graphics g)
    {
        g.drawImage(image, 10, 10, this);
    }
  public boolean imageUpdate(Image img, int flags, int x, int y, int w, int h)
  {
      if ((flags & ALLBITS) != 0) { 
          repaint(x, y, w, h);      
      } 
      return (flags & ALLBITS) == 0;
  }
}
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Ejuemplo Java Desplazamiento : AdjustmentListener Scrollbar adjustmentValueChanged(AdjustmentEvent e)

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=desplazamientoenborde.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class desplazamientoenborde extends Applet implements AdjustmentListener
{
    Scrollbar hScroll1, hScroll2, vScroll1, vScroll2;
    TextPanel t1;
    public void init()
    {
        setLayout(new BorderLayout());
        hScroll1 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 1, 1, 100);
        add("North", hScroll1);
        hScroll1.addAdjustmentListener(this);
        vScroll1 = new Scrollbar(Scrollbar.VERTICAL, 1, 1, 1, 100);
        add("West", vScroll1);
        vScroll1.addAdjustmentListener(this);
        hScroll2 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 1, 1, 100);
        add("South", hScroll2);
        hScroll2.addAdjustmentListener(this);
        vScroll2 = new Scrollbar(Scrollbar.VERTICAL, 1, 1, 1, 100);
        add("East", vScroll2);
        vScroll2.addAdjustmentListener(this);
        t1 = new TextPanel();
        add("Center", t1);
    }
    public void adjustmentValueChanged(AdjustmentEvent e)
    {
        if(e.getAdjustable() == hScroll1){
            hScroll2.setValue(hScroll1.getValue());
        }
        if(e.getAdjustable() == vScroll1){
            vScroll2.setValue(vScroll1.getValue());
        }
        if(e.getAdjustable() == hScroll2){
            hScroll1.setValue(hScroll2.getValue());
        }
        if(e.getAdjustable() == vScroll2){
            vScroll1.setValue(vScroll2.getValue());
        }
        t1.x = (int) (getSize().width * (float) hScroll1.getValue() / 100);
        t1.y = (int) (getSize().height * (float) vScroll1.getValue() / 100);
        t1.repaint();
    }
}
class TextPanel extends Panel
{
    TextField Text1;
    public int x = 0, y = 0;
    public void paint (Graphics g)
    {
        g.drawString("¡Hola desde Java!", x, y);
    }
}   
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Ejemplo Lista en Java Applet ActionListener

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=lista.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class lista extends Applet implements ActionListener {
    List list1;
    TextField text1;
    public void init(){
        text1 = new TextField(20);
        add(text1);
        list1 = new List(4);
        list1.add("Elemento 1");
        list1.add("Elemento 2");
        list1.add("Elemento 3");
        list1.add("Elemento 4");
        list1.add("Elemento 5");
        list1.add("Elemento 6");
        list1.add("Elemento 7");
        list1.add("Elemento 8");
        list1.add("Elemento 9");
        add(list1);
        list1.addActionListener(this);
    }
    public void actionPerformed(ActionEvent e) {
        if(e.getSource() == list1){
            text1.setText(((List) e.getSource()).getSelectedItem());
        }
    }
}
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Ejemplo Java ActionListener actionPerformed (ActionEvent e) SCROLLBARS_BOTH

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=reemplazar.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class reemplazar extends Applet implements ActionListener
{
    TextArea textarea1;
    Button button1;
    public void init()
    {
        textarea1 = new TextArea("Ya es la hora.", 5, 20,
            TextArea.SCROLLBARS_BOTH);
        add(textarea1);
        button1 = new Button("Cambiar el texto seleccionado");
        add(button1);
        button1.addActionListener(this);
    }
    public void actionPerformed (ActionEvent e){
        if(e.getSource() == button1){
            textarea1.replaceRange("¡Hola desde Java!",
                textarea1.getSelectionStart(),
                textarea1.getSelectionEnd()) ;
        }
    }
}
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Ejemplo Java : ActionListener actionPerformed(ActionEvent e) Button loopIndex

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=seleccionmult.class
    WIDTH=300
    HEIGHT=200 >
</APPLET>
*/
public class seleccionmult extends Applet implements ActionListener {
    List list1;
    TextField text1;
    Button button1;
    String selections[];
    public void init(){
        text1 = new TextField(40);
        add(text1);
        list1 = new List(4, true);
        list1.add("Elemento 1");
        list1.add("Elemento 2");
        list1.add("Elemento 3");
        list1.add("Elemento 4");
        list1.add("Elemento 5");
        list1.add("Elemento 6");
        list1.add("Elemento 7");
        list1.add("Elemento 8");
        list1.add("Elemento 9");
        add(list1);
        button1 = new Button("Mostrar las selecciones");
        button1.addActionListener(this);
        add(button1);
    }
    public void actionPerformed(ActionEvent e)
    {
        String outString = new String("Usted seleccionó:");
        if(e.getSource() == button1){
            selections = list1.getSelectedItems();
            for(int loopIndex = 0; loopIndex < selections.length; loopIndex++){
                outString += " " + selections[loopIndex];
            }
            text1.setText(outString);
        }
    }
}
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Ejemplo JAVA : ActionListener Button actionPerformed ActionEvent

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=areadetexto.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class areadetexto extends Applet implements ActionListener {
    TextArea textarea1;
    Button button1;
    public void init(){
        textarea1 = new TextArea("", 10, 20, TextArea.SCROLLBARS_BOTH);
        add(textarea1);
        button1 = new Button("¡Haga clic aquí!");
        add(button1);
        button1.addActionListener(this);
    }
    public void actionPerformed (ActionEvent e)
    {
        String msg = "¡Hola desde Java!";
        if(e.getSource() == button1){
            textarea1.insert(msg, 0);
        }
    }
}
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Ejemplo Java: actionPerformed ActionEvent ActionListener

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/*
<APPLET
    CODE=buscar.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class buscar extends Applet implements ActionListener
{
    TextArea textarea1;
    Button button1;
    public void init()
    {
        textarea1 = new TextArea("Ya es la hora.", 5, 20, TextArea.SCROLLBARS_BOTH);
        add(textarea1);
        button1 = new Button("Buscar \"hora\"");
        add(button1);
        button1.addActionListener(this);
    }
    public void actionPerformed (ActionEvent e){
        if(e.getSource() == button1){
            String s = textarea1.getText();
            String s2 = new String("hora");
            int location = s.indexOf(s2);
            textarea1.select(location, location + s2.length()) ;
        }
    }
}
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Java: TextPanel ScrollPane Applet : Desplazamiento de Texto

import java.applet.Applet;
import java.awt.*;
/*
<APPLET
    CODE=cuadrodedesplazamiento.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/
public class cuadrodedesplazamiento extends Applet
{
    ScrollPane scrollpane1;
    TextPanel t1;
    public void init(){
        scrollpane1 = new ScrollPane(ScrollPane.SCROLLBARS_ALWAYS);
        t1 = new TextPanel();
        scrollpane1.add(t1);
        add(scrollpane1);
    }
}
class TextPanel extends Panel
{
    public Dimension getPreferredSize()
    {
        return new Dimension(400, 400);
    }
    public void paint (Graphics g)
    {
        g.drawString ("Esta es una cadena de texto larga que " +
            "parece continuar y continuar y continuar....", 0, 60);
    }
}
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Ejemplo Java AdjustmentListener adjustmentValueChanged AdjustmentEvent

import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;
/*
<APPLET
    CODE=desplazamiento2.class
    WIDTH=200
    HEIGHT=200 >
</APPLET>
*/

public class desplazamiento2 extends Applet implements AdjustmentListener
{
    Scrollbar scroll1, scroll2;
    int x = 0;
    public void init()
    {
        scroll1 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 10, 1, 100);
        add(scroll1);
        scroll1.addAdjustmentListener(this);
    }
    public void paint(Graphics g)
    {
        g.drawString("¡Hola desde Java!", x, 60);
    }
    public void adjustmentValueChanged(AdjustmentEvent e)
    {
        if(e.getAdjustable() == scroll1) {
            x = (int) (getSize().width * (float) scroll1.getValue() / 100);
            repaint();
        }
    }
}
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Ejemplo adjustmentValueChanged AdjustmentEvent AdjustmentListener Java

import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;
/*
<APPLET
    CODE=desplazamiento.class
    WIDTH=400
    HEIGHT=100 >
</APPLET>
*/

public class desplazamiento extends Applet implements AdjustmentListener
{
    TextField text1;
    Scrollbar scroll1, scroll2;
    public void init()
    {
        scroll1 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 20, 1, 200);
        add(scroll1);
        scroll1.addAdjustmentListener(this);
        text1 = new TextField(20);
        add(text1);
        scroll2 = new Scrollbar(Scrollbar.VERTICAL, 1, 20, 1, 200);
        add(scroll2);
        scroll2.addAdjustmentListener(this);
    }

    public void adjustmentValueChanged(AdjustmentEvent e)
    {
        if(e.getAdjustable() == scroll1 ||
            e.getAdjustable() == scroll2) {
            text1.setText("Horizontal: " + scroll1.getValue() +
                " Vertical: " + scroll2.getValue());
        }
    }
}
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