Divide JscrollPane into 2 picure viewer with scroll bar

Question

Hello to all, help me, i must divide a JScrollPane into 2 sub-windows in witch putting 2 different images.
The image that i put at left is loaded by a JFileChooser.
This is the code, my problem is into load_file() function.
Help me, thanks a lot.
Escuse me for my bad english.
package Crypto;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.applet.*;
import java.net.*;
import javax.imageio.*;
import javax.swing.*;
import javax.swing.event.*;
import java.io.File.*;
import javax.swing.filechooser.FileFilter;
import java.io.*;
public class Crypto extends JFrame implements ActionListener {
private BufferedImage sorgente = null;
private BufferedImage shares = null;
private BufferedImage somma = null;
private JMenuBar mb;
private JMenu menu1;
private JMenu menu2;
private JMenu menu3;
private JButton go;
private JButton set_n;
private JButton set_k;
private JButton op;
private JButton schemi;
private JMenuItem item_01;
private JMenuItem item_02;
private JMenuItem item_03;
private JMenu item_04;
private JMenuItem item_04_a;
private JMenuItem item_04_b;
private JMenuItem item_05;
private JMenuItem item_06;
private JMenuItem item_07;
private JMenuItem item_08;
private BorderLayout layout = new BorderLayout();
private JToolBar tb = new JToolBar();
private int k = 2;
private int n = 4;
private String formato = "PNG";
private File original;
private File sovra_imp;
private Schema curr;
private ImageIcon ii = new ImageIcon();
private JScrollPane JSPanel;
private ScrollablePicture picture;
public Crypto() {
this.getContentPane().setLayout(layout);
this.getContentPane().add(BorderLayout.NORTH,tb);
JSPanel = new JScrollPane();
//JSPanel.setSize(150, 250);
this.getContentPane().add(BorderLayout.WEST, JSPanel);
mb = new JMenuBar();
mb.setAutoscrolls(true);
setJMenuBar(mb);
menu1= new JMenu("File");
mb.add(menu1);
item_01 = new JMenuItem("Apri file ...");
menu1.add(item_01);
item_02 = new JMenuItem("Quit ...");
menu1.add(item_02);
menu2= new JMenu("Impostazioni");
mb.add(menu2);
item_03 = new JMenuItem("Formato salvataggio shares");
menu2.add(item_03);
item_05 = new JMenuItem("Modifica numero partecipanti");
menu2.add(item_05);
item_06 = new JMenuItem("Imposta grado di visibilit�");
menu2.add(item_06);
item_04 = new JMenu("Schemi");
item_04_a = new JMenuItem ("Schema corrente");
item_04.add (item_04_a);
item_04_b = new JMenuItem("Modifica schema corrente");
item_04.add (item_04_b);
menu2.add(item_04);
menu3= new JMenu("Help");
mb.add(menu3);
item_07 = new JMenuItem("Guida");
menu3.add(item_07);
item_08 = new JMenuItem("About");
menu3.add(item_08);
op = new JButton ("Apri file ");
op.addActionListener(this);
tb.add(op);
go = new JButton("Crea shares");
go.addActionListener(this);
tb.add(go);
set_k = new JButton("Modifica visibilit� shares");
set_k.addActionListener(this);
tb.add(set_k);
set_n = new JButton("Modifica n. partecipanti");
set_n.addActionListener(this);
tb.add(set_n);
schemi = new JButton("Modifica schema corrente");
schemi.addActionListener(this);
tb.add(schemi);
item_01.addActionListener(this);
item_02.addActionListener(this);
item_03.addActionListener(this);
item_04_a.addActionListener(this);
item_04_b.addActionListener(this);
item_05.addActionListener(this);
item_06.addActionListener(this);
item_07.addActionListener(this);
item_08.addActionListener(this);
curr = Schema.carica_schema ("2-2-b-w");
this.setBounds(150, 150, 800, 500);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setTitle("Crypto magic");
this.setVisible(true);
public void actionPerformed(java.awt.event.ActionEvent ae) {
Object source = ae.getSource();
Class sourceClass = source.getClass();
if (sourceClass.getName().equals("javax.swing.JMenuItem")){
     JMenuItem ch = (JMenuItem) source;
if (ch == item_01){
load_file();
}else if (ch == item_02){
close_frame();
}else if (ch ==item_03){
scegli_formato();
}else if (ch == item_04_a){
schema_corrente();
}else if (ch == item_04_b){
cambia_schema();
}else if (ch == item_05){
set_n();
}else if (ch == item_06){
set_k();
}else if (ch == item_07){
guida();
}else about();
if (sourceClass.getName().equals("javax.swing.JButton")){
JButton jb = (JButton) source;
if (jb == go){
crea_shares();
}else if (jb == set_n){
set_n();
}else if (jb == op){
load_file();
}else if (jb == set_k){
set_k();
public void load_file() {
JFileChooser fc = new JFileChooser();
fc.setAcceptAllFileFilterUsed(false);
fc.setFileFilter(new ImageFilter());
int retval = fc.showOpenDialog(this);
try{
if (retval == JFileChooser.APPROVE_OPTION){
original = fc.getSelectedFile();
//String nome = original.getName();
sorgente = ImageIO.read (original);
ii.setImage(sorgente);
picture = new ScrollablePicture(ii, 1);
JSPanel = new JScrollPane(picture, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
this.getContentPane().add(BorderLayout.WEST, JSPanel);
this.repaint();
}catch (Exception e){}
void close_frame(){
System.exit(0);
void scegli_formato(){
Impostazioni i = new Impostazioni(0);
void set_n(){
Impostazioni i = new Impostazioni(2);
void set_k (){
Impostazioni i = new Impostazioni(1);
Schema schema_corrente(){
return curr;
void cambia_schema(){}
void guida(){
void about(){
void crea_shares(){
public class Impostazioni extends JFrame implements ChangeListener{
JTabbedPane panel = new JTabbedPane();
Impostazioni(int i){
FSS c1 = new FSS();
SET_K c2 = new SET_K();
SET_N c3 = new SET_N();
panel.add("Formato shares", c1);
panel.add("Modifica K", c2);
panel.add("Modifica N", c3);
panel.addChangeListener(this);
if ( i == 0){
panel.setSelectedComponent(c1);
}else if ( i == 1){
panel.setSelectedComponent(c2);
}else if (i == 2){
panel.setSelectedComponent(c3);
getContentPane().add(panel);
this.setResizable(false);
this.setBounds(200, 200, 500, 300);
this.setTitle("Impostazioni");
this.setVisible(true);
public void stateChanged(ChangeEvent e) {
int pos = panel.getSelectedIndex();
String title = panel.getTitleAt(pos);
setTitle(title);
public class FSS extends JPanel implements ActionListener{
private JComboBox cb;
private JLabel et;
JLabel ico;
Icon i1 = new ImageIcon("C:/forte/sampledir/Crypto/JPGIcon.jpg");
Icon i2 = new ImageIcon("C:/forte/sampledir/Crypto/PNGIcon.jpg");
FSS(){
this.setLayout(new FlowLayout(FlowLayout.CENTER, 20, 30));
int i;
String item []= {"JPG", "PNG"};
for (i = 0; i < 1; i++)
if (item == formato) break;
String msg = "\n\n\n\n\nIl formato attualmente in uso � "+formato+"\n\n";
et = new JLabel(msg);
add(et);
JLabel et2 = new JLabel ("Modidica il formato di salvataggio delle shares ");
if (formato =="JPG"){
ico = new JLabel(i1);
}else {ico = new JLabel(i2);}
add (ico);
add (et2);
cb = new JComboBox(item);
cb.setSelectedIndex(i);
cb.addActionListener(this);
add(cb);
public void actionPerformed(java.awt.event.ActionEvent ae) {
JComboBox cb = (JComboBox)ae.getSource();
String selectedItem = (String)cb.getSelectedItem();
int ind = cb.getSelectedIndex();
formato = selectedItem;
et.setText("Il formato attualmente in uso � "+selectedItem);
if (formato == "PNG"){
ico.setIcon(i2);
}else{
ico.setIcon(i1);
public class SET_K extends JPanel implements ActionListener{
private JLabel et3;
SET_K(){
this.setLayout(new FlowLayout(FlowLayout.CENTER, 40, 40));
String msg = "Il valore attuale di k � "+k+"\n\n";
et3 = new JLabel(msg);
et3.setFont(new Font("Tim", Font.BOLD, 16 ));
add (et3);
JButton but2 = new JButton ("Modifica K");
add (but2);
but2.addActionListener(this);
public void actionPerformed(java.awt.event.ActionEvent ae) {
Object source = ae.getSource();
int value;
Class sourceClass = source.getClass();
if (sourceClass.getName().equals("javax.swing.JButton")){
Kappa kappa= new Kappa();
value = kappa.get_K();
if ((value > n) ||(value < 2)){
JOptionPane err = new JOptionPane();
String err_msg ="Errore, il valore di K deve essere un intero compreso tra 2 e " +n;
err.showMessageDialog(null,err_msg , "Errore", JOptionPane.ERROR_MESSAGE);
this.setVisible(false);
}else{
k = value;
JOptionPane ok_ = new JOptionPane();
ok_.showMessageDialog(null, "Modifica effettuata con successo. ");
et3.setText("Il valore attuale di K � " +value);
this.setVisible(false);
public class SET_N extends JPanel implements ActionListener{
private JLabel et4;
SET_N(){
this.setLayout(new FlowLayout(FlowLayout.CENTER, 40, 40));
String msg = "Il valore attuale di n � "+n+"\n\n";
et4 = new JLabel(msg);
et4.setFont(new Font("Tim", Font.BOLD, 16 ));
add (et4);
JButton but3 = new JButton ("Modifica N");
add (but3);
but3.addActionListener(this);
public void actionPerformed(java.awt.event.ActionEvent ae) {
Object source = ae.getSource();
int value;
Class sourceClass = source.getClass();
if (sourceClass.getName().equals("javax.swing.JButton")){
Kappa kappa= new Kappa();
value = kappa.get_K();
if (value < k){
JOptionPane err = new JOptionPane();
String err_msg ="Errore, il valore di N deve essere un intero superiore o uguale a " +k;
err.showMessageDialog(null,err_msg , "Errore", JOptionPane.ERROR_MESSAGE);
this.setVisible(false);
}else{
n = value;
JOptionPane ok_ = new JOptionPane();
ok_.showMessageDialog(null, "Modifica effettuata con successo. ");
et4.setText("Il valore attuale di N � " +value);
this.setVisible(false);
public int salva_schema(Schema s){
String nome = s.get_name();
nome = nome + ".ctm";
try{
FileOutputStream fos = new FileOutputStream (nome);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(s);
oos.close();
return 1;
catch (Exception ioe){
return -1;
public Schema leggi_schema (String nome){
try{
nome = nome + ".ctm";
FileInputStream fis = new FileInputStream (nome);
ObjectInputStream ois = new ObjectInputStream(fis);
Schema salvato = (Schema)(ois.readObject());
ois.close();
return salvato;
catch (Exception ioe){
return null;
public static void main(String args[]){
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) { }
JFrame f = new Crypto();
f.setVisible(true);
package Crypto;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
/* ScrollablePicture.java is used by ScrollDemo.java. */
public class ScrollablePicture extends JLabel
implements Scrollable,
MouseMotionListener {
private int maxUnitIncrement = 1;
private boolean missingPicture = false;
public ScrollablePicture(ImageIcon i, int m) {
super(i);
if (i == null) {
missingPicture = true;
setText("No picture found.");
setHorizontalAlignment(CENTER);
setOpaque(true);
setBackground(Color.white);
maxUnitIncrement = m;
//Let the user scroll by dragging to outside the window.
setAutoscrolls(true); //enable synthetic drag events
addMouseMotionListener(this); //handle mouse drags
//Methods required by the MouseMotionListener interface:
public void mouseMoved(MouseEvent e) { }
public void mouseDragged(MouseEvent e) {
//The user is dragging us, so scroll!
Rectangle r = new Rectangle(e.getX(), e.getY(), 1, 1);
scrollRectToVisible(r);
public Dimension getPreferredSize() {
if (missingPicture) {
return new Dimension(320, 480);
} else {
return super.getPreferredSize();
public Dimension getPreferredScrollableViewportSize() {
return getPreferredSize();
public int getScrollableUnitIncrement(Rectangle visibleRect,
int orientation,
int direction) {
//Get the current position.
int currentPosition = 0;
if (orientation == SwingConstants.HORIZONTAL) {
currentPosition = visibleRect.x;
} else {
currentPosition = visibleRect.y;
//Return the number of pixels between currentPosition
//and the nearest tick mark in the indicated direction.
if (direction < 0) {
int newPosition = currentPosition -
(currentPosition / maxUnitIncrement)
* maxUnitIncrement;
return (newPosition == 0) ? maxUnitIncrement : newPosition;
} else {
return ((currentPosition / maxUnitIncrement) + 1)
* maxUnitIncrement
- currentPosition;
public int getScrollableBlockIncrement(Rectangle visibleRect,
int orientation,
int direction) {
if (orientation == SwingConstants.HORIZONTAL) {
return visibleRect.width - maxUnitIncrement;
} else {
return visibleRect.height - maxUnitIncrement;
public boolean getScrollableTracksViewportWidth() {
return false;
public boolean getScrollableTracksViewportHeight() {
return false;
public void setMaxUnitIncrement(int pixels) {
maxUnitIncrement = pixels;

Answer 1

Instead of "new ImageFilter()", use this file filter:
public static javax.swing.filechooser.FileFilter SOLOMENTE_JPG_GIF_PNG=
new javax.swing.filechooser.FileFilter(){
public String getDescription(){
return "jpg, gif, o png";
public boolean accept(java.io.File file){
String n= file.getName();
return n.endsWith(".jpg") || n.endsWith(".gif") || n.endsWith(".png");
public void load_file() {
JFileChooser fc = new JFileChooser();
fc.setAcceptAllFileFilterUsed(false);
fc.setFileFilter(SOLOMENTE_JPG_GIF_PNG); // <-- NUEVO
int retval = fc.showOpenDialog(this);
try{
if (retval == JFileChooser.APPROVE_OPTION){
original = fc.getSelectedFile();
//String nome = original.getName();
sorgente = ImageIO.read(original);
ii.setImage(sorgente);
picture = new ScrollablePicture(ii, 1);
JSPanel = new JScrollPane(picture, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
this.getContentPane().add(BorderLayout.WEST, JSPanel);
this.repaint();
}catch (Exception e){}