Pls take a look at this program

Question

i have try to mimic function of magic bar in photoshop.
but i am stick to the initial phase.
who can help me to see what's wrong with the program?
it displays in a mess. i have examined it for 2 days and can not figure it out.
can any one help me with this?
thanks advance
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.swing.filechooser.FileFilter;
import java.beans.*;
import java.awt.image.*;
public class MagicBar extends WindowAdapter implements MouseListener,
                                        ActionListener,ComponentListener{
JFrame frame;
JPanel contentpane;
JCanvas top;
JPanel p;
JFileChooser fdialog;
filefilter ffilter,bmpfilter,jpgfilter,giffilter,bothfilter;
File file;
int w,h;
boolean change;
Point[] Direct;
int R,G,B;
int count=0;
JPanel accessory;
FilePreview previewer;
JScrollPane sp;
JButton load,exit,clear,copy;
ImageIcon image; //
Image img; //image to be loaded
BufferedImage drawnImage; //image to be drawn
BufferedImage bfimage,newbfimage; //bufferedimage to operate
Raster raster;
int[] pixels;
Graphics2D g2d;
public MagicBar(){
drawnImage=null;
Direct=new Point[4];
for(int i=0;i<4;i++){
     Direct=new Point();
Direct[0].x=-1;
Direct[0].y=0;
Direct[1].x=0;
Direct[1].y=-1;
Direct[2].x=1;
Direct[2].y=0;
Direct[3].x=0;
Direct[3].y=1;
frame=new JFrame("MagicBar");
load=new JButton("Load");
load.addActionListener(this);
exit=new JButton("EXit");
exit.addActionListener(this);
copy=new JButton("Copy");
copy.addActionListener(this);
clear=new JButton("Clear");
clear.addActionListener(this);
p=new JPanel();
p.setLayout(new GridLayout(1,4));
p.add(load);
p.add(exit);
p.add(copy);
p.add(clear);
fdialog=new JFileChooser();
jpgfilter=new filefilter("jpg","JPEG File");
bmpfilter=new filefilter("bmp","BitMap File");
giffilter=new filefilter("gif","Gif File");
bothfilter=new filefilter(new String[]{"gif","jpg"},"GIF&JPEG File");
filefilter pngfilter=new filefilter("png","PNG File");
fdialog.addChoosableFileFilter(jpgfilter);
fdialog.addChoosableFileFilter(giffilter);
fdialog.addChoosableFileFilter(bmpfilter);
fdialog.addChoosableFileFilter(pngfilter);
fdialog.addChoosableFileFilter(bothfilter);
fdialog.setCurrentDirectory(new File("C:/jdk1.3/demo/jfc/Java2D/images"));
previewer=new FilePreview(fdialog);
fdialog.setAccessory(previewer);
top=new JCanvas();
top.addMouseListener(this);
sp=new JScrollPane(top);
contentpane=new JPanel();
contentpane.setLayout(new BorderLayout());
contentpane.add(sp,BorderLayout.CENTER);
contentpane.add(p,BorderLayout.SOUTH);
frame.setContentPane(contentpane);
frame.setSize(300,300);
frame.addWindowListener(this);
frame.setVisible(true);
public void mouseEntered(MouseEvent me){
public void mouseExited(MouseEvent me){
public void mouseClicked(MouseEvent me){
public void mousePressed(MouseEvent me){
public void mouseReleased(MouseEvent me){
     int x=me.getX();
     int y=me.getY();
     if((pixels!=null)&&(isValid(x,y))){
          handlesinglepixel(x,y,pixels[x+y*w]);
          //System.out.println("pixels not null "+Integer.toHexString(pixels[x+y*w]));
          drawnImage.setRGB(x,y,0x00ffffff);
          count=0;
          digMore(x,y);
          top.repaint();
public boolean isValid(int xx,int yy){
     return (xx<w)&&(yy<h)&&(xx+yy*w<pixels.length);
public void actionPerformed(ActionEvent e){
     JButton bb=(JButton)(e.getSource());
     if(bb==load){
          fdialog.showOpenDialog(frame);
          file=fdialog.getSelectedFile();
          if(file!=null){
               top.loadImage();
               top.revalidate();
               top.repaint();
               clear.setEnabled(true);
               copy.setEnabled(true);
               return;
     if(bb==exit){
          Quit();
          return;
     if(bb==copy){
          if(drawnImage==null){return;}
          newbfimage=new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
          float[] elements = new float[9]; // create 2D array
          for (int i = 0; i < 9; i++) {
               elements[i] = 0.0f;
          elements[1]=-1.0f;
          elements[3]=-1.0f;
          elements[5]=-1.0f;
          elements[7]=-1.0f;
          elements[4]=5.0f;
                    // use the array of elements as argument to create a Kernel
          Kernel myKernel = new Kernel(3, 3, elements);
          ConvolveOp simpleEdge = new ConvolveOp(myKernel);
                    // sourceImage and destImage are instances of BufferedImage
          simpleEdge.filter(bfimage, newbfimage); // blur the image
          drawnImage=newbfimage;
          g2d.drawImage(drawnImage,0,0,top);
          return;
     if(bb==clear){
          if(drawnImage==null){return;}
          clear.setEnabled(false);
          copy.setEnabled(false);
          drawnImage=null;
          //pixels=null;
          //g2d.clearRect(0,0,w,h);
          top.setPreferredSize(new Dimension(0,0));
          w=0;h=0;
          top.revalidate();
          top.repaint();
          return;
public void digMore(int x, int y){
     count++;
     int tx,ty;
     int tindx;
     int tpix;
     for (int i=0;i<4;i++){
          tx=x+Direct[i].x;
          ty=y+Direct[i].y;
          tindx=tx+ty*w;
          if(isValid(tx,ty)){
               tpix=pixels[tindx];
               if(accept(tpix)){
                    drawnImage.setRGB(tx,ty,0x00ffffff);
                    pixels[tindx]=0x00ffffff;
                         if(count<1000){
                         digMore(tx,ty);
public boolean accept(int pix){
int rr=getRed(pix);
int gg=getGreen(pix);
int bb=getBlue(pix);
return ((Math.abs(R-rr)<20)&&(Math.abs(G-gg)<20)&&(Math.abs(B-bb)<20));
public int getRed(int pix){
     return (pix>>16)&0xff;
public int getGreen(int pix){
     return (pix>>8)&0xff;
public int getBlue(int pix){
     return (pix)&0xff;
public void handlesinglepixel(int x, int y,int pixel) {
int red = (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = (pixel ) & 0xff;
R=red;G=green;B=blue;
// Deal with the pixel as necessary...
System.out.println("("+x+","+y+")"+"\tred="+red+" green="+green+" blue="+blue);
System.out.println();
public void windowClosing(WindowEvent we){
     Quit();
public void Quit(){
          frame.setVisible(false);
          frame.dispose();
          System.exit(0);
public void componentHidden(ComponentEvent e){
public void componentMoved(ComponentEvent e){
public void componentResized(ComponentEvent e){
public void componentShown(ComponentEvent e){
// Invoked when the component has been made visible.
class JCanvas extends JPanel {
     public JCanvas() {
     super();
     setPreferredSize(new Dimension(10,10));
     setVisible(true);
     public void loadImage() {
     if(file != null) {
               String imgfile=file.getPath();
               // This method ensures that all pixels have been loaded before returning.
               img = new ImageIcon(imgfile).getImage();
               w=img.getWidth(null);
               h=img.getHeight(null);
               //System.out.println("image:w="+w+" h="+h);
               if((w<=0)||(h<=0)){
               return;
               top.setPreferredSize(new Dimension(w,h));
               top.revalidate();
               pixels = new int[w * h];
               PixelGrabber pg = new PixelGrabber(img, 0, 0, w, h, pixels, 0, w);
               try {
               pg.grabPixels();
               } catch (InterruptedException e) {
               System.err.println("interrupted waiting for pixels!");
               return;
               if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
               System.err.println("image fetch aborted or errored");
               return;
                         bfimage=new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
                         bfimage.createGraphics().drawImage(img,0,0,null);
                         raster=bfimage.getData();
                         drawnImage=new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
                         drawnImage=bfimage;
     public void paint(Graphics g) {
          //if(drawnImage==null){loadImage();} not necessary
          int x = getWidth()/2 - w/2;
          int y = getHeight()/2 - h/2;
          if(y < 0) {
          y = 0;
          if(x < 5) {
          x = 5;
          /*     Point floc=frame.getLocation();
               int tx,ty;
               tx=(frame.getSize().width-w-frame.getInsets().right-frame.getInsets().left)/2
                                   +frame.getInsets().left;
               ty=(frame.getSize().height-h-p.getSize().height-frame.getInsets().top-frame.getInsets().bottom)/2
                         +frame.getInsets().top;
               tx=tx+floc.x;ty=ty+floc.y;
               setLocation(tx,ty); */
          g2d=(Graphics2D)g;
          if(drawnImage!=null){
               g2d.drawImage(drawnImage,0,0,w,h,top);
          } else {
               g2d.clearRect(0,0,w,h);
public static void main(String [] args){
     MagicBar mb=new MagicBar();

Answer 1

oh, sorry i forget to attach filefilter.java and FilePreview.java
here are they.
import javax.swing.*;
import javax.swing.filechooser.FileFilter;
import java.util.Hashtable;
import java.util.*;
import java.io.File;
public class filefilter extends FileFilter{
private Vector filters;
private String extension;
private String descript;
public filefilter(){
     filters=new Vector();
     extension="";
     descript="";
public filefilter(String ext,String descript){
     this();
     filters.add(ext);
     if(ext!=null){this.extension=ext;}
     if(descript!=null){this.descript=descript;}
public filefilter(String exts[],String descript){
     this();
     for(int i=0;i<exts.length;i++){
          filters.add(exts);
     //if(ext!=null){this.extension=ext;}
     if(descript!=null){this.descript=descript;}
public boolean accept(File f){
     if(f!=null){
          if(f.isDirectory()){
               return true;
          String ext=getExt(f);
          if(ext!=null&&filters.contains(ext)){
               return true;
     return false;
public String getExt(File f){
     if(f!=null){
          return getExt(f.getName());
     }else{
          return null;
public String getExt(String fname){
     int i=fname.lastIndexOf('.');
     if(i>0&&i<fname.length()-1){
          return fname.substring(i+1).toLowerCase();
     return null;
public String getDescription(){
if(filters==null||filters.size()==0){return null;}
String Des=descript+"(."+(String)filters.get(0);;
int size=filters.size();
for(int i=1;i<size;i++){
     Des=Des+","+(String)filters.get(i);
Des=Des+")";
return Des;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.swing.filechooser.FileFilter;
import java.beans.*;
import java.awt.image.*;
public class FilePreview extends JComponent implements PropertyChangeListener {
     ImageIcon thumbnail = null;
     File f = null;
     public FilePreview(JFileChooser fc) {
     setPreferredSize(new Dimension(100, 50));
     fc.addPropertyChangeListener(this);
     public void loadImage() {
     if(f != null) {
          ImageIcon tmpIcon = new ImageIcon(f.getPath());
          if(tmpIcon.getIconWidth() > 90) {
          thumbnail = new ImageIcon(
               tmpIcon.getImage().getScaledInstance(90, -1, Image.SCALE_DEFAULT));
          } else {
          thumbnail = tmpIcon;
     public void propertyChange(PropertyChangeEvent e) {
     String prop = e.getPropertyName();
     if(prop == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY) {
          f = (File) e.getNewValue();
          if(isShowing()) {
          loadImage();
          repaint();
     public void paint(Graphics g) {
     if(thumbnail == null) {
          loadImage();
     if(thumbnail != null) {
          int x = getWidth()/2 - thumbnail.getIconWidth()/2;
          int y = getHeight()/2 - thumbnail.getIconHeight()/2;
          if(y < 0) {
          y = 0;
          if(x < 5) {
          x = 5;
          thumbnail.paintIcon(this, g, x, y);