COMMUNICATION BETWEEN JAVASCRIPT AND JAVA APPLET: US$20 AWARD FOR SOLUTION!

Question

COMMUNICATION BETWEEN JAVASCRIPT AND JAVA APPLET PROBLEM (Easy Filter Java Applet) -
US$20 TO ANYONE WHO CAN RESOLVE THE PROBLEM
To forum visitors:
I am prepared to pay a standard shareware fee of US$20 to a user who can resolve this technical problem.
If your advice resolves the problem, I'll forward the payment to your postal address (include your
address with your reply, and also your email address)
I am attempting to enable a HTML button (using Javascript's onClick command) to directly input a number into one of the parameter text boxes in the Easy Filter Java applet (ie, enter a new color value number in the text field of the standard Colors Multiplicator Filter interface).
The applet is Freeware and can be downloaded at: http://www.javazoom.net/applets/easyfilter10/EasyFilter10.html
(It is a very effective bitmap display and editing utility)
To achieve this, I am trying to access the part of the applet that defines and sets the textbox. The text box is defined in the .class file by accessing the parameter details in the genericfilter.txt file (accompanies the .class files). I need to access 'private String appletInitialize()' and then one of the 'textFieldParameters' which sets the textbox.
I understand the basic syntax for referencing the applet:
document.appletname.setString("An example"). However, accessing the text fields in this applet is more complex!!
Please can you recommend the correct Javascript syntax to achieve communication with the applet.
Thank you for your kind assistance.
JM Graham
[email protected]
The Java source code for the applet: EasyFilter.class
# Easy Filter - E.B/JavaZOOM 1999 #
# Contact: [email protected] #
# http://javazoom.hypermart.net #
/* Originally compiled from EasyFilter.java */
import java.awt.*;
import java.io.*;
import java.net.*;
import java.applet.Applet;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.MemoryImageSource;
import java.awt.image.PixelGrabber;
import java.util.Vector;
public synchronized class EasyFilter extends Applet implements KeyListener
private String paramFileName;
private Color bgColor;
private Color fgColor;
private Color parColor;
private Color sepColor;
private Color titleColor;
private Color helpColor;
private int WinWidth;
private int WinHeight;
private String title;
private String logoFileName;
private String originalImageFileName;
private String filteredCaption;
private String originalCaption;
private Vector paramsName;
private Vector paramsValue;
private Vector paramsComment;
private Panel panelParameters[];
private Label labelParameters[];
private TextField textFieldParameters[];
private Label labelComments[];
private int nbParameters;
private ScrollPane scrollPaneParams;
private Panel panelParams;
private Image theLogo;
private Image theOriginalImage;
private Image theFilteredImage;
private int theOriginalPixelArray[];
private int logoWidth;
private int logoHeight;
private int imageWidth;
private int imageHeight;
private drawCanvas canvasTitle;
private Panel panelTitle;
private Label labelTitle;
private Panel panelImages;
private Panel panelOriginalImage;
private drawCanvas canvasOriginalImage;
private Label labelOriginalImage;
private Panel panelFilteredImage;
private drawCanvas canvasFilteredImage;
private Label labelFilteredImage;
private Panel panelHelp;
private Label labelHelp;
private int Yspc;
private FilterImplementation theFilter;
public void init()
String string = null;
string = appletInitialize();
setBackground(bgColor);
if (string != null)
removeAll();
setBackground(Color.white);
setForeground(Color.black);
Label label = new Label(new StringBuffer("Error: ").append(string).toString(), 1);
Panel panel = new Panel();
panel.add(label);
add(panel);
setLayout(new FlowLayout(1, 5, Yspc));
public void keyPressed(KeyEvent keyEvent)
panelHelp.removeAll();
boolean flag = true;
if (KeyEvent.getKeyText(keyEvent.getKeyCode()).equals("Enter"))
for (int i = 0; i < nbParameters; )
try
paramsValue.setElementAt(new Double(textFieldParameters.getText()), i);
i++;
catch (NumberFormatException e)
labelHelp.setText(labelParameters[i].getText() + ": Not a Number");
flag = false;
break;
if (flag == 1)
labelHelp.setText(" .... Running, please wait .... ");
labelHelp.setAlignment(1);
panelHelp.add(labelHelp);
panelHelp.doLayout();
theFilter.updateParameters(paramsValue);
theFilter.computeFilter();
theFilteredImage = createImage(new MemoryImageSource(theFilter.getFinalImageWidth(), theFilter.getFinalImageHeight(), theFilter.getFinalImageBuffer(), 0, theFilter.getFinalImageWidth()));
canvasFilteredImage.setImage(theFilteredImage);
canvasFilteredImage.setBounds(0, 0, theFilter.getFinalImageWidth(), theFilter.getFinalImageHeight());
canvasFilteredImage.repaint();
panelHelp.removeAll();
labelHelp.setText("- Done -");
else
labelHelp.setText("- Press Enter to run the Filter -");
labelHelp.setAlignment(1);
panelHelp.add(labelHelp);
panelHelp.doLayout();
public void keyReleased(KeyEvent keyEvent)
public void keyTyped(KeyEvent keyEvent)
private String appletInitialize()
WinWidth = size().width;
WinHeight = size().height;
if (getParameter("bgcolor") == null)
bgColor = new Color(0, 0, 40);
else
bgColor = new Color(Integer.parseInt(getParameter("bgcolor"), 16));
if (getParameter("fgcolor") == null)
fgColor = new Color(255, 255, 255);
else
fgColor = new Color(Integer.parseInt(getParameter("fgcolor"), 16));
if (getParameter("sepcolor") == null)
sepColor = new Color(158, 128, 128);
else
sepColor = new Color(Integer.parseInt(getParameter("sepcolor"), 16));
if (getParameter("parcolor") == null)
parColor = new Color(24, 24, 24);
else
parColor = new Color(Integer.parseInt(getParameter("parcolor"), 16));
if (getParameter("titlecolor") == null)
titleColor = new Color(255, 255, 0);
else
titleColor = new Color(Integer.parseInt(getParameter("titlecolor"), 16));
if (getParameter("helpcolor") == null)
helpColor = new Color(0, 255, 255);
else
helpColor = new Color(Integer.parseInt(getParameter("helpcolor"), 16));
paramsName = new Vector();
paramsValue = new Vector();
paramsComment = new Vector();
paramFileName = getParameter("paramfile");
String string = readParams(paramFileName);
if (string != null)
return string;
MediaTracker mediaTracker = new MediaTracker(this);
theOriginalImage = getImage(getDocumentBase(), originalImageFileName);
mediaTracker.addImage(theOriginalImage, 0);
if (logoFileName != null)
theLogo = getImage(getDocumentBase(), logoFileName);
mediaTracker.addImage(theLogo, 1);
try
mediaTracker.waitForAll();
catch (InterruptedException e1)
return "Error while loading image";
if (mediaTracker.isErrorAny())
return "Error while loading image";
if (logoFileName != null)
logoWidth = theLogo.getWidth(this);
logoHeight = theLogo.getHeight(this);
imageWidth = theOriginalImage.getWidth(this);
imageHeight = theOriginalImage.getHeight(this);
theOriginalPixelArray = new int[imageWidth * imageHeight];
PixelGrabber pixelGrabber = new PixelGrabber(theOriginalImage, 0, 0, imageWidth, imageHeight, theOriginalPixelArray, 0, imageWidth);
try
pixelGrabber.grabPixels();
panelTitle = new Panel();
canvasTitle = new drawCanvas();
labelTitle = new Label();
panelTitle.setLayout(new FlowLayout(1, 10, Yspc));
add(panelTitle);
panelTitle.setBackground(bgColor);
panelTitle.add(canvasTitle);
canvasTitle.setImage(theLogo);
canvasTitle.setBounds(0, 0, logoWidth, logoHeight);
labelTitle.setText(title);
catch (InterruptedException e2)
return "Internal Error, Try RELOAD !";
if (title != null)
panelTitle.add(labelTitle);
labelTitle.setForeground(titleColor);
labelTitle.setFont(new Font("Dialog", 1, 14));
panelImages = new Panel();
panelOriginalImage = new Panel();
canvasOriginalImage = new drawCanvas();
labelOriginalImage = new Label();
panelFilteredImage = new Panel();
canvasFilteredImage = new drawCanvas();
labelFilteredImage = new Label();
panelImages.setLayout(new FlowLayout(1, 10, Yspc));
add(panelImages);
panelImages.setBackground(bgColor);
panelOriginalImage.setLayout(new BorderLayout(0, 2));
panelImages.add(panelOriginalImage);
panelOriginalImage.setBackground(Color.black);
panelOriginalImage.add("Center", canvasOriginalImage);
canvasOriginalImage.setImage(theOriginalImage);
canvasOriginalImage.setBounds(0, 0, imageWidth, imageHeight);
labelOriginalImage.setText(originalCaption);
labelOriginalImage.setAlignment(1);
panelOriginalImage.add("South", labelOriginalImage);
labelOriginalImage.setBackground(Color.lightGray);
labelOriginalImage.setForeground(Color.black);
labelOriginalImage.setFont(new Font("SansSerif", 0, 10));
panelFilteredImage.setLayout(new BorderLayout(0, 2));
panelImages.add(panelFilteredImage);
panelFilteredImage.setBackground(Color.black);
panelFilteredImage.add("Center", canvasFilteredImage);
theFilter = new FilterImplementation(paramsValue, theOriginalPixelArray, imageWidth, imageHeight);
theFilter.computeFilter();
theFilteredImage = createImage(new MemoryImageSource(theFilter.getFinalImageWidth(), theFilter.getFinalImageHeight(), theFilter.getFinalImageBuffer(), 0, theFilter.getFinalImageWidth()));
canvasFilteredImage.setImage(theFilteredImage);
canvasFilteredImage.setBounds(0, 0, theFilter.getFinalImageWidth(), theFilter.getFinalImageHeight());
labelFilteredImage.setText(filteredCaption);
labelFilteredImage.setAlignment(1);
panelFilteredImage.add("South", labelFilteredImage);
labelFilteredImage.setBackground(Color.lightGray);
labelFilteredImage.setFont(new Font("SansSerif", 0, 10));
scrollPaneParams = new ScrollPane(0);
panelParams = new Panel();
nbParameters = paramsName.size();
int i = WinHeight - (33 + 7 * Yspc + logoHeight + imageHeight + 23);
if (i < Yspc + 2 + 24)
i = Yspc + 2 + 24;
scrollPaneParams.setBounds(0, 0, WinWidth - 10, i);
panelParams.setLayout(new GridLayout(nbParameters, 1, 5, Yspc / 2));
scrollPaneParams.add(panelParams);
panelParams.setBackground(sepColor);
panelParameters = new Panel[nbParameters];
labelParameters = new Label[nbParameters];
textFieldParameters = new TextField[nbParameters];
labelComments = new Label[nbParameters];
for (int j = 0; j < nbParameters; j++)
panelParameters[j] = new Panel();
panelParameters[j].setLayout(new FlowLayout(0, 5, 1));
panelParams.add(panelParameters[j]);
panelParameters[j].setBackground(parColor);
labelParameters[j] = new Label();
labelParameters[j].setText((String)paramsName.elementAt(j));
panelParameters[j].add(labelParameters[j]);
labelParameters[j].setForeground(fgColor);
labelParameters[j].setFont(new Font("Dialog", 1, 12));
textFieldParameters[j] = new TextField(8);
textFieldParameters[j].setText(paramsValue.elementAt(j).toString());
panelParameters[j].add(textFieldParameters[j]);
textFieldParameters[j].setBackground(fgColor);
textFieldParameters[j].addKeyListener(this);
labelComments[j] = new Label();
labelComments[j].setText((String)paramsComment.elementAt(j));
panelParameters[j].add(labelComments[j]);
labelComments[j].setForeground(fgColor);
add(scrollPaneParams);
panelHelp = new Panel();
labelHelp = new Label();
panelHelp.setLayout(new FlowLayout(1, 5, 0));
add(panelHelp);
panelHelp.setBackground(bgColor);
labelHelp.setText(" Change colour values and press enter ");
labelHelp.setAlignment(1);
panelHelp.add(labelHelp);
labelHelp.setForeground(helpColor);
return null;
private String readParams(String string1)
Object object1;
String string2;
if (string1 == null)
return "Filename of filter's parameters needed";
try
URL uRL = new URL(getDocumentBase(), string1);
URLConnection uRLConnection = uRL.openConnection();
uRLConnection.setDoInput(true);
uRLConnection.setUseCaches(false);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(uRLConnection.getInputStream()));
string2 = null;
catch ()
return object1.getMessage();
catch ()
return object1.getMessage();
catch ()
return object1.getMessage();
if (bufferedReader != null)
Object object2;
try
for (object2 = bufferedReader.readLine(); object2 != null && string2 == null; object2 = bufferedReader.readLine())
string2 = extractFormat(object2);
catch ()
string2 = object2.getMessage();
finally
bufferedReader.close();
if (string2 != null)
return string2;
else
return null;
private String extractFormat(String string1)
if (string1.length() == 0)
return null;
int i = 0;
int j = string1.indexOf(" ", i);
if (j == -1)
return "Bad format error (space missing)";
String string2 = string1.substring(i, j);
if (string2.equals("TITLE"))
i = j;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in TITLE missing)";
i = j + 1;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in TITLE missing)";
title = string1.substring(i, j);
return null;
if (string2.equals("ORIGINALCAPTION"))
i = j;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in ORIGINALCAPTION missing)";
i = j + 1;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in ORIGINALCAPTION missing)";
originalCaption = string1.substring(i, j);
return null;
if (string2.equals("FILTEREDCAPTION"))
i = j;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in FILTEREDCAPTION missing)";
i = j + 1;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in FILTEREDCAPTION missing)";
filteredCaption = string1.substring(i, j);
return null;
if (string2.equals("LOGO"))
i = j + 1;
j = string1.length();
logoFileName = string1.substring(i, j);
return null;
if (string2.equals("ORIGINALIMAGE"))
i = j + 1;
j = string1.length();
originalImageFileName = string1.substring(i, j);
return null;
if (!string2.equals("PARAM"))
return null;
i = j;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format in a PARAM line";
i = j + 1;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format in a PARAM line";
paramsName.addElement(string1.substring(i, j));
i = j + 2;
j = string1.indexOf(32, i);
if (j == -1)
return "Bad format in a PARAM line";
try
paramsValue.addElement(new Double(string1.substring(i, j)));
j = string1.indexOf(34, i);
catch (NumberFormatException e)
return "Bad format in a PARAM line";
if (j == -1)
return "Bad format (Double quote in PARAM comment missing)";
i = j + 1;
j = string1.indexOf(34, i);
if (j == -1)
return "Bad format (Double quote in PARAM comment missing)";
paramsComment.addElement(string1.substring(i, j));
return null;
public EasyFilter()
logoHeight = 33;
Yspc = 5;

Answer 1

Addition to my above submission
To clarify, I'll offer the US$20 to the FIRST person who offers me a workable solution to the problem, not to everyone!!!
JMGRAHAM