How do I listen for changes in a container's components?

I have a JScrollPane that contains a JTextPane. I want any Container that can possibly contain my JScrollPane to be able to listen for changes in the JTextPane's Document.
For example, at the moment I'm using a JTabbedPane to hold a number of my JScrollPanes and I want to alter the tab title when any associated JScrollPane-JTextPane-Document is updated.
Any suggestions on how best to handle this?

I would use a controller object that manages all your gui components (tabs, scrolls, documents, text panes). Your controller object can register as a listener to the appropriate component, and when it changes, update the title of a tab (or do whatever else) as appropriate.
Never put business logic like this stuff inside the actual gui components. Create, layout, etc. all the gui components (and related components like Document) from another controller like object instead. It makes handling the various listener stuff like this much easier. Read up on MVC (model view controller) stuff for more info.
As for the actual mechanics, you could get the document that is used in the JTextPane and register as a DocumentListener. As a document listener, you get notified of all changes that are made to that document.

Similar Messages

How do I listen for change in the global position of a Node

Hi there,
I want to create a Wire/Connection node between two scene nodes. I want this Wire node to be updated when one of the nodes is moving. In the common scenario I would listen for change events in the target nodes position and update the Wire :
targetNode1.translateXProperty().addListener(new ChangeListener<Number>() {
public void changed(ObservableValue value, Number oldValue, Number newValue) {
wire.setStartX(targetNode1.getTranslateX());
wire.setStartX(targetNode1.getTranslateY());
wire.setEndX(targetNode2.getTranslateX());
wire.setEndY(targetNode2.getTranslateY());
The problem is that the target nodes are children of another container nodes(that are actually moving). So listening for change events in the translate properties of the target nodes does not work(their parent nodes are actually moving)
Is there way to listent for change in the global position of the target nodes relative to the Scene?

It sounds very similar to a problem I posted about earlier...
How to implement a UI similar to a UML Diagram with connections?
I ended up making my own special bounds property, that updates when the parent's special bounds property changes.
I also had to listen to the parentProperty change event to add/remove my listener on the parent node.
All in all, a pain in the butt. There should be an easier way.
The shortcoming of the solution is that all the nodes in the hierarchy must have my special bounds property implemented (ie. they're all classes under my codebase such that I can implement it), which for the moment is true... I'd like a cleaner solution however.

Listening for Changes to JTextArea

I am writing a program that listens for changes to the contents of a JTextArea to obtain input for its execution. But I have implemented DocumentListener, PropertyChangeListener to listen for changes to the JTextArea for deriving input without success. Please could anyone advice on what to do.
My code is below.
   myListener implements DocumentListener{
   JTextArea txt = new JTextArea();
   txt.getDocument().addDocumentListener(this);
   public void changedUpdate(DocumentEvent e){}
   public void removeUpdate(DocumentEvent e){}
   public void insertUpdate(DocumentEvent e){
    try{
     //my code for obtaining input from txt is here
     int start = e.getOffset();
     Document doc = e.getDocument();
    }catch(BadLocationException ble){
}

Here's a link to the Swing tutorial on "How to Write a Document Listener":
http://java.sun.com/docs/books/tutorial/uiswing/events/documentlistener.html

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Any way to listen for changes in Spark TextArea?

Hello,
What is the best way to listen for changes in a Spark TextArea? My scenario is simple: I need to know when some text is added or deleted (with from/to index).
Regards,
Dinko

s:TextArea does have a chang event - http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/spark/components/TextAr ea.html.

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How do I go for SSCC(Serial Shipping Container Code) thorough PI sheet.
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Hi,
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SWF panel listener for changed selection

In short, my question is as follows. Is it possible to create a listener which
detects when the current selection in the Flash authoring tool has changed,
and informs my SWF panel? This does not have to be a listener per se,
it can be some hand-crafted process which consumes some reasonable amount of processor time.
I describe my question more precisely below.
Suppose that I want to create an SWF extension panel for Flash (in Flash or Flex),
and I would like the panel to display a property of the object currently selected on scene
in the Flash IDE -- like the instance name of the object (if it exists).
I can use JSFL to detect the instance name of the selected object, and pass the string to the
SWF panel using call(), for instance. The problem is that I don't know how
to detect that the user has selected the object, or that the selection has changed.
Ideally, I would like to add an event listener that listens for such an action in the flash authoring tool.
However, using JSFL, this does not seem to be possible (I can only listen to events such as frame changed
or layer changed, but not selection changed).
I tried the following solutions:
1. Periodically check in JSFL whether the current selection has changed.
The problem is that in JSFL, there is no sleep function, or anything alike. The javascript
methods setInterval and setTimeout do not work in JSFL. Therefore, in order to periodically check for changes,
one must actively loop. This is extremely resource-consuming -- in fact, it hangs the flash IDE.
2. The periodic check can be triggered by the SWF panel itself. In actionscript, I can use setInterval to periodically
invoke the selection update function via JSFL. I have set the interval to 400 milliseconds, which gives a reasonably quick
reaction to changes. However, the functionality I want to implement is in fact more complicated than just retrieving the
instance name of the selected object. As a consequence, performing this operation every 400 milliseconds still consumes
too much processor time (the flash IDE consumes 30% of my processor time, even if the user doesn't do anything).
Therefore, I still would like to find a solution which does not use the processor when the user does not do anything in the Flash IDE.

I'm trying to do the same thing. Did you find a solution?

Listen for change in JTextField

I would like to write an event listener to listen for any changes made to a JTextField. Normally I would think that keyListeners would do the trick except that the contents of this field can be altered by the application itself, and I would like to trap those changes too.
Does anyone know of an event listener that listens for any changes made in the text of a JTextField, regardless of how those changes are made?

use DocumentListener
for more info see http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html#doclisteners

How can mc_instance listen for MouseEvent?

hello;
my_mc_instance.addEventListener( MouseEvent.MOUSE_DOWN ,
a_function ) ;
I do not understand why my_mc_instance even knows what a
mouseevent is; for instance, I have to know what a "knock on the
door" is before I can listen for it;
movieclips DO NOT inherit from: Mouse or MouseEvent or even
Event;
movieclips inherit from:
MovieClip --> Sprite --> DisplayObjectContainer -->
InteractiveObject --> DisplayObject --> EventDispatcher
--> Object
so how do they even know what a MouseEvent is?
it would seem to me that trying to add a mouseevent listener
to my_mc_instance would never fire since movieclips do not inherit
any mouse-related stuff;
furthermore, according to MovieClip.as, MovieClip class
already has methods that are apparently firing for the mouseevents:
ActionScript Code:
function onMouseDown():Void;
function onMouseMove():Void;
function onMouseUp():Void;
function onPress():Void;
function onRelease():Void;
function onReleaseOutside():Void;
function onRollOut():Void;
function onRollOver():Void; ...
which makes me wonder why it is even necessary to add
mouse-related listeners to an mc;
any thoughts?
thanks
dsdsdsdsd

Hey,
The reason movie clips dispatch mouse events is because movie
clips inherit from InteractiveObject. All InteractiveObjects
dispatch mouse events, so naturally, movie clips dispatch mouse
events.
For an object to be able to dispatch events, it doesn't have
to inherit from the specific event class (MouseEvent class), just
another class that dispatches those events (InteractiveObject).
The script you included contains methods from AS2. You can't
use them in AS3, so the only way to trigger anything with the mouse
is to add event listeners.

JTextfield listening for changes from other class

Hi,
Assuming I have a Jtextfield in one of the class1 extend Jframe,
how do I update the jtextfield so that it could up make accessible by other class and continuously updated to reflect the input for value rom another class2.
In other words very much similar to the observable model view concept
class 1 may be look like
private void initComponents() {
jTextField1 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jTextField1.setEditable(false);
class 2 may be look similar to the following
public void out_1(){
setStop1("N");
for (int i=1;i<100;i++){
class_1.getJTextField1().setText(String.valueOf(i)); // System.out.println(i);
setOuti(i);
setStop1("N");

HI,
I have attempted with the following coding , test 1 the source display generated using Netbeans GUI , t est2 the worker code ,and mybean the bean , so far nothing seems to work .
I have not try the threaded swing concept as I am not familar with the concurrency but i am not sure whether propertylistener will do the job or not
In summary , list of method employed are :
binding the jtextfield1 to a bean,
jtextfield add document listener ,
Coding objective
1. Test 1 defined jtexfield1 and jbutton
2 Jbutton added actionlistener , where upon click,
Execute Test 2 which will assign a series of integer to the bean , own setters & getters, Output is achieved via Test 1 jtextfield1 supposingly to display all the running number from 1 to 99 continuously until the test2 out_1 method finished the execution
Anyone could provide the assistance .
Thank
* Test_1.java
* Created on July 25, 2007, 9:23 PM
package sapcopa;
import java.beans.PropertyChangeListener;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;
import sapcopa.MyBean.*;
public class Test_1 extends javax.swing.JFrame {
/** Creates new form Test_1 */
// private Test_2 t2=new Test_2();
private String input_txt;
public Test_1() {
myBean1=new MyBean();
myBean1.addPropertyChangeListener(new java.beans.PropertyChangeListener(){
public void propertyChange(java.beans.PropertyChangeEvent evt) {
bean_chg(evt);
initComponents();
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
// <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
private void initComponents() {
myBean1 = new sapcopa.MyBean();
jTextField1 = new javax.swing.JTextField();
jTextField1.getDocument().addDocumentListener(new MyDocumentListener());
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jTextField1.setEditable(false);
jTextField1.setText(myBean1.getRecord_Process());
jTextField1.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
public void propertyChange(java.beans.PropertyChangeEvent evt) {
txt1_chg(evt);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
But1(evt);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 250, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(32, 32, 32)
.addComponent(jButton1)))
.addContainerGap(131, Short.MAX_VALUE))
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 29, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(21, 21, 21)
.addComponent(jButton1)
.addContainerGap(216, Short.MAX_VALUE))
pack();
}// </editor-fold>//GEN-END:initComponents
private void txt1_chg(java.beans.PropertyChangeEvent evt) {//GEN-FIRST:event_txt1_chg
// TODO add your handling code here:
//myBean1=new MyBean();
try {
jTextField1.setText(myBean1.getRecord_Process());
} catch (Exception e){
e.printStackTrace();
}//GEN-LAST:event_txt1_chg
private void bean_chg(java.beans.PropertyChangeEvent evt){
jTextField1.setText(myBean1.getRecord_Process());
private void But1(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_But1
//getJTextField1().getDocument().addDocumentListener(new MyDocumentListener());
Test_2 t2=new Test_2();
t2.out_1();
try{
System.out.println("Button 1 mybean->"+myBean1.getRecord_Process());
} catch (Exception e){
e.printStackTrace();
// TODO add your handling code here:
}//GEN-LAST:event_But1
* @param args the command line arguments
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Test_1().setVisible(true);
public javax.swing.JTextField getJTextField1() {
return jTextField1;
public void setJTextField1(javax.swing.JTextField jTextField1) {
this.jTextField1 = jTextField1;
class MyDocumentListener implements DocumentListener {
final String newline = "\n";
public void insertUpdate(DocumentEvent e) {
// updateLog(e, "inserted into");
String vstr=myBean1.getRecord_Process().toString();
jTextField1.setText(vstr);
public void removeUpdate(DocumentEvent e) {
//updateLog(e, "removed from");
String vstr=myBean1.getRecord_Process().toString();
jTextField1.setText(vstr);
public void changedUpdate(DocumentEvent e) {
//Plain text components don't fire these events.
String vstr=myBean1.getRecord_Process().toString();
jTextField1.setText(vstr);
public void updateLog(DocumentEvent e, String action) {
Document doc = (Document)e.getDocument();
int changeLength = e.getLength();
// jTextField1.setText(String.valueOf(changeLength));
String vstr=myBean1.getRecord_Process().toString();
jTextField1.setText(vstr);
public String getInput_txt() {
return input_txt;
public void setInput_txt(String input_txt) {
this.input_txt = input_txt;
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton jButton1;
private javax.swing.JTextField jTextField1;
private sapcopa.MyBean myBean1;
// End of variables declaration//GEN-END:variables
* Test_2.java
* Created on July 25, 2007, 9:26 PM
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
package sapcopa;
import sapcopa.MyBean.*;
public class Test_2 {
private Test_1 t1=new Test_1();
private int outi;
private String stop1;
MyBean mybean;
/** Creates a new instance of Test_2 */
public Test_2() {
public void out_1(){
setStop1("N");
mybean=new MyBean();
for (int i=1;i<100;i++){
mybean.setRecord_Process(String.valueOf(i));
setOuti(i);
setStop1("N");
setStop1("Y");
public int getOuti() {
return outi;
public void setOuti(int outi) {
this.outi = outi;
public String getStop1() {
return stop1;
public void setStop1(String stop1) {
this.stop1 = stop1;
* MyBean.java
* Created on July 24, 2007, 12:00 AM
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
package sapcopa;
import javax.swing.JTextField;
public class MyBean {
/** Creates a new instance of MyBean */
public MyBean() {
* Holds value of property record_Process.
private JTextField txt_rec_process;
private String record_Process;
* Utility field used by bound properties.
private java.beans.PropertyChangeSupport propertyChangeSupport = new java.beans.PropertyChangeSupport(this);
* Adds a PropertyChangeListener to the listener list.
* @param l The listener to add.
public void addPropertyChangeListener(java.beans.PropertyChangeListener l) {
propertyChangeSupport.addPropertyChangeListener(l);
* Removes a PropertyChangeListener from the listener list.
* @param l The listener to remove.
public void removePropertyChangeListener(java.beans.PropertyChangeListener l) {
propertyChangeSupport.removePropertyChangeListener(l);
* Getter for property record_Process.
* @return Value of property record_Process.
public String getRecord_Process() {
return this.record_Process;
* Setter for property record_Process.
* @param record_Process New value of property record_Process.
public void setRecord_Process(String record_Process) {
String oldRecord_Process = this.record_Process;
this.record_Process = record_Process;
propertyChangeSupport.firePropertyChange("record_Process", oldRecord_Process, record_Process);
* Holds value of property rec_Match.
private String rec_Match;
* Getter for property rec_Match.
* @return Value of property rec_Match.
public String getRec_Match() {
return this.rec_Match;
* Setter for property rec_Match.
* @param rec_Match New value of property rec_Match.
public void setRec_Match(String rec_Match) {
String oldRec_Match = this.rec_Match;
this.rec_Match = rec_Match;
propertyChangeSupport.firePropertyChange("rec_Match", oldRec_Match, rec_Match);
public JTextField getTxt_rec_process() {
return txt_rec_process;
public void setTxt_rec_process(JTextField txt_rec_process) {
JTextField oldTxt_rec_process=this.txt_rec_process;
this.txt_rec_process = txt_rec_process;
propertyChangeSupport.firePropertyChange("txt_rec_process", oldTxt_rec_process, txt_rec_process);
}

Is there any event listener for changing the selection of layer?

Hi all,
I am looking into an event listener which fires on changing the selection of layer. I found 'Select' event listener which fires on selecting the different object.
Actually the problem with Select event listener is that when we select an object and move it and deselect it by clicking on the document, event fires on the selection of that object. But if we again select the same object and move it, no event is fired at that time.
Is there any workaround of this? So that the event is fired every time when we select the same object.
Please help me on this..
Regards,
VG.

Thanks for the reply..
Actually I want the same behaviour as in illustrator i.e
- Select a layer. (Notifier calls the listener)
- Move it.
- Click on the document.
- Again select the same layer. (Notifier calls the listener again)
- Move it.
But in photoshop,
- Select a layer. (Notifier calls the listener)
- Move it.
- Click on the document.
- Again select the same layer. (Notifier doesnot calls the listener again as the layer is already selected in panel as you explained.)
- Move it.
Is there any way to get the same behaviour of illustrator in photoshop?

Listening for change events on a JTable

Hi
me = Java newbie!
Well I've been building an app to read EXIF data from JPEG files using the imageio API and Swing. Learning both along the way.
Stumbling block is that I am outputting the EXIF data into a JTable, inside a JScrollPane. These 2 components then become associated with a JInternalFrame container of the class MyInternalFrame.
Works!
Next job is to enable user to select a row in the table which then displays the image file.
I know I can use ListSelectionEvent to detect a row selection and that 2 events are fired.
I put some code into MyInternalFrame class to register a ListSelectionEvent, but I can't see how to reference MyInternalFrame from within this code....see below:
package EXIFReader;
import java.io.File;
import java.io.FilenameFilter;
import javax.swing.JInternalFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
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public class MyInternalFrame extends JInternalFrame {
static int openFrameCount = 0;
static final int xOffset = 30, yOffset = 30;
File file;
File[] directoryMembers = null;
public MyInternalFrame(File aFile) { //aFile rererences a directory containing jpeg files//
super(null,
true, //resizable
true, //closable
true, //maximizable
true);//iconifiable
file = aFile;
//Set the window's location.
this.setLocation(xOffset*openFrameCount, yOffset*openFrameCount);
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String name) {
return name.endsWith(".jpg");}};//Filter out any files in the directory that ain't jpegs
directoryMembers = file.listFiles(filter);
int i = 0;
String[][] tableData= new String [directoryMembers.length][5];
String[]headers = new String[]{"File Name","Date Taken",
"F-Number","Exposure",
"Flash Settings"};
for (File dirfile: directoryMembers)
try {
if(dirfile!=null){
tableData[i] = new ExifReader(dirfile).getEXIFData();//populate the table with jpeg file names
i++;}}
catch (Exception ex) {
System.out.print("Error" + ex);
if (tableData[0] != null){
final JTable myTable = new JTable(tableData,headers);
this.setSize(900,(50+(directoryMembers.length)*19));
myTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
this.getContentPane().add(new JScrollPane(myTable),"Center");//add the JTable and JScrollPanel to this MyInternal Frame and display it! - cool it works!
ListSelectionModel myLSM = myTable.getSelectionModel();
myLSM.addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent le) {
int[] rows = myTable.getSelectedRows();//want to respond to selections and then display the image as a JInternalFrame but got confused about references from within this listener - need help!
Any gentle nudges?!
P
I can respond to these events using a JFrame, but how can I display the image in a JInternalFrame?

Use code tags to post codes -- [code]CODE[/code] will display asCODEOr click the CODE button and paste your code between the {code} tags that appear.
To get better help sooner, post a [_SSCCE_|http://mindprod.com/jgloss/sscce.html] that clearly demonstrates your problem.
db

Listener for changes in file

Hi
I am trying to solve a problem that needs me to display server logs to client developer using an applet.
I've written a logserver that reads the logfile and spits the output to the socket where my applet is connected to and reading for new data.
The problem I am facing is that I don't know how to tell the logserver that there is new stuff in the logfile that needs to be read and send to the socket so that Applet can read it and display it.
Can I register some kind of listner to this log file and set up a callback that then reads this file?
Thanks
Desi

Create a Runnable. Read the time stamp of the file using getLastModified. The thread checks after some time the new time stamp.
If value has changed just trigger an event.
Hope that helps.

Way to listen for change in JTable cell?

I am having troubles trying to catch a key event while the user is entering text inside a given JTable cell (x/y location). The JTable only seems to manage String objects in it's cells so I can't place a JTextField in there with a KeyListener on it.
Currently, I can only get control of the application once the user has left the cell they are editing.
Does anyone have an example of a JTable 'cell KeyListener' scenario? At this point I want to see if I can print 'hello world' each time I type a character within a cell. Then I'll go from there....

If you want to know when the contents of a cell have been updated you should use a TableModelListener.
If you want to know when a character is added/removed from the cell editor then you need to first understand how this works with a simple text field.
Typically you would use a DocumentListener to receive notifies of a change to the text field. However, within the DocumentEvent you wouldn't be able to change the text field as this notification comes after the text field has already been updated.
If you need to ability to intercept changes to the text field before they happen, then you would need to use a DocumentFilter. An example of using a DocumentFilter is given in the Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html#filter]Text Component Features.
Once you get your regular text field working the way you want, the next step to create a DefaultCellEditor using this JTextField and use this editor in your JTable. The above tutorial also has a section on using editors in a table.

How to add history for changes on custom fields in PO

Hi all,
I have added custom fields to purchase orders via ME21N, ME22N, ME23N. When i update the changes on the custom fields, there is no history kept in ME22N or ME23N screen. Is there a way I can add my custom changes to the po history ?
Any suggestions are welcome.
thanks
Joyce

Hello!
What kind of "history" do you mean? If you would like to store entries in transparent table EKBE, the M.Seema's suggestion may be reasonable. But if you mean that changes need to be logged by means of Document Changes Service, you should get hold of information here http://help.sap.com/saphelp_nw2004s/helpdata/en/2a/fa015b493111d182b70000e829fbfe/frameset.htm

How do I listen for changes in a container's components?

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