"JTabbedPane & WindowClosing"

Question

Hi All Java Programmers,
I would appreciate if you can provide me with any kind of article, souceCode, demo anything.
This is My Scenarion:
I have a JTabbedPane. I have some editable JTextFields there. If the user make any mistake I display error messages and disable the cancel button so they can't close the window until and unless they correct the errors. Inspite of trying my best I couldn't solve the following three issues(I am not sure if any of them is bug or what).
Problem 1: If there is an error and I try to change the tab, it allows me to do that and the error message pops up after changing the tab. How can I protect this so I won't be able to change the tab until and unless I correct the error? And the error message will also pop up anytime I try to change the tab.
Problem 2: If there is an error it allows me to close the window and none of the error messages pop up. How can I protect this?
Problem 3: Let's say there is an error. I go to another application. When I come back the application is frozen and the cursor is not there anymore.
Any kind of help will be appreciated.
Thanks,
N

Answer 1

Here are some general suggestions of how to handle the problems
Problem one:
set last_tabpane_selected to 0 to initialize
on the tabbed pane set a change listener
tabPane.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
// verify the fields on the last_tabpane_selected
// if you do not pass verification use the tabbedPane changeSelection function to force
// the correct pane and then display your error.
// if passed set last_tabpane_selected to current one
Keep last_tabpane_selected
Problem two:
On the frame you are using add an internal frame listener
/* Initialize exit control */
setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
addInternalFrameListener(new InternalFrameAdapter() {
public void internalFrameActivated(InternalFrameEvent e){}
public void internalFrameClosed(InternalFrameEvent e){}
public void internalFrameClosing(InternalFrameEvent e){
int selectedPane = tabPane.getSelectedIndex(); //identify current table on displayed
// here call routine to verify fields on the selectedPane tabPane
// if they pass
dispose();
// else just continue
public void internalFrameDeactivated(InternalFrameEvent e){}
public void internalFrameDeiconified(InternalFrameEvent e){}
public void internalFrameIconified(InternalFrameEvent e){}
public void internalFrameOpened(InternalFrameEvent e){}
Problem three:
I have no answer but have had similar problems.
rykk