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dingfelder wrote:

> I am trying to make my application ignore clicks on the X in the
> top right.  I have read on the web that you do this via:
> 
> setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
> 
> Other posts have said you also do:
> 
> addWindowListener( new WindowAdapter() { public void
> windowClosing(WindowEvent e) { System.out.println("exit was
> pressed"); } });
> 
> When I do these both in my JFrame, the windowClosing event does
> indeed get called because I see the message, but then it goes ahead
> and exits.
> 
> How can I make it NOT exit?

I don't think you can intercept and cancel the window
closing event.  Perhaps all you can do is set the
frame to be visible again.  Annoying, but unless you
change the container to a dialog box, for which you
do get a chance to cancel an attempt to close, you
are stuck ... unless someone knows some other trick.


-- 


Paul Furbacher (TeamB)

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>I don't think you can intercept and cancel the window
>closing event.  Perhaps all you can do is set the
>frame to be visible again.  Annoying, but unless you
>change the container to a dialog box, for which you
>do get a chance to cancel an attempt to close, you
>are stuck ... unless someone knows some other trick.
>-- 
>Paul Furbacher (TeamB)

You mention setting the frame visible again... this seems to me to imply that the window frame has not exited bu just become invisible.

If this is true, then I could deal with that... although I assume the app might flicker when becoming visible?

If this is not, then I assume all the data the user has entered would dissipear which is not good.

dingfelder wrote:

> How can I make it NOT exit?

A crude way to do it is throw an exception; that's the only thing I
know of that stops a window closing event.

If you want to take control of the closing event, then you can do the
following:

myFrame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

and then write code elsewhere (e.g. in a button handler) that calls
either hide() or dispose(), depending on what you want to do with the
frame when you're done.

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dingfelder wrote:
> I am trying to make my application ignore clicks
> on the X in the top right.  I have read on the web
> that you do this via:
> 
> setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
> 
> Other posts have said you also do:
>         
> addWindowListener( new WindowAdapter() {
>    public void windowClosing(WindowEvent e) {
>        System.out.println("exit was pressed");
>    }            
> });   
> 
> When I do these both in my JFrame, the windowClosing
> event does indeed get called because I see the message,
> but then it goes ahead and exits.  
> 
> How can I make it NOT exit?

Actually, I didn't read your message carefully enough.
With the defaultCloseOperation property set to
DO_NOTHING_ON_CLOSE, the frame does not close unless
you have written code in the windowClosing handler
to actually hide it [setVisible(false)].  So, if
you are seeing the frame close, it's because somewhere
in your code, you are indeed hiding the window, or
calling System.exit(0).

(I just did a test of this by creating a new project,
adding a single frame which has a main() method.
I added a handler for windowClosing as you show above.
I added a "Quit" button which when pushed invokes System.exit().
That is, I double-clicked on the button in the UI Designer
and in the actionPerformed() method which JBuilder generated,
I wrote "System.exit(0);"

With the defaultCloseOperation set as above, nothing
happens when the "X" in the title bar of the window
is pressed except to print out the message to JBuilder's
Message Pane.

Only when I press the "Quit" button does the window close.
However, the windowClosing() event is not generated when
I hit the "Quit" button.  (This is just as expected.)
If you want to confirm whether to quit, you have to
do that in the button's actionPerformed() handler.


-- 


Paul Furbacher (TeamB)

   Save time, search the archives:
        http://info.borland.com/newsgroups/ngsearch.html

   Is it in Joi Ellis's Faq-O-Matic?
        http://www.visi.com/~gyles19/fom-serve/cache/1.html

   Finally, please send responses to the newsgroup only.
   That means, do not send email directly to me.
   Thank you.