Notification Question

[Gregg Bolinger]

Ok, I have a JToolBar with JButtons on a JFrame with a JDesktopPane. We'll pretend that is all one class.
Now, in another class I have a JInternalFrame which I add to the JDestopPane via one of the Buttons on the JToolbar.
After I open this InternalFrame I need to disable the Button. That part is easy. But when I close the JInternalFrame, how do I notify the Button to enable itself?
Right now my JButton is static and I dot reference the JButton object from my JInternalFrame. Is this the only way? Or is there a better way? I would prefer a non-static approach.
Thanks.

[Michael Morris]

Hi Gregg,
You should be able to do it with a java.beans.PropertyChangeListener. You can send a pseudo-property named "buttonState" or whatever and have either the button or its Frame listen for changes in that property. I posted a rather lengthy example here:
ComponentMediater

You certainly don't have to go to that much trouble for one component though. I used this to keep several components in a consistent state and it worked very well and is incredibly easy to use once you get the Mediator running.
Hope this helps,
Michael Morris

[Nathan Pruett]

But the button knows about the JInternalFrame because it's launching it, right?

Try something like this in the actionPerformed method of the button...

public void actionPerformed( ActionEvent evt ) {
    JInternalFrame frame = //Whatever internal frame class you are using...
    frame.addInternalFrameListener( new InternalFrameAdapter() {
        public void internalFrameOpened( InternalFrameEvent e ) {
            // I am assuming the button itself is 
            // the action listener, if not, you'll
            // have to do something like :
            // ((JButton)evt.getSource()).setEnabled( false );
            this.setEnabled( false );
        }
        
        public void internalFrameClosed( InternalFrameEvent e ) {
            this.setEnabled( true );
        }
    } );  
    
    // further code, like adding the frame to the
    // desktop, opening it, etc.
}

[Gregg Bolinger]

That's interesting Nate. I had never thought of trying that. I will see how it works for me.
Michael. Thanks for your reply as well.