Re: Detecting Mouse Over Tab on JTabbedPane

From:

Hal Vaughan <hal@thresholddigital.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 03 Sep 2006 12:00:05 -0400

Message-ID:

<z6SdnddX_KZMZmfZnZ2dnUVZ_oidnZ2d@comcast.com>

Michael Rauscher wrote:

Hal Vaughan schrieb:

I tried finding this and hope I've missed the obvious or that it's
something easy I just didn't find.

I know I can set tool tips for a tab on a JTabbedPane object. I'd like
to have a "help" JTextArea off to the side of my main interface to use to
provide more info than I can in a tool tip. Ideally, when the user puts
the mouse pointer over a tab, I'd like to have a listener that will
detect
that and change the text in the help section. In other words, I need to
be able to make an actionlistener that will know when the pointer is over
a tab (not when it changes or is clicked on).

Is that possible?

Sure. It's a MouseMotionListener you'll have to add to the JTabbedPane
instance, e. g. something like this one:

MouseMotionListener listener = new MouseMotionAdapter() {
     private int oldIx = -1;

     public void mouseMoved( MouseEvent e ) {
         JTabbedPane tp = (JTabbedPane)e.getSource();
         int ix = tp.indexAtLocation( e.getX(), e.getY() );

         if ( ix == oldIx )
             return;

         oldIx = ix;

         if ( ix == -1 )
             return;

         doSomethingUseful();
     }
};

Bye
Michael

I tried adding this like this:

addMouseMotionListener(new MouseMotionAdapter() {...});

(The ... contained all the code above.) I replaced "doSomethingUseful()"
with "System.out.println("Tab index: " + ix)" and it never printed
anything, so I finally added "System.out.println("Movement...");" before
the line to get the JTabbedPane from the event and never got a printout
from there.

Is there another step I need to do to make sure I actually get the info or
that the listener is called?

Thanks!

Hal