Re: Java Swing


"Nuno Silva" ...

> Hi, I'm pretty new to Swing, and I'm at the hello
> world example code from java.sun.com.

Your problem would be no different in AWT...

> I'm trying to add next to the JLabel a JButton,
> and next to frame.getContentPane().add(label);
> I do the same for the JButton created,
> but in the GUI only shows the button.
> Can you explain to me why this happens
> and why not appending the button next to
> the label?

The default LayoutManager in a Frame/JFrame is BorderLayout, that has 5
areas, in which only one component can exist at one time.

frame.getContentPane().add(label);

....is "equal" to:

frame.getContentPane().add(label, BorderLayout.CENTER);

So when you "add" the button, it actually *replaces* the label.

> And how should I do to
> make them put together?

There's a lot of possibilities.

You could start with changing the "adding" to actually use different areas,
e.g.

frame.getContentPane().add(label, BorderLayout.CENTER);
frame.getContentPane().add(button, BorderLayout.SOUTH);

....or you could change the LayoutManager to something else than a
BorderLayout before adding the components:

frame.getContentPane().setLayout( new FlowLayout() );

frame.getContentPane().add(label);
frame.getContentPane().add(button);

http://java.sun.com/j2se/1.5.0/docs/api/java/awt/BorderLayout.html
http://java.sun.com/j2se/1.5.0/docs/api/java/awt/FlowLayout.html


BTW, if you're using the latest version (1.5), there's no longer a need for
the "getContentPane()", as you can use "add" directly on the JFrame (which
forwards it to the pane).


// Bjorn A



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