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I am using Java CardLayout to switch between cards and JPanel. When activity starts in android I can use onLoad, or similar to check if the activity is now open. What is the equivalent to this in swing? How can I know if the JPanel (Card) is now in front? 

public class FirstScreen extends JPanel 
{
//am I visible now?
}
mKorbel
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Dim
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    A Panel should go inside a Frame. You mean being visible into the Frame or the frame itself to be visible in the OS desktop? – Aritz Aug 06 '13 at 12:43
  • The JPanel is inside frame in other class, when I open it I use show function. When the FirstScreen is shown I need to know about this in itself. – Dim Aug 06 '13 at 12:47

1 Answers1

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Implement windowActivated() in a WindowListener or WindowAdapter, as shown in How to Write Window Listeners and this example. See also How to Write a Component Listener.

Addendum: To receive notification that a particular card was selected, use a PropertyChangeEvent, as shown here, or an AncestorEvent, as shown here.

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trashgod
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  • @mKorbel: good idea; there's an `AncestorListener` example [here](http://stackoverflow.com/a/17993449/230513). – trashgod Aug 06 '13 at 13:45