Event Handling with the Swing Component Set - The Definitive Guide to Java Swing - page 47

Figure 2-10. Default focus ordering
Moving the Focus
As an example of some basic capabilities, let's look at how to create two listeners to handle
input focus: a MouseListener that moves the input focus to a component when the mouse
enters its space, and an ActionListener that transfers the input focus to the next component.
The MouseListener merely needs to call requestFocusInWindow() when the mouse enters
the component.
import java.awt.*;
import java.awt.event.*;
public class MouseEnterFocusMover extends MouseAdapter {
public void mouseEntered(MouseEvent mouseEvent) {
Component component = mouseEvent.getComponent();
if (!component.hasFocus()) {
component.requestFocusInWindow();
}
}
}
For the ActionListener , you need to call the focusNextComponent() method for the
KeyboardFocusManager .
import java.awt.*;
import java.awt.event.*;