See http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html
The policy of a Swing application is determined by LayoutFocusTraversalPolicy. You can set a focus traversal policy on any Container by using the setFocusCycleRoot method.
Alternatively you can pass focus-traversal-policy-providers to the FocusTraversalPolicy() methods instead of focus cycle roots.
Use the isFocusTraversalPolicyProvider() method to determine whether a Container is a focus-traversal-policy-provider. Use the setFocusTraversalPolicyProvider() method to set a container for providing focus traversal policy.
