private static boolean canBeFocusOwner( Component c ) {
		// see Component.canBeFocusOwner()
		if( c == null || !c.isEnabled() || !c.isVisible() || !c.isDisplayable() || !c.isFocusable() )
			return false;

		// special handling for combo box
		// see LayoutFocusTraversalPolicy.accept()
		if( c instanceof JComboBox ) {
			JComboBox<?> comboBox = (JComboBox<?>) c;
			return comboBox.getUI().isFocusTraversable( comboBox );
		}

		// check whether component has an empty input map to skip components that
		// are focusable, but do nothing when focused (e.g. JLabel)
		// see LayoutFocusTraversalPolicy.accept()
		if( c instanceof JComponent ) {
			InputMap inputMap = ((JComponent)c).getInputMap( JComponent.WHEN_FOCUSED );
			while( inputMap != null && inputMap.size() == 0 )
				inputMap = inputMap.getParent();
			if( inputMap == null )
				return false;
		}

		return true;
	}
Does the same as super.navigateFocusedComp() with the exception that components
with empty input map (e.g. JLabel) are skipped.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatToolBarUI.java