UMG mouse/focus questions

  1. I want to use XBox Controller to control the menu,the problem is, How can I prevent the user to use the TAB key or the left stick to focus specific widgets like border panels,
    2.How can I modify the visual of the dotted line shown after you focus on a widget

I have found the function in SWidget::Paint, the function is use to draw the dotted line,can any one show me an example about how to use it,or maybe another way to Solve my problem.