1 Focus

     2 =====

     3 

     4 Only one widget can have focus at the time.

     5 Top widget has link to currently focused widget in 'focuswidget'.

     6 

     7 Events emitted on change: focus, unfocus

     8 

     9 mousedown - focus widget under mouse

    10 

    11 tab - focus next child in container (depends on canfocus())

    12 shift-tab - previous child

    13 

    14 hide() -> unfocus

    15 

    16 tab/shift-tab into / out off containers?

    17 trapfocus # if True, tab cycles inside container

    18 

    19 widget.hasfocus()