1 Event handling

     2 ==============

     3 

     4 Keyboard event propagation

     5 --------------------------

     6 

     7 top widget -> focuswidget -> focuswidget's parent -> focuswidget's parent's parent -> ...and so forth

     8 

     9 1 top window

    10 4   window

    11 3     container

    12 2       edit box

    13 

    14 

    15 Other event propagation

    16 -----------------------