Arrow keys: 'up', 'down', 'right', 'left'.
Function keys: from 'f1' to 'f12'.
Others: 'home', 'end', 'insert', 'delete', 'pageup', 'pagedown',
'tab', 'enter', 'backspace' (same as 'delete' on OSX keyboards),
'escape'.
Control with one of the following keys: 'a', 'b', 'c', 'd', 'e', 'f',
'h', 'k', 'l', 'n', 'p', 't', 'u', 'w'.