This could be augmented to do whatever is required to make
this control enable
External_KillFocus()
External_SetFocus()
InitializeWindow()
Normally this will get replaced (not augmented) by a mixin at
the same level.
Page_Object(Integer state)
PreInitializeWindow()
Normally this is not used. This is called right before the
windows control is created. Can be used to set windows
styles.
set(integer h1 integer h2)
Currently form based classes cancel the set focus message if
there are no form_windows (which there will not be in an
external class). So we force windows to do the focus change. This
behavior may change in the future.