@foreach

Invokes callback on each non-internal child of this.

See forall for details on what constitutes an “internal” child. For all practical purposes, this function should iterate over precisely those child widgets that were added to the container by the application with explicit add calls.

It is permissible to remove the child from the callback handler.

Most applications should use @foreach, rather than forall.

Parameters:

this	a Container
callback	a callback
callback_data	callback user data