A TextField is a text component that is editable when it is focused on.
It provides the same editing operations as TextBox and
follows the same specification to the extent that TextFields
can practically be considered TextBoxes that are inserted
into a Form. It can have an initial value that is displayed
at initialization. TextFields are always the same width
as the Form they are placed in, but the amount of rows
they use can be set.
TextField is always focusable.
For implementation notes relating to TextField,
see TextBox implementation
notes.