>From a UI perspective, if the typed character is invalid (or makes an
invalid situation), then simply refuse it; put nothing into the
TextMorph, and, optionally, flash it.

On Wed, Aug 28, 2013 at 3:57 PM, Casimiro de Almeida Barreto
<casimiro.barreto at gmail.com> wrote:
> What would be the best way of validating input in TextMorph (for
> instance, allowing input only of numeric characters or only of small cap
> letters)?
>