Hi Esteban,

As an entry point, you have PluggableTextFieldMorph.
You can build one with
UITheme class >> newTextEntryIn: aThemedMorph for: aModel get: getSel set: setSel class: aClass getEnabled: enabledSel help: helpText

see the 'class:' argument. As an example, if you pass Integer, then a specific converter is used so that you can only enter a valid integer.
AFAIK, so far we have converters for String and Number.

To implement new converters (to and from Date as an example), dig into
PluggableTextFieldMorph>>convertTo: aClass
    "Set the converter object class."

    self converter isNil
        ifTrue: [self converter: (ObjectStringConverter forClass: aClass)]
        ifFalse: [self converter objectClass: aClass]

and indeed, it would be could to integrate new converters.

See SetingDeclaration>>inputWidgetForString as an client example.

Cheers
Alain