I don't think so, but you can trim it after it has been submitted. As far as I know, the only thing you can control (at least on android without physic keyboard) is input type to show different virtual keyboards.
Maybe I don't understand the question, but couldn't you have a counter that would increase by 1 with every button press, then, if it reached a certain limit, would just ignore anymore input?
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As far as I know, the only thing you can control (at least on android without physic keyboard) is input type to show different virtual keyboards.
http://docs.giderosmobile.com/reference/gideros/TextInputDialog/Event.COMPLETE#Event.COMPLETE
Maybe a Candy component have it, but you need to check, I am guessing