TextFlow Password Masking?

Apologies if I've missed this in the documentation, but is there any way to create a 'starred' password field (as one would with displayAsPassword on normal TextFields) using TextFlow?  TLFTextField has displayAsPassword but I understand editing is not available with these fields.

I've been hacking something together but figured I should ask if there's a standard way of doing this.

Many thanks for your help.