B4J Question Controlling test input into textfield?

Hi Erel
Any chance you've created a video on controlling textField input?
i.e where input is restricted to a string of characters (e.g. :,"abcdef....xyz","YN", "XYX") and numeric characters (e.g. 0123456789." ?
Coupled with editing features using keyboard keypress control characters e.g CR, BS, DEL, INS, ESC, etc
If no video, is there code available that does specifically this.

Cheers
Colin