MaskEdit control looks by default like on the picture below. It allows user to type single line texts restricted to specified pattern. It uses validators to validate user input. By default there is no validator assigned and internal one is used. This default validator allow simple masking. The mask could be set via "Mask" property. Default validator support following special symbolc in mask: # - digit, * - alpabetic charachter. All other symbols expected to be the same. For example, the mask ###-###-#### could be used to specify phone number. User can only type texts like 956-658-444.
If you need more soficticated validator, you just need to create a class derived from IMaskValidator and assign it to a MaskEdit control via
setValidator() method. In this validator you may implement any validation logic you want.