A TextInputFormatter that allows only the insertion of whitelisted characters patterns.
Since this formatter only removes characters from the text, it attempts to preserve the existing TextEditingValue.selection to values it would now fall at with the removed characters.
- BlacklistingTextInputFormatter, which uses a blacklist instead of a whitelist.
TextEditingValue oldValue, TextEditingValue newValue) → TextEditingValue
Called when text is being typed or cut/copy/pasted in the EditableText. [...]
Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
) → String
Returns a string representation of this object.