Disable EditText inputs while keeping it focused

Question

I have a EditText field, variable name valueInputField.

I listen to the text input change, what I want to achieve is during inputting, when the input format DOESN'T matches a regular expression, I would like to stop showing more inputs, but keep the field focused & user is able to type on keyboard still just that no real effect will take to the field.

@OnTextChanged(R.id.value_input)
protected void onTextChanged(CharSequence charSequence) {
   String inputChars = charSequence.toString().trim();
   // if doesn't match regular expression, stop showing more inputs
   if (!inputChars.matches(MY_REGEXP)) {
      // this doesn't achieve what I need.
      valueInputField.setInputType(0)
   }
}

I tried above way, it doesn't work. How to achieve what I need?

Answer 1

maybe you should try below logic

maxLength=inputChars.length
if (!inputChars.matches(MY_REGEXP)) {
editText.setFilters(new InputFilter[] {new InputFilter.LengthFilter(maxLength)});
}

above program will set a max length of EditText when it does not match regexp.

Answer 2

You have to add an InputFilter to your textView:

here's an example:

editText.filters = arrayOf(object: InputFilter {
   override fun filter(source: CharSequence?, start: Int, end: Int, dest: Spanned?, dstart: Int, dend: Int): CharSequence {
      if (Regex("[0-9]*").matches(source!!)) {
         return source
      } else {
         return source.subSequence(start, end-1)
      }
   }
})

This filter method gets called everytime the input in the editText is being invoked. You can return the source when it matches a regex, otherwise, you can return a subSequence of the source, without the last char inserted.

The code example is in Kotlin, the translation shouldn't give you any problem :)