Question

Is it possible to auto insert characters into an EditText as the user inputs data?

I.e. if the user is entering a long number such as 123456789012, is it possible for this number to appear as he is typing it in the edit text box, but with a dash every 4th character?

So as you type the number above you would see it being entered in the EditText box but would look like this: 1234-5678-9012.

Currently I have an app where you can enter a long number and then press a button and it inserts the dashes for you, but I’m curious if it could be done as you type?

Many thanks for any help.

Answer 1

By tagging android, I think you are discussing about android editText, is so you can do it by listening the TextChangedListener,

EDITED: for backspace

editText.addTextChangedListener(new TextWatcher() {
            int len=0;
            @Override
            public void afterTextChanged(Editable s) { 
                String str = editText.getText().toString(); 
                 if(str.length()==4&& len <str.length()){//len check for backspace 
                    editText.append("-");
                }
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {

             String str = editText.getText().toString(); 
              len = str.length();
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {  
            }


        });