Format credit card in edit text in android

Question

How to make EditText accept input in format:

4digit 4digit 4digit 4digit 

I tried Custom format edit text input android to acc

Answer 1

I know this question is a bit old but I need an implemantation of this for IBAN's and not satisfied with the given answers. So I wrote some code for this. But it takes the "pattern" and "divider" as parameters so it can be use for credit card numbers too.

This is the extended text watcher class.

import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

public class IbanTextWatcher implements TextWatcher {

    private int[] pattern;
    private String divider;
    private String before;
    private EditText field;
    private boolean dividerDeleted;


    public IbanTextWatcher(int[] pattern, String divider, EditText field) {
        this.divider = divider;
        this.pattern = pattern;
        this.field = field;
    }


    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        before = charSequence.toString();

        if (!String.valueOf(charSequence).equals("") && charSequence.length() > i) {
            if (String.valueOf(before.charAt(i)).equals(getDivider())) {
                dividerDeleted = true;
            } else {
                dividerDeleted = false;
            }
        }
    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void afterTextChanged(Editable editable) {

        String input = editable.toString().replaceAll("\\s", "");
        StringBuilder output = new StringBuilder();
        boolean error = false;
        int currentIndex = 0;
        int cursorPosition = getField().getSelectionStart();
        int lengthBefore;
        int currentPatternMember = 0;

        //prevent user to delete the divider
        if (dividerDeleted && cursorPosition != getField().getText().length()) {
            getField().setText(getBefore());
            getField().setSelection(cursorPosition + 1);
            return;
        } else if (input.equals(getBefore().replaceAll("\\s", ""))) {
            return;
        }

        for (int i = 0; i < getPattern().length; i++) {
            error = false;
            currentPatternMember = getPattern()[i];
            try {
                output.append(input.substring(currentIndex, currentIndex + currentPatternMember));
            } catch (StringIndexOutOfBoundsException e) {
                error = true;
            }

            if (!error) {
                if (i != getPattern().length - 1) {
                    output.append(getDivider());
                }
                currentIndex += currentPatternMember;
            } else {
                break;
            }
        }

        if (error) {
            output.append(input.substring(currentIndex, input.length()));
        } 

        cursorPosition = getField().getSelectionStart();
        lengthBefore = getBefore().length();
        getField().setText(output.toString());

        if (cursorPosition != lengthBefore && cursorPosition != lengthBefore + 1) {
            getField().setSelection(cursorPosition);
        } else {
            getField().setSelection(getField().getText().length());
        }
    }

    public int[] getPattern() {
        return pattern;
    }

    public String getDivider() {
        return divider;
    }

    public String getBefore() {
        return before;
    }

    public EditText getField() {
        return field;
    }
}

And this is how I use it:

int[] pattern = {2,4,4,4,4,4,2}; // 
iban.addTextChangedListener(new IbanTextWatcher(pattern, " ", iban); //here iban is my edittext field

By the way, I set the max length of the field in xml.