textwatcher - Automatically add dash in phone number in Android

Question

Instead of 5118710, it should be 511-8710. I'd like to add a dash after the user the user inputted 3 digits already in the EditText. The maximum length of the EditText is 7 digits only.

After I figured out the above problem, I've got stuck in coding again. When I already inputted 3 digits, it appends dash (that's what I'd like to happen) but my problem here is that the next 3 digits also appends dash (Like this: 511-871-)... Please help me with this. thanks!

    txt_HomeNo.addTextChangedListener(new TextWatcher() {

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

            boolean flag = true;
            String eachBlock[] = txt_HomeNo.getText().toString().split("-");
            for (int i = 0; i < eachBlock.length; i++) {
                if (eachBlock[i].length() > 3) {
                    flag = false;
                }
            }

            if (flag) {

                txt_HomeNo.setOnKeyListener(new OnKeyListener() {

                    @Override
                    public boolean onKey(View v, int keyCode, KeyEvent event) {

                        if (keyCode == KeyEvent.KEYCODE_DEL)
                            keyDel = 1;
                        return false;
                    }
                });

                if (keyDel == 0) {

                    if (((txt_HomeNo.getText().length() + 1) % 4) == 0) {

                        if (txt_HomeNo.getText().toString().split("-").length <= 3) {
                            txt_HomeNo.setText(txt_HomeNo.getText() + "-");
                            txt_HomeNo.setSelection(txt_HomeNo.getText().length());
                        }
                    }
                    a = txt_HomeNo.getText().toString();
                } else {
                    a = txt_HomeNo.getText().toString();
                    keyDel = 0;
                }

            } else {
                txt_HomeNo.setText(a);
            }

        }

Answer 1

The most straightforward solution is to use PhoneNumberFormattingTextWatcher which will format the number according to the system locale.

XML:

<EditText
    android:id="@+id/phone_number"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/enter_phone_number"
    android:inputType="phone" />

Add addTextChangedListener() in your class:

EditText phoneNumber = (EditText)findViewById(R.id.phone_number);
phoneNumber.addTextChangedListener(new PhoneNumberFormattingTextWatcher());