README.md

Use as:

UsPhoneNumberFormatter addLineNumberFormatter = new UsPhoneNumberFormatter(
    new WeakReference<EditText>(mYourEditText));
mYourEditText.addTextChangedListener(addLineNumberFormatter);

The modified version UsPhoneNumberFormatter.java will prevent extra input using source from:

• http://stackoverflow.com/a/14001872/1815624

This is in comparison to the

• Orignal source from http://stackoverflow.com/a/23659268/1815624

NoExtraDigits-UsPhoneNumberFormatter.java

    private class UsPhoneNumberFormatter implements TextWatcher {
        //This TextWatcher sub-class formats entered numbers as 1 (123) 456-7890
        private boolean mFormatting; // this is a flag which prevents the
        // stack(onTextChanged)
        private boolean clearFlag;
        private int mLastStartLocation;
        private String mLastBeforeText;
        private WeakReference<EditText> mWeakEditText;

        public UsPhoneNumberFormatter(WeakReference<EditText> weakEditText) {
            this.mWeakEditText = weakEditText;
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            if (after == 0 && s.toString().equals("1 ")) {
                clearFlag = true;
            }
            mLastStartLocation = start;
            mLastBeforeText = s.toString();
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            // TODO: Do nothing
        }

        @Override
        public void afterTextChanged(Editable s) {
            // Make sure to ignore calls to afterTextChanged caused by the work
            // done below
            if (!mFormatting) {
                mFormatting = true;
                int curPos = mLastStartLocation;
                String beforeValue = mLastBeforeText;
                String currentValue = s.toString();
                String formattedValue = formatUsNumber(s);
                if (currentValue.length() > beforeValue.length()) {
                    int setCusorPos = formattedValue.length()
                            - (beforeValue.length() - curPos);
                    if (
                            (currentValue.length() <= 14 && !currentValue.startsWith("1"))
                                    ||
                                    (currentValue.length() <= 16 && currentValue.startsWith("1"))
                            )
                        mWeakEditText.get().setSelection(setCusorPos < 0 ? 0 : setCusorPos);
                } else {
                    int setCusorPos = formattedValue.length()
                            - (currentValue.length() - curPos);
                    if(setCusorPos > 0 && !Character.isDigit(formattedValue.charAt(setCusorPos -1))){
                        setCusorPos--;
                    }
                    mWeakEditText.get().setSelection(setCusorPos < 0 ? 0 : setCusorPos);
                }
                mFormatting = false;
                int totalDigitCount = s.length();
                String allString = s.toString();
                if(
                    (totalDigitCount == 14 && !allString.startsWith("1"))
                      ||
                    (totalDigitCount == 16 && allString.startsWith("1"))
                ){
                    //todo When this is validated...
                } else {
                    //todo When This is not validated...
                }
            }
        }

        private String formatUsNumber(Editable text) {
            StringBuilder formattedString = new StringBuilder();
            // Remove everything except digits
            int p = 0;
            while (p < text.length()) {
                char ch = text.charAt(p);
                if (!Character.isDigit(ch)) {
                    text.delete(p, p + 1);
                } else {
                    p++;
                }
            }
            // Now only digits are remaining
            String allDigitString = text.toString();

            int totalDigitCount = allDigitString.length();

            if (totalDigitCount == 0){
                // May be the total length of input length is greater than the
                // expected value so we'll remove all formatting
                text.clear();
                text.append(allDigitString);
                return allDigitString;
            }
            int alreadyPlacedDigitCount = 0;
            // Only '1' is remaining and user pressed backspace and so we clear
            // the edit text.
            if (allDigitString.equals("1") && clearFlag) {
                text.clear();
                clearFlag = false;
                return "";
            }
            if (allDigitString.startsWith("1")) {
                formattedString.append("1 ");
                alreadyPlacedDigitCount++;
            }
            // The first 3 numbers beyond '1' must be enclosed in brackets "()"
            if (totalDigitCount - alreadyPlacedDigitCount > 3) {
                formattedString.append("("
                        + allDigitString.substring(alreadyPlacedDigitCount,
                        alreadyPlacedDigitCount + 3) + ") ");
                alreadyPlacedDigitCount += 3;
            }
            // There must be a '-' inserted after the next 3 numbers
            if (totalDigitCount - alreadyPlacedDigitCount > 3) {
                formattedString.append(allDigitString.substring(
                        alreadyPlacedDigitCount, alreadyPlacedDigitCount + 3)
                        + "-");
                alreadyPlacedDigitCount += 3;
            }
            // All the required formatting is done so we'll just copy the
            // remaining digits.
            if (totalDigitCount > alreadyPlacedDigitCount) {
                formattedString.append(allDigitString
                        .substring(alreadyPlacedDigitCount));
            }

            text.clear();
            if (
                    (totalDigitCount > 10 && !allDigitString.startsWith("1"))
                            ||
                            (totalDigitCount > 11 && allDigitString.startsWith("1"))
                    ) {
                String tempTxt = removeLastChar(formattedString.toString());
                text.append(tempTxt);
                mLastBeforeText = tempTxt;
            } else {
                text.append(formattedString.toString());
            }
            return formattedString.toString();
        }


        private String removeLastChar(String str) {
            return str.substring(0,str.length()-1);
        }
    }

UsPhoneNumberFormatter.java

    private class UsPhoneNumberFormatter implements TextWatcher {
        //This TextWatcher sub-class formats entered numbers as 1 (123) 456-7890
        private boolean mFormatting; // this is a flag which prevents the
        // stack(onTextChanged)
        private boolean clearFlag;
        private int mLastStartLocation;
        private String mLastBeforeText;
        private WeakReference<EditText> mWeakEditText;
    
        public UsPhoneNumberFormatter(WeakReference<EditText> weakEditText) {
            this.mWeakEditText = weakEditText;
        }
    
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            if (after == 0 && s.toString().equals("1 ")) {
                clearFlag = true;
            }
            mLastStartLocation = start;
            mLastBeforeText = s.toString();
        }
    
        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            // TODO: Do nothing
        }
    
        @Override
        public void afterTextChanged(Editable s) {
            // Make sure to ignore calls to afterTextChanged caused by the work
            // done below
            if (!mFormatting) {
                mFormatting = true;
                int curPos = mLastStartLocation;
                String beforeValue = mLastBeforeText;
                String currentValue = s.toString();
                String formattedValue = formatUsNumber(s);
                if (currentValue.length() > beforeValue.length()) {
                    int setCusorPos = formattedValue.length()
                            - (beforeValue.length() - curPos);
                    mWeakEditText.get().setSelection(setCusorPos < 0 ? 0 : setCusorPos);
                } else {
                    int setCusorPos = formattedValue.length()
                            - (currentValue.length() - curPos);
                    if(setCusorPos > 0 && !Character.isDigit(formattedValue.charAt(setCusorPos -1))){
                        setCusorPos--;
                    }
                    mWeakEditText.get().setSelection(setCusorPos < 0 ? 0 : setCusorPos);
                }
                mFormatting = false;
            }
        }
    
        private String formatUsNumber(Editable text) {
            StringBuilder formattedString = new StringBuilder();
            // Remove everything except digits
            int p = 0;
            while (p < text.length()) {
                char ch = text.charAt(p);
                if (!Character.isDigit(ch)) {
                    text.delete(p, p + 1);
                } else {
                    p++;
                }
            }
            // Now only digits are remaining
            String allDigitString = text.toString();
    
            int totalDigitCount = allDigitString.length();
    
            if (totalDigitCount == 0
                    || (totalDigitCount > 10 && !allDigitString.startsWith("1"))
                    || totalDigitCount > 11) {
                // May be the total length of input length is greater than the
                // expected value so we'll remove all formatting
                text.clear();
                text.append(allDigitString);
                return allDigitString;
            }
            int alreadyPlacedDigitCount = 0;
            // Only '1' is remaining and user pressed backspace and so we clear
            // the edit text.
            if (allDigitString.equals("1") && clearFlag) {
                text.clear();
                clearFlag = false;
                return "";
            }
            if (allDigitString.startsWith("1")) {
                formattedString.append("1 ");
                alreadyPlacedDigitCount++;
            }
            // The first 3 numbers beyond '1' must be enclosed in brackets "()"
            if (totalDigitCount - alreadyPlacedDigitCount > 3) {
                formattedString.append("("
                        + allDigitString.substring(alreadyPlacedDigitCount,
                        alreadyPlacedDigitCount + 3) + ") ");
                alreadyPlacedDigitCount += 3;
            }
            // There must be a '-' inserted after the next 3 numbers
            if (totalDigitCount - alreadyPlacedDigitCount > 3) {
                formattedString.append(allDigitString.substring(
                        alreadyPlacedDigitCount, alreadyPlacedDigitCount + 3)
                        + "-");
                alreadyPlacedDigitCount += 3;
            }
            // All the required formatting is done so we'll just copy the
            // remaining digits.
            if (totalDigitCount > alreadyPlacedDigitCount) {
                formattedString.append(allDigitString
                        .substring(alreadyPlacedDigitCount));
            }
    
            text.clear();
            text.append(formattedString.toString());
            return formattedString.toString();
        }
    
    }

Hi,
tapping "1" on empty editText(wrapped around android.support.design.widget.TextInputLayout),
why do I get:
java.lang.IndexOutOfBoundsException: setSpan (2 ... 2) ends beyond length 1
...