Blacklist : Add helper methods

import android.os.UserHandle;

import android.provider.Settings;

import android.provider.Telephony.Blacklist;

import android.telephony.PhoneNumberUtils;

import android.telephony.TelephonyManager;

import android.text.TextUtils;

import android.util.Log;

import android.util.Pair;

import java.util.ArrayList;

import java.util.List;

import java.util.Locale;

import com.android.internal.telephony.CallerInfo;

                Settings.System.PHONE_BLACKLIST_REGEX_ENABLED, 0,

                UserHandle.USER_CURRENT_OR_SELF) != 0;

    }

    public static Pair<String, Boolean> isValidBlacklistInput(Context context, String number) {

        final Pair<String, Boolean> normalizeResult = BlacklistUtils.normalizeNumber(

                context, number);

        final String normalizedNumber = normalizeResult.first;

        boolean isRegex = normalizedNumber.indexOf('%') >= 0 ||

                normalizedNumber.indexOf('_') >= 0;

        // For non-regex numbers, apply additional validity checking if

        // they didn't pass e164 normalization

        if (!isRegex && !normalizeResult.second && !BlacklistUtils.isValidPhoneNumber(number)) {

            // number was invalid

            return new Pair<String, Boolean>(normalizedNumber, false);

        }

        return new Pair<String, Boolean>(normalizedNumber, true);

    }

    /**

     * Normalizes the passed in number and tries to format it according to E164.

     * Returns a pair of

     * - normalized number

     * - boolean indicating whether the number is a E164 number or not

     */

    public static Pair<String, Boolean> normalizeNumber(Context context, String number) {

        int len = number.length();

        StringBuilder ret = new StringBuilder(len);

        for (int i = 0; i < len; i++) {

            char c = number.charAt(i);

            // Character.digit() supports ASCII and Unicode digits (fullwidth, Arabic-Indic, etc.)

            int digit = Character.digit(c, 10);

            if (digit != -1) {

                ret.append(digit);

            } else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {

                String actualNumber = PhoneNumberUtils.convertKeypadLettersToDigits(number);

                return normalizeNumber(context, actualNumber);

            } else if (i == 0 && c == '+') {

                ret.append(c);

            } else if (c == '*') {

                // replace regex match-multiple character by SQL equivalent

                ret.append('%');

            } else if (c == '.') {

                // replace regex-match-single character by SQL equivalent

                ret.append('_');

            }

        }

        String normalizedNumber = ret.toString();

        String e164Number = toE164Number(context, normalizedNumber);

        return Pair.create(e164Number != null ? e164Number : normalizedNumber, e164Number != null);

    }

    public static String toE164Number(Context context, String src) {

        // Try to retrieve the current ISO Country code

        TelephonyManager tm = (TelephonyManager)

                context.getSystemService(Context.TELEPHONY_SERVICE);

        String countryCode = tm.getSimCountryIso();

        Locale numberLocale = TextUtils.isEmpty(countryCode)

                ? context.getResources().getConfiguration().locale

                : new Locale("", countryCode);

        return PhoneNumberUtils.formatNumberToE164(src, numberLocale.getCountry());

    }

    public static boolean isValidPhoneNumber(String address) {

        for (int i = 0, count = address.length(); i < count; i++) {

            if (!PhoneNumberUtils.isISODigit(address.charAt(i))) {

                return false;

            }

        }

        return true;

    }

    public static boolean isInputRegex(String input) {

        return input.indexOf('%') >= 0 ||

                input.indexOf('_') >= 0;

    }

}