StringUtil.java

/*
 *  Copyright (C) 2010-2016 Stichting Akvo (Akvo Foundation)
 *
 *  This file is part of Akvo Flow.
 *
 *  Akvo Flow is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Akvo Flow is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Akvo Flow.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.akvo.flow.util;

import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.text.TextUtils;

/**
 * simple string convenience functions
 * 
 * @author Christopher Fagiani
 */
public class StringUtil {

    public static final char SPACE_CHAR = '\u0020';

    /**
     * checks a string to see if it's null or has no non-whitespace characters
     * 
     * @param s
     * @return
     */
    public static boolean isNullOrEmpty(@Nullable String s) {
        return s == null || s.trim().length() == 0;
    }

    /**
     * copy a string transforming all control chars (like newline and tab) into spaces
     */
    @NonNull
    public static String controlToSpace(@Nullable String val) {
        String result = "";
        if (val == null) {
            return result;
        }
        for (int i = 0; i < val.length(); i++) {
            if (val.charAt(i) < SPACE_CHAR)
                result = result + SPACE_CHAR;
            else
                result = result + val.charAt(i);
        }

        return result;
    }

    public static boolean isValid(@Nullable String value) {
        return !TextUtils.isEmpty(value) && !value.equalsIgnoreCase("null");
    }
}