Gadgetbridge/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/StringUtils.java

/*  Copyright (C) 2017-2018 Carsten Pfeiffer, João Paulo Barraca

    This file is part of Gadgetbridge.

    Gadgetbridge is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Gadgetbridge 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
package nodomain.freeyourgadget.gadgetbridge.util;

import android.support.annotation.NonNull;

public class StringUtils {

    @NonNull
    public static String truncate(String s, int maxLength){
        if (s == null) {
            return "";
        }

        int length = Math.min(s.length(), maxLength);
        if(length < 0) {
            return "";
        }

        return s.substring(0, length);
    }

    public static String pad(String s, int length){
        return pad(s, length, ' ');
    }

    public static String pad(String s, int length, char padChar){
        while(s.length() < length) {
            s += padChar;
        }
        return s;
    }

    /**
     * Joins the given elements and adds a separator between each element in the resulting string.
     * There will be no separator at the start or end of the string. There will be no consecutive
     * separators (even in case an element is null or empty).
     * @param separator the separator string
     * @param elements the elements to concatenate to a new string
     * @return the joined strings, separated by the separator
     */
    @NonNull
    public static StringBuilder join(String separator, String... elements) {
        StringBuilder builder = new StringBuilder();
        if (elements == null) {
            return builder;
        }
        boolean hasAdded = false;
        for (String element : elements) {
            if (element != null && element.length() > 0) {
                if (hasAdded) {
                    builder.append(separator);
                }
                builder.append(element);
                hasAdded = true;
            }
        }
        return builder;
    }

    @NonNull
    public static String getFirstOf(String first, String second) {
        if (first != null && first.length() > 0) {
            return first;
        }
        if (second != null) {
            return second;
        }
        return "";
    }

    public static boolean isEmpty(String string) {
        return string != null && string.length() == 0;
    }

    public static String ensureNotNull(String message) {
        if (message != null) {
            return message;
        }
        return "";
    }
}