<?php

/**
 *
 * @author Tomáš Naibrt <tomas@naibrt.cz>
 */
class saPhpExcel
{
    static protected $alphabet = array ("A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z");
    /**
     * Vrátí označení následujícího sloupce
     *
     * @param string $columnChar
     * @return string
     */
    public static function getNextColumnChar($columnChar = 'A')
    {
        $result = '';
        $char = $columnChar[strlen($columnChar) - 1];

        if($char == 'Z')
        {
            if(strlen($columnChar) > 1)
            {
                $result = self::getNextColumnChar(substr($columnChar, 0, strlen($columnChar) - 1)).self::$alphabet[0];
            }
            else
            {
                $result = self::$alphabet[0].self::$alphabet[0];
            }
        }
        else
        {
            $key = array_keys(self::$alphabet, $char);
            if(strlen($columnChar) > 1)
            {
                $result = substr($columnChar, 0, strlen($columnChar) - 1).self::$alphabet[$key[0]+1];
            }
            else
            {
                $result = self::$alphabet[$key[0]+1];
            }
        }

        return $result;
    }
}