86 lines
3.3 KiB
PHP
86 lines
3.3 KiB
PHP
<?php
|
|
|
|
declare(strict_types=1);
|
|
|
|
namespace OpenSpout\Reader\XLSX\Helper;
|
|
|
|
use OpenSpout\Common\Exception\InvalidArgumentException;
|
|
|
|
/**
|
|
* @internal
|
|
*/
|
|
final class CellHelper
|
|
{
|
|
// Using ord() is super slow... Using a pre-computed hash table instead.
|
|
private const columnLetterToIndexMapping = [
|
|
'A' => 0, 'B' => 1, 'C' => 2, 'D' => 3, 'E' => 4, 'F' => 5, 'G' => 6,
|
|
'H' => 7, 'I' => 8, 'J' => 9, 'K' => 10, 'L' => 11, 'M' => 12, 'N' => 13,
|
|
'O' => 14, 'P' => 15, 'Q' => 16, 'R' => 17, 'S' => 18, 'T' => 19, 'U' => 20,
|
|
'V' => 21, 'W' => 22, 'X' => 23, 'Y' => 24, 'Z' => 25,
|
|
];
|
|
|
|
/**
|
|
* Returns the base 10 column index associated to the cell index (base 26).
|
|
* Excel uses A to Z letters for column indexing, where A is the 1st column,
|
|
* Z is the 26th and AA is the 27th.
|
|
* The mapping is zero based, so that A1 maps to 0, B2 maps to 1, Z13 to 25 and AA4 to 26.
|
|
*
|
|
* @param string $cellIndex The Excel cell index ('A1', 'BC13', ...)
|
|
*
|
|
* @throws InvalidArgumentException When the given cell index is invalid
|
|
*/
|
|
public static function getColumnIndexFromCellIndex(string $cellIndex): int
|
|
{
|
|
if (!self::isValidCellIndex($cellIndex)) {
|
|
throw new InvalidArgumentException('Cannot get column index from an invalid cell index.');
|
|
}
|
|
|
|
$columnIndex = 0;
|
|
|
|
// Remove row information
|
|
$columnLetters = preg_replace('/\d/', '', $cellIndex);
|
|
|
|
// strlen() is super slow too... Using isset() is way faster and not too unreadable,
|
|
// since we checked before that there are between 1 and 3 letters.
|
|
$columnLength = isset($columnLetters[1]) ? (isset($columnLetters[2]) ? 3 : 2) : 1;
|
|
|
|
// Looping over the different letters of the column is slower than this method.
|
|
// Also, not using the pow() function because it's slooooow...
|
|
switch ($columnLength) {
|
|
case 1:
|
|
$columnIndex = self::columnLetterToIndexMapping[$columnLetters];
|
|
|
|
break;
|
|
|
|
case 2:
|
|
$firstLetterIndex = (self::columnLetterToIndexMapping[$columnLetters[0]] + 1) * 26;
|
|
$secondLetterIndex = self::columnLetterToIndexMapping[$columnLetters[1]];
|
|
$columnIndex = $firstLetterIndex + $secondLetterIndex;
|
|
|
|
break;
|
|
|
|
case 3:
|
|
$firstLetterIndex = (self::columnLetterToIndexMapping[$columnLetters[0]] + 1) * 676;
|
|
$secondLetterIndex = (self::columnLetterToIndexMapping[$columnLetters[1]] + 1) * 26;
|
|
$thirdLetterIndex = self::columnLetterToIndexMapping[$columnLetters[2]];
|
|
$columnIndex = $firstLetterIndex + $secondLetterIndex + $thirdLetterIndex;
|
|
|
|
break;
|
|
}
|
|
|
|
return $columnIndex;
|
|
}
|
|
|
|
/**
|
|
* Returns whether a cell index is valid, in an Excel world.
|
|
* To be valid, the cell index should start with capital letters and be followed by numbers.
|
|
* There can only be 3 letters, as there can only be 16,384 rows, which is equivalent to 'XFE'.
|
|
*
|
|
* @param string $cellIndex The Excel cell index ('A1', 'BC13', ...)
|
|
*/
|
|
private static function isValidCellIndex(string $cellIndex): bool
|
|
{
|
|
return 1 === preg_match('/^[A-Z]{1,3}\d+$/', $cellIndex);
|
|
}
|
|
}
|