Refactor Xls Reader

src/PhpSpreadsheet/Reader/Xls/Biff5.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheet\Reader\Xls;
+
+use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
+use PhpOffice\PhpSpreadsheet\Reader\Exception as ReaderException;
+use PhpOffice\PhpSpreadsheet\Reader\Xls;
+
+class Biff5 extends Xls
+{
+    /**
+     * Reads a cell range address in BIFF5 e.g. 'A2:B6' or 'A1'
+     * always fixed range
+     * section 2.5.14.
+     */
+    public static function readBIFF5CellRangeAddressFixed(string $subData): string
+    {
+        // offset: 0; size: 2; index to first row
+        $fr = self::getUInt2d($subData, 0) + 1;
+
+        // offset: 2; size: 2; index to last row
+        $lr = self::getUInt2d($subData, 2) + 1;
+
+        // offset: 4; size: 1; index to first column
+        $fc = ord($subData[4]);
+
+        // offset: 5; size: 1; index to last column
+        $lc = ord($subData[5]);
+
+        // check values
+        if ($fr > $lr || $fc > $lc) {
+            throw new ReaderException('Not a cell range address');
+        }
+
+        // column index to letter
+        $fc = Coordinate::stringFromColumnIndex($fc + 1);
+        $lc = Coordinate::stringFromColumnIndex($lc + 1);
+
+        if ($fr == $lr && $fc == $lc) {
+            return "$fc$fr";
+        }
+
+        return "$fc$fr:$lc$lr";
+    }
+
+    /**
+     * Read BIFF5 cell range address list
+     * section 2.5.15.
+     */
+    public static function readBIFF5CellRangeAddressList(string $subData): array
+    {
+        $cellRangeAddresses = [];
+
+        // offset: 0; size: 2; number of the following cell range addresses
+        $nm = self::getUInt2d($subData, 0);
+
+        $offset = 2;
+        // offset: 2; size: 6 * $nm; list of $nm (fixed) cell range addresses
+        for ($i = 0; $i < $nm; ++$i) {
+            $cellRangeAddresses[] = self::readBIFF5CellRangeAddressFixed(substr($subData, $offset, 6));
+            $offset += 6;
+        }
+
+        return [
+            'size' => 2 + 6 * $nm,
+            'cellRangeAddresses' => $cellRangeAddresses,
+        ];
+    }
+}