Fix getPrevious getNext functions

Author: Alkarex

src/XlsxFastEditorCell.php

@@ -71,7 +71,7 @@ public function getPreviousCell(): ?XlsxFastEditorCell
 			if ($c->localName === 'c') {
 				return new XlsxFastEditorCell($this->editor, $this->sheetNumber, $c);
 			}
-			$c = $this->c->previousElementSibling;
+			$c = $c->previousElementSibling;
 		}
 		return null;
 	}
@@ -84,10 +84,10 @@ public function getNextCell(): ?XlsxFastEditorCell
 	{
 		$c = $this->c->nextElementSibling;
 		while ($c !== null) {
-			if ($c->localName === 'r') {
+			if ($c->localName === 'c') {
 				return new XlsxFastEditorCell($this->editor, $this->sheetNumber, $c);
 			}
-			$c = $this->c->nextElementSibling;
+			$c = $c->nextElementSibling;
 		}
 		return null;
 	}

src/XlsxFastEditorRow.php

@@ -56,10 +56,10 @@ public function getPreviousRow(): ?XlsxFastEditorRow
 	{
 		$r = $this->r->previousElementSibling;
 		while ($r !== null) {
-			if ($r->localName === 'r') {
+			if ($r->localName === 'row') {
 				return new XlsxFastEditorRow($this->editor, $this->sheetNumber, $r);
 			}
-			$r = $this->r->previousElementSibling;
+			$r = $r->previousElementSibling;
 		}
 		return null;
 	}
@@ -72,10 +72,10 @@ public function getNextRow(): ?XlsxFastEditorRow
 	{
 		$r = $this->r->nextElementSibling;
 		while ($r !== null) {
-			if ($r->localName === 'r') {
+			if ($r->localName === 'row') {
 				return new XlsxFastEditorRow($this->editor, $this->sheetNumber, $r);
 			}
-			$r = $this->r->nextElementSibling;
+			$r = $r->nextElementSibling;
 		}
 		return null;
 	}

tests/test.php

@@ -64,6 +64,7 @@
 
 	$row4 = $xlsxFastEditor->getRow($sheet1, 4);
 	assert($row4 !== null);
+	assert($row4->getPreviousRow()?->getNextRow()?->number() === 4);
 	assert($row4->getCellOrNull('D4')?->name() === 'D4');
 	assert($row4->getCellOrNull('d4')?->name() === 'D4');
 	assert($row4->getCellOrNull('D')?->name() === 'D4');
@@ -75,6 +76,10 @@
 	}
 	assert($ex instanceof \InvalidArgumentException);
 
+	$cellD4 = $row4->getCell('D4');
+	assert($cellD4 !== null);
+	assert($cellD4->getPreviousCell()?->getNextCell()?->name() === 'D4');
+
 	assert(XlsxFastEditor::cellOrderCompare('B3', 'AA23') < 0);
 	assert(XlsxFastEditor::cellOrderCompare('AA23', 'AB23') < 0);
 	assert(XlsxFastEditor::cellOrderCompare('BB22', 'BB123') < 0);