Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
private function writeWindow2()
    {
        $record = 0x023E; // Record identifier
        $length = 0x0012;

        $grbit = 0x00B6; // Option flags
        $rwTop = 0x0000; // Top row visible in window
        $colLeft = 0x0000; // Leftmost column visible in window

        // The options flags that comprise $grbit
        $fDspFmla = 0; // 0 - bit
        $fDspGrid = $this->phpSheet->getShowGridlines() ? 1 : 0; // 1
        $fDspRwCol = $this->phpSheet->getShowRowColHeaders() ? 1 : 0; // 2
        $fFrozen = $this->phpSheet->getFreezePane() ? 1 : 0; // 3
        $fDspZeros = 1; // 4
        $fDefaultHdr = 1; // 5
        $fArabic = $this->phpSheet->getRightToLeft() ? 1 : 0; // 6
        $fDspGuts = $this->outlineOn; // 7
        $fFrozenNoSplit = 0; // 0 - bit
        // no support in PhpSpreadsheet for selected sheet, therefore sheet is only selected if it is the active sheet
        $fSelected = ($this->phpSheet === $this->phpSheet->getParent()->getActiveSheet()) ? 1 : 0;
        $fPaged = 1; // 2
        $fPageBreakPreview = $this->phpSheet->getSheetView()->getView() === SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW;

        $grbit = $fDspFmla;
        $grbit |= $fDspGrid << 1;
        $grbit |= $fDspRwCol << 2;
        $grbit |= $fFrozen << 3;
        $grbit |= $fDspZeros << 4;
        $grbit |= $fDefaultHdr << 5;
        $grbit |= $fArabic << 6;
        $grbit |= $fDspGuts << 7;
        $grbit |= $fFrozenNoSplit << 8;
        $grbit |= $fSelected << 9;
        $grbit |= $fPaged << 10;
        $grbit |= $fPageBreakPreview << 11;

        $header = pack('vv', $record, $length);
        $data = pack('vvv', $grbit, $rwTop, $colLeft);

        // FIXME !!!
        $rgbHdr = 0x0040; // Row/column heading and gridline color index
        $zoom_factor_page_break = ($fPageBreakPreview ? $this->phpSheet->getSheetView()->getZoomScale() : 0x0000);
        $zoom_factor_normal = $this->phpSheet->getSheetView()->getZoomScaleNormal();

        $data .= pack('vvvvV', $rgbHdr, 0x0000, $zoom_factor_page_break, $zoom_factor_normal, 0x00000000);

        $this->append($header . $data);
    }
private function writeWindow2()
    {
        $record = 0x023E; // Record identifier
        $length = 0x0012;

        $grbit = 0x00B6; // Option flags
        $rwTop = 0x0000; // Top row visible in window
        $colLeft = 0x0000; // Leftmost column visible in window

        // The options flags that comprise $grbit
        $fDspFmla = 0; // 0 - bit
        $fDspGrid = $this->phpSheet->getShowGridlines() ? 1 : 0; // 1
        $fDspRwCol = $this->phpSheet->getShowRowColHeaders() ? 1 : 0; // 2
        $fFrozen = $this->phpSheet->getFreezePane() ? 1 : 0; // 3
        $fDspZeros = 1; // 4
        $fDefaultHdr = 1; // 5
        $fArabic = $this->phpSheet->getRightToLeft() ? 1 : 0; // 6
        $fDspGuts = $this->outlineOn; // 7
        $fFrozenNoSplit = 0; // 0 - bit
        // no support in PhpSpreadsheet for selected sheet, therefore sheet is only selected if it is the active sheet
        $fSelected = ($this->phpSheet === $this->phpSheet->getParent()->getActiveSheet()) ? 1 : 0;
        $fPaged = 1; // 2
        $fPageBreakPreview = $this->phpSheet->getSheetView()->getView() === SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW;

        $grbit = $fDspFmla;
        $grbit |= $fDspGrid << 1;
        $grbit |= $fDspRwCol << 2;
        $grbit |= $fFrozen << 3;
        $grbit |= $fDspZeros << 4;
        $grbit |= $fDefaultHdr << 5;
        $grbit |= $fArabic << 6;
        $grbit |= $fDspGuts << 7;
        $grbit |= $fFrozenNoSplit << 8;
        $grbit |= $fSelected << 9;
        $grbit |= $fPaged << 10;
        $grbit |= $fPageBreakPreview << 11;

        $header = pack('vv', $record, $length);
        $data = pack('vvv', $grbit, $rwTop, $colLeft);

        // FIXME !!!
        $rgbHdr = 0x0040; // Row/column heading and gridline color index
        $zoom_factor_page_break = ($fPageBreakPreview ? $this->phpSheet->getSheetView()->getZoomScale() : 0x0000);
        $zoom_factor_normal = $this->phpSheet->getSheetView()->getZoomScaleNormal();

        $data .= pack('vvvvV', $rgbHdr, 0x0000, $zoom_factor_page_break, $zoom_factor_normal, 0x00000000);

        $this->append($header . $data);
    }
Write BIFF record Window2.