Problem on multi-pages preview with QGraphicsScene

Hi,

I have a QGraphicsScene with size( 318, 3565 ), and need to print it on 4 pages of A4 paper.

But first I need to preview it. I got ghost in between pages in the previewer (see attached images). Is there a way to remove the ghost?

Many thanks

Code:

void QfwPrintPreviewWindow::printPreview( QPrinter* printer )
{
  qreal left, top, right, bottom;
  printer->getPageMargins( &left, &top, &right, &bottom, QPrinter::Inch );
  printer->setPageMargins( left, 0, right, 0, QPrinter::Inch );
 
  QSizeF pSize = printer->pageRect( QPrinter::Inch ).size();
  qreal pWidth = pSize.width() * printer->logicalDpiX();
  qreal pHeight = pSize.height() * printer->logicalDpiY();
 
  QSizeF sSize = m_scene->sceneRect().size();
  qreal sWidth = sSize.width();
  qreal sHeight = sSize.height();
 
  int pages = std::ceil( sHeight / pHeight );
 
  QRectF targetRect( QPointF( 0, 0 ), QSizeF( pWidth, pHeight ) );
  QRectF sourceRect( QPointF( 0, 0 ), QSizeF( sWidth, pHeight ) );
 
  QPainter painter( printer );
 
  for ( int idx = 0; idx < pages; idx++ ) {
    painter.drawRect( targetRect );
    m_scene->render( &painter, targetRect, sourceRect );
 
    // move printer 1 page down
    sourceRect.translate( 0, pHeight );
 
    // create new page
    if ( idx < pages - 1 ) {
      printer->newPage();
    }
  }
}