Different PDF coordinates depending on the zoom factor

HI,

I've created a tool to get pdf coordinates from a user selection
(based on rectangle drawn during a mouse event), but I'm having issues
to get the PDF coordinates (it seems I'm having different results
depending on the zoom factor I have set up). Is this right? Or am I
doing something wrong?

public void mousePressed(MouseEvent mouseEvent) {
  screenX1 = mouseEvent.getX();
  screenY1 = mouseEvent.getY();
  Point2D firstPageVertex = pdfView.convScreenPtToPagePt(screenX1,
screenY1);
  pageX1 = firstPageVertex.getX(); // it varies depending on the zoom
factor
  pageY1 = firstPageVertex.getY(); // it varies depending on the zoom
factor
}

@Override
public void mouseReleased(MouseEvent mouseEvent) {
  screenX2 = mouseEvent.getX();
  screenY2 = mouseEvent.getY();
  Point2D secondPageVertex = pdfView.convScreenPtToPagePt(screenX2,
screenY2);
  pageX2 = secondPageVertex.getX();// it varies depending on the zoom
factor
  pageY2 = secondPageVertex.getY();// it varies depending on the zoom
factor
}