public class PptToPDFConverter extends  pptx ToPDFConverter {
 private Slide[] slides;
 public PptToPDFConverter(InputStream inStream, OutputStream outStream, boolean showMessages, boolean closeStreamsWhenComplete) {
 super(inStream, outStream, showMessages, closeStreamsWhenComplete);
 }
 @Override
 protected Dimension processSlides() throws IOException {
 SlideShow ppt = new SlideShow(inStream);
 Dimension dimension = ppt.getPageSize();
 slides = ppt.getSlides();
 return dimension;
 }
 @Override
 protected int getNumSlides(){
 return slides.length;
 }
 @Override
 protected void drawOntoThisGraphic(int index,  graphics 2D graphics){
 slides[index].draw(graphics);
 }
 @Override
 protected Color getSlideBGColor(int index){
 return slides[index].getBackground().getFill().getForegroundColor();
 }
}