Just got it to work!!!

Apparently I had to stick something like...

Qt Code: 
  1. QTimer timer;
  2.     QObject::connect(&timer, SIGNAL(timeout()), &scene, SLOT(advance()));
  3.     timer.start(100);
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in the main function to get it to operate correctly. If my intuition is correct, timeout is called when the timer counts down from 100 to 0 and it then calls advance(), and then the timer starts again at 100 and repeats the cycle. So, it seems to be a way for everything to synchronize.

Now, it's time for some real development to begin.

Qt Code: 
  1. #include <QApplication>
  2. #include <QGraphicsEllipseItem>
  3. #include <QGraphicsScene>
  4. #include <QGraphicsView>
  5.  
  6. #include <qdatetime.h>
  7. #include <qmainwindow.h>
  8. #include <qstatusbar.h>
  9. #include <qmessagebox.h>
  10. #include <qmenubar.h>
  11. #include <qapplication.h>
  12. #include <qpainter.h>
  13. #include <qprinter.h>
  14. #include <qlabel.h>
  15. #include <qimage.h>
  16. #include <qpixmap.h>
  17. #include <QMouseEvent>
  18. #include <QStyleOptionGraphicsItem>
  19. #include <qdebug.h>
  20. #include <stdlib.h>
  21. #include <qtimer.h>
  22.  
  23. QString myImgName = "myimg.png";
  24. static QImage *myImg;
  25.  
  26.  
  27.   static const int imageRTTI = 984376;
  28.  
  29.  
  30. class ImageItem: public QGraphicsRectItem
  31. {
  32. public:
  33.     ImageItem( QImage img );
  34.     int rtti () const { return imageRTTI; }
  35.     void advance(int phase);
  36. protected:
  37.     void paint( QPainter *, const QStyleOptionGraphicsItem *option, QWidget *widget );
  38. private:
  39.     QImage image;
  40.     QPixmap pixmap;
  41.     int state;
  42. };
  43.  
  44.  
  45. void ImageItem::advance(int phase)
  46. {
  47.         moveBy(0,1);
  48. }
  49.  
  50.  
  51. ImageItem::ImageItem( QImage img )
  52.     : image(img)
  53. {
  54.     state = 0;
  55.     setRect(0, 0, image.width(), image.height());
  56.     setFlag(ItemIsMovable);
  57. #if !defined(Q_WS_QWS)
  58.     pixmap = pixmap.fromImage(image, Qt::OrderedAlphaDither);
  59. #endif
  60. }
  61.  
  62. void ImageItem::paint( QPainter *p, const QStyleOptionGraphicsItem *option, QWidget * )
  63. {
  64. // On Qt/Embedded, we can paint a QImage as fast as a QPixmap,
  65. // but on other platforms, we need to use a QPixmap.
  66. #if defined(Q_WS_QWS)
  67.     p->drawImage( option->exposedRect, image, option->exposedRect, Qt::OrderedAlphaDither );
  68. #else
  69.     p->drawPixmap( option->exposedRect, pixmap, option->exposedRect );
  70. #endif
  71. }
  72.  
  73. int main( int argc, char **argv )
  74. {
  75.  
  76.     QApplication app(argc, argv);
  77.  
  79.     scene.setSceneRect( -100.0, -100.0, 200.0, 200.0 );
  80.  
  81.     myImg = new QImage;
  82.     myImg->load(myImgName);
  83.  
  84.  
  85.     QAbstractGraphicsShapeItem* i = new ImageItem(*myImg);
  86.     scene.addItem(i);
  87.     i->setPos(-50,-50);
  88.  
  89.     QTimer timer;
  90.     QObject::connect(&timer, SIGNAL(timeout()), &scene, SLOT(advance()));
  91.     timer.start(100);
  92.  
  93.     QGraphicsView view( &scene );
  94.     view.setRenderHints( QPainter::Antialiasing );
  95.     view.show();
  96.  
  97.     return app.exec();
  98. }
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