First, thank you all for your questions and your answers, I've been learning a lot just by searching and finding perfect information in these forums.

Now, my problem which I couldn't find the solution: I'm not successfully getting mouse cursor position in main window's status bar, based on its movement around a QGraphicsView. It was working perfect when I was using a QWidget instead of QGraphicsView, but I had to change it due to some project new requirements. Also, I should print to an external file the points that were clicked so far. That's not working anymore, too.

The current symptom is: the mouse current coordinates are shown in the status bar, but only in the extremes, i.e., x<=2, y<=2, x>=right-2 or y>=bottom-2. Odd, isn't it?

I've reimplemented QGraphicsScene and QGraphicsView this way:

Qt Code: 
  1. #ifndef WHITESPACESCENE_H
  2. #define WHITESPACESCENE_H
  3.  
  4. #include <QGraphicsScene>
  5.  
  6. class WhiteSpaceScene : public QGraphicsScene
  7. {
  8.     Q_OBJECT
  9. public:
  10.     WhiteSpaceScene (qreal x, qreal y, qreal width, qreal height, QObject * parent = 0);
  11.  
  12. protected:
  13.     void mousePressEvent(QMouseEvent *event);
  14.  
  15. private:
  16.     void printPoint(const QPoint &clickedPoint);
  17. };
  18.  
  19. #endif // WHITESPACESCENE_H
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Qt Code: 
  1. #include "whitespacescene.h"
  2.  
  3. WhiteSpaceScene::WhiteSpaceScene (qreal x, qreal y, qreal width, qreal height, QObject * parent) :
  4.     QGraphicsScene(x, y, width, height, parent)
  5. {
  6.  
  7. }
  8.  
  9. void WhiteSpaceScene::mousePressEvent(QMouseEvent *event)
  10. {
  11.     if (event->button() == Qt::LeftButton)
  12.     {
  13.             printPoint(event->pos());
  14.     }
  15. }
  16.  
  17. void WhiteSpaceScene::printPoint(const QPoint &clickedPoint)
  18. {
  19. ...
  20. }
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Qt Code: 
  1. #ifndef WHITESPACEVIEW_H
  2. #define WHITESPACEVIEW_H
  3.  
  4. #include <QGraphicsView>
  5.  
  6. class WhiteSpaceView : public QGraphicsView
  7. {
  8.     Q_OBJECT
  9. public:
  10.     explicit WhiteSpaceView(QGraphicsScene * scene, QWidget * parent = 0);
  11. };
  12.  
  13. #endif // WHITESPACEVIEW_H
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Qt Code: 
  1. #include "whitespaceview.h"
  2.  
  3. WhiteSpaceView::WhiteSpaceView(QGraphicsScene * scene, QWidget * parent) :
  4.     QGraphicsView(scene, parent)
  5. {
  6.     setAttribute(Qt::WA_StaticContents); // won't change contents on widget resizing
  7.     setRenderHint(QPainter::Antialiasing);
  8.     setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
  9.     setBackgroundBrush(QColor(255, 255, 255));
  10.     setMouseTracking(true);
  11.     setCursor(Qt::CrossCursor);
  12. }
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In mainwindow.cpp I have an event filter which wasn't modified:
Qt Code: 
  1. bool MainWindow::eventFilter(QObject*, QEvent *event)
  2. {
  3.     if (event->type() == QEvent::MouseMove)
  4.     {
  5.         QMouseEvent *mouseCursor = static_cast<QMouseEvent*>(event);
  6.         statusBar()->showMessage(QString("(x,y) coordinates: (%1,%2)").arg(mouseCursor->x()).arg(mouseCursor->y()));
  7.     }
  8.     else if (event->type() == QEvent::Leave)
  9.     {
  10.         statusBar()->showMessage("");
  11.     }
  12.     return false;
  13. }
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And finally:
Qt Code: 
  1. #include <QtGui/QApplication>
  2. #include "mainwindow.h"
  3. #include "whitespacescene.h"
  4. #include "whitespaceview.h"
  5.  
  6. int main(int argc, char *argv[])
  7. {
  8.     QApplication a(argc, argv);
  9.     MainWindow *window = new MainWindow;
  10.  
  11.     WhiteSpaceScene *whitespace = new WhiteSpaceScene(0, 0, 350, 350);
  12.     WhiteSpaceView *whitespaceview = new WhiteSpaceView(whitespace);
  13.     whitespaceview->installEventFilter(window);
  14.     window->setCentralWidget(whitespaceview);
  15.     window->show();
  16.     return a.exec();
  17. }
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In the old main, I had a call to my subclassed QWidget (instead of two calls: QGraphicsScene and QGraphicsView) and the event filter was installed on it (subwidget->installEventFilter(window)).

I've also tried to declare using standard QGraphicsView and QGraphicsScene to see if my subclasses were the problem, but the exact same symptom occurs.

Any suggestions?
Thanks a lot in advance.