174     bool scroll(const QRegion &area, int dx, int dy);

   174     bool scroll(const QRegion &area, int dx, int dy);

   175 

   175 

   176     QImage image() const { return img; }

   176     QImage image() const { return img; }

   177     QPoint painterOffset() const;

   177     QPoint painterOffset() const;

   178 

   178 

   179     bool lock(int timeout = -1);

   181     bool lock(int timeout = -1);

   180     void unlock();

   182     void unlock();

   181 

   183 

   182 protected:

   184 protected:

   183     QImage::Format preferredImageFormat(const QWidget *widget) const;

   185     QImage::Format preferredImageFormat(const QWidget *widget) const;