Hello, All !

I developed class,

Qt Code: 
  1. class XGisCanvasView : public QtCanvasView
  2. {
  3.     private:
  4.         Q_OBJECT
  5.     public:
  6.         XGisCanvasView (QWidget *parent=NULL);
  7.         virtual ~XGisCanvasView (void);
  8.  
  9.         QPoint getPos (void) const { return scr; }
  10.  
  11.     signals:
  12.         void contentsMouseMove (QMouseEvent *e);
  13.         void mousePress (QMouseEvent *e);
  14.         void mouseRelease (QMouseEvent *e);
  15.         void mouseDoubleClick (QMouseEvent *e);
  16.         void mouseContextMenu (QContextMenuEvent *e);
  17.         void resize (QResizeEvent *e);
  18.  
  19.     protected:
  20.         virtual void contentsMouseMoveEvent (QMouseEvent *e);
  21.         virtual void contentsMousePressEvent (QMouseEvent *e);
  22.         virtual void contentsMouseReleaseEvent (QMouseEvent *e);
  23.         virtual void contentsMouseDoubleClickEvent (QMouseEvent *e);
  24.         virtual void contentsContextMenuEvent (QContextMenuEvent *e);
  25.         virtual void resizeEvent (QResizeEvent *e);
  26.  
  27.     private:
  28.         QPoint scr;
  29.         QtCanvas* pCanvas;
  30. };
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wsview.cpp
Qt Code: 
  1. XGisCanvasView :: XGisCanvasView(QWidget *parent/*=NULL*/) : QtCanvasView (parent), scr (QPoint(0, 0))
  2. {
  3.     setMouseTracking ( true );
  4.     viewport()->setMouseTracking ( true );
  5.  
  6.     int x = width();
  7.     int y = height();
  8.     if ( parent )
  9.     {
  10.         x = parent->width();
  11.         y = parent->height();
  12.     }
  13.     qDebug ("width = %d height = %d", x, y);
  14.     pCanvas = new QtCanvas ( );
  15.     qDebug ("QtCanvas init");
  16.     pCanvas->resize (x, y);
  17.  
  18.     setCanvas( pCanvas );
  19.     qDebug ("QtCanvas set");
  20.     this->canvas()->update();
  21.     bool isTrace = hasMouseTracking();
  22.     bool isVTrace = viewport()->hasMouseTracking();
  23.     if ( isTrace )
  24.         qDebug ("Mouse tracking is on");
  25.     else
  26.         qDebug ("Mouse tracking is off");
  27.     if ( isVTrace )
  28.         qDebug ("Viewport Mouse tracking is on");
  29.     else
  30.         qDebug ("Viewport Mouse tracking is off");
  31. }
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After setCanvas() function variables isTrace and isVTrace are true, but event contentsMouseMoveEvent (QMouseEvent *e) does not generated.
If I comment setCanvas() function, all mouse movements are traced normally. Where is problem ?

Best regards,
Yuriy Rusinov.