setCanvas blocks mouse movement on QtCanvasView

[YuriyRusinov]

Hello, All !

I developed class,

class XGisCanvasView : public QtCanvasView
{
    private:
        Q_OBJECT
    public:
        XGisCanvasView (QWidget *parent=NULL);
        virtual ~XGisCanvasView (void);
 
        QPoint getPos (void) const { return scr; }
 
    signals:
        void contentsMouseMove (QMouseEvent *e);
        void mousePress (QMouseEvent *e);
        void mouseRelease (QMouseEvent *e);
        void mouseDoubleClick (QMouseEvent *e);
        void mouseContextMenu (QContextMenuEvent *e);
        void resize (QResizeEvent *e);
 
    protected:
        virtual void contentsMouseMoveEvent (QMouseEvent *e);
        virtual void contentsMousePressEvent (QMouseEvent *e);
        virtual void contentsMouseReleaseEvent (QMouseEvent *e);
        virtual void contentsMouseDoubleClickEvent (QMouseEvent *e);
        virtual void contentsContextMenuEvent (QContextMenuEvent *e);
        virtual void resizeEvent (QResizeEvent *e);
 
    private:
        QPoint scr;
        QtCanvas* pCanvas;
};

class XGisCanvasView : public QtCanvasView
{
    private:
        Q_OBJECT
    public:
        XGisCanvasView (QWidget *parent=NULL);
        virtual ~XGisCanvasView (void);

        QPoint getPos (void) const { return scr; }

    signals:
        void contentsMouseMove (QMouseEvent *e);
        void mousePress (QMouseEvent *e);
        void mouseRelease (QMouseEvent *e);
        void mouseDoubleClick (QMouseEvent *e);
        void mouseContextMenu (QContextMenuEvent *e);
        void resize (QResizeEvent *e);

    protected:
        virtual void contentsMouseMoveEvent (QMouseEvent *e);
        virtual void contentsMousePressEvent (QMouseEvent *e);
        virtual void contentsMouseReleaseEvent (QMouseEvent *e);
        virtual void contentsMouseDoubleClickEvent (QMouseEvent *e);
        virtual void contentsContextMenuEvent (QContextMenuEvent *e);
        virtual void resizeEvent (QResizeEvent *e);

    private:
        QPoint scr;
        QtCanvas* pCanvas;
};

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wsview.cpp

XGisCanvasView :: XGisCanvasView(QWidget *parent/*=NULL*/) : QtCanvasView (parent), scr (QPoint(0, 0))
{
    setMouseTracking ( true );
    viewport()->setMouseTracking ( true );
 
    int x = width();
    int y = height();
    if ( parent )
    {
        x = parent->width();
        y = parent->height();
    }
    qDebug ("width = %d height = %d", x, y);
    pCanvas = new QtCanvas ( );
    qDebug ("QtCanvas init");
    pCanvas->resize (x, y);
 
    setCanvas( pCanvas );
    qDebug ("QtCanvas set");
    this->canvas()->update();
    bool isTrace = hasMouseTracking();
    bool isVTrace = viewport()->hasMouseTracking();
    if ( isTrace )
        qDebug ("Mouse tracking is on");
    else
        qDebug ("Mouse tracking is off");
    if ( isVTrace )
        qDebug ("Viewport Mouse tracking is on");
    else
        qDebug ("Viewport Mouse tracking is off");
}

XGisCanvasView :: XGisCanvasView(QWidget *parent/*=NULL*/) : QtCanvasView (parent), scr (QPoint(0, 0))
{
    setMouseTracking ( true );
    viewport()->setMouseTracking ( true );

    int x = width();
    int y = height();
    if ( parent )
    {
        x = parent->width();
        y = parent->height();
    }
    qDebug ("width = %d height = %d", x, y);
    pCanvas = new QtCanvas ( );
    qDebug ("QtCanvas init");
    pCanvas->resize (x, y);

    setCanvas( pCanvas );
    qDebug ("QtCanvas set");
    this->canvas()->update();
    bool isTrace = hasMouseTracking();
    bool isVTrace = viewport()->hasMouseTracking();
    if ( isTrace )
        qDebug ("Mouse tracking is on");
    else
        qDebug ("Mouse tracking is off");
    if ( isVTrace )
        qDebug ("Viewport Mouse tracking is on");
    else
        qDebug ("Viewport Mouse tracking is off");
}

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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.

[wysota]

Are events with mouse button depressed still being fired?

[YuriyRusinov]

I don't know. Which way they have to be verified ?

[wysota]

Press and hold your mouse button over the canvas view and move the cursor

[YuriyRusinov]

I pressed and holded mouse button on QtCanvasView, contentsMouseMoveEvent () is generated, but I have to generate this event without pressing mouse button.

[wysota]

but I have to generate this event without pressing mouse button.

Sure, but now we know the problem is with tracking and not with posting events.

Why do you reference the viewport() of the canvas view anyway? Where do you check that contentsMouseMoveEvent? On the viewport or on the view directly?

[YuriyRusinov]

I reference to the viewport() because some documentation on QtCanvasView examples and my thread in qt-interest recommend this. I check contentsMouseMoveEvent in my class directly, using qDebug("Contents Mouse move event"). When I move mouse without pressing button, qDebug does not out anything.

[wysota]

You could try enabling the tracking again after you set the canvas. There is nothing in the setCanvas() source code which could directly cause such a misbehaviour, but maybe one of the methods which get called from there mess something up.

[YuriyRusinov]

Problem was solved by adding this->widget()->setMouseTrackine (true); and removing all others such instructions. Thanks a lot.