Move QGraphicsProxyWidget

[RThaden]

Hi all,

I didn't find a solution for my problem up to now:
I have a derived class from QGraphicsProxyWidgets and want to move these in a QGraphicsScene.What I did up to now was reimplementing mousePressEvent, mouseReleaseEvent and mouseMoveEvent and called the implementations of QGraphicsItem for these events. That worked fine, but now I have a problem since I added a QPushButton in my widget which resides in the proxy widget and the mousePressEvents are not forwarded.
So, I removed my own implementations of the mouse event handlers with the result that I can use the QPushButton normally but lost the ability to move the widgets.
I'd like to have both.

Any suggestions what I have to do?
Reimplement the move functionality with itemChanged and setPos?
Or forware mouseClicks to the widgets?

Best regards,

Rainer

[RThaden]

Hi all,

I found a solution. Seems a bit hackish to me, am thankful for an opinion:

void ProxyWidget::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    QPointF pos = event->pos();
    QPointer<QWidget> alienWidget = widget()->childAt(pos.toPoint());
    if (qobject_cast<QPushButton*>(alienWidget))
    {
        QGraphicsProxyWidget::mousePressEvent(event);
        grabbedByWidget=true;
    }
    else
    {
        QGraphicsItem::mousePressEvent(event);
        grabbedByWidget=false;
    }
}
 
void ProxyWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
    if (grabbedByWidget)
        QGraphicsProxyWidget::mouseReleaseEvent(event);
    else
        QGraphicsItem::mouseReleaseEvent(event);
    grabbedByWidget=false;
}
 
void ProxyWidget::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
    if (grabbedByWidget)
        return;
    QGraphicsItem::mouseMoveEvent(event);
}

void ProxyWidget::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    QPointF pos = event->pos();
    QPointer<QWidget> alienWidget = widget()->childAt(pos.toPoint());
    if (qobject_cast<QPushButton*>(alienWidget))
    {
        QGraphicsProxyWidget::mousePressEvent(event);
        grabbedByWidget=true;
    }
    else
    {
        QGraphicsItem::mousePressEvent(event);
        grabbedByWidget=false;
    }
}

void ProxyWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
    if (grabbedByWidget)
        QGraphicsProxyWidget::mouseReleaseEvent(event);
    else
        QGraphicsItem::mouseReleaseEvent(event);
    grabbedByWidget=false;
}

void ProxyWidget::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
    if (grabbedByWidget)
        return;
    QGraphicsItem::mouseMoveEvent(event);
}

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That is, I call either the implementations for the mouse event handlers of QGraphicsItem or QGraphicsProxyWidget depending on the mouse position. If I find a QPushButton under the mouse, I call the widgets handler.

Regards,

Rainer

[aamer4yu]

Normally a graphics item is movable if u set the flags properly. Why did you need to re implement the mouse events?

[RThaden]

It is a QGraphicsProxyWidget, not a QGraphicsItem

[aamer4yu]

And isnt QGraphicsProxyWidget a descendant of QGraphicsItem

[RThaden]

Yes it is. But derived classes sometimes override implementations
QGraphicsProxyWidget has own implementations for the mouse event handlers that do not support moving it by default.
Instead they have to care for the contained QWidget to get the mouse events.

[wagmare]

little suggestion ...
add this QGraphicsProxyWidget to a QGraphicsRectItem as parent .... just like padnavigator example's roundrectitem.cpp ... u canmove the RoundRectItem ...

[RThaden]

Thanks wagmare for this helpful suggestion. I will try that and report the results, however it will take some time, since my approach works (but smells a bit) and so the priority is a bit low at the moment.

Best regards,

Rainer

[meazza]

How exactly did you accomplish this? I have a similar problem, but I cant move my proxywidgets at all in the scene. Been trying all morning but with no success. So I am hoping that you can give me some pointers.

I have also made a class deriving from QGraphicsProxyWidget but it wont allow me to pass the QGraphicsItem events

[RThaden]

meazza,

you see my solution. I posted the code. That worked.
I derived from QGraphicsProxyWidget and in the constructor, I did

setFlag(ItemIsMovable);
setFlag(ItemIsSelectable);

setFlag(ItemIsMovable);
setFlag(ItemIsSelectable);

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It's some time ago and I don't remember all the details.

Regards,

Rainer