Question about drag and drop in QGraphicsView

[meazza]

I have to click on the edge of the item, and it has to be on the pixel. Very hard to click it with the mouse.

[wysota]

Apparently the inside of the item is empty. If simply setting a brush doesn't help you'll have to reimplement the shape() of the item.

[meazza]

I fixed it i think. I thought since i add the items during a pressEvent and when i tried to move the item i press the mouse so the pressEvent funktion was called hence not allowing me to move it. So added QGraphicsScene::mousePressEvent(mouseEvent); if iwas not adding items in the pressEvent.

Well it works now but do you find this a reasonable solution?

[wysota]

I don't think adding items in a mouse press event is a reasonable solution. I tend to lean towards more high-level solutions.

[meazza]

Well I am not a master of zen yet , but hopefully someday I will be. What would that high-level solution be? Just asking out of curiosity, not gonna try it out this time. Not high-level yet .

Thanks for all your help

[wysota]

Like emitting a signal "hey, I want item to be added at these coordinates" and then handling it in a dedicated method that can be called from different contexts. And mousePress is probably a bad place to do it anyway, mouseRelease would be a better one.

[liran ritkop]

What about the solution of reimplement the function mouseMoveEvent()?
You can do something like that too:

void Object::mouseMoveEvent(QMouseEvent *event){
   PolygonItem->move(event->x(),event->y());
}

void Object::mouseMoveEvent(QMouseEvent *event){
   PolygonItem->move(event->x(),event->y());
}

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[wysota]

Sure but why if you have the ItemIsMovable flag?

[meazza]

I have found another question. How do QWidgets behave in the graphicsscene? Do I need to use the QGraphicsProxyWidget to be able to move it or? Because i cant set flags to a normal QWidget.

Embedded *MyWidget = new Embedded();
        QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget();
        proxy  = addWidget(MyWidget);
        proxy->setFlags(QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
        proxy->setPos(mouseEvent->scenePos());
        addItem(proxy);
        figur = 0;

Embedded *MyWidget = new Embedded();
        QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget();
        proxy  = addWidget(MyWidget);
        proxy->setFlags(QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
        proxy->setPos(mouseEvent->scenePos());
        addItem(proxy);
        figur = 0;

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I tried this and it positions as i would like to but cant move it..Maybe I am waaaay out there on this one

[wysota]

I'd say you can't move it because the widget handles the event so it never reaches the scene code responsible for moving the item.