Context Menu on QGraphicsWidget

Question

In my application I have two object type. One is field item, other is composite item. Composite items may contain two or more field items. Here is my composite item implementation.

#include "compositeitem.h"

CompositeItem::CompositeItem(QString id,QList<FieldItem *> _children)
{
   children = _children;
}

CompositeItem::~CompositeItem()
{
}

QRectF CompositeItem::boundingRect() const
{
 FieldItem *child;
     QRectF rect(0,0,0,0);
     foreach(child,children)
     {
        rect = rect.united(child->boundingRect());
     }
    return rect;
}

void CompositeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option,   QWidget *widget )
  {
   FieldItem *child;
   foreach(child,children)
   {
      child->paint(painter,option,widget);
   }
  }

  QSizeF CompositeItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
  {
   QSizeF itsSize(0,0);
   FieldItem *child;
   foreach(child,children)
   {
      // if its size empty set first child size to itsSize
      if(itsSize.isEmpty())
          itsSize = child->sizeHint(Qt::PreferredSize);
      else
      {
          QSizeF childSize = child->sizeHint(Qt::PreferredSize);
              if(itsSize.width() < childSize.width())
                  itsSize.setWidth(childSize.width());
              itsSize.setHeight(itsSize.height() + childSize.height());
      }
  }
  return itsSize;
     }

     void CompositeItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
     {
          qDebug()<<"Test";
     }

My first question is how I can propagate context menu event to specific child.

Picture on the above demonstrates one of my possible composite item.

If you look on the code above you will see that I print "Test" when context menu event occurs.

When I right click on the line symbol I see that "Test" message is printed. But when I right click on the signal symbol "Test" is not printed and I want it to be printed.

My second question what cause this behaviour. How do I overcome this.

@mosg Sorry I forgot to write my first question. I edited the question. — onurozcelik, May 11 '10 at 13:06

score 0 · Answer 1 · answered May 11 '10 at 21:51

0

Could you try reimplementing your contextMenu with the mouseRelease event instead?

void CompositeItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
        if(event->button() == Qt::RightButton)
        {
            contextMenu->popup(QCursor::pos());
        }
}

answered May 11 '10 at 21:51

Vicken Simonian

411
4
6

Due to an advice I edited boundingRect code. I guess it is a neat idea to unite childs boundingRects. But this time item can' t catch events like contextmenuevent and mousepressevent. So my prior problem is to catch events. Do you have an idea what may cause this? – onurozcelik May 12 '10 at 08:26

score 0 · Answer 2 · answered May 13 '10 at 07:20

I figured out that there may be two solutions for catching events. First one is reimplementing shape function. In my case it will be implemented like this.

QPainterPath shape() const
{
  QPainterPath path;
  path.addRect(boundingRect());
  return path;
}

Second one is to use QGraphicsItemGroup
It will be good idea to use QGraphicsItemGroup if you diretly adding your items to scene. But in my case I have to subclass QGraphicsItemGroup because of I am using a layout. So temporarily I choose writing my own item.

Context Menu on QGraphicsWidget

2 Answers2