Problems with signals and slots [probably c++ issue]

[Nayrb]

I apologise for being too vague.

The function is the QGraphicsScene::mouseDoubleClickEvent().

1) The first "it" is the object, I wanted to update the QTreeWidget whenever the object is being double-clicked.
2) The second "it" refers to the same object which has not been instantiated.
3) The third "it" refers to the connection that I wanted to connect between the myCable object and myScene object, however I only instantiate the myCable object in one of myScene methods.
4) The fourth "it" refers to the myCable object which I have instantiate in one of the myScene methods.

E.g. myScene.cpp

void myScene::myCableToolsDrawSlot(int x, int y, int x2, int y2)
{
myCable cable = new myCable();
...
...
}

[ChrisW67]

If "the object" (presumably intended to be a QGraphicsItem) has not been instantiated then it cannot be double-clicked. Your description is not doing you any favours.

If you have implemented a double-click handler on the scene then you can determine the scene objects that are at the double-click position with QGraphicsScene::itemAt() or QGraphicsScene::items(). Your scene can emit any signal it likes to update a QTableWidget. There is no need for a connection between an item in the scene and the scene (graphics items are not QObjects and cannot emit signals anyway). There's no need for a connection between the graphics item and and external table widget.

When your scene creates a new item the scene can tell the table widget about it if need be.