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I have now tried for hours to make sense of how QGraphicsItem behaves with respect to children. I create a new QGraphicsItem B (actually an own subclass of it), and then add it to another QGraphicsItem A as child by invoking the setParentItem method on B. Immediately after that A has B as child. I have verified with some debug code that iterates over the children of A. Then A is added to a List of As in a Manager. Some time later in the program, in a QWidget the lists iterator is obtained from the manager. I then iterate over the list of As and check the children for each of them and all of them are gone. I have verified in the debugger that the Manager is really the same instance and the list is also the same instance. Somehow this really puzzles me, who in the Qt FWK decides for me that my A objects do no longer need their children?

I'm a newby to Qt and C++, also with extensive development experience from java to objective-c so I have some hope it is a speciality of Qt I'm not aware of, not entirely my own stupidity...

Best Regards,

André

André
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    Please post the relevant part of the code where you build that B and add it to A. It could be an object lifetime issue. – Mat Nov 20 '11 at 12:12
  • It was an object lifetime issue. I stored a reference to a local object and tried to access it in another scope. – André Apr 14 '12 at 10:36

1 Answers1

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FYI: QGraphicsItemGroup specially designed for grouping.

// Group all selected items together

QGraphicsItemGroup *group = scene->createItemGroup(scene->selecteditems());

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Dmitry
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