Notifying subclass of QAbstractItemModel about changes

Question

Hello. I've got a question about notifying a model of the changes made to some other object which it stores a reference to.

I'm aware of the signal dataChanged(), but I'm not sure how to use it. For example, my model stores a reference to some other object (let's call it myObjPtr). The model queries myObjPtr for its contents only when the methods rowCount(), columnCount(), data() and others are called on the model.

Then, if I make some changes to the contents of myObjPtr, how should I notify the model so that it could emit the dataChanged() signal with proper arguments? Should I use the model's setData() method? Which arguments should I pass to it if I, for instances, deleted or replaced some elements in myObjPtr?

Thank you.

Answer 1

If I understand what you're asking, then the easiest way is for myObjPtr to have a signal it emits when it is changed, and have that emit the dataChanged() signal in the model. Bear in mind that the dataChanged() signal is specific about what data changed. If you can't get that degree of precision, you can also call reset() in the model, which causes all information to be updated.