Re: [Qt-qml] Injecting an item into model coming from C++ or "translating" C++ model into another QML model

[Artem Marchenko]

Thanks, Bo Your UI obviously mixes concepts in the same area, which is why you have a problem with the low-end model code. Indeed it is so. To be precise, there are two conceptually different, yet related models. 1. One is to have a contact list coming from the messenger API. OK, I add a couple of custom properties, yet it is still pretty much an external contact list and it would be good to keep it this way - easier to verify, easier to sync (I don't trust messenger API much, so it's good to have isolated point of contact). 2. Another one is the model for list shown in the UI. That can have an extra item (my own contacts) or maybe even hide some item (voice test contact always provided by a messenger). These two models are indeed conceptually different yet one can be transformed into another one using a couple of clear and simple rules. *Options* So what I am asking for is an advice (or maybe somebody even has similar experience) on how to do such a transformation. One possibility is to to make 2nd model in a pure QML (manipulate ListModel whenever c++ model changes). Another one is to have 2nd model in C++. Another option is to have just one model on a C++ side, inject and remove items there and/or maybe have special attribute to tell whether a particular item is hidden. Cheers, Artem. Bo Thorsen 20 квітня 2012 р. 11:20 Yes, you can do this in QML, coupled with some _javascript_ and signal handlers. But why on earth would you want to, when it's so much easier to have it in the model? If you want to, you can add a bool flag on each item that says if it's your special item or not. Let it sit in the model, it's *by far* the easiest for you. If you are worried about tainting your model with something that doesn't match the concept it models, then you're on the wrong track. Your UI obviously mixes concepts in the same area, which is why you have a problem with the low-end model code. Fix your UI to not show a special item that is a different concept, or accept that you should add it to the model. I would choose one of those two options, because the others are worse. Bo Thorsen, Fionia Software. Artem Marchenko 20 квітня 2012 р. 01:53 Hi All I've go a model coming from C++ (Inhertited from QAbstractListItemModel) that is basically a list of contact for an instant messenger. App's UI, however, is to include one more special contact representing the current user (it makes sense on our devices with extremely discouraged chrome elements such as extra headers, scrollbars, etc). I can certainly, modify the model on C++ side, yet.. this special item is really just about the UI representation and therefore it seems very logical to me to perform such a modification in QML side. Is there a way to somehow inject an item into a model coming from C++? Or maybe there is a way to apply some rules to C++ model and make a QML ListModel or something like that as a result? Or how would you do it? Cheers, Artem. P.S. In most of cases there are going to be just a few elements in the model so cloning of model if needed shouldn't effect performance and memory use much

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