It depends. The current outcome could potentially never have been a problem to begin with if the view simply represented the same data between being refreshes. This was at least my motivation for suggesting it in the first place.
Spontaneously, I'm thinking that the XML hierarchy would be parsed into an object hierarchy which would be directly represented by the view. The view and model would inherently support being edited and any ad-hoc solutions would become superflous. The problem the OP is having basically sounds like what the item views were designed to solve and I'd think it would consume more time and effort to try and re-implement it on top of convenience objects. I couldn't say for sure. It's merely an observation based on the information I got. Best, Marcus > On 15 Apr 2015, at 21:25, Justin Israel <[email protected]> wrote: > > Switching to a view/model is not going to change the outcome of the current > approach. Clearing the data is still clearing the data. QTreeWidget is a > subclass of QTreeView with a built in model. You could use > QPersistentModelIndex, and get the model from the widget with model(), but if > you clear it, then the index will invalidate anyways. > > There are two approaches you could take. One would be to change how you > handle updates to data and not respond by clearing the whole model, but > rather to update data for what has actually changed, and add and remove > items. It would be the same with a view/model, except you would be handling > the changes from the model instead of the widget. Then persistent model > indexes would also work. > > Or you could continue dumping and rebuilding every time, but store some kind > of unique reference as data on each item so that you can save it before > clearing, and check for it when you restore. Maybe some kind of xml path. If > there is no unique type of identifier that you can associate with each item > in reference to the xml, then you probably don't have a choice but to be more > granular with how you manage the changes to your data. > > Justin > >> On Thu, 16 Apr 2015 5:00 AM Marcus Ottosson <[email protected]> wrote: >> The strength of widget views in general is that they are very easy to get >> started with compared to item views, but fall short in more complex >> use-cases. >> >> It does sound like you would be better off with an item view, however >> whether or not it's viable to switch is mostly a matter of how much further >> you intend on extending and maintaining your current implementation. It's >> quite likely that you are at a point where the amount of work involved in >> adding new functionality requires an exponentially increasing amount of work >> to get done due to having to fight the convenience provided by the widget >> view, and jidging by your example I'd say that this seems to be the case. On >> the other hand, if you're close to finishing and don't think it will need >> much maintenance once done then it's questionable whether the effort is >> worth it. >> >> Item views are undeniably more complex than their widget counterparts but >> their complexity is really only a reflection of how complex the data you're >> working with really is, and hierarchical data especially is amongst the most >> complex data there is. >> >> To put an analogy on your problem, you've been working with Microsoft Movie >> Maker and are looking to do things that Nuke has no problem doing. Do you >> learn Nuke, or find ways around the problem in Movie Maker? >> >>> On 15 Apr 2015, at 17:17, Ben Hearn <[email protected]> wrote: >>> >>> I am representing XML data in a tree view and enabling the editing of this >>> XML data, when the user changes some data in the editable fields the view >>> is then updated to represent this new data. >>> >>> I have not used QTreeView or any model information yet. Are there any huge >>> differences with adding items and editing them? Also is there that much of >>> a benefit in switching from QtTreeWidget especially since I am quite a leap >>> into the project at current. >>> >>> >>>> On 15 April 2015 at 17:37, Marcus Ottosson <[email protected]> wrote: >>>> Without fully understanding what you're up to, you may be better off with >>>> a QTreeView and QAbstractItemModel. The model would keep track of >>>> hierarchy, and your view simply represent it. 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