On 09/26/2014 09:33 AM, William Hallatt wrote: > Hi everyone, > > I have just started playing with Qt’s MVC classes and have created a > hierarchical model to display in a QTreeView. Some of the nodes, however, > have a > fair amount of children and when I expand these nodes (or, heaven forbid, > expandAll), the app hangs for a remarkably long time. > > I have read everything I can on lazy model loading and have implemented what I > believe to be correct fetchMore and canFetchMore methods, yet this does not > seem > to make a difference since fetchMore only gets called once on an expand > (however, the tree expands to the correct level and to the very last child > which > I find very confusing). > > So, my questions are: > > 1. Does lazy model loading actually affect the expansion of nodes? > 2. Is there a way I could improve the performance? > > I have been banging my head against this for two days now so any help will be > appreciated. >
Are you running with a debug or release build of Qt. What does a profiler show. > The code for my item and model classes is available here: > > https://www.dropbox.com/sh/8vc1s29wvmvpp07/AAChJVKhjUuXJy9dxjlT6ErRa?dl=0 > > Thanks! > > > > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest > _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
