Hm, that's annoying. I wonder if you could cook up a small example of this that we could play around with? Perhaps we can work out what needs to change to get this working.
As a workaround in the meantime, I wonder whether prefetching one level deeper would work (though I perfectly understand that this could be a significant cost). ~d On 2014-01-24 09:52, Donald Allen wrote: > I've written a personal finance manager, having become dissatisfied > with Gnucash after many years of use. My own system, Newcash, is > written in C/GTK3/Sqlite3 (I will be making it available via github > when the documentation is ready). In recent months, I've become > interested in Haskell (I've written a lot of Lisp and Scheme code over > the years) and I re-wrote the Newcash report generator (originally > written in Python to process Gnucash's xml file and thus was pretty > ugly and needed re-writing) in Haskell. Enthusiastic about the > language and pleased with the performance of the report generator, I > decided to experiment with re-writing Newcash itself in Haskell, for > all the reasons that Haskell is to be preferred to C. > > > But I've run into a show-stopper. Here's the situation: the Newcash > initial window displays the tree of accounts. Not wanting to endure > long startup times (a big issue with Gnucash), I initially want to > populate the tree model with the root, its children, and its > grandchildren. The root gets expanded, so the children are visible, > but the grandchildren are present, so the children are expandable. A > callback is set up to handle the TreeView's testExpandRow signal, > indicating that the user has requested expansion of one of the nodes. > I do this initial setup of the accounts window prior to calling > mainGUI the first time. This all works fine. > > > The trouble starts if I try to expand one of the root's children by > clicking it. The root's grandchildren are already present, but > callback attached to the testExpandRow needs to add the grandchildren > of the clicked node, so that if it has children, it will appear > expandable. The callback receives both an iter and a path to the > clicked node. It uses the path in a loop that adds the grandchildren > of the clicked node to the TreeStore. This succeeds, but when the > callback returns, I get an error message: > > > ** (Newcash:920): CRITICAL **: gtk2hs_store_iter_has_child: assertion > 'iter->stamp == store->stamp' failed > > and the display fails to refresh, with the clicked node expanded. If I > click the same node again, it expands correctly (the grandchildren are > already present, courtesy of the response to the previous click). > > I'm guessing that the iter being passed to the callback (which I don't > use; as mentioned before, the insertion of the grandchildren is done > using the path derived from the path of the clicked node, using > treeStoreInsert) has a time-stamp as of the time the first > testExpandRow signal was issued. In response to that signal, I add > some nodes to the store. I'm guessing that doing so updates the > time-stamp on the store and that the two time-stamps are compared upon > return from signal processing, and they are no longer equal. The > second click does nothing to the store (my callback is smart enough to > know that a node has already been processed and doesn't add its > grandchildren twice), so the second time the node is clicked, the > time-stamp comparison works. > > ------------------------------------------------------------------------------ > CenturyLink Cloud: The Leader in Enterprise Cloud Services. > Learn Why More Businesses Are Choosing CenturyLink Cloud For > Critical Workloads, Development Environments & Everything In Between. > Get a Quote or Start a Free Trial Today. > http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk > _______________________________________________ > Gtk2hs-devel mailing list > Gtk2hs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/gtk2hs-devel ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Gtk2hs-devel mailing list Gtk2hs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gtk2hs-devel
