Ulrich wrote: > The tree has 3 to 4 levels. Let's say the first level contains 30 items, > the second level 2000 and the third contains 7000 "folders". The last > level contains 50,000 items. > > I thought it would be a good idea (?) to store the data in a database > like SQLite, because this is provided by PyQt and it is searchable. I > would store the 50,000 items in one table like this: > FOLDER_NAME_LVL1, FOLDER_NAME_LVL2, .., ITEM_NAME other data > ... > with such a table it would be possible to build the tree: > FOLDER_NAME_LVL1 > +-----FOLDER_NAME_LVL2 > --------+------ITEM_NAME > etc. etc. > > So where is my Problem? Such a tree should be displayed with a > QT-Treeview. There are two different ways: Item-based or model-view > based. A model-view based approach could become difficult, because the > model has to build tree-nodes from a 2-Dimensional Table. Does something > like this already exist in PyQt? On the other hand, I have to create all > the 50,000 nodes at once if I use the Item-based approach.
You don't actually have to create all items at once with the tree-widget item-based approach. You can just create the visible items (that have open parents). Then create a method that loads children on demand and connect it to the itemExpanded(QTreeWidgetItem*) signal. To get the "+" button to display properly, you can add a single dummy child item to each closed parent item, then delete it when actually loading the real children. Doug. _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
