I'd like to build a completion for a QLineEdit which can take several completion models and organizes them as categories.
I have a working solution based on a QSortFilterProxyModel and a tree model for the items:
The root items in the model show up as category, and the children of each root-item show up as filtered items. Then there's a customized QTreeView so this is displayed properly, tabbing ignores categories, etc.
This works fine - however it makes it very hard to write new completions (e.g. for the possible values for a setting).
Each completion needs to be a tree model with all categories in it. I'd prefer to write simple list models for each category, and then being able to combine them to a QTreeModel, i.e. something like this (pseudo-ish Python code):
commands = CommandListModel()
settings = SettingListModel()
completion.setModels([('commands', commands), ('settings', settings)])
There are some different solutions I had in mind, but I'm not sure what route to go, as all of them feel non-trivial to implement:
- Write a
QAbstractProxyModel-like class (or a custom model) which combines several list models to one tree model, and leave the view part as-is.
Writing custom tree models in Python is hard however (and typically segfaults if you do anything wrong), and I've had performance issues with it in the past (compared to a QStandardItemModel, as there are some thousand items in the underlying models).
- Write functions for each model which fill a tree model (given a category and a list of items).
This makes it harder to write dynamic models rather than just having a list of static items.
- Use several list models, and adjust the view to be a
QVBoxLayoutofQListViews.
This sounds the most promising to me so far. However, implementing tabbing through the completion and filtering so it works right might be troublesome as well, and resizing the sub-views appropriately too.
Is there some easier way to do this I haven't considered? Which approach is likely to be the least painful down the road?