[Qt-qml] hasChildren attribute for Qml Model?

[Martin Jones]

On Tue, 20 Apr 2010 07:56:17 pm ext Stephen Kelly wrote:
> Martin Jones wrote:
> > On Mon, 19 Apr 2010 10:09:17 pm ext Stephen Kelly wrote:
> >> In QTreeView, that's a [+] which you can click to expand.
> > 
> > You could add a Q_INVOKABLE method to your model to get the child count,
> > similar to the setRoot() method in this example:
> > 
> > http://qt.nokia.com/doc/4.7-snapshot/qml-visualdatamodel.html#rootIndex-
> 
> prop
> 
> 
> 
> Indeed, however, it gets complicated when an intermediate proxy model
> filters out all the children.
> 
> That is common in my case because it is something like a filesystem where
> on one side is the folder structure and on the other side is the files in
> the selected folder. In the view that is showing only the folder
> structure, hasChildren is true only if it has subfolders. Files are
> already filtered out.
> 
> First I put a method similar to what you describe in the proxy actually
> sent into the qml environment, but then when I added another proxy I had
> to move the logic to that class. That's not a good solution.
> 
> Currently I have an invokable method in a globally accessible application
> object to figure out if the correct proxy hasChildren at a particular row.
> The method will have to be updated if ever the application changes. It's a
> bit too much magic for me, so the best place for a solution is further down
> the stack in Qt.

We'll add something along the lines of a "hasChildren" property to the 
delegate.

-- 
Martin