[Qt-qml] hasChildren attribute for Qml Model?

[Stephen Kelly]

Martin Jones wrote:

> 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.
> 

Awesome, thanks.