[PyQt] QDataWidgetMapper and addMapping with a custom property name: setProperty never called

[Phil Thompson]

On Tue, 9 Nov 2010 20:29:43 +0100, TP <paratribulations at free.fr> wrote:
> Hello,
> 
> I currently use QDataWidgetMapper with a custom property name:
> 
> self.mapper.addMapping( widget, index, propertyName )
> 
> Now let us look at the private method populate() of 
> src/gui/itemviews/qdatawidgetmapper.cpp (Qt source code):
> 
> //////
> void QDataWidgetMapperPrivate::populate(WidgetMapper &m)
> {
>     if (m.widget.isNull())
>         return;
> 
>     m.currentIndex = indexAt(m.section);
>     if (m.property.isEmpty())
>         delegate->setEditorData(m.widget, m.currentIndex);
>     else
>         m.widget->setProperty(m.property, 
> m.currentIndex.data(Qt::EditRole));
> }
> //////
> 
> So, the .setEditorData() method of the delegate is called when there is
no 
> custom property name, and on the contrary the .setProperty() method of
the 
> widget under consideration is called when a custom property name is 
> specified (this is my case).
> 
> I use QTextEdit with a custom property name ("plainText" instead of the 
> default property "html"), I have tried to write my own QTextEdit, 
> QTextEdit2, with a specialized setProperty method to perform some action

> before setting the property:
> 
> class QTextEdit2( QTextEdit ):
>    def __init__( self, parent = None ):
>       super( QTextEdit2, self ).__init__( parent )
>    def setProperty( self, name, qvariant ):
>       # some code to do some action
>       super( QTextEdit2, self ).setProperty( name, qvariant )
> 
> But this *setProperty method is never called*, contrary of what we
should 
> expect due to the code of QDataWidgetMapper.cpp above!
> All is happening as if the setProperty method of the C++ parent object 
> (QTextEdit) is called, but not the method setProperty defined in the
> Python 
> code of the used widget, QTextEdit2.
> 
> What is the problem?

setProperty() isn't virtual so you can't reimplement it in Python.

Phil