[Qgis-developer] Create groups in python plugins

[Andres Manz]

Hi list,

While implementing QgsLegendInterface for the Python API, I ran into
another problem: QgsLegend inherits from QTreeWidget, which inherits
from QObject. As QgsLegendInterface should have signals and slots, it
should inherit from QObject, too. When QgsLegend implements
QgsLegendInterface, I get the diamond problem: Both,
QgsLegendInterface and QTreeWidget inherit from QObject. How should I
handle that? Up to now, there are three possibilities:

1. QgsLegendInterface inherits from QTreeWidget and QgsLegend only
implements QgsLegendInterface. Not a very nice solution, and the
members of QTreeWidget would be exposed to the python scripter.

2. QgsLegendInterface is a "wrapper" class for QgsLegend. It holds a
pointer to the QgsLegend and inherits from QObject.

3. Split up QgsLegend, so the part that doesn't inherit from
QTreeWidget could implement QgsLegendInterface. QgsLegend is a huge
class, so it would be a lot of work to do that.

Do you have any other solutions? Or could you recommend one of the above?

Regards
Andres