[PySide] inter-object communications

[John Ehresman]

On 11/8/13 11:01 AM, Henry Gomersall wrote:
> Ah, ok. So PySide creates a parallel class heirarchy, with methods that
> can call back into Python. Out of interest, how is this check on being a
> python implemented subclass performed? (a pointer to the relevant code
> would be awesome!).

At a high level, the code for a method named "foo" is (untested code 
that omits error handling and ref counting):
C++WrapperClass::foo(args...)
{
   override = PyObject_GetAttrString(pySelf, "foo");
   if (override != NULL) {
     result = PyObject_Call(override, args...);
     return result;
   }
   else {
     return C++BaseClass::foo(args...);
   }
}

Best way to get a more detailed look (for me, at least) is to look at 
the generated code.  In a built PySide tree, look at 
PySide/QtGui/PySide/QtGui/qwidget_wrapper.cpp in the build directory. 
The QWidgetWrapper::setVisible method is the override for the 
QWidget::setVisible method.

Cheers,

John