Add proper return value to event overriden in python

Currently the controllers implemented in python cannot report the the event processing
system in sofa that there is no need anymore to process the event.

The PR allows to do. Every onXXXXXX() that implement an event processor can no return a value.
If it is None or False then processing of event use this to continue the propagation
If it is True (aka: has been processed/no more further), then the SOFA system will not proposed to other component to process the same event

Author: damienmarchal

bindings/Sofa/src/SofaPython3/Sofa/Core/Binding_Controller.cpp

@@ -68,7 +68,7 @@ void Controller_Trampoline::reinit()
 
 /// If a method named "methodName" exists in the python controller,
 /// methodName is called, with the Event's dict as argument
-void Controller_Trampoline::callScriptMethod(
+bool Controller_Trampoline::callScriptMethod(
         const py::object& self, Event* event, const std::string & methodName)
 {
     if(f_printLog.getValue())
@@ -81,8 +81,13 @@ void Controller_Trampoline::callScriptMethod(
     if( py::hasattr(self, methodName.c_str()) )
     {
         py::object fct = self.attr(methodName.c_str());
-        fct(PythonFactory::toPython(event));
+        py::object result = fct(PythonFactory::toPython(event));
+        if(result.is_none())
+            return false;
+
+        return py::cast<bool>(result);
     }
+    return false;
 }
 
 void Controller_Trampoline::handleEvent(Event* event)
@@ -95,13 +100,17 @@ void Controller_Trampoline::handleEvent(Event* event)
         {
             py::object fct = self.attr(name.c_str());
             if (PyCallable_Check(fct.ptr())) {
-                callScriptMethod(self, event, name);
+                bool isHandled = callScriptMethod(self, event, name);
+                if(isHandled)
+                    event->setHandled();
                 return;
             }
         }
 
         /// Is the fallback method available.
-        callScriptMethod(self, event, "onEvent");
+        bool isHandled = callScriptMethod(self, event, "onEvent");
+        if(isHandled)
+            event->setHandled();
     });
 }
 

bindings/Sofa/src/SofaPython3/Sofa/Core/Binding_Controller.h

@@ -50,7 +50,7 @@ class Controller_Trampoline : public Controller
     std::string getClassName() const override;
 
 private:
-    void callScriptMethod(const pybind11::object& self, sofa::core::objectmodel::Event* event,
+    bool callScriptMethod(const pybind11::object& self, sofa::core::objectmodel::Event* event,
         const std::string& methodName);
 };