Implement set and get signal value

	  * src/dynamic-graph-py.cc,
	  * src/dynamic_graph/signal_base.py,
	  * src/signal-base-py.cc.

src/dynamic-graph-py.cc

@@ -19,6 +19,8 @@ namespace dynamicgraph {
     namespace signalBase {
       extern PyObject* create(PyObject* self, PyObject* args);
       extern PyObject* getTime(PyObject* self, PyObject* args);
+      extern PyObject* getValue(PyObject* self, PyObject* args);
+      extern PyObject* setValue(PyObject* self, PyObject* args);
     }
     namespace entity {
       extern PyObject* create(PyObject* self, PyObject* args);
@@ -99,6 +101,10 @@ static PyMethodDef dynamicGraphMethods[] = {
    "create a SignalBase C++ object"},
   {"signalbase_get_time", dynamicgraph::python::signalBase::getTime,
    METH_VARARGS, "Get time of  a SignalBase"},
+  {"signal_base_get_value", dynamicgraph::python::signalBase::getValue,
+   METH_VARARGS, "Read the value of a signal"},
+  {"signal_base_set_value", dynamicgraph::python::signalBase::setValue,
+   METH_VARARGS, "Set the value of a signal"},
   // Entity
   {"create_entity", dynamicgraph::python::entity::create, METH_VARARGS,
    "create an Entity C++ object"},

src/dynamic_graph/signal_base.py

@@ -29,3 +29,17 @@ class SignalBase:
         """
         return wrap.signalBaseGetTime(self.object)
 
+    @property
+    def value(self) :
+        """
+        Read the value of a signal
+        """
+        return wrap.signal_base_get_value(self.object)
+
+    @value.setter
+    def value(self) :
+        """
+        Set the signal as a constant signal with given value.
+        If the signal is plugged, it will be unplugged
+        """
+        return wrap.signal_base_set_value(self.object, value)

src/signal-base-py.cc

@@ -5,8 +5,7 @@
 
 #include <Python.h>
 #include <iostream>
-//#include <sstream>
-//#include <string>
+#include <sstream>
 
 #include <dynamic-graph/signal-base.h>
 
@@ -27,17 +26,17 @@ namespace dynamicgraph {
       PyObject* create(PyObject* self, PyObject* args)
       {
 	char *name = NULL;
-	
+
 	if (!PyArg_ParseTuple(args, "s", &name))
 	  return NULL;
-	
+
 	SignalBase<int>* obj = NULL;
 	obj = new SignalBase<int>(std::string(name));
-	
+
 	// Return the pointer
 	return PyCObject_FromVoidPtr((void*)obj, destroy);
       }
-      
+
       /**
 	 \brief Destroy an instance of InvertedPendulum
       */
@@ -46,7 +45,7 @@ namespace dynamicgraph {
 	SignalBase<int>* obj = (SignalBase<int>*)self;
 	delete obj;
       }
-      
+
       PyObject* getTime(PyObject* self, PyObject* args)
       {
 	void* pointer = NULL;
@@ -58,10 +57,46 @@ namespace dynamicgraph {
 
 	pointer = PyCObject_AsVoidPtr(object);
 	SignalBase<int>* obj = (SignalBase<int>*)pointer;
-	
+
 	int time = obj->getTime();
 	return Py_BuildValue("i", time);
       }
+
+      PyObject* getValue(PyObject* self, PyObject* args)
+      {
+	void* pointer = NULL;
+	PyObject* object = NULL;
+	if (!PyArg_ParseTuple(args,"O", &object))
+	  return NULL;
+	if (!PyCObject_Check(object))
+	  return NULL;
+
+	pointer = PyCObject_AsVoidPtr(object);
+	SignalBase<int>* signal = (SignalBase<int>*)pointer;
+
+	std::ostringstream value;
+	signal->get(value);
+	return Py_BuildValue("s", value.str());
+      }
+
+      PyObject* setValue(PyObject* self, PyObject* args)
+      {
+	void * pointer = NULL;
+	PyObject* object = NULL;
+	char* valueString = NULL;
+
+	if (!PyArg_ParseTuple(args,"Os", &object, &valueString))
+	  return NULL;
+	if (!PyCObject_Check(object))
+	  return NULL;
+
+	pointer = PyCObject_AsVoidPtr(object);
+	SignalBase<int>* signal = (SignalBase<int>*)pointer;
+	std::istringstream value(valueString);
+
+	signal->set(value);
+	return Py_BuildValue("");
+      }
     }
   }
 }