Gui: export scene graph to file or buffer

src/Gui/Application.cpp

@@ -231,39 +231,40 @@ FreeCADGui_subgraphFromObject(PyObject * /*self*/, PyObject *args)
 }
 
 static PyObject *
-FreeCADGui_replaceSwitchNodes(PyObject * /*self*/, PyObject *args)
+FreeCADGui_exportSubgraph(PyObject * /*self*/, PyObject *args)
 {
+    const char* format = "VRML";
     PyObject* proxy;
-    if (!PyArg_ParseTuple(args, "O", &proxy))
+    PyObject* output;
+    if (!PyArg_ParseTuple(args, "OO|s", &proxy, &output, &format))
         return nullptr;
 
     void* ptr = 0;
     try {
         Base::Interpreter().convertSWIGPointerObj("pivy.coin", "SoNode *", proxy, &ptr, 0);
         SoNode* node = reinterpret_cast<SoNode*>(ptr);
-        SoNode* replace = SoFCDB::replaceSwitches(node);
-        if (replace) {
-            replace->ref();
+        if (node) {
+            std::string formatStr(format);
+            std::string buffer;
 
-            std::string prefix = "So";
-            std::string type = replace->getTypeId().getName().getString();
-            // doesn't start with the prefix 'So'
-            if (type.rfind("So", 0) != 0) {
-                type = prefix + type;
+            if (formatStr == "VRML") {
+                SoFCDB::writeToVRML(node, buffer);
             }
-            else if (type == "SoFCSelectionRoot") {
-                type = "SoSeparator";
+            else if (formatStr == "IV") {
+                buffer = SoFCDB::writeNodesToString(node);
+            }
+            else {
+                throw Base::ValueError("Unsupported format");
             }
 
-            type += " *";
-            PyObject* proxy = 0;
-            proxy = Base::Interpreter().createSWIGPointerObj("pivy.coin", type.c_str(), (void*)replace, 1);
-            return Py::new_reference_to(Py::Object(proxy, true));
-        }
-        else {
-            Py_INCREF(Py_None);
-            return Py_None;
+            Base::PyStreambuf buf(output);
+            std::ostream str(0);
+            str.rdbuf(&buf);
+            str << buffer;
         }
+
+        Py_INCREF(Py_None);
+        return Py_None;
     }
     catch (const Base::Exception& e) {
         PyErr_SetString(PyExc_RuntimeError, e.what());
@@ -334,9 +335,10 @@ struct PyMethodDef FreeCADGui_methods[] = {
     {"subgraphFromObject",FreeCADGui_subgraphFromObject,METH_VARARGS,
      "subgraphFromObject(object) -> Node\n\n"
      "Return the Inventor subgraph to an object"},
-    {"replaceSwitchNodes",FreeCADGui_replaceSwitchNodes,METH_VARARGS,
-     "replaceSwitchNodes(Node) -> Node\n\n"
-     "Replace Switch nodes with Separators"},
+    {"exportSubgraph",FreeCADGui_exportSubgraph,METH_VARARGS,
+     "exportSubgraph(Node, File or Buffer, [Format='VRML']) -> None\n\n"
+     "Exports the sub-graph in the requested format"
+     "The format string can be VRML or IV"},
     {"getSoDBVersion",FreeCADGui_getSoDBVersion,METH_VARARGS,
      "getSoDBVersion() -> String\n\n"
      "Return a text string containing the name\n"

src/Gui/SoFCDB.cpp

@@ -301,7 +301,7 @@ SoNode* Gui::SoFCDB::replaceSwitches(SoNode* node)
     return replaceSwitchesInSceneGraph(node);
 }
 
-bool Gui::SoFCDB::writeToVRML(SoNode* node, const char* filename, bool binary)
+void Gui::SoFCDB::writeToVRML(SoNode* node, std::string& buffer)
 {
     SoNode* noSwitches = replaceSwitchesInSceneGraph(node);
     noSwitches->ref();
@@ -313,13 +313,19 @@ bool Gui::SoFCDB::writeToVRML(SoNode* node, const char* filename, bool binary)
     SoVRMLGroup* vrmlRoot = tovrml2.getVRML2SceneGraph();
     vrmlRoot->setInstancePrefix(SbString("o"));
     vrmlRoot->ref();
-    std::string buffer = SoFCDB::writeNodesToString(vrmlRoot);
+    buffer = SoFCDB::writeNodesToString(vrmlRoot);
     vrmlRoot->unref(); // release the memory as soon as possible
 
     // restore old settings
     vrml2.setOverrideMode(false);
     vrml2.apply(noSwitches);
     noSwitches->unref();
+}
+
+bool Gui::SoFCDB::writeToVRML(SoNode* node, const char* filename, bool binary)
+{
+    std::string buffer;
+    writeToVRML(node, buffer);
 
     Base::FileInfo fi(filename);
     if (binary) {

src/Gui/SoFCDB.h

@@ -44,6 +44,7 @@ public:
     /// helper to apply a SoWriteAction to a node and write it to a string
     static const std::string& writeNodesToString(SoNode * root);
     static bool writeToVRML(SoNode* node, const char* filename, bool binary);
+    static void writeToVRML(SoNode* node, std::string& buffer);
     // Write to VRML or Inventor file
     static bool writeToFile(SoNode* node, const char* filename, bool binary);
     /*! container for app lifetime storage. See SoFCCSysDragger for details