+ raise error message when trying to mesh without netgen support

src/Mod/Fem/App/FemMeshShapeNetgenObject.cpp

@@ -118,8 +118,8 @@ App::DocumentObjectExecReturn *FemMeshShapeNetgenObject::execute(void)
 
 
     SMESHDS_Mesh* data = const_cast<SMESH_Mesh*>(newMesh.getSMesh())->GetMeshDS();
-	const SMDS_MeshInfo& info = data->GetMeshInfo();
-	int numFaces = data->NbFaces();
+    const SMDS_MeshInfo& info = data->GetMeshInfo();
+    int numFaces = data->NbFaces();
     int numNode = info.NbNodes();
     int numTria = info.NbTriangles();
     int numQuad = info.NbQuadrangles();
@@ -135,9 +135,11 @@ App::DocumentObjectExecReturn *FemMeshShapeNetgenObject::execute(void)
 
     // set the value to the object
     FemMesh.setValue(newMesh);
-#endif
 
     return App::DocumentObject::StdReturn;
+#else
+    return new App::DocumentObjectExecReturn("The FEM module is built without NETGEN support. Meshing will not work!!!", this);
+#endif
 }
 
 //short FemMeshShapeNetgenObject::mustExecute(void) const

src/Mod/Fem/Gui/TaskDlgMeshShapeNetgen.cpp

@@ -34,6 +34,7 @@
 #include <Gui/Application.h>
 #include <Gui/Document.h>
 #include <Gui/Command.h>
+#include <Gui/MainWindow.h>
 #include <Gui/WaitCursor.h>
 
 #include "ViewProviderFemMeshShapeNetgen.h"
@@ -98,7 +99,13 @@ bool TaskDlgMeshShapeNetgen::accept()
         if(param->touched)
         {
             Gui::WaitCursor wc;
-            FemMeshShapeNetgenObject->recompute();
+            App::DocumentObjectExecReturn* ret = FemMeshShapeNetgenObject->recompute();
+            if (ret) {
+                wc.restoreCursor();
+                QMessageBox::critical(Gui::getMainWindow(), tr("Meshing failure"), QString::fromStdString(ret->Why));
+                delete ret;
+                return true;
+            }
         }
 
         // hide the input object

src/Mod/Fem/Gui/ViewProviderFemMeshShapeNetgen.cpp

@@ -25,12 +25,14 @@
 
 #ifndef _PreComp_
 # include <Standard_math.hxx>
+# include <QCoreApplication>
 #endif
 
 #include "ViewProviderFemMeshShapeNetgen.h"
 #include "TaskDlgMeshShapeNetgen.h"
 
-#include "Gui/Control.h"
+#include <Gui/Control.h>
+#include <Gui/MainWindow.h>
 
 
 using namespace FemGui;
@@ -38,6 +40,8 @@ using namespace FemGui;
 
 
 
+/* TRANSLATOR FemGui::ViewProviderFemMeshShapeNetgen */
+
 PROPERTY_SOURCE(FemGui::ViewProviderFemMeshShapeNetgen, FemGui::ViewProviderFemMeshShape)
 
 
@@ -63,10 +67,16 @@ bool ViewProviderFemMeshShapeNetgen::setEdit(int ModNum)
     if (ModNum == ViewProvider::Default) {
         // clear the selection (convenience)
         Gui::Selection().clearSelection();
-
+#ifdef FCWithNetgen
         Gui::Control().showDialog(new TaskDlgMeshShapeNetgen(this));
-
         return true;
+#else
+        QMessageBox::critical(Gui::getMainWindow(),
+            QCoreApplication::translate("FemGui::ViewProviderFemMeshShapeNetgen", "Meshing failure"),
+            QCoreApplication::translate("FemGui::ViewProviderFemMeshShapeNetgen", "The FEM module is built without NETGEN support. Meshing will not work!!!")
+        );
+        return false;
+#endif
     }
     else {
         return ViewProviderDocumentObject::setEdit(ModNum);