DocumentObject: introduce object ID

Each object now has an integer ID that is unique with its containing
document. It is meant to serve the same purpose as internal object name
but easier to manipulate.

src/App/Document.cpp

@@ -152,6 +152,8 @@ struct DocumentP
     // Array to preserve the creation order of created objects
     std::vector<DocumentObject*> objectArray;
     std::map<std::string,DocumentObject*> objectMap;
+    std::map<long,DocumentObject*> objectIdMap;
+    long lastObjectId;
     DocumentObject* activeObject;
     Transaction *activeUndoTransaction;
     int iTransactionMode;
@@ -169,6 +171,7 @@ struct DocumentP
 #endif //USE_OLD_DAG
 
     DocumentP() {
+        lastObjectId = 0;
         activeObject = 0;
         activeUndoTransaction = 0;
         iTransactionMode = 0;
@@ -1666,6 +1669,7 @@ void Document::writeObjects(const std::vector<App::DocumentObject*>& obj,
         writer.Stream() << writer.ind() << "<Object "
         << "type=\"" << (*it)->getTypeId().getName()     << "\" "
         << "name=\"" << (*it)->getExportName()       << "\" "
+        << "id=\"" << (*it)->getID()       << "\" "
         << "ViewType=\"" << (*it)->getViewProviderNameStored() << "\" ";
 
         // See DocumentObjectPy::getState
@@ -1705,15 +1709,23 @@ Document::readObjects(Base::XMLReader& reader)
     setStatus(Document::KeepTrailingDigits, !reader.doNameMapping());
     std::vector<App::DocumentObject*> objs;
 
+
     // read the object types
     reader.readElement("Objects");
     int Cnt = reader.getAttributeAsInteger("Count");
+    long lastId = 0;
     for (int i=0 ;i<Cnt ;i++) {
         reader.readElement("Object");
         std::string type = reader.getAttribute("type");
         std::string name = reader.getAttribute("name");
         const char *viewType = reader.hasAttribute("ViewType")?reader.getAttribute("ViewType"):0;
 
+        if(!testStatus(Status::Importing) && reader.hasAttribute("id")) {
+            // if not importing, then temporary reset lastObjectId and make the
+            // following addObject() generate the correct id for this object.
+            d->lastObjectId = reader.getAttributeAsInteger("id")-1;
+        }
+
         // To prevent duplicate name when export/import of objects from
         // external documents, we append those external object name with
         // @<doccument name>. Before importing (here means we are called by
@@ -1737,6 +1749,8 @@ Document::readObjects(Base::XMLReader& reader)
             // digits we make an object 'Cut' referencing itself.
             App::DocumentObject* obj = addObject(type.c_str(), obj_name, /*isNew=*/ false, viewType);
             if (obj) {
+                if(lastId < obj->_Id)
+                    lastId = obj->_Id;
                 objs.push_back(obj);
                 // use this name for the later access because an object with
                 // the given name may already exist
@@ -1753,6 +1767,8 @@ Document::readObjects(Base::XMLReader& reader)
             Base::Console().Error("Cannot create object '%s': (%s)\n", name.c_str(), e.what());
         }
     }
+    if(!testStatus(Status::Importing))
+        d->lastObjectId = lastId;
 
     reader.readEndElement("Objects");
     setStatus(Document::KeepTrailingDigits, keepDigits);
@@ -2001,6 +2017,8 @@ void Document::restore (bool delaySignal)
     }
     d->objectArray.clear();
     d->objectMap.clear();
+    d->objectIdMap.clear();
+    d->lastObjectId = 0;
     d->activeObject = 0;
 
     Base::FileInfo fi(FileName.getValue());
@@ -2930,6 +2948,9 @@ DocumentObject * Document::addObject(const char* sType, const char* pObjectName,
 
     // insert in the name map
     d->objectMap[ObjectName] = pcObject;
+    // generate object id and add to id map;
+    pcObject->_Id = ++d->lastObjectId;
+    d->objectIdMap[pcObject->_Id] = pcObject;
     // cache the pointer to the name string in the Object (for performance of DocumentObject::getNameInDocument())
     pcObject->pcNameInDocument = &(d->objectMap.find(ObjectName)->first);
     // insert in the vector
@@ -3026,6 +3047,9 @@ std::vector<DocumentObject *> Document::addObjects(const char* sType, const std:
 
         // insert in the name map
         d->objectMap[ObjectName] = pcObject;
+        // generate object id and add to id map;
+        pcObject->_Id = ++d->lastObjectId;
+        d->objectIdMap[pcObject->_Id] = pcObject;
         // cache the pointer to the name string in the Object (for performance of DocumentObject::getNameInDocument())
         pcObject->pcNameInDocument = &(d->objectMap.find(ObjectName)->first);
         // insert in the vector
@@ -3087,6 +3111,9 @@ void Document::addObject(DocumentObject* pcObject, const char* pObjectName)
 
     // insert in the name map
     d->objectMap[ObjectName] = pcObject;
+    // generate object id and add to id map;
+    if(!pcObject->_Id) pcObject->_Id = ++d->lastObjectId;
+    d->objectIdMap[pcObject->_Id] = pcObject;
     // cache the pointer to the name string in the Object (for performance of DocumentObject::getNameInDocument())
     pcObject->pcNameInDocument = &(d->objectMap.find(ObjectName)->first);
     // insert in the vector
@@ -3114,6 +3141,9 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName)
 {
     std::string ObjectName = getUniqueObjectName(pObjectName);
     d->objectMap[ObjectName] = pcObject;
+    // generate object id and add to id map;
+    if(!pcObject->_Id) pcObject->_Id = ++d->lastObjectId;
+    d->objectIdMap[pcObject->_Id] = pcObject;
     d->objectArray.push_back(pcObject);
     // cache the pointer to the name string in the Object (for performance of DocumentObject::getNameInDocument())
     pcObject->pcNameInDocument = &(d->objectMap.find(ObjectName)->first);
@@ -3218,6 +3248,7 @@ void Document::removeObject(const char* sName)
     }
 
     pos->second->setStatus(ObjectStatus::Remove, false); // Unset the bit to be on the safe side
+    d->objectIdMap.erase(pos->second->_Id);
     d->objectMap.erase(pos);
 }
 
@@ -3261,6 +3292,7 @@ void Document::_removeObject(DocumentObject* pcObject)
 
     // remove from map
     pcObject->setStatus(ObjectStatus::Remove, false); // Unset the bit to be on the safe side
+    d->objectIdMap.erase(pcObject->_Id);
     d->objectMap.erase(pos);
 
     for (std::vector<DocumentObject*>::iterator it = d->objectArray.begin(); it != d->objectArray.end(); ++it) {
@@ -3528,6 +3560,15 @@ DocumentObject * Document::getObject(const char *Name) const
         return 0;
 }
 
+DocumentObject * Document::getObjectByID(long id) const
+{
+    auto it = d->objectIdMap.find(id);
+    if(it!=d->objectIdMap.end())
+        return it->second;
+    return 0;
+}
+
+
 // Note: This method is only used in Tree.cpp slotChangeObject(), see explanation there
 bool Document::isIn(const DocumentObject *pFeat) const
 {

src/App/Document.h

@@ -261,6 +261,8 @@ class AppExport Document : public App::PropertyContainer
     DocumentObject *getActiveObject(void) const;
     /// Returns a Object of this document
     DocumentObject *getObject(const char *Name) const;
+    /// Returns a Object of this document by its id
+    DocumentObject *getObjectByID(long id) const;
     /// Returns true if the DocumentObject is contained in this document
     bool isIn(const DocumentObject *pFeat) const;
     /// Returns a Name of an Object or 0

src/App/DocumentObject.cpp

@@ -54,7 +54,7 @@ DocumentObjectExecReturn *DocumentObject::StdReturn = 0;
 //===========================================================================
 
 DocumentObject::DocumentObject(void)
-    : ExpressionEngine(),_pDoc(0),pcNameInDocument(0)
+    : ExpressionEngine(),_pDoc(0),pcNameInDocument(0),_Id(0)
 {
     // define Label of type 'Output' to avoid being marked as touched after relabeling
     ADD_PROPERTY_TYPE(Label,("Unnamed"),"Base",Prop_Output,"User name of the object (UTF8)");

src/App/DocumentObject.h

@@ -106,6 +106,8 @@ class AppExport DocumentObject: public App::TransactionalObject
 
     /// returns the name which is set in the document for this object (not the name property!)
     const char *getNameInDocument(void) const;
+    ///
+    long getID() const {return _Id;}
     /// returns the name that is safe to be exported to other document
     std::string getExportName(bool forced=false) const;
     virtual bool isAttachedToDocument() const;
@@ -416,6 +418,9 @@ class AppExport DocumentObject: public App::TransactionalObject
 private:
     // accessed by App::Document to record and restore the correct view provider type
     std::string _pcViewProviderName;
+
+    // unique identifier (ammong a document) of this object.
+    long _Id;
 
 private:
     // Back pointer to all the fathers in a DAG of the document

src/App/DocumentObjectPy.xml

@@ -215,5 +215,11 @@ or None if the GUI is not up</UserDocu>
 			</Documentation>
 			<Parameter Name="MustExecute" Type="Boolean"/>
 		</Attribute>
+		<Attribute Name="ID" ReadOnly="true">
+			<Documentation>
+                <UserDocu>The unique identifier (among its document) of this object</UserDocu>
+			</Documentation>
+			<Parameter Name="ID" Type="Int"/>
+		</Attribute>
 	</PythonExport>
 </GenerateModel>

src/App/DocumentObjectPyImp.cpp

@@ -686,3 +686,7 @@ int DocumentObjectPy::setCustomAttributes(const char* attr, PyObject *obj)
 
     return 0;
 }
+
+Py::Int DocumentObjectPy::getID() const {
+    return Py::Int(getDocumentObjectPtr()->getID());
+}

src/App/DocumentPyImp.cpp

@@ -550,11 +550,14 @@ PyObject*  DocumentPy::recompute(PyObject * args)
 
 PyObject*  DocumentPy::getObject(PyObject *args)
 {
-    char *sName;
-    if (!PyArg_ParseTuple(args, "s",&sName))     // convert args: Python->C 
-        return NULL;                             // NULL triggers exception 
+    long id = -1;
+    char *sName = 0;
+    if (!PyArg_ParseTuple(args, "s",&sName))  {   // convert args: Python->C 
+        if(!PyArg_ParseTuple(args, "i", &id))
+            return NULL;                             // NULL triggers exception 
+    }
 
-    DocumentObject *pcFtr = getDocumentPtr()->getObject(sName);
+    DocumentObject *pcFtr = sName?getDocumentPtr()->getObject(sName):getDocumentPtr()->getObjectByID(id);
     if (pcFtr)
         return pcFtr->getPyObject();
     else