From 7a45d74bc7319d3c9d996b5705b760b8d4dd5285 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 18 Oct 2019 15:38:58 +0200
Subject: [PATCH] + implement a correct cleaning of a parameter group without
 creating ghost instances of ParameterGrp

---
 src/Base/Parameter.cpp | 48 ++++++++++++++++++++++++++++++------------
 src/Base/Parameter.h   |  1 +
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/src/Base/Parameter.cpp b/src/Base/Parameter.cpp
index 9aeacb75af..4142a3fac5 100644
--- a/src/Base/Parameter.cpp
+++ b/src/Base/Parameter.cpp
@@ -891,27 +891,37 @@ void ParameterGrp::Clear(void)
     std::vector<DOMNode*> vecNodes;
 
     // checking on references
-    std::map <std::string ,Base::Reference<ParameterGrp> >::iterator It1;
-    for (It1 = _GroupMap.begin();It1!=_GroupMap.end();++It1) {
-        if (It1->second.getRefCount() > 1)
-            Console().Warning("ParameterGrp::Clear(): Group clear with active references");
+    std::vector<std::string> removeGrp;
+    for (auto it = _GroupMap.begin();it!=_GroupMap.end();++it) {
+        // If a group is referenced by some observer then do not remove it
+        // but clear it
+        if (!it->second->ShouldRemove()) {
+            it->second->Clear();
+        }
+        else {
+            removeGrp.push_back(it->first);
+        }
     }
 
     // remove group handles
-    _GroupMap.clear();
+    for (auto it : removeGrp) {
+        auto pos = _GroupMap.find(it);
+        vecNodes.push_back(pos->second->_pGroupNode);
+        _GroupMap.erase(pos->first);
+    }
 
-    // searching all nodes
-    for (DOMNode *clChild = _pGroupNode->getFirstChild(); clChild != 0;  clChild = clChild->getNextSibling()) {
-        vecNodes.push_back(clChild);
+    // searching all non-group nodes
+    for (DOMNode *child = _pGroupNode->getFirstChild(); child != 0;  child = child->getNextSibling()) {
+        if (XMLString::compareString(child->getNodeName(), XStr("FCParamGroup").unicodeForm()) != 0)
+            vecNodes.push_back(child);
     }
 
     // deleting the nodes
-    DOMNode* pcTemp;
-    for (std::vector<DOMNode*>::iterator It=vecNodes.begin();It!=vecNodes.end();++It) {
-        pcTemp = _pGroupNode->removeChild(*It);
-        //delete pcTemp;
-        pcTemp->release();
+    for (auto it = vecNodes.begin(); it != vecNodes.end(); ++it) {
+        DOMNode *child = _pGroupNode->removeChild(*it);
+        child->release();
     }
+
     // trigger observer
     Notify("");
 }
@@ -919,6 +929,18 @@ void ParameterGrp::Clear(void)
 //**************************************************************************
 // Access methods
 
+bool ParameterGrp::ShouldRemove() const
+{
+    if (this->getRefCount() > 1)
+        return false;
+    for (auto it : _GroupMap) {
+        bool ok = it.second->ShouldRemove();
+        if (!ok)
+            return false;
+    }
+    return true;
+}
+
 XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *ParameterGrp::FindElement(XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *Start, const char* Type, const char* Name) const
 {
     if (XMLString::compareString(Start->getNodeName(), XStr("FCParamGroup").unicodeForm()) != 0 &&
diff --git a/src/Base/Parameter.h b/src/Base/Parameter.h
index 474d78b414..90c8c71830 100644
--- a/src/Base/Parameter.h
+++ b/src/Base/Parameter.h
@@ -236,6 +236,7 @@ protected:
     ~ParameterGrp();
     /// helper function for GetGroup
     Base::Reference<ParameterGrp> _GetGroup(const char* Name);
+    bool ShouldRemove() const;
 
     XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *FindNextElement(XERCES_CPP_NAMESPACE_QUALIFIER DOMNode *Prev, const char* Type) const;