App: replace boolean with enum

src/App/Application.cpp

@@ -1150,22 +1150,30 @@ std::string Application::getHelpDir()
 #endif
 }
 
-int Application::checkLinkDepth(int depth, bool no_throw) {
-    if(_objCount<0) {
+int Application::checkLinkDepth(int depth, MessageOption option)
+{
+    if (_objCount < 0) {
         _objCount = 0;
-        for(auto &v : DocMap)
+        for (auto &v : DocMap) {
             _objCount += v.second->countObjects();
+        }
     }
-    if(depth > _objCount+2) {
+
+    if (depth > _objCount + 2) {
         const char *msg = "Link recursion limit reached. "
                 "Please check for cyclic reference.";
-        if(no_throw) {
+        switch (option) {
+        case MessageOption::Quiet:
+            return 0;
+        case MessageOption::Error:
             FC_ERR(msg);
             return 0;
-        }else
+        case MessageOption::Throw:
             throw Base::RuntimeError(msg);
+        }
     }
-    return _objCount+2;
+
+    return _objCount + 2;
 }
 
 std::set<DocumentObject *> Application::getLinksTo(

src/App/Application.h

@@ -63,6 +63,12 @@ enum GetLinkOption {
     GetLinkExternal = 8,
 };
 
+enum class MessageOption {
+    Quiet, /**< Suppress error. */
+    Error, /**< Print an error message. */
+    Throw, /**< Throw an execption. */
+};
+
 
 /** The Application
  *  The root of the whole application
@@ -420,14 +426,15 @@ public:
     /** Check for link recursion depth
      *
      * @param depth: current depth
-     * @param no_throw: whether to throw exception
+     * @param option: whether to throw exception, print an error message or quieten any output.
+     * In the latter case the caller must check the returned value.
      *
      * @return Return the maximum remaining depth.
      *
      * The function uses an internal count of all objects in all documents as
      * the limit of recursion depth.
      */
-    int checkLinkDepth(int depth, bool no_throw=true);
+    int checkLinkDepth(int depth, MessageOption option = MessageOption::Error);
 
     /** Return the links to a given object
      *

src/App/ApplicationPy.cpp

@@ -832,7 +832,7 @@ PyObject *Application::sCheckLinkDepth(PyObject * /*self*/, PyObject *args)
         return nullptr;
 
     PY_TRY {
-        return Py::new_reference_to(Py::Int(GetApplication().checkLinkDepth(depth,false)));
+        return Py::new_reference_to(Py::Int(GetApplication().checkLinkDepth(depth, MessageOption::Throw)));
     }PY_CATCH;
 }
 

src/App/Document.cpp

@@ -3021,7 +3021,7 @@ void Document::getLinksTo(std::set<DocumentObject*> &links,
 
     std::vector<const DocumentObject*> current(1,obj);
     for(int depth=0;!current.empty();++depth) {
-        if(!GetApplication().checkLinkDepth(depth,true))
+        if(!GetApplication().checkLinkDepth(depth, MessageOption::Error))
             break;
         std::vector<const DocumentObject*> next;
         for(const App::DocumentObject *o : current) {

src/App/Link.cpp

@@ -1043,7 +1043,7 @@ DocumentObject *LinkBaseExtension::getContainer(){
 }
 
 DocumentObject *LinkBaseExtension::getLink(int depth) const{
-    if (!GetApplication().checkLinkDepth(depth,true))
+    if (!GetApplication().checkLinkDepth(depth, MessageOption::Error))
         return nullptr;
     if(getLinkedObjectProperty())
         return getLinkedObjectValue();