Added handle_legacy_composite() callback to configuration layer

to support conversion of multiple configuration keys into one
or multiple other configuration keys.

src/libslic3r/Config.cpp

@@ -797,6 +797,9 @@ ConfigSubstitutions ConfigBase::load(const boost::property_tree::ptree &tree, Fo
             // ignore
         }
     }
+    // Do legacy conversion on a completely loaded dictionary.
+    // Perform composite conversions, for example merging multiple keys into one key.
+    this->handle_legacy_composite();
     return std::move(substitutions_ctxt.substitutions);
 }
 

src/libslic3r/Config.hpp

@@ -2160,6 +2160,10 @@ protected:
     // If the opt_key is no more valid in this version of Slic3r, opt_key is cleared by handle_legacy().
     // handle_legacy() is called internally by set_deserialize().
     virtual void                    handle_legacy(t_config_option_key &/*opt_key*/, std::string &/*value*/) const {}
+    // Called after a config is loaded as a whole.
+    // Perform composite conversions, for example merging multiple keys into one key.
+    // For conversion of single options, the handle_legacy() method above is called.
+    virtual void                    handle_legacy_composite() {}
 
 public:
 	using ConfigOptionResolver::option;

src/libslic3r/PrintConfig.cpp

@@ -4323,6 +4323,13 @@ void PrintConfigDef::handle_legacy(t_config_option_key &opt_key, std::string &va
     }
 }
 
+// Called after a config is loaded as a whole.
+// Perform composite conversions, for example merging multiple keys into one key.
+// Don't convert single options here, implement such conversion in PrintConfigDef::handle_legacy() instead.
+void PrintConfigDef::handle_legacy_composite(DynamicPrintConfig &config)
+{
+}
+
 const PrintConfigDef print_config_def;
 
 DynamicPrintConfig DynamicPrintConfig::full_print_config()

src/libslic3r/PrintConfig.hpp

@@ -166,6 +166,8 @@ CONFIG_OPTION_ENUM_DECLARE_STATIC_MAPS(PerimeterGeneratorType)
 
 #undef CONFIG_OPTION_ENUM_DECLARE_STATIC_MAPS
 
+class DynamicPrintConfig;
+
 // Defines each and every confiuration option of Slic3r, including the properties of the GUI dialogs.
 // Does not store the actual values, but defines default values.
 class PrintConfigDef : public ConfigDef
@@ -174,6 +176,7 @@ public:
     PrintConfigDef();
 
     static void handle_legacy(t_config_option_key &opt_key, std::string &value);
+    static void handle_legacy_composite(DynamicPrintConfig &config);
 
     // Array options growing with the number of extruders
     const std::vector<std::string>& extruder_option_keys() const { return m_extruder_option_keys; }
@@ -258,6 +261,12 @@ public:
     // handle_legacy() is called internally by set_deserialize().
     void                handle_legacy(t_config_option_key &opt_key, std::string &value) const override
         { PrintConfigDef::handle_legacy(opt_key, value); }
+
+    // Called after a config is loaded as a whole.
+    // Perform composite conversions, for example merging multiple keys into one key.
+    // For conversion of single options, the handle_legacy() method above is called.
+    void                handle_legacy_composite() override
+        { PrintConfigDef::handle_legacy_composite(*this); }
 };
 
 void handle_legacy_sla(DynamicPrintConfig &config);