SelectionProperty: inherits from AbstractSelectionProperty

GUI/Model/Descriptor/SelectionProperty.h

@@ -18,6 +18,18 @@
 #include "GUI/Model/Descriptor/SelectionDescriptor.h"
 #include "GUI/Support/XML/Streamer.h"
 
+//! Abstract base class for SelectionProperty to ease referencing.
+class AbstractSelectionProperty {
+public:
+    virtual ~AbstractSelectionProperty() = default;
+
+    //! Set currently selected option
+    virtual void setCurrentIndex(int newIndex) = 0;
+
+    //! Get currently selected option
+    virtual int currentIndex() const = 0;
+};
+
 //! Class for representing a selection, its attributes and its accessors.
 //!
 //! A "selection" in this context is a class instance out of a range of possible class instances.
@@ -49,7 +61,7 @@
 //! \sa SelectionDescriptor
 //!
 template <typename Catalog>
-class SelectionProperty {
+class SelectionProperty : public AbstractSelectionProperty{
 public:
     using CatalogedType = typename Catalog::CatalogedType;
 
@@ -61,7 +73,9 @@ public:
     template <typename... ArgsForCreation>
     void init(const QString& label, const QString& tooltip, ArgsForCreation... argsForCreation)
     {
-        initFields(label, tooltip);
+        initFieldsAndSetter(label, tooltip, argsForCreation...);
+        setCurrentIndex(0);
+
         initDescriptor(label, tooltip, argsForCreation...);
         m_descriptor.setCurrentIndex(0);
     }
@@ -83,7 +97,9 @@ public:
     {
         m_initializer = initializer;
 
-        initFields(label, tooltip);
+        initFieldsAndSetter(label, tooltip);
+        setCurrentIndex(0);
+
         initDescriptor(label, tooltip);
         m_descriptor.setCurrentIndex(0);
     }
@@ -108,7 +124,9 @@ public:
         m_initializer = initializer;
         m_types = types;
 
-        initFields(label, tooltip);
+        initFieldsAndSetter(label, tooltip);
+        setCurrentIndex(0);
+
         initDescriptor(label, tooltip);
         m_descriptor.setCurrentIndex(0);
     }
@@ -154,14 +172,22 @@ public:
     }
 
 private:
-    void initFields(const QString& label, const QString& tooltip) {
+    template <typename... ArgsForCreation>
+    void initFieldsAndSetter(const QString& label, const QString& tooltip, ArgsForCreation... argsForCreation) {
         m_label = label;
         m_tooltip = tooltip;
         m_options.clear();
         for (const auto type : m_types)
             m_options << Catalog::uiInfo(type).menuEntry;
 
+        currentIndexSetter = [=](int current) {
+            auto* p = Catalog::create(m_types[current], argsForCreation...);
+            if (m_initializer)
+                m_initializer(p, m_p.get());
+            m_p.reset(p);
+        };
     }
+
     template <typename... ArgsForCreation>
     void initDescriptor(const QString& label, const QString& tooltip,
                         ArgsForCreation... argsForCreation)
@@ -190,6 +216,9 @@ private:
     QStringList options() {return m_options;}
     CatalogedType* currentItem() {return m_p.get();}
 
+    void setCurrentIndex(int newIndex) override { currentIndexSetter(newIndex); }
+    int currentIndex() const override { return m_types.indexOf(Catalog::type(m_p.get())); }
+
 private:
     SelectionDescriptor<CatalogedType*>
         m_descriptor; //!< descriptor, holding attributes like label, tooltip
@@ -201,6 +230,9 @@ private:
     QStringList m_options; //!< List of options, usually presented as combo entries
     QVector<typename Catalog::Type> m_types = Catalog::types();
 
+    //! Reimplementable function to set currently selected option.
+    std::function<void(int)> currentIndexSetter = nullptr;
+
     //! initializer function. Can be empty.
     //! The first argument is the new item, the second is the old one if present; can be null.
     //! This is intended to maybe copy values from the old to the new selection. oldItem also can be