Change the type of OptionUIItem's m_ui_item from void* to GncOptionUIItem.

A locally-opaque class wrapping whatever sort of widget ptr one needs.
Thanks, warlord!

libgnucash/app-utils/gnc-option.hpp

@@ -125,6 +125,8 @@ struct OptionClassifier
 using GncMultiChoiceOptionEntry = std::pair<std::string, std::string>;
 using GncMultiChoiceOptionChoices = std::vector<GncMultiChoiceOptionEntry>;
 
+class GncOptionUIItem;
+
 /**
  * Holds a pointer to the UI item which will control the option and an enum
  * representing the type of the option for dispatch purposes; all of that
@@ -140,9 +142,9 @@ class OptionUIItem
 {
 public:
     GncOptionUIType get_ui_type() { return m_ui_type; }
-    void* const get_ui_item() {return m_ui_item; }
+    GncOptionUIItem* const get_ui_item() {return m_ui_item; }
     void clear_ui_item() { m_ui_item = nullptr; }
-    void set_ui_item(void* ui_item)
+    void set_ui_item(GncOptionUIItem* ui_item)
     {
         if (m_ui_type == GncOptionUIType::INTERNAL)
         {
@@ -169,7 +171,7 @@ protected:
     OptionUIItem& operator=(const OptionUIItem&) = default;
     OptionUIItem& operator=(OptionUIItem&&) = default;
 private:
-    void* m_ui_item;
+    GncOptionUIItem* m_ui_item;
     GncOptionUIType m_ui_type;
 };
 
@@ -359,7 +361,7 @@ public:
     {
         return boost::apply_visitor(GetDocstringVisitor(), m_option);
     }
-    void set_ui_item(void* ui_elem)
+    void set_ui_item(GncOptionUIItem* ui_elem)
     {
         return boost::apply_visitor(SetUIItemVisitor(ui_elem), m_option);
     }
@@ -367,7 +369,7 @@ public:
     {
         return boost::apply_visitor(GetUITypeVisitor(), m_option);
     }
-    void* const get_ui_item()
+    GncOptionUIItem* const get_ui_item()
     {
         return boost::apply_visitor(GetUIItemVisitor(), m_option);
     }
@@ -465,13 +467,13 @@ private:
     };
     struct SetUIItemVisitor : public boost::static_visitor<>
     {
-        SetUIItemVisitor(void* ui_item) : m_ui_item{ui_item} {}
+        SetUIItemVisitor(GncOptionUIItem* ui_item) : m_ui_item{ui_item} {}
         template <class OptionType>
         void operator()(OptionType& option) const {
             option.set_ui_item(m_ui_item);
         }
     private:
-        void* m_ui_item;
+        GncOptionUIItem* m_ui_item;
     };
     struct GetUITypeVisitor :
         public boost::static_visitor<GncOptionUIType>
@@ -482,10 +484,10 @@ private:
         }
     };
     struct GetUIItemVisitor :
-        public boost::static_visitor<void* const >
+        public boost::static_visitor<GncOptionUIItem* const >
     {
         template <class OptionType>
-        void* const operator()(OptionType& option) const {
+        GncOptionUIItem* const operator()(OptionType& option) const {
             return option.get_ui_item();
         }
     };

libgnucash/app-utils/gnc-optiondb.cpp

@@ -80,14 +80,15 @@ GncOptionDB::get_default_section() const noexcept
 }
 
 void
-GncOptionDB::set_ui_item(const char* section, const char* name, void* ui_item)
+GncOptionDB::set_ui_item(const char* section, const char* name,
+                         GncOptionUIItem* ui_item)
 {
     auto option = find_option(section, name);
     if (!option) return;
     option->set_ui_item(ui_item);
 }
 
-void* const
+GncOptionUIItem* const
 GncOptionDB::get_ui_item(const char* section, const char* name)
 {
     auto option = find_option(section, name);

libgnucash/app-utils/gnc-optiondb.hpp

@@ -52,8 +52,8 @@ public:
     void unregister_option(const char* section, const char* name);
     void set_default_section(const char* section);
     const GncOptionSection* const get_default_section() const noexcept;
-    void set_ui_item(const char* section, const char* name, void* ui_item);
-    void* const get_ui_item(const char* section, const char* name);
+    void set_ui_item(const char* section, const char* name, GncOptionUIItem* ui_item);
+    GncOptionUIItem* const get_ui_item(const char* section, const char* name);
     GncOptionUIType get_ui_type(const char* section, const char* name);
     void set_ui_from_option(const char* section, const char* name,
                             std::function<void(GncOption&)> func);
@@ -74,8 +74,8 @@ private:
     std::vector<GncOptionSection> m_sections;
     bool m_dirty = false;
 
-    std::function<void*()> m_get_ui_value;
-    std::function<void(void*)> m_set_ui_value;
+    std::function<GncOptionUIItem*()> m_get_ui_value;
+    std::function<void(GncOptionUIItem*)> m_set_ui_value;
 };
 
 using GncOptionDBPtr = std::unique_ptr<GncOptionDB>;

libgnucash/app-utils/test/gtest-gnc-option.cpp

@@ -202,6 +202,13 @@ private:
     std::string m_value;
 };
 
+class GncOptionUIItem
+{
+public:
+    GncOptionUIItem(GncUIItem* widget) : m_widget{widget} {}
+    GncUIItem* m_widget;
+};
+
 class GncOptionUITest : public ::testing::Test
 {
 protected:
@@ -222,6 +229,7 @@ TEST_F(GncOptionUI, test_option_ui_type)
 TEST_F(GncOptionUI, test_set_option_ui_item)
 {
     GncUIItem ui_item;
-    m_option.set_ui_item(&ui_item);
-    EXPECT_EQ(&ui_item, static_cast<const GncUIItem*>(m_option.get_ui_item()));
+    GncOptionUIItem option_ui_item{&ui_item};
+    m_option.set_ui_item(&option_ui_item);
+    EXPECT_EQ(&ui_item, m_option.get_ui_item()->m_widget);
 }

libgnucash/app-utils/test/gtest-gnc-optiondb.cpp

@@ -78,6 +78,23 @@ private:
     std::string m_value;
 };
 
+class GncOptionUIItem
+{
+public:
+    GncOptionUIItem(GncUIType* widget) : m_widget{widget} {}
+    GncUIType* m_widget;
+};
+
+class GncOptionUITest : public ::testing::Test
+{
+protected:
+    GncOptionUITest() :
+        m_option{"foo", "bar", "baz", "Phony Option", std::string{"waldo"},
+            GncOptionUIType::STRING} {}
+
+    GncOption m_option;
+};
+
 class GncOptionDBUITest : public ::testing::Test
 {
 protected:
@@ -99,18 +116,20 @@ protected:
 TEST_F(GncOptionDBUITest, test_set_ui_item)
 {
     GncUIType entry;
-    m_db->set_ui_item("foo", "bar", &entry);
-    EXPECT_EQ(&entry, static_cast<GncUIType*>(m_db->get_ui_item("foo", "bar")));
+    GncOptionUIItem ui_item(&entry);
+    m_db->set_ui_item("foo", "bar", &ui_item);
+    EXPECT_EQ(&entry, m_db->get_ui_item("foo", "bar")->m_widget);
 }
 
 TEST_F(GncOptionDBUITest, test_ui_value_from_option)
 {
     GncUIType entry;
+    GncOptionUIItem ui_item(&entry);
     const char* value{"waldo"};
-    m_db->set_ui_item("foo", "bar", &entry);
+    m_db->set_ui_item("foo", "bar", &ui_item);
     m_db->set_ui_from_option("foo", "bar", [](GncOption& option){
-            auto ui_item = static_cast<GncUIType* const>(option.get_ui_item());
-            ui_item->set_value(option.get_value<std::string>());
+            auto new_ui_item = option.get_ui_item();
+            new_ui_item->m_widget->set_value(option.get_value<std::string>());
         });
     EXPECT_STREQ(value, entry.get_value().c_str());
 }
@@ -118,12 +137,13 @@ TEST_F(GncOptionDBUITest, test_ui_value_from_option)
 TEST_F(GncOptionDBUITest, test_option_value_from_ui)
 {
     GncUIType entry;
+    GncOptionUIItem ui_item(&entry);
     const char* value{"pepper"};
-    m_db->set_ui_item("foo", "bar", &entry);
+    m_db->set_ui_item("foo", "bar", &ui_item);
     entry.set_value(value);
     m_db->set_option_from_ui("foo", "bar", [](GncOption& option){
-            auto ui_item = static_cast<GncUIType* const>(option.get_ui_item());
-            option.set_value(ui_item->get_value());
+            auto new_ui_item = option.get_ui_item()->m_widget;
+            option.set_value(new_ui_item->get_value());
         });
     EXPECT_STREQ(value, m_db->lookup_string_option("foo", "bar").c_str());
 }