Refactor difficulty name translation into new class

New class ModDifficultyNames handles looking up mod-specific difficult name
defaults and their translations in the .game file.

plugins/dm.difficulty/DifficultySettingsManager.cpp

@@ -52,7 +52,8 @@ void DifficultySettingsManager::loadDefaultSettings() {
     }
 }
 
-void DifficultySettingsManager::loadMapSettings() {
+void DifficultySettingsManager::loadMapSettings()
+{
     // Construct a helper walker
     DifficultyEntityFinder finder;
     GlobalSceneGraph().root()->traverse(finder);
@@ -69,64 +70,101 @@ void DifficultySettingsManager::loadMapSettings() {
     }
 }
 
-void DifficultySettingsManager::loadDifficultyNames()
+namespace
 {
-    // Locate the worldspawn entity
-    Entity* worldspawn = map::current::getWorldspawn();
 
-    // Try to locate the difficulty menu entity, where the default names are defined
-    IEntityClassPtr menuEclass = GlobalEntityClassManager().findClass(
-        game::current::getValue<std::string>(GKEY_DIFFICULTY_ENTITYDEF_MENU)
-    );
+// Class to manage mod-specific difficulty names (which are probably string
+// table entries like "#str_000300") and their English translations (we
+// maintain these translations separately in the .game file since we don't have
+// any support for parsing the mod-specific translation data).
+class ModDifficultyNames
+{
+    // Lookup table of strings and their translations
+    std::map<std::string, std::string> _transStrings;
 
-    // Obtain translations for the string table entries from the .game file
-    xml::NodeList transNodes = game::current::getNodes(
-        GKEY_DIFFICULTY_ENTITYDEF_MENU + "/string"
-    );
-    std::map<std::string, std::string> transStrings;
-    for (auto xmlNode: transNodes)
+    // Mod-specific entity giving default difficulty names
+    IEntityClassPtr _menuEclass;
+
+public:
+
+    // Construct and initialise
+    ModDifficultyNames()
+    : _menuEclass(
+        GlobalEntityClassManager().findClass(
+            game::current::getValue<std::string>(GKEY_DIFFICULTY_ENTITYDEF_MENU)
+        )
+    )
     {
-        transStrings[xmlNode.getAttributeValue("id")] = xmlNode.getContent();
+        // Load translations from xml nodes in the .game file
+        xml::NodeList transNodes = game::current::getNodes(
+            GKEY_DIFFICULTY_ENTITYDEF_MENU + "/string"
+        );
+        for (auto xmlNode: transNodes)
+        {
+            _transStrings[xmlNode.getAttributeValue("id")] = xmlNode.getContent();
+        }
     }
 
-    // greebo: Setup the default difficulty levels using the found entityDef
+    // Return the translated name for a key, such as "diff0Default"
+    std::string getNameForKey(const std::string& nameKey) const
+    {
+        if (_menuEclass)
+        {
+            EntityClassAttribute attr = _menuEclass->getAttribute(nameKey);
+            std::string rawName = attr.getValue();
+            if (!rawName.empty())
+            {
+                // Look for a translation, otherwise use the raw name
+                auto found = _transStrings.find(rawName);
+                if (found != _transStrings.end())
+                    return found->second;
+                else
+                    return rawName;
+            }
+        }
+
+        return "";
+    }
+};
+
+}
+
+void DifficultySettingsManager::loadDifficultyNames()
+{
+    // Locate the worldspawn entity
+    Entity* worldspawn = map::current::getWorldspawn();
+
+    // Load mod-specific difficulty names if possible
+    ModDifficultyNames diffNames;
+
+    // Look up a name for each difficulty level, starting with a map-specific
+    // name set on the worldspawn, then falling back to mod default names and
+    // then autogenerated names.
     int numLevels = game::current::getValue<int>(GKEY_DIFFICULTY_LEVELS);
     for (int i = 0; i < numLevels; i++)
     {
         std::string nameKey = "diff" + std::to_string(i) + "default";
 
         // First, try to find a map-specific name
-        if (worldspawn != NULL) {
+        if (worldspawn)
+        {
             std::string name = worldspawn->getKeyValue(nameKey);
-            if (!name.empty()) {
+            if (!name.empty())
+            {
                 // Found a setting on worldspawn, take it
                 _difficultyNames.push_back(name);
                 continue; // done for this level
             }
         }
 
-        // If the above failed, try to load the default setting, which we will
-        // need to translate from a string table entry into English.
-        if (menuEclass)
-        {
-            EntityClassAttribute attr = menuEclass->getAttribute(nameKey);
-            std::string rawName = attr.getValue();
-            if (!rawName.empty())
-            {
-                // Look for a translation, otherwise use the raw name
-                auto found = transStrings.find(rawName);
-                if (found != transStrings.end())
-                    _difficultyNames.push_back(found->second);
-                else
-                    _difficultyNames.push_back(rawName);
-
-                // Finished for this difficulty level
-                continue;
-            }
-        }
-
-        // Fall back to a non-empty default
-        _difficultyNames.push_back(std::to_string(i));
+        // If there is no map-specific name, use a mod default
+        std::string defaultName = diffNames.getNameForKey(nameKey);
+        if (!defaultName.empty())
+            // Use the (hopefully translated) mod-specific default name
+            _difficultyNames.push_back(defaultName);
+        else
+            // Fall back to a non-empty default
+            _difficultyNames.push_back(std::to_string(i));
     }
 }