Storyscreen/Parser: don't keep parsing if special action was already executed

Just realized this was a small regresison in e97b992 , since the entire function wasn't handled by one
large if/else if/else block anymore.

src/storyscreen/controller.cpp

@@ -41,8 +41,10 @@ controller::controller(const vconfig& data, const std::string& scenario_name)
 	resolve_wml(data);
 }
 
-void controller::resolve_wml_helper(const std::string& key, const vconfig& node)
+bool controller::resolve_wml_helper(const std::string& key, const vconfig& node)
 {
+	bool found = false;
+
 	if(key == "part" && !node.empty()) {
 		part_pointer_type const story_part(new part(node));
 		// Use scenario name as part title if the WML doesn't supply a custom one.
@@ -51,7 +53,10 @@ void controller::resolve_wml_helper(const std::string& key, const vconfig& node)
 		}
 
 		parts_.push_back(story_part);
+		found = true;
 	}
+
+	return found;
 }
 
 } // end namespace storyscreen

src/storyscreen/controller.hpp

@@ -50,7 +50,7 @@ public:
 
 private:
 	/** Inherited from story_parser. */
-	virtual void resolve_wml_helper(const std::string& key, const vconfig& node) override;
+	virtual bool resolve_wml_helper(const std::string& key, const vconfig& node) override;
 
 	std::string scenario_name_;
 

src/storyscreen/parser.cpp

@@ -34,7 +34,9 @@ void story_parser::resolve_wml(const vconfig& cfg)
 		const vconfig node = i->second;
 
 		// Execute any special actions derived classes provide.
-		resolve_wml_helper(key, node);
+		if(resolve_wml_helper(key, node)) {
+			continue;
+		}
 
 		// [if]
 		if(key == "if") {

src/storyscreen/parser.hpp

@@ -40,7 +40,7 @@ public:
 	 * May be implemented by derived classes to perform additional actions
 	 * When executing @ref resolve_wml.
 	 */
-	virtual void resolve_wml_helper(const std::string& key, const vconfig& node) = 0;
+	virtual bool resolve_wml_helper(const std::string& key, const vconfig& node) = 0;
 };
 
 } // namespace storyscreen

src/storyscreen/part.cpp

@@ -230,16 +230,22 @@ void part::resolve_wml(const vconfig& cfg)
 	story_parser::resolve_wml(cfg);
 }
 
-void part::resolve_wml_helper(const std::string& key, const vconfig& node)
+bool part::resolve_wml_helper(const std::string& key, const vconfig& node)
 {
+	bool found = false;
+
 	// [background_layer]
 	if(key == "background_layer") {
 		background_layers_.push_back(node.get_parsed_config());
+		found = true;
 	}
 	// [image]
 	else if(key == "image") {
 		floating_images_.push_back(node.get_parsed_config());
+		found = true;
 	}
+
+	return found;
 }
 
 } // end namespace storyscreen

src/storyscreen/part.hpp

@@ -328,7 +328,7 @@ private:
 	virtual void resolve_wml(const vconfig& cfg) override;
 
 	/** Inherited from story_parser. */
-	virtual void resolve_wml_helper(const std::string& key, const vconfig& node) override;
+	virtual bool resolve_wml_helper(const std::string& key, const vconfig& node) override;
 
 	static BLOCK_LOCATION string_tblock_loc(const std::string& s);