Make GetApplicableFiles() static and don't create a loader unless it can load from that directory.

stepmania/src/NotesLoader.cpp

@@ -9,13 +9,6 @@
 #include "NotesLoaderBMS.h"
 #include "NotesLoaderKSF.h"
 
-bool NotesLoader::Loadable( const RString &sPath )
-{
-	vector<RString> list;
-	GetApplicableFiles( sPath, list );
-	return !list.empty();
-}
-
 void NotesLoader::GetMainAndSubTitlesFromFullTitle( const RString &sFullTitle, RString &sMainTitleOut, RString &sSubTitleOut )
 {
 	const RString sLeftSeps[]  = { "\t", " -", " ~", " (", " [" };
@@ -35,26 +28,14 @@ void NotesLoader::GetMainAndSubTitlesFromFullTitle( const RString &sFullTitle, R
 
 NotesLoader *NotesLoader::MakeLoader( const RString &sDir )
 {
-	NotesLoader *ret;
+	vector<RString> list;
 	
-	/* Actually, none of these have any persistant data, so we 
-	* could optimize this, but since they don't have any data,
-	* there's no real point ... */
-	ret = new SMLoader;
-	if(ret->Loadable( sDir )) return ret;
-	delete ret;
-	
-	ret = new DWILoader;
-	if(ret->Loadable( sDir )) return ret;
-	delete ret;
-	
-	ret = new BMSLoader;
-	if(ret->Loadable( sDir )) return ret;
-	delete ret;
-	
-	ret = new KSFLoader;
-	if(ret->Loadable( sDir )) return ret;
-	delete ret;
+#define CHECK_LOADER(x) x::GetApplicableFiles( sDir, list ); if( list.size() ) return new x
+	CHECK_LOADER( SMLoader  );
+	CHECK_LOADER( DWILoader );
+	CHECK_LOADER( BMSLoader );
+	CHECK_LOADER( KSFLoader );
+#undef CHECK_LOADER
 	
 	return NULL;
 }

stepmania/src/NotesLoader.h

@@ -10,8 +10,6 @@ class Song;
 class NotesLoader
 {
 protected:
-	virtual void GetApplicableFiles( const RString &sPath, vector<RString> &out )=0;
-
 	set<RString> BlacklistedImages;
 
 public:
@@ -20,7 +18,6 @@ public:
 	static void GetMainAndSubTitlesFromFullTitle( const RString &sFullTitle, RString &sMainTitleOut, RString &sSubTitleOut );
 	virtual bool LoadFromDir( const RString &sPath, Song &out ) = 0;
 	virtual void TidyUpData( Song &song, bool cache ) { }
-	bool Loadable( const RString &sPath );
 
 	static NotesLoader *MakeLoader( const RString& sDir );
 };

stepmania/src/NotesLoaderBMS.h

@@ -32,7 +32,7 @@ class BMSLoader: public NotesLoader
 	map<RString,int> m_mapWavIdToKeysoundIndex;
 
 public:
-	void GetApplicableFiles( const RString &sPath, vector<RString> &out );
+	static void GetApplicableFiles( const RString &sPath, vector<RString> &out );
 	bool LoadFromDir( const RString &sDir, Song &out );
 };
 

stepmania/src/NotesLoaderDWI.h

@@ -26,7 +26,7 @@ class DWILoader: public NotesLoader
 	RString m_sLoadingFile;
 
 public:
-	void GetApplicableFiles( const RString &sPath, vector<RString> &out );
+	static void GetApplicableFiles( const RString &sPath, vector<RString> &out );
 	bool LoadFromDir( const RString &sPath, Song &out );
 };
 

stepmania/src/NotesLoaderKSF.h

@@ -17,7 +17,7 @@ class KSFLoader: public NotesLoader
 	void LoadTags( const RString &str, Song &out );
 
 public:
-	void GetApplicableFiles( const RString &sPath, vector<RString> &out );
+	static void GetApplicableFiles( const RString &sPath, vector<RString> &out );
 	bool LoadFromDir( const RString &sDir, Song &out );
 
 private:

stepmania/src/NotesLoaderSM.h

@@ -33,7 +33,7 @@ public:
 		return LoadFromSMFile( sPath, out );
 	}
 
-	void GetApplicableFiles( const RString &sPath, vector<RString> &out );
+	static void GetApplicableFiles( const RString &sPath, vector<RString> &out );
 	bool LoadFromDir( const RString &sPath, Song &out );
 	void TidyUpData( Song &song, bool cache );
 	static bool LoadTimingFromFile( const RString &fn, TimingData &out );