[ScreenSelectMusic] add a code for closing the current folder from any location (a la DDR X2)

[metric will be added with the next batch of theme commits]

src/CodeDetector.cpp

@@ -51,6 +51,7 @@ const char *CodeNames[] = {
 	"SaveScreenshot2",
 	"CancelAllPlayerOptions",
 	"BackInEventMode",
+	"CloseCurrentFolder",
 };
 XToString( Code );
 
@@ -76,6 +77,11 @@ void CodeDetector::RefreshCacheItems( RString sClass )
 	}
 }
 
+bool CodeDetector::EnteredCloseFolder( GameController controller )
+{
+	return EnteredCode(controller,CODE_CLOSE_CURRENT_FOLDER);
+}
+
 bool CodeDetector::EnteredNextGroup( GameController controller )
 {
 	return EnteredCode(controller,CODE_NEXT_GROUP);

src/CodeDetector.h

@@ -45,6 +45,7 @@ enum Code {
 	CODE_SAVE_SCREENSHOT2,
 	CODE_CANCEL_ALL_PLAYER_OPTIONS,
 	CODE_BACK_IN_EVENT_MODE,
+	CODE_CLOSE_CURRENT_FOLDER,
 	NUM_Code	// leave this at the end
 };
 
@@ -60,6 +61,7 @@ public:
 	static bool EnteredCode( GameController controller, Code code );
 	static bool EnteredPrevGroup( GameController controller );
 	static bool EnteredNextGroup( GameController controller );
+	static bool EnteredCloseFolder( GameController controller );
 
 	// todo: move to PlayerOptions.h -aj
 	void ChangeScrollSpeed( GameController controller, bool bIncrement );

src/ScreenSelectMusic.cpp

@@ -739,6 +739,18 @@ bool ScreenSelectMusic::DetectCodes( const InputEventPlus &input )
 			AfterMusicChange();
 		}
 	}
+	else if( CodeDetector::EnteredCloseFolder(input.GameI.controller) )
+	{
+		if( GAMESTATE->IsAnExtraStageAndSelectionLocked() )
+			m_soundLocked.Play();
+		else
+		{
+			RString sCurSection = m_MusicWheel.GetSelectedSection();
+			m_MusicWheel.SelectSection(sCurSection);
+			m_MusicWheel.SetOpenSection("");
+			AfterMusicChange();
+		}
+	}
 	else
 	{
 		return false;