add GenericTweenOff

stepmania/src/ScreenWithMenuElements.cpp

@@ -232,7 +232,19 @@ void ScreenWithMenuElements::ResetTimer()
 
 void ScreenWithMenuElements::StartTransitioningScreen( ScreenMessage smSendWhenDone )
 {
-	TweenOffScreen();
+	if( GenericTweenOff() )
+	{
+		this->PlayCommand( "Off" );
+
+		// If we're a stacked screen, then there's someone else between us and the
+		// background, so don't tween it off.
+		if( !SCREENMAN->IsStackedScreen(this) )
+			SCREENMAN->PlaySharedBackgroundOffCommand();
+	}
+	else
+	{
+		TweenOffScreen();
+	}
 
 	if( WAIT_FOR_CHILDREN_BEFORE_TWEENING_OUT )
 	{

stepmania/src/ScreenWithMenuElements.h

@@ -44,6 +44,7 @@ protected:
 	 * TweenOnScreen will not be called.  (Eventually, all screens should
 	 * use this, and this will be removed.) */
 	virtual bool GenericTweenOn() const { return false; }
+	virtual bool GenericTweenOff() const { return false; }
 
 	AutoActor			m_sprUnderlay;
 	AutoActor			m_autoHeader;