only skip GUI-updates when connected to frequently changing controllers

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@1449 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/controller.h

@@ -74,11 +74,24 @@ public:
 		m_sampleExact = _exact;
 	}
 
-	ControllerTypes type( void ) const
+	inline ControllerTypes type( void ) const
 	{
 		return( m_type );
 	}
 
+	// return whether this controller updates models frequently - used for
+	// determining when to update GUI
+	inline bool frequentUpdates( void ) const
+	{
+		switch( m_type )
+		{
+			case LfoController: return( TRUE );
+			case PeakController: return( TRUE );
+			default:
+				break;
+		}
+		return( FALSE );
+	}
 
 	virtual const QString & name( void ) const
 	{

src/gui/widgets/knob.cpp

@@ -603,6 +603,8 @@ void knob::enterValue( void )
 void knob::friendlyUpdate( void )
 {
 	if( model()->getControllerConnection() == NULL ||
+		model()->getControllerConnection()->getController()->
+						frequentUpdates() == FALSE ||
 				controller::runningFrames() % (256*4) == 0 )
 	{
 		update();