added empty() to check whether there is any relevant note

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@348 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/pattern.h

@@ -159,6 +159,8 @@ public:
 		return( m_instrumentTrack );
 	}
 
+	bool empty( void );
+
 
 public slots:
 	virtual void update( void );

src/tracks/pattern.cpp

@@ -1180,6 +1180,22 @@ void pattern::updateBBTrack( void )
 
 
 
+bool pattern::empty( void )
+{
+	for( noteVector::iterator it = m_notes.begin(); it != m_notes.end();
+									++it )
+	{
+		if( ( *it )->length() != 0 )
+		{
+			return( FALSE );
+		}
+	}
+	return( TRUE );
+}
+
+
+
+