Make all plots subscribe to their sources

plot.cpp

@@ -20,6 +20,16 @@
 #include "plot.h"
 
 Plot::Plot(std::shared_ptr<AbstractSampleSource> src) : sampleSource(src)
+{
+	sampleSource->subscribe(this);
+}
+
+Plot::~Plot()
+{
+	sampleSource->unsubscribe(this);
+}
+
+void Plot::invalidateEvent()
 {
 
 }