begin cleanup on gps code

src/Observer.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <Arduino.h>
+
+#include <list>
+
+class Observable;
+
+class Observer
+{
+    Observable *observed;
+
+public:
+    Observer() : observed(NULL) {}
+
+    virtual ~Observer();
+
+    void observe(Observable *o);
+
+    virtual void onNotify(Observable *o) = 0;
+};
+
+class Observable
+{
+    std::list<Observer *> observers;
+
+public:
+    void notifyObservers()
+    {
+        for (std::list<Observer *>::const_iterator iterator = observers.begin(); iterator != observers.end(); ++iterator)
+        {
+            (*iterator)->onNotify(this);
+        }
+    }
+
+    void addObserver(Observer *o)
+    {
+        observers.push_back(o);
+    }
+
+    void removeObserver(Observer *o)
+    {
+        observers.remove(o);
+    }
+};
+