Initial Commit with small working example.

GraphicsObject.h

@@ -0,0 +1,35 @@
+#ifndef GRAPHICSOBJECT_H
+#define GRAPHICSOBJECT_H
+
+class GraphicsObject
+{
+public:
+	// 2nd arg: pointer to callback function that takes a reference to an int as an argument
+	GraphicsObject(int set_x)
+		{
+			x = set_x;
+			user_data = NULL;
+			callback = NULL; // function pointer
+		}
+	GraphicsObject(void (*set_callback)(int&, void*), void *set_user_data)
+		{
+			x = 0;
+			user_data = set_user_data;
+			callback = set_callback; // function pointer
+		}
+	int X()
+		{
+			// If you are SUPPOSED to callback, ...
+			if(callback)
+				// ... do so to ask for the new X value
+				callback(x, user_data);
+			return x; // either this was just set by callback, or it was always set by constructor.
+		}
+//private:
+	int x;
+	void *user_data;
+private:
+	void (*callback)(int&, void*);
+};
+
+#endif